VMS 3010 Summary Notes PDF

**W1 Clinical reasoning** Integrate clinical & contextual factors -\> decisions on diagnosis, tx ops & prognoses **T1** -- pattern recognition, intuitive, more error risk **T2** -- analytical, inductive, takes time, structured Problem -\> system -\> location -\> lesion **Min database**: haem, serum biochem, urinalysis **W1 Intro to surgery** **SOAP** -- subjective (O seen), objective (TPR), assessment (interpret, ddx), plan **HEAP** -- hx, exam, assessment, plan **Halstead's principles**: THA TAPE Tissue handling gentle, haemostasis, aseptic, accurate tissue apposition, tension-free, preserve blood supply, eliminate dead space **W1 Intro to pharmacology** (mechanism & actions of drugs) **INN --** international non-proprietary name -- generic name -- ID active ingredient **Proprietary name** -- brand name **Classify drug**: physiochemical property, MoA, clinical outcome, **Physical characteristics**: tablet, inject, spot on, drench **Excipient**: inactive medium for drug - poultry liver powder flavouring, stearic acid emulsifier **VMD**: product info database **Prescribing**: assess patient -\> ID tx ops -\> present ops to O -\> prescribe -\> give info -\> monitor & review **W1 ADME** **Absorption**: drug from site given -\> systemic circulation. **Dissolution**: size, hydrophobicity **Physiochem props**: solubility **Diffusion**: conc grad, size, ° ionisation, non-polar unionised drugs dissolve **Bio factors**: blood flow, pH, SA, gut motility **Bypass absorption**: IV = quick, FT, precise, short acting, irritant **Depot injections**: slow release **Sustained release**: PRID **Distribution**: reversible passage of drugs -- tissues, organs, compartments, \ ↓ perfused tissues OR hep metabolism -\> renal excretion **Ketamine**: phencyclidine derivative, quick onset, acidic pH = pain when inject, 10% sol, hep metabolism -\> norketamine (excreted in cat, further metabolised in dog & horse), no reversal **Alfaxalone**: synthetic neuroactive steroid - IV/IM/SC (d/f/r), fast onset, dose dependent CV/resp depression, ↓ICP, myorelax **Propofol**: hypnotic alkyl phenol -- IV, d/f -- short onset & duration -- lipid water macroemulsion, lipid sol, v protein bound, \[1%\] **Etomidate**: imidazole derivative, IV, no licence in UK, quick onset. Low dose = GABAA enhancer, high dose = GABAA ag. **Co-induction**: 2+ drugs for anaesthesia induction, drug synergism, dose sparing effect, cost sparing, ↑ CV stability **Central muscle relaxation**: depress internuncial transmission @ SC/brainstem -- benzodiazepines **Peripheral muscle relaxation**: action @ NMJ (ACh receptor) **W1 Inhalational agents** **Properties:** unconsciousness, muscle relaxation, poor analgesia (except from NO) **Saturated vapour P (SVP)** - P exerted by vapour on surroundings in closed container @ eqm @ spec temp. ↑ = ↑ \[inhalant\] **Solubility**:measure as partition coefficient-solvent's capacity to dissolve anaesthetic gas. \[inhalant\]~solvent~:\[inhalant\]~gas~ \@eqm **Blood/gas partition coefficient**: low blood solubility -\> rapid eqm -\> rapid induction, change of anaesthetic depth & elim **High** = lots of anaesthetic dissolved in blood before eqm Intermed = isoflurane Low ideal -- sevo/desflurane **Oil/gas partition coefficient**: anaesthetic potency **MAC**: conc of anaesthetic agent at which 50% of patients fail to response to standard supramaximal noxious stimulus - % **Vapouriser**: liquid anaesthetic -\> vapour form -- added to FGF -- control anaesthetic conc to patient **PK uptake**: agents high to low P until eqm. [Anaesthesia depth] depends on [PP of drugs in brain] = alveolar PP of agent key **PK elim. & recovery**: return of consciousness depends on [rate of ↓ of P~brain~] - exhale, metabolise, GA long = in fat = slower **PD CV system**: ↑ myocardial contractility, vasodilation -\> hypotension & ↓ CO **PD cerebral**: reversible, CNS unresponsive, ↓ cerebral metabolic rate, ↑ ICP **PD respiratory**: ↑ RR but ↓ TV, ↓ alveolar vent, ↓ response to hypercapnia & hypoxaemia, resp muscle relax & bronchodilation = ↑ dead space **Hep.bil. system**: ↓ hep func, hepcell injury, inhibit P450 **PD renal**: ↓ GFR & renal blood flow, mild. Sevoflurane =\> nephrotoxicity **PD muscle**: myorelaxation, ↑ cell metabolic activity **PD Immune system**: ↓ **PD** **Uterus**: ↓ contractility & blood flow **NO**: quick onset, gas, analgesic, min CV & resp effects, low potency, ↑ ICP & cerebral blood flow, 2^nd^ gas effect **2^nd^ gas effect**: ability of 1 gas to accelerate rise of alveolar conc of 2^nd^ gas when given together. Speed anaesthetic induction **Diffusion hypoxia (3^rd^ gas/fink effect)** -- NO stopped = quick diffusion (low blood sol) blood -\> alveoli = dilute \[inspired O2\] = ↓ PaCO2 = ↓ resp drive Solve by giving 100% O2 on recovery **Mitigate risks**: daily leak test, reg maint, min safe FGF, squeeze breathing bag w/ air before disconnect, avoid facemask, scavenging system, education, ventilation of operating & recovery rooms **Online Clinical Records** Info relating to patient, how made decisions (thought process + clinical reasoning), help others continue care in absence Clear, concise, complete, contemporaneous **Dispute resolution**: evidence of circumstances, X assumptions, legal doc **GDPR**: disclose records to O if ask **Common pitfalls:** inappropriate comments, brief but not too much, leave out bits **Online Intro to vet anaesthesia** **Anaesthesia**: lack of feeling **Analgesia**: X pain in response to normally painful stimulation **Nociception**: process of encoding noxious stimuli (transduction, transmission, modulation) **GA**: state of consciousness produced by drugs given, IDd by controlled & reversible depression of CNS & perception **Local a**: loss of pain sensation in circumscribed area **Regional anaesthesia**: insensibility to pain in larger area (oft defined by innervation pattern of affected nerves) Ideal a agent: quick onset & recovery, high lipid solubility, no CV/resp depression, no emetic effects or excitation or toxicity **Pre-anaesthetic exam**: hx, physical exam, O edu., individual plan-stabilise pre-existing condition, antianxiety 2h b4 travel **Fasting**: ↓ gastro-oesophageal reflux & asp pneumonia, ↓ stomach size. \~6h. reduce for diabetic, neonatal & geriatric ↑ ASA status = ↑ risk **ET tube**: pick 3 options, if brachy = even more **Pre-oxygenation**: give high fraction inspired O2 b4 induction, good to increase body O2 stores -\> delay hypoxaemia onset **Endotracheal intubation**: in trachea? -- condensation, capnograph, give breath, check ET tube cuff (20-30 cm H20 ideal P) **After induction**: ABC, D (drugs/a depth), E (equipment, eyes), F (forms) **Adequate anaesthesia plane**: medium plane 2 -- reg shallow breathes, reg HR, no palp reflex, eyes VM, relaxed jaw tone **Extubationb**: sternal if poss, deflate ET cuff, dog -- swallow or head/limb moves, cat -- ear flick or strong medial palp reflex **Recovery**: critical, ↑ risk morbidity & mortality, warm & calm enviro. **Delayed**-- xs drug/depth, prolonged a, cold, ↓ glucose **Emergency delirium**: state of stress/unease/anxiety - vocal, panting, restless, uncoordinated thrash, can give a-2 agonist **Online Breathing systems** **Rebreathing**: some of expired alveolar gases inspired as part of next tidal vol **Avoid rebreathing**: Non-rebreathing system -- adequate FGF (circuit x minute vol) MV - vol air moved in/out of lung in 1 min (MV = TV x RR) (TV = 15ml/kg x RR) Rebreathing system -- use CO2 absorber **Non-rebreathing systems: APL valve** -- spring loaded P release -control P for controlled vent. **Safety valve**= xs gas escape **Reservoir/breathing bag**: of O2 & a. gases. For assisted/controlled vent & monitoring. Protects patient from xs P. 2-6x TV **Breathing hoses**: insp & exp limbs, corrugated plastic/rubber, diameter to promote low resistance to gas flow **Magill Mapleson A**: spont breathing, APL @ patient end, bad for dental/oral sx. 10-30kg patient. FGF 0.75-1x MV **Lack mod Mapleson A**: spont breathing, bag on insp limb, APL on exp. Parallel coaxial config (exp limb inside insp limb). 10-30kg patient. FGF 0.75-1x MV. Mini lack \10kg patient **Online Anaesthetic equipment** **Gas supply**: Schrader ports & probes colour coded -- pipelines connect to a machine. Cylinders main source of gases Cylinders connect to a machine w/ yoke/bodok seal -- pin index system (pipeline-schrader-\> a machine -yoke-\> cylinder) **O2 concentrators**: extract o2 from surrounding air, portable, need battery **Pressure gauge**: confirm gas supply **P regulators**: **P reducing valve** -- reduce high/variable P in cylinder to lower constant P -\> flowmeter -\> patient **O2 failure alarm**: for 7mins or until o2 supply back, activated at less than 200kPa P. **Master on-off switch**-turn off O2 flow **Flowmeter**: control O2/air/NO to patient. P ↓ to atm, label & colour coded knobs. O2 & NO interlocked = avoid hypoxic mix **Vaporiser:** flowmeter \> backbar\> vaporisers - control \[volatile agents\] to patients. Compensate for temp/gas flow changes **Common gas outlet (CGO**): gas out of a machine -\> breathing system -\> patient -- where breathing system connected **O2 flush valve/emergency O2**: 100% O2 at 30-70 L/min w/ no anaesthetic agent. Bypass flowmeters & vaporiser X if patient connected to machine: high P = barotrauma risk Removes a gases & NO in emergency, fill breathing bag **Scavenging**: ↓ personnel exposure to wasta a agents, connect to APL. **Active** = extractor fan **Passive** = activated charcoal **Online ECG interpretation** ![](media/image4.png)**P** -- atrial depol **QRS** -- vent depol **T** -- vent repol **PR** -- electrical impulse SA node to ventricles **Sinus arrhythmia** -- variable SA node firing rate -- vagal tone changes -- abnormal in cat not dog ![](media/image6.png)**Sinus tachycardia** - \>100/150 bpm dog, \>180 bpm in cat. PR shorter, light anaesthesia, pain **Sinus bradycardia -** \5, straight, above, below, two/through, erasure of growth plate/crush **W2 Problem wounds & drains** **Factors affecting wound healing**: patient (nutrition, disease, chemo), wound (contam, perfusion, necrosis, tension) **Disrupted wounds**: P wounds(eg. decubital ulcers, tuber coxae, sternum, move q1-4h) or wound in area of movement & P (wound over joints, paw pad wounds -- compression w/ weight bearing -\> spreads would edges apart) **Chronic movement/P wounds**: axillary & inguinal wounds -- collar, shearing movement w/ ambulation Wound tension, infection, haematoma, suturing nonviable tissue, wound molestation =\> **disrupted wound** **Prevent bandage sores:** place well & monitor, less padding over bony prominence, care w/ rigid fixation (nb swelling) **Infected wound:** X wound healing, closed wound dehiscence **↑ E to tissues** =↑ vasc damage, shearing/FB = deadspace **Dead space**: warm, moist, low O2, proteins, immune response can't penetrate =\> abscess --\> bust & drain -- heal by gran **Chronic draining sinus**: abscess X heal by granulation -- poor drainage, FB, devitalised tissue **Common FB entry**: interdigital, ear canal, conjunctiva, oropharynx **Draining tract approach**: xray, smear, C&S, sx explore, remove cause, 2^nd^ intention healing or excise on block, lavage, (AB) **Cat bite abscess**: quick swell, or systemically ill w/o swell. **W/ abscess** = drain then [ABs & pain relief]. No abscess= X drain **Stick injury**: oropharyngeal penetrating trauma. **Acute** \7d, X ill, more common **Surgical drain:** tissue apposition & obliteration of dead space -- remove fluid (media for bac growth), relieve P (affects perfusion), remove inflamm mediators **Open passive drain**: penrose -- cap action, gravity, high SA:vol, prox end in wound, exit @ stab incision by wound, dressing **Closed suction active drain**: fenestrations, airtight cav X lose vacuum if not airtight, occlude w/ clots, oft buster collar **Ingress/egress drain**: use in inguinal/axillary region- prevent suction drawing bac into drain, remove like passive drain **Drain complications**: ↑ risk contam, patient interference, drainage failure, potential seeing if neoplasia **Thoracocentesis** -- intermittent q4-5hrs, ✓ quantify small amount **Ab drainage**: palliative for ascites, aseptic peritonitis **W2 AM 1** **Antimicrobial**: substance that destroys/inhibits microorganisms **Antibiotics**: substances produced by1 organism that selectively destroys/inhibits growth of another **MIC:** lower conc of AM that will inhibit visible growth of microorganism after overnight incubation in vitro **Clinical breakpoints**: take account of clinical data to overcome some of in vitra MIC data limitations **Time-dependent AM**: efficacy dependent on time AM above MIC, ↑dose = ~~↑~~effect, dose at MIC for 5-7d **Conc-dependent AM**: efficacy depends on conc above MIC. ↑dose = ↑effect, dose at highest tolerable for short time **Critically important AMs**: class only to treat serious bac infection in people (caused by bac from non-human sources or resistance genes from non-human sources) **Empirical prescribing**: treat on bases of most likely cause of disease in absence of definitive tests **Responsible AM use:** work w/ O to avoid use, avoid inappropriate use, right drug 4 right bug, monitor AM Se, minimise use, record & justify deviation from protocol, report tx failure to VMD **W2 AM 2** **β-lactam AB**: interfere w/ bac wall syn transpeptidation. Bactericidal & time-dependent. G+ve & -ve bac. UGT 1° infection **Tetracycline** AB: inhibit prot syn. Bacteriostatic & time-dependent. D -- doxycycline, oxytetracycline, chlortetracycline **Sulfonamides, DRIs &combo**: interfere w/ folic acid production=\>affect purine syn. Bactericidal & time dependent. TMPS **Nitroimidazoles**: prevent DNA repair = X nucleic acid func. Bactericidal & conc-dependent. Anaerobes. Metronidazole. **Aminoglycosides**: inhibit prot syn. Bactericidal & conc-dependent. G-ve anaerobes. Gentamicin, streptomycin, amikacin **Macrolides & lincosamides**: inhibit prot syn. Bacteriostatic & time dependent. G+ve bac & Mycoplasma, Class C **Amphenicol**: X prot syn. Bacteriostatic& time dependent. C Florfenicol (LA resp tract infection), chloramphenicol (topical) **Fluoroquinolones**: X DNA syn. Bactericidal & conc. G-ve. B Enrofloxacin (resp/GIT infection, marbofloxacin, danofloxacin **W2 Physics of radiograph & radiation safety** e- from cathode -\> anode (+ve) tungsten target -\> release E in form of photon -\> e- escape to collimator **kV** -- peak voltage across cathode & anode -- ↑ = ↑ photons, E & ↑ penetration e- KINETIC E PENETRATION **mA** -- tube current to cathode filament -- ↑ = ↑ no. e- & photons, ↑ heat in cathode filament NO. of e- CONTRAST **mAs** = mA x time (s) -- measure intensity of beam -- intensity = total no & E of all xray photons **FFD** -- distance between focal spot on anode & detector under patient. Quantity of radiation at any point is prop.to 1/(FFD)^2^ **Attenuation**: Absorption removes E transferred to patient = CONTRAST. ↑ w/ ↑ atomic number (↑ e-?) **Attenuation:** Scatter: remove E emitted away from patient, ↑ w/ ↑ kV, =\> bad contrast due to fogging (random blackening) **Emulsion**: create image. Photon + silver bromide crystal =silver atom deposited =latent image (need chemical processing) **Using screens & cassettes**: ✓ ↓ dose, ↓ exposure time, ↓ motion blurring, ↓ scatter. X ↓ resolution **Computer radiographs (CR)**: cassette has [storage-phosphor image plate w/ photostimulable crystals] -\> xray [E absorbed] & stored during exposure = [latent image] -\> cassette in processor & [scanned by laser] to set stored [E as visible light] -\> [photodiodes capture light] emitted -\> [digital] signal -\> plate exposed to [white light to delete] latent image **Direct radiograph**: [flat panel detectors] to convert xray -\> electrical change. Signal from detector to computer wire or not **Digital radiography**: X ↑ set up cost & ongoing maint, may overlook overexposure, interpretation limited w/ bad computer ✓ ↑ tolerance to sup-op exposure factors, can manipulate, share & store image, fast, no replacement fil cost **X-ray tissue interaction**: deterministic (severity of damage ∝ dose given), stochastic (probability of damage ∝ dose given, no threshold radiation level), hereditary (stochastic effect in exposed offspring) **Radiation protection:** clinical justification for use, ALARA exposure, X exceed legal dose limit **Limit occupational exposure**: ↑ time, distance (double distance ↓ exposure risk 4-fold), lead PPE (DOESN'T protect from 1° beam), personal dosimeter (electronic or film badge, under PPE, change every 3m), X wet/dirty coat (=artefacts) **W2 Interpretation, image quality & faults** **Pink Camels Collect XL Apples:** position, centre, collimation, exposure, labelling, artefacts **Position**: minimise geometric distortion (areas @ primary beam edge angles), magnification (closer to playe = closer to true side), orthogonal view (ID abnormalities in 3D), centering (bony landmarks, close collimation = ↓ scatter, ↑ contrast) **Film/screen faults:** too dark = overexposed/developed, fogging -\> ↓kV, too white = underexposed/developed -\> ↑kV. **Quality**: **artefacts**: no L/R marker or name, poor position, collimation, movement blue, fogging, double exposure **Post exposure digital faults**: partial erasure/fading = don't process quick enough, white specks/lines (on cassette), Moire artefact (alt. light & dark bands) **Workstation faults**: incorrect cropping & algorithm on computer, uberschwinger artefact (uniform dark zone around plate) **Description**: Roentgen signs -- SNOMPS -- size, number, opacity, margination, position, shape **Border effacement aka silhouette sign** -- 2 strucs same opacity & in contact -- see w/ pleural/peritoneal effusion **W2 Basic Ultrasonography** Use transmission of sound waves through tissue to produce image. Current applied to [piezo-electric crystals] in transducer -\> change [shape & oscillate] =\> US [wave] -\> returning sound waves received at transducer = crystal [compression] = electric [voltage] -\> signal [amplified, converted & displayed] as dot on screen Wave **reflected** back to transducer = **echo** **Refraction**: change in wave direction due to diff tissue velocities **Diffraction**: change in wave direction through opening/around barrier. **Attenuation**: Wave E loss due to scatter/absorption **Probes: linear array**: line of crystals, rectangle, no near field artefact, large footprint **Axial res:** ability to determine 2 points along path of beam, ↑ freq = better axial res **High frequency**: ✓ axial res, quicker beam attenuation, poor penetration (cardiac scan) ![](media/image21.png)**Low frequency**: poor axial res, slower beam attenuation, ✓penetration **Lateral res**: ability to determine 2 point perpendicular to beam. Narrow beam = better lat res **Gain**: overall brightness of image. Too high = ↑ noise **TGC**: brightness @ diff levels through tissue **Focus/focal zone**: where image optimised by focussing sound wave, improves lateral resolution **Artefacts: SEA PRAM** -- Slice thickness (pseudosludge w/ sharp border), edge shadowing (acoustic shadow distal to lat aspect cystic struc), acoustic shadowing (complete reflection of v reflective surface =\> distal shadow, **comet tail** if gas) Poor probe contact (bad clipping, less gel), reverberation (= parallel bright lines), acoustic enhancement (lack of attenuation, bright area deep to fluid struc), mirror image (@ curved reflective surface) **Ab US**: emergency = POCUS-- ID free fluid, scan DH, SR, HR, CC - ✓ safe, X GA, ✓ res, morphological info, real time, cheap X limited func info, not for diffuse disease, need to clip & oft sedation, gas interferes, need practice, sample to ID disease **Lateral recumbency**: L = RL, BS, P, D, RP, RKA R = LL, GFB, S, LP, LKA, SI, C, UB **Echocardiography**: heart murmur, weird ECG/xray, hypertension, dyspnoea, syncope LHS 5-7^th^ ICS RHS 3-6^th^ ICS **R parasternal view** - long axis, or [short] axis (CAMP chordae tendinar, aortic & mitral valve, pap muscle), subcostal view, L apical 4/5 chamber view, B/M mode, doppler to see blood flow (BART -- blue away red towards) **Thoracic US**: Rib: hyperechoic line w/ distal acoustic shadow, Lung = smooth hyperechoic line. **TFAST** ID pleural space disease & pericardial effusion -- 2x CTS, 2x PCS, diaphragmaticohepatic view (DH) **BLUE assessment**: assess pulmonary parenchyma: cdll, mdll, phll, crll regions **W2 Monitoring in vet anaesthesia f** **Aims**: adequate depth, good analgesia, systems as physiologically normal as pos, ID changes, response to tx, safety **Resp monitor**: RR & rhythm, capnograph, pulse-ox, mm colour, TV, blood gas analysis **↑RR** = pain, too hot, light a plane **Capnography:** graphical view of capnometry (breath by breath analysis of expired CO2) Normal ET CO2: 35-45mmHg FiCO2 = inspired CO2 levels ETCO2 = end tidal CO2 Hypocapnia \45mmHg **Diff between ETCO2 & PaCO2** = alveolar dead space -- some alveoli permanently perfused & not part of gas exchange +-------------+-------------+-------------+-------------+-------------+ | | **Metabolis | **Pulmonary | **Alveolar | **Technical | | | m** | perfusion** | vent** | errors** | +=============+=============+=============+=============+=============+ | **↓ ETCO2** | Hypothermia | ↓ CO | Hyperventil | Disconnect | | | | | ation | | | | Hypothyroid | ↓ BP | | Obstruction | | | ism | | Asthma | /leak | | | | Hypovolaemi | | | | | Drugs/a | a | Apneoa | ET tube | | | depth | | | cuff | | | | | | deflated | +-------------+-------------+-------------+-------------+-------------+ | **↑ ETCO2** | Hyperthermi | ↑ CO | Hypoventila | Exhausted | | | a | | tion | CO2 | | | | ↑ BP | | absorber | | | Hyperthyroi | | Rebreathing | | | | dism | | | Inadequate | | | | | | FGF | | | Fever | | | | | | | | | Faulty | | | | | | valves | +-------------+-------------+-------------+-------------+-------------+ **Pulse-ox** -- arterial blood **Hypoxaemia** = SpO2 \L shunt, ↓FiO2 **Hypoventilation causes**: position, ab distended, pul/NMK disease, pain, obesity **Tx** w/ O2, manual vent, ↓ a depth **Apnoea/resp arrest**: drug, deep a, vagal stim, nerve damage, cardiac arrest. **Tx** w/ O2, intubate&ventilate, ↓ a depth, CPR **Tachypnoea**: light a plane, pain, ↑ CO2, hypoxaemia **AV block** tx: drug reversal, antichol. drugs, pacemaker if 3^rd^ degree **AIVR/v-fib/vent tachy**: cause (disease, drugs, pain), tx w/ lidocaine bolus +/- defib **Bradycardia**: drugs, deep a, ↑ ICP, vagal response, hypothermia **Tachycardia**: ↓ diastolic filling. **Causes**: SNS stim, drug, disease, anaemia, hypoxaemia. **Tx**: underlying cause, β-blockers **Hypotension causes**: vasodilation (↓ volatile agent, FT), ↓ preload (FT), ↓ contractility (+ inotrope), bradycardia (drug ant.) **Hypertension**: ↑myocardial work & O2 demand **Causes**: pain, light plane, hypercapnia, met acidosis, heart/renal disease **Haemorrhage:** = ↑ CO. 60 ml/kg f/c/s/r 90ml/kg d/h **Blood vol**: f/c/s/r 6/7% BW, d/h 9% BW **Transfusion**: loss \>20% **Hypothermia**: \ ↓ tissue perfusion, need rapid replacement **Dehydration**: ↓ fluid vol within interstitial space, slow replacement Free water deficit (L) = **Osmolality:** \[dissolved particles\] in fluid rel to solvent mass **Hypertonic:** ↑ osmolality - shrink **Hypotonic:** lyse **Crystalloids**: crystalloid comp dissolved in water oft + buffer. **Isotonic**: like ECF, most IVS -\>ISF ✓replace & resuscitate **Saline sol**: 0.9% NaCl, acidifying, chloride shift ✓hypoNa, hyperCa, hypoCl met alkalosis **Hartmann's:** alkalising, has lactate (HCO3- precursor) = HCO3 sparing effect, ✓ peri-op FT, urethral obstruction -\> hyperK -\> bradycardia, [replace & resuscitate] **Colloids**: macromolecules suspended in crystalloid soil, last longer in IVS, ✓ hypoproteinaemia (= ↓ risk oedema) **Hypovol (resuscitation) tx**: buffered isotonic crystalloid bolus in 15-30m (cat 5-10ml/kg, dog 15-20ml/kg), monitor close **Dehydration tx**: balanced isotonic crystalloids, calculate amount w/ total fluid deficit then give over 12-24h **Maint. tx:** hypotonic crystalloids (cat 40ml/kg/d, d 60ml/kg/d) BOTH ↓ -\> 2ml/kg/hr **Peds**: cat 2.5x dose, d 3x -\> 5ml/kg/hr **Restricted fluid approach**: cat 3ml/kg/hr, dog 5ml/kg/hr. Use to counteract ↓ CO & vasodilation, IV cannula patency **Free flow fluid admin**: 20 drops/ml for adult, 60 drops/ml for peds. Gravity assisted, risk of fluid overload/air embolism **W3 Pain management in vet med** **Pain:** unpleasant sensory & emotional experience assoc w/resembling actual/potential tissue damage **Transduction**: noxious stimuli \--nociceptor-\> AP → **Transmission**: C fibres -- dull pain, Aδ -- local sharp, Aβ -- touch → **Dosal horn SC**: synapse w/ 2^nd^ order neurons --interneuron\--\> asc tract to brain (α motor neurons -- reflex arc) → **Modulation**: ↑/↓ pain sensation, desc inhibitory path, gate control theory → **Projection**: nociceptive info to brain → **Perception**: conscious processing of pain **Acute** **pain**: abrupt start, heal days/weeks, self limiting **Chronic** **pain**: longer than normal healing time/no healing, \>1-3m **Nociceptive & inflamm pain**: protective **Somatic pain:** localise, sharp, intense **Visceral pain**: dull, diffuse **Neuropathic pain**: from injury of somatosensory system (nerves, SC, brain). Damage -\> inflam -\> inflam mediators -\> hyperexcitable peripheral nociceptors -\> activated -\> peripheral sensitisation **Allodynia**: pain sensation in response to nonpainful stim. **Hyperalgesia**: exagg pain sensation to normally painful stim. **Pain assessment**: HR, BP, RR, plasma cortisol in assoc w/ behaviour. **Unidimensional** (0-10 pain) **Multidimensional** (Glasgow composite pain scale) -- assess intensity, emotional & sensory comps of pain **Facial pain scales** (grimace scale) - ✓ no direct interaction Helsinki chronic pain index (HCPI) **P mats** for gait analysis, **accelerometery** to register activity, **algometer** to record P able to tolerate **Tx pain to avoid**: SNS & stress response activation, immunodepression, ↓ wound healing, inflamm, ↓ appetite **Tramadol**: weak mu-receptor & a-2 agonist, inhibit NE & serotonin reuptake in CNA **Local anaesthetics**: Ca2+ channel blockers = X transmission of nociceptive inputs, narrow TI, lidocaine/bupivacaine **Lidocaine**: short onset & duration, bolus & CRI, block Na+ channels, anti-inflamm, antiarrhythmic, ↑ gut motility, V+ **Paracetamol**: COX-3 inhibition (brain) -- antipyretic effect, acute + chronic pain, weak analgesia & antiinflamm, dogs only **Amantadine**: NMDA antagonist = block pain transmission, ↓ central sensitisation = long duration, chronic pain **Acupuncture**: small flexible needles inserted into acupoints, endorphin release & wound healing? Gate control theory **Ice therapy**: ↓ painful stimuli transmission, ↓ inflamm & tissue metabolism, ✓acute/inflamm pain **Hot therapy**: muscle spasm relief, arthritis, ↑ circulation, ✓chronic pain **LASER:** photochemical effect **Transcut electrical nerve stim (TENS):** Low voltage electric current - pain & inflamm tx -- gate control theory, ↑endorphins **W3 Approach to emergency patient** **1** -- resucitation **2**- emergent eg. snake bite/heat stroke **3**- urgent eg. serious cut **4**- non-urgent eg. small cut **5** -- stable **Telephone triage**: listen, ask qus as may not be actual emergency **Dogs**: V+/D+ **Cat**: trauma/wound **Prepare**: O2 -\> fluids (catheter) -\> analgesia. Atropine & adrenaline resuscitation drugs. Bloods. Stop obvious bleeds. ABS **SAMPLE hx:** signalment, allergies, meds, past illness, last normal, events leading to emergency **Urinary system**: AKI, obstruction, check bradycardia (K+) **Min emergency database:** PCV, TP, BUN, lactate, K+ **Oxygen**: FiO2 30-40%. Not more than 50% for more than 24hrs -- O2 toxicity (free radicals form) **6 point fluid therapy plan**: needed?, type, vol, rate, route, monitoring method **Initial stabilisation**: crystalloid bolus 10-20ml/kg over 5 mins **Fluid needed** = replacement + maint + ongoing losses **W3 Surgical haemostasis** **Haemostasis**: ↑ visualisation, X SSI/haemorrhage, ↑post-op healing **Shock**: ↓ perfusion, tachy/bradycardia, hypotension **Intra-op blood loss:** extent inversely prop to technical & anticipatory skills of vet. **Quantify** w/ swabs, suctioned, on floor **Avoid surgical bleeds**: know anatomy, wide clip & large incision, dissect tissue appropriately -- blunt dissect if poss **Post-op haemorrhage** -- ineffective haemostasis, resolution of intra-op hypotension (BP restored) **Direct P -- tamponade**- minor bleed/temp control of larger bleed -- compress w/ swab/finger -- xs P = platelets cant migrate **Haemostatic forceps**: crush tissue, [tips] for small vessel (parallel), [jaw] for larger/deeper vessel (perpendicular) **Ligation:** most secure, for larger vessels. **Instrument tie:** ↓ tactile feel, ↓ suture material, ✓ deep lig **Vascular clips: metal clips (Hemoclips) --** tissue dissected free from vessel. Vessel diameter 1/3 -- 2/3 length of clip **Electrosurgery**: vessel \ thermal E to seal vessel **Radiosurgery**: high frequency waves, doesn't need skin contact **Adrenaline**: small superficial wound **US energy (harmonic scalpel)** -- vibration shakes cells = heat coag. & vessel sealing. **Hotblade**: bipolar vessel sealer **Topical haemostatic agents**: scaffold -\> clot formation. If granuloma forms -- remove b4 closure **Active topical haemostatic agents**: thrombin (trigger coagulation), polyethylene glycol (coseal) **Tourniquet**: ↓ arterial blood to distal limb. = ischaemic & anaerobic resp =\> lactic acid = pain. Not \>5hrs (K+ buildup) **Esmarch bandage**: lower limb exsanguination. ✓ digital amputation **P**: ab wrap/P bandage -- haemoab, ↓ movement **W3 Implanted materials** (anything in body that remains for some period) **Needle**: shape, size (gauge), swaged (↓ likely to lose, ↓ trauma) vs eyed **Needle X sec**: Taper point (round bodied) -- parenchymatous organs, fat, muscle. Cutting -- fascia/skin **Suture duration**: how long to be fully absorbed/lose strength **Strength**: how much force can withstand w/o breaking **Suture characteristics**: CPR KM DR -- capillarity (ability to spread liquid along length -- bad), persistence (how long in tissue), resistance (to infection), knot security (ability to resist knot slippage), memory (ability to return to original shape), drag (ability to pass through), rxn (to tissue) **Suture size**: USP -- no ↑ as size ↓ (2-0 dog, 3-0 cat), metric -- no↑ as size ↑ **Monofilament:** 1 strand, ↓ drag, ↑ resistance to bac, can weaken w/ crimping -- ethilon, prolene, PDS, monocryl **Multifilament**: braided/twisted - ↑ tensile strength, knot security, drag, ↓ memory. Can coat w/ antibac products & ↓ drag **Non-absorbable**: slow healing tissues, X lose tensile strength, can elicit rxn =\> encapsulation by fibrous tissue **Nylon**: polyamide, ethilon, supramid, skin sutures, secure drain, fix tendon/hernia, ↓drag, ↑tissue rxn, bad knot security **Prolene**: polypropylene, vascular strucs, tendon/hernia repair, 100% strength retention, ↑ reactivity, poor knot security **Absorbable**: for tissue inaccessible after implantation, lose tensile strength in 90d, short vs long duration (+/-21d) **Catgut**: natural, twisted, chromic catgut w/ chromium trioxide = strong & lasts, phagocytosis, good knot security, FB rxn, unpredictable tensile strength & rate of degradation, 30d absorption **PDS**: synthesis, polydioxanone, slow healing struc w/o permanent suture eg. ab wall, ruptured diaphragm, muscle, hydrolysis, ↑memory & ↓ drag. 180d absorption. **Monocryl**: synthetic, polyglicoprone 25, fast healing struc w/ min forces eg. subcut, intradermal, mucosa. ↓ rxn & drag, good knot security, 100d absorption, lose strength quickly **Vicryl**: synthetic, braided, polyglactin 910, uses like monocryl + oral cav, good knot security, ↓rxn, easy to use, can fray **Suture selection:** strong as tissue used in, tensile strength loss rate parallel to increase wound strength, big knot = ↑ rxn **Tissues**: skin & tendon w/ non absorb. Multifil. in subcut/fascia. Skin (reverse), cutting, viscera round body, rest tapercut **Interrupted sutures**: monofil 4 throws, multi 3 thows X ↑ material & knots ✓ precisely adjust tension, easy to place & remove, 1 knot fail X affect others. **Cont sutures**: 1 throw @ start, 2 @ end, subcut, linea alba, cystotomy ✓ air & fluid, quicker, ↓ material, even tension **Horizontal mattress** suture: everting, tension away from skin edge, skin **Vertical mattress**: skin/fascia, relieve tension **Purse string**: temp closure of hollow viscous around struc, secure tubes **Finger-trap**: secure tubes exiting body **Remove suture** after 10d. If tension, 14-21d + tension relieving sutures to remove in 3-5d **Tissue glue**: cyanoacrylates -- instant water tight seal -- sloughs in 5-10d. **Staple**: stainless steel B shape, quick, evert a bit **Implants**: surgical mesh (polypropylene), ortho, artificial urethral sphincter. **Issues**: mechanical failure, SSI, bone f\# **W3 Abdominal imaging** Exposure: low kV, high mAs, end expiratory view = ↓ movement blur, use grid so ↓ scatter **Prep**: no food for 12hrs, wee & poo before, dry coat, enema & GA before if urinary study, X sedated/GA for GI contrast study **Position**: VD & RL most important (+LL) **Ileus**: abnormal ↑ = more than 1.6x height L5, asses no of dilated loops (gas/fluid) **Small i**: partial FB obstruction -gravel sign. **Intussusception** - worms in young, neoplasia in old, sausage shape mass in ab **Large i**: **constipation** = dilation + opaque faeces. **Displacement**: ventral = big kidney, dorsal - big bladder/prostate/uterus **Positive contrast**: more opaque than ST, barium sulphate, coat mucosa **Generalised hepatomegaly**: pylorus caudally displaced. **Neoplasia**: haemoab., hepatomegaly, spleen mid ab mass **PSS**: microhepatica **Kidneys**: Cat 2.4-3.0x L2, Dog 2.5-3.5x L2 **Dog prostate**: height X more than 70% height pelvic brim **Urinary tract**: **double contrast cystogram**: Iodine +ve, air/CO2 (fills bladder) -ve - ID wall thickness/lesions/calculi **Retrograde urethrogram** -- male dysuria - prefilled catheter into terminal urethra = urethra occluded --hindlimbs cranial **Retrograde vaginourethrogram** -- female bladder wall rupture/urethral disease - catheter into vestibule & vulva clamped, urethra occluded, infuse contrast gently, exposure [before] end of injection **IV urography --** contrast given IV, check renal parameters, need IVFT & GA -- lat & VD view immed post injection & at 5, 10m. Lat @ 15m. ID internal architecture of kidneys, delineate ureters, dx ectopic ureter **W3 Limb radiography** 2 orthogonal views @ right angles to each other, joint ↑ & ↓ f\#, also contralat limb, 1/3 long bone prox & distal to joint **CT**: ↑ ST diff, X superimposition -- bone lesion/erosion, f\# **MRI**: ↑ ST diff than CT -- ligs, menisci, cartilage, muscle disease **US**: swelling around joint/muscle, tendon thick, muscle/tendon defect, discharging sinus tract, guide FNA **Change in tissue mass**: [diffuse ↑] = subcut fluid/oedema, [local ↑] = abscess, haematoma, [atrophy] = disuse, neurogenic **Change in opacity**: [↑] = artefact, calcifi/ossification, [↓] = fat, gas **Bone lesion**: mono/polystotic, focal, general, (a)sym **Lesion location**: epi (end), meta, dia(middle)physis **Aggressive**: permeative bone, poorly defined edge, cortical spikes **Bone opacity**: artefacts, new bone = sclerosis = radiopaque, bone loss = lysis = radiolucent **New bone**: internal (in med cav) -- [reactive] (↑ thickness & homogenous), [neoplastic] (non-homog.). Periosteal -- from injury **Bone loss:** osteopenia (general D in bone radiopacity from diet/disuse/↓ hormone). Due to: **Joint changes**: space, margins, articular surface alignment, subchondral bone & loose bodies (osteo/enthesophytes) **W3 Head, neck & spine radiography** **Brachy**: crowded teeth, ↓ frontal sinus, X occipital crest, small thick walled tym bullae, ↑soft palate, long curved mandible **Mesaticephalic** -- equal length cranium & nose **Tym bullae**: dog =rostrocaudal open mouth, cat = rostral 10° ventral-CdD **Lesion swell** = oblique lat, **Nasal cav vs mand teeth** = DV vs VD intra-oral, **Front sinus**=rostrocaudal & CdD closed mouth **US**: ocular & orbital strucs eg. retinal detachment **May find**: f\#, hydrocephalus, neoplasia, craniomandibular osteotomy ![](media/image24.png)**Dental xray**: bisecting angle technique -- image short/long = adjust tube angle. Root longer = tube lat **Pulp cav** = black, lamina dura = white line, periodontal lig = outer black line. **FORL** -- feline odontoclastic resorptive lesions = no pulp cav or periodontal lig **Neck&spine xray**: grid, ✓collimation, orthogonal views V**D view**= spinous ps. oval central opacities, same size transv. ps. **Lat view** = spine parallel to table top - atlas wing, transverse C6 process, rib origins, lumbar transv. processes, ilia wings [Upper cervical] C2-3, [lower c.] C5-6, [mid-thoracic] T8, [thoracolumbar junc] T13-L1, [mid-lumbar] L4-5, [lumbosacral] L7-S1 **Spinal xray**: vertebral alignment, length/shape/opacity v bodies, IVD space width & opacity, v end plates contour & opacity **IVDD**: calcified disc material in IVD space, T12-L3 **Melography**: inject contrast into subarachnoid space, seizure risk **W3 Thoracic imaging** High kV, low mAs = ↓ movement blur. [Insp] view. **Cardiac issues**: RL & DV **Lung path**: RL & VD **Pul mets**: RL, LL, VD Sedate/GA? - ✓ position, ↓ movement blur, ↓ stress, can time xray for end insp. **Mediastinum**: space between R & L pleural cavs. **Mediastinal shift**: movement of mediastinum away from midline **Heart size**: cat: 2-2.5 ICS, dog: 2.5-3.5 ICS, no more than 2/3 width thorax on insp DV view **VHS**: Cat: 7.5. Dog: 8.7-10.7 **Vertebral LA size**: ventral carina -\> caudal LA where intersects w/ dorsal bit of vena cava. Same line starting at T4 cranial edge & extend caudally. 2.3+ = LA big **Trachea**: lat view, neutral head, size X change in resp cycle, in D mediastinum. Tracheal stripe sign =luminal air (oft megao) **Lung**: [artificial] opacity **↑** w/ fat, expiration, atelectasis, pleural disease [Genuine] opacity ↓ air vol, ↑ ST/fluid in lung **Pulmonary vessel**: veins ventral & central, arteries close to a bronchus, a & v same size. **Pleural effusion:** most bilat, DV best for small effusion, wider interlobar fissures, silhouette sign, scalloped lobe borders **Pneumothorax**: radiolucent areas in thorax peripheral, ↑lung opacity **Tension pneumothorax**: air in pleural space can't leave, opaque lobes, wide ICS **Alveolar pattern**: oedema/exudate/blood/neoplastic cells - ↑lung opacity, lobar sign (↑visibility of individual lobe borders) ---------------- *Localisation* ---------------- **Interstitial**: unstruc/reticular pattern (diffuse ISS swelling), nodular (cannonball/miliary pattern) **Cannonball**: ST density w/ radiolucent centre **Miliary pattern**: small multiple coalescing nodules **Bronchial**: tram line (longitudinal), donuts (transverse), thick bronchial walls **Vascular:** big pul **v** (CHF), big pul **a** (angiostrongylus, pul hypertension), **narrow** (hypovol, hypOac)\ **W4 Surgical site infection I & II** **Prevent pre-op**: scrubs (↓ debris, higher thread count better), theatre hat (↓ hair/bac contam), theatre shoes/covers (↓ external back, more of mental barrier), masks (protect from saliva & microorganisms), gloves (protect from resident flora) **Patient prep:** remove transient organisms from skin, ↑ endogenous bac microflora, bathe only if heavily soiled, wide clip, no razors, vacuum, clean & disinfect, final aseptic skin prep once in theatre (concentric circles or back&forth), draping **Antiseptic:** chemical on vet/patient to kill microbial organisms, rapid (3m), persistent (X recol for 6h), residual action (5d) Sterilium denatures proteins (bad 4 virus/spores) Iodophors block cell memb prot syn (best \@0.1%) Chlorhexidine affects cell memb & coagulates cell contents (bad 4 spores, bacteriostatic at low conc, cidal & high) **Theatre design:** min traffic, 1 entrance, clean& contam areas, instrument cupboards in theatre, doors swing both ways, sealed windows w/ no ledge, damp dust every day, only necessary equipment, lighting easy to change w/ ↓ heat **Ventilation**: 18-24°C, 40-60% humidity, 20 air changes/hr, **+ve P vent** =↓ airborne contam w/ squames & resp drops **Protocols**: clean walls, floors, doors daily, broad spec surface disinfectant, mop head hot washed daily, colour coded **Sterilisation**: destroy all microorganisms INC spores. **Disinfection**: destroy/↓no. microorganisms NOT SPORES& X growth **Spaulding's classification:** high risk -- penetrate skin or blood -- sterilise. Intermed - X penetrate mm -- sterilise/high level disinfect. Low -- contact skin -- clean w/ detergent **Instrument manual clean**: pre-soak, disinfect, remove visible organic debris, enzymatic cleaner loosens, soft nylon brush **Clean ultrasonically**: small gas bubbles implode =\> vacuum - remove debris via cavitation. Must rinse & dry. NOT STERILE **Packing instruments**: must be dried w/ filtered medical grade compressed air. Open position, cover edges w/ gauze **Packaging**: paper/plastic pouch, reuseable woven weave (140), non-woven disposable (cellulose), boxes **Autoclave**: kill microorganisms through coag & denaturation of proteins by moist heat. Pre-vacuum type most common **Sterilisation: Ethylene oxide:** alkylates microbial DNA, 48-60°C & 20-40% humidity, delicate equip., TOXIC & FLAMMABLE **Cold sterilisation: 2% glutaraldehyde**: 10m to disinfect, 10hrs \@21°C to sterilise **Prevent peri-op:** IV broad spec prophylactic ABs 30m b4 sx - clean-contam or worse sx or clean ortho **Halstead's**: ↑ perfusion = ↑O2, WBCs, inflamm proteins = ↑ healing, X dead space = ↓ wound fluid accumulation, tension = caps loose, ↓ perfusion, ↑ likely dehiscence **Prevent post-op**: incisional care & advice -- weak fibrin seal 6h -- waterproof, easily disrupted, disruption = bac enter, limit handling, ↑ kennel hygiene, buster collar **Nosocomial infection**: horizonal & vertical transmission, barrier nurse, C&S infected wound **Superficial incisional SSI**: skin/SC, superficial purulent discharge, pain, red, swell **Deep incisional SSI:** deep ST, purulent discharge from deep in incision, dehiscence, abscess **Organ/space SSI**: any body part, purulent discharge, abscess, +ve culture **Causes:** clip too early, a length (30%↑ risk w/ +1hr), sx length (50%↑ risk w/ +1hr), propofol (3.8% ↑ risk), male (T immunosuppressive?), endocrinopathies (HAC, DM, hypothyroidism), 30% ↑ risk w/ +1 person **Consequences:** ↑ wound management, ↑ morbidity & mortality, ↑ hospitalisation, ↑ cost, ↓ client confidence **Tx**: no systemic signs = swab for C&S, ABs alone, encourage resolution w/ surgical tx **If septic**: IVFT, ABs, analgesia, sx **W4 Cancer & chemotherapy** **Chemo:** disease tx by using chemical substances, esp cancer tx by drugs (cytotoxic or cytostatic), can =\> GI toxicity **Cytotoxic drug dose**: max tolerated dose = ↑ fractional kill w/ each tx -pulse dosing @ intervals = normal tissue recovers **Combo chemo**: ↑ effective, ↓ selection P, chose ones w/ diff MoAs, X interfere w/ each other or have overlapping toxicities **Stages**: induction (intense to induce remission), maintenance (maintain remission), re-induction (tumour relapse, back to initial protocol), rescue (tumour resistant to current tx, change drugs) **Factors affecting success**: tumour cell type, drug distribution, resistance (MDR1 upreg =pumps cancer drugs out of cells) **Treatment timing**: as early as poss - log phase of growth best but can't detect clinically at this stage **Neoadjuvant**: shrink tumour pseudocapsule -\> thick collagenised capsule w/ no viable tumour cells = easier excision **Adjuvant chemo**: after sx, delay/avoid microscopic mets or recurrence after incomplete surgical margins **Palliative chemo**: low dose chemo to ↑ QoL & ↓ symptoms Oral ≠↓ toxicity **IV** -- flush 1st for patency, minimise peripheral v trauma, extravasation = tissue damage, pruritic, ulcers **Intra-arterial chemo**: catheter direct to tumour via artery = ↑ conc dose to target site & ↓ exposure @ healthy tissues **Intracavitary chemo:** conc dose to specific body area - malignant effusion, mesotheliomas, ↑ QoL, ↓ toxicity **Haematologic toxicity**: neutropenia/thrombocytopenia2000 neutrophils = good level -- prevent sepsis **Reduce dose** & tx w/ ABs if n.phil count \ DCM **Urinary system toxicity**: sterile cystitis - cyclophosphamide chemo -- tx: split high dose -- irreversible if fibrosis **Nephrotoxicity**: cisplatin (X CAT) **Hepatotoxicity**: lomustine, stop if ↑ ALT **Alopecia/hyperpig**: doxorubicin **Hypersensitivity**: asparaginase (skin rxn, facial oedema) -\> stop drug. Doxorubicin = mast cell degran **W4 Field radiography MUST** place generator on stand **Challenges**: expensive equipment w/ large animal, no control zone, variable facilities, working w/ O/untrained staff, time P **3 ppl**: hold horse, hold plate, take image. **Controlled area**: avoid stable, flat/dry/level ground, quiet, dark, power, space **Temporary radiation control zone**: 2m safety area around horse **PPE**: in controlled area, lead lined stuff + dosimeter **Personal monitoring**: 20mSv/yr 18+, 6mSv 16-18yr, 1mSv for public **Patient prep**: restrain, xylazine/detom/Romifidine, stand on fat even surface, clean area well, hoof prep, can pack feet ![](media/image26.png)**Exposure factors**: ↑ mAs for ↑ tissue thickness **Position**: limb/joint vertical in dorsal/sagittal places for WB & flexed views **Marker**: DORAL or LATERAL to region images **Refer**: need high exposure eg. neck/back/chest, need bucky system to maintain alignment **Standard series**: LM, DPm/Pt, DLat-PmMed oblique, DMed-PmLat oblique **Skyline navicular**: palmaroprox-palmarodistal oblique **Upright pedal**: dorsoprox-palmaodistal oblique **W3 Large animal field surgery** ✓ convenient, cheaper, ↓ biosecurity risk, ↓ stress X ↑ infection risk, ↓ resources & assistance **Horse**: castrate, stitch up **Sheep**: C-sec, castrate, ex-lap **Alpaca**: castrate, tooth root abscess, f\# **Pig**: repair hernia, amputate digit, C-sec **Refer**: complex sx, poor restraint, high value animal, ↑ risk litigation/infection **Drugs**: LA, NSAIDs, oxytocin, xylazine sed, ABs, dopram stim calf breathing **Aseptic prep**: heavy duty -\> surgical clip, iodine inactivate microbes (2m kill time, inactivated by organic debris), chlorhexidine (5m kill time), ↓ susceptible to inactivation by organic debris, persistent residual effect **Manage risk**: isolate, physical& chemical restraint, tail immobilisation, prioritise human safety, operate under cover **G+** on **skin, G-** in **GIT/repro tract AMs** should reach MIC in target organ at time of sx if poss -- IM 1-2h before, IV at time of **Wound infection**:necrotic tissue/haematoma bac growth med, ↓immunity w/ tissue damage, infected suture, dead space **Patient care**: X bullying, weather protection, isolation? , fly control in summer, educate O in aftercare, analgesia, move ↓ **W4 Fundamentals of toxicology** **Acute toxicity:** adverse effects from single dose or several doses in short time **Chronic**: long term exposure. Cumulative. **Novel drug development**: in vitro toxicology studies -\> pre-clin development (acute toxicology study 1-4wks high dose + reprotoxicology studies) -\> clinical development (chronic toxicology 3-6m low dose, carcinogenicity study 2yrs, low dose) **Common poisons**: grape/raisin = renal failure. Rat poison = haemorrhage. Adder bite = shock/collapse. Antifreeze = ataxia **Vet Poisons Info Service** (VPIS) **Emetics**: use only if less than 3hrs after ingestion. X if poison corrosive Decontamination w/ **activated charcoal** -- adsorb if in direct contact w/ liquid toxin -- best use less than 1hr after ingestion **Type A** -- augmented -- predictable toxic effect related to pharmacological action, dose-dependent **Type B** -- bizarre -- unrelated to PC action -- hypersensitivity rxns (I -- allergic/anaphylaxis/atopy, II -- antibody, III -- immune complex, IV -- delayed) **Type C** -- chronic -- cumulative toxicity after prolonged use **Type D** -- delayed -- teratogenic/carcinogenic **Type E** -- end of use -- effect only seen after drug stopped **Pharmacovigilance** -- detect, assess, understand & prevent adverse effects -- report unexpected adverse events to VMD **Info for SAR** (suspected adverse event) **report**: identified reporter, affected animal info, product concerned & SAR details **EMETIC:** Apomorphine/ropinirole -- dog -- D2 agonist -- stim CRTZ. Xylazine -- cat -- a-2 agonist -- stim emetic centre **W4 Gastrointestinal therapeutics I** **ANTIEMETICS:** Metoclopramide **--** dog, horse - D2 antagonist + **PRO KINETIC** -- suppress CRTZ , ↑ ACh release in upper GIT Ondansetron -- dog, cat - anti-serotonergic (5-HT) Maropitant -- dog, cat -- NK1 receptor antagonist -- 24hr action **ACIDBLOCKER:** Omeprazole -- horse - proton pump inhibitor -- suppress stomach acid secretion Antacid (Al(OH)3, Mg(OH)2, CaCO3). Misoprostol -- EGUS - synthetic prostaglandin E1 analogue - ↑ blood to parietal cells **PROKINETIC:** metoclopramide. Lidocaine -- horse - ↑ intraop gastric motility **LAXATIVE:** Lactulose -- fermented in large i to acetate + lactate =\> osmotic laxative effect Liquid paraffin = lubricant **ANITDIARRHOEAL:** loperamide -- opioid agonist - ↓ propulsive i contractions, ↑ segmentation & GI sphincter tone Kaolin-pectin -- demulcent & adsorbent Hyoscine -- equine colic -- antimuscarinic & antispasmodic **W4 Gastrointestinal therapeutics II** **Tempt eating:** wet/warm food, small portion, shallow bowl, hand feed, remove after 20-30m **Anorexia** 2ndary to smthg **APPETITESTIMULANT:** Mirtazapine -- noradrenaline & serotonergic ant. Cyproheptadine -- non-selective serotonergic ant Capromorelin -- ghrelin agonist **Intestinal microbiota**: bac cells 10x more than host cells -- synergistic **Prebiotics**: selectively fermented ingredients that support beneficial micro-organisms **Probiotics**: live microorganisms in amounts that have health benefit to host **Synbiotics**: pre + probiotics **Acute haemorrhagic diarrhoea syndrome**: *C. perfringens* -- peracute blood D+/V+, haemoconc w/ normal plasma prots **1 -- benzimidazoles** -- white -- Fenbendazole - broad spec - binds to parasite tubulin = X glucose uptake, glycogen depletion **2 -- imidazothiazoles** -yellow -levamisole - nicotinic ag. - act as nicotinic ACh receptors =rapid, reversible paralysis - nems **3 -- macrocyclic lactones** -- clear - [Avermectin] (ivermectin & selamectin), [Milbemycin] (milbemycin & moxidectin) **4 -- acetonitrile derivatives** -- orange **5 -- spiroindoles** - purple **Isoquinolones** -- praziquantel -- narrow spec -- parasite integument damage =\> tetanic muscular contraction & paralysis **Toltrazuril** -- antiprotozoal agent -- Eimeria spp & developmental stages of Coccidia **W4 Disorders of GIT** Hx & physical exam -\> problem list -\> symptomatic tx -\> resolution **True anorexia** : ↓ appetite **Psuedoanorexia**: hungry but unable to eat **Oral cav**: Psuedoanorexia, weird jaw movement, pain, hypersal, ↓ weight gain, halitosis, NOTHING **Lips, oral mucosa, gums palate**: neoplasia (STS), trauma, feline eosinophilic gran complex, papillomavirus, FMD, BTV **Salivary glands**: mucoceles, sialadenitis (painful) **Jaw:** f\#, Actinomyces bovis = lumpy jaw, abscess, neoplasia **Oropharynx**: tonsils & cricopharyngeal muscles, DYSPHAGIA -- neoplasia (SCS), cricop. achalasia/dysphagia, polymyopathy & polyneuropathy (affect swallow reflex) **Oesophagus narrows at** : pharyngo-oesophageal sphincter, gastro-oesophageal sphincter, thoracic inlet, heart base **Nausea**: ↓ in lower oesophageal sphincter & oesophageal motility & ↑ small i retrograde motility **Expulsion** **of gastric contents**: simultaneous contraction of **Retching**: ab muscle contracts & marked ab effort ab muscles + diaphragm -\> -ve intrathoracic P -\> gastric content to oesophagus -\> mouth **Stomach**: V+, anorexia. **Disorders**: gastritis, ulcers, FB, pyloric stenosis, bloat, GDV, TRIP, Parvo, Trichostrongylus **Small i**: **D+ -** normal frequency & urgency, X mucous/strain, melena, ↑vol **Large i D+:** haematochezia, urgent, normal vol **Large i** = D+ & constipation -- adenocarc., salmonella, campyb, corona/parvo, giardia, histoplasma, non spec inflamm **Ex-lap** X great -- risk of peritonitis & dehiscence **Gran. colitis:** E. coli - boxer, Frenchie **Rectum & anus:** tenesmus, scoot, poo shape diff **Disorders**: benign polyp, adenocarc., prolapse, perineal hernia, **W4 Vomiting in companion animals** +---------+---------+---------+---------+---------+---------+---------+ | **GI | **Extra | | | | | | | conditi | -GI | | | | | | | ons** | conditi | | | | | | | | ons** | | | | | | +=========+=========+=========+=========+=========+=========+=========+ | **Stoma | **Small | **Large | **Metab | **Toxin | **Abdom | **Neuro | | ch** | i** | i** | olic/ | / | inal** | ** | | | | | endocri | drug** | | | | | | | ne** | | | | +---------+---------+---------+---------+---------+---------+---------+ | Gastrit | Inflamm | Inflamm | Renal/h | NSAIDs | Pancrea | Vestibu | | is | | | ep | | titis | lar | | | FB | Obstipa | disease | Chemo | | | | Ulcer | | tion | | | Periton | Pain | | | Infecti | | HypoAC | Poison | itis | | | Motilit | on | | | | | Smell | | y | | | Diabeti | | Hepbil | | | issue | Neoplas | | c | | disease | Trauma | | | ia | | ketoaci | | | | | GDV FB | | | dosis | | Pyometr | Encepha | | | Intussu | | | | a | litis | | Pyloric | sceptio | | | | | | | stenosi | n | | | | | | | s | | | | | | | +---------+---------+---------+---------+---------+---------+---------+ **History:** signalment, prev medical hx, diet, duration, what, scavenge, faeces, how often/severe **Specific** -- pain, bloat, icterus, solid struc, head tilt **Serious signs** -- pyrexia, tachycardia, weak pulse, dehydrated **Min database**: dehydration = ↑ PCV & TS Bleeding = ↑ urea HypoK **Endoscopy**: gastric FB, neoplasia, ulcer, inflamm **Ex-lap** if GB, neoplasia, GDV, pyometra, septic peritonitis **Acute** = antiemetic, analgesia, saline/Hartmann's , antacids, acid blocker **Chronic** = symptomatic & disease spec tx. **Poor prognosis** w/ neoplasia, chronic renal failure. **Good** for hypoAC, FB, hyperthyroid **W4 Diarrhoea in companion animals -** XS faecal water & ↑ frequency faecal output **Acute small i D+:** bac, virus, parasite, drugs, insecticides, diet change, FB, intussusception, renal/hep disease **Chronic small i D+:** food-responsive chronic enteropathy, chronic gastritis/enteritis, ulcer, mesenteric neoplasm, CHF **Acute large i D+:** non-spec colitis, obstructive, hookworm, giardia, campyb., clostridia **Chronic D+:** IBD, parasite, neoplasia **Large i diarrhoea**: SNAP test for Giardia, Parvo, FeLV, FIP **Exclusion diet trial (4-8wks)** -- restricted novel protein **Large i D+ Tx**: FT, transfuse blood, AB, anthelmintics, anti-diarrhoeal, acid blocker, vit supp, sx 4 neoplasia, immunosuppressive therapy 4 IBD **Rule out extra GI causes**: EPI, pancreatitis (pancreatic lipase immunoreactivity test), renal disease (SDMA/creatinine), hep insufficiency (bile acid stim), hyperthyroidism (TRH stim), hypoadrenocorticism (ACTH stim) **W5 Intestinal neoplasia in dog & cat** **Dx:** coffee ground vomit 1-3m, haematemesis, blood in stool, palpable mass, weight loss, PLE, anaemia, can do xray **FNA** for lymphoma, excisional biopsy for staging **US:** can't see layers w/ alt echogenicity, dilated fluid filled SI loops **Lymphoma**: circumferential symm [hypoechoic] **Adenocarcinoma**: (a)symm [mixed] echogenicity **Intussusception**: [↑] circumference symm target **GIST**: express CD117 --leiomyosarcomas & leiomyomas = hypoglycaemia **Gastric neoplasia**: **benign** adenomatous polp, leiomyoma. **Malignant**: adenocarcinoma (dog), leiomyosarcoma **Gastric carcinoma**: 8yr old male -- raised plaques w/ ulcers & diffuse infiltrating masses -- poor prognosis esp in dog **Feline adenocarcinoma**: mets = 5m survive, no mets = 1yr **Alimentary adenocarcinoma**: cat SI, dog colon/rectum **Pyloric resection**: Bilroth I = gastroduodenostomy - harder, Bilroth II = gastrojejunostomy - ↑ risk **Small i tumours**: most common in cat -- lymphoma, dog -- lymphoma/carcinoma -- old, male survive 1yr - get LI tumour more **Adenomatous polyps** -- cat duodenum, dog rectum **I tumour tx**: sx excision, doxorubicin neoadjuvant chemo, NSAIDs **P leak test of anastomosis**: Inject 10ml into bowel to create 30-40mmHg P (3x4x physiologic P) & see if leaks **W5 Hepatobiliary & pancreatic diseases** Non-spec signs, biochem profile indicates liver func **ALT** -- hepatocellular injury & necrosis -- chronic hepatitis -- young dog w/ portal vasc abnormalities **AST** -- hepcell injury -- also ↑ w/ skeletal/cardiac muscle inflamm **ALP** -- lines biliary tract & bone source - ↑ w/ glucocorticoids, biliary disease, osteosarcoma **GGT** -- primary hep neoplasia. Dog ↑ w/ glucocorticoid, LA ↑ w/ bile duct/liver disease, Horse ↑ w/ acute liver disease, **Bile acid stim test**: starve 12hrs -\> blood sample -\> feed -\> 2hrs -\> blood sample **Increase**: abnormal portal blood flow -- PSS, hepcell dysfunc -- X extract bile acids from portal circulation, Cholestasis (bile from hepcyte to biliary canalicular system transporter failure -- X in cholestatic animal -- masks hep dysfunc/PSS) **Horse** -- no gall bladder, ↑ = ↓ feed intake for 2+d or foal \ assess severity -\> tx plan Accurate hx = ✓ ddx -- assess severity, duration & ID risk factors **Risk factors**: changed/↑ hours stabled, geographical area (soil sand), feed (↑ concs), vices (crib biting/windsucking), drugs (opioid, a-2 agonist, atropine), time (spring), parasites (tapeworm for ileal impaction, cyathostomins for gut wall damage, ascarids in foal) **False colic**: non-GI source of ab painliver/urinary disease, peritonitis, intra-ab abscess/neoplasia **1.** **Observe from distance** (resp rate, depth, distension, faeces) **2. Assess CV status-** hypovol/endotox = \>60hr, red mm, 3+ CRT, bad=sluggish jug refill & weak pulse (dehydrated=dry mm) **3. Auscultate GIT --** borborygmi of asc. colon -- hypermotile w/ spasmodic colic. Local hypomotility = localised GIT stasis, general absence = GIT ileus (most common) **Impact of pain on clinical exam:** 40-60 HR, tachypnoea, xylazine good- quick acting, assess CV status before giving again Donkeys: dull = emergency, can do rectal exam -- impaction colic most common -- hyperlipaemia 2ndary risk (NEBAL) **Trans-rectal exam**: [Spasmodic] =normal [Pelvic flexure] = firmer in L ventral ab [Caecal impaction] = firm in right mid ab [R dorsal displacement or nephrosplenic entrapment] = LI gas distension SI [strangulating] obstruction = distended loops **NG intubation**: nasogastric reflux. MORE THAN 2 litres = abnormal -- indicates mostly SI obstruction -- also therapeutic Abdominocentesis: serosanguinous peritoneal fluid & ↑ peritoneal fluid:blood ratio = strangulating lesion **Bloods**: PCV/TP, blood lactate less than 2 = normal **FLASH** (fast localised ab sonography of horses) -- assess not palpable struc eg. SI distension, wall thickness, motility **Analgesia**: xylazine/detom/Romifidine, opioid butorphanol, **NSAIDs** bute or flunixin meglumine -- slow onset & duration **Spasmolytic -- anticholinergic** -- N-Butylscopolamine -- smooth muscle relaxant -- quick onset & duration **Enteral fluids**: do unless NG reflux -- isotonic bolus **Impaction colic** = MgSO4 -- osmotic effect to soften gut content **Refer**: no response to analgesia, HR more than 60, rapid deterioration despite therapy, more than 2L NG reflux, recurrent **W5 Conditions of equine upper GIT** **Choke** -- physical oesophageal obstruction -- eat food quick, dry coarse feed, poor mastication, dental disease **1. Give time --** most self resolve **2. Sedate --** lower head to encourage drainage, IV a-2 + buscopan to relax muscle **3. Massage oesophagus** to encourage breakdown **4. NG tube** -- careful not to damage oesophagus **5. Low vol lavage w/ NG tube** -- lubricate NOT FLUSH obstruction **6. High vol lavage/endoscopic removal** -- refer -- ensure airway protected **Long term complications**: stricture forms (circular fibrous submuc. scarring), diverticulum forms, oesophageal rupture **Recurrent choke**: dental disease=incomplete food mastication → complete dental exam - feed pre-chopped fine roughage **Prevention**: damp high risk hard feed, small vol regularly, not immed post-exercise, ↓ excitement b4 feed **ESGS**: direct contact w/ gastric acid -- along curvatures dorsal to margo plicatus -- common in performance horse **EGGD**: breakdown in mucosal defences. Inflam → hyperaemia → erosion → ulcers -pyloric region common **Primary** assoc w/ intensive management & normal GIT **2ndary** assoc w/ delayed gastric emptying from another disease **Signs**: vague, poor performance, altered appetite, weight loss **Gastroscopy** for def dx **Tx:** pH \> 4. ↓ HCl = ↑ pH **Tx**: sucralfate mucosal protectant, 4mg/kg for 28d acid blockers (antacid q1-3hrs, can't use misoprostol w/ omeprazole) **Risk**: same as \^ + ↓ prostaglandin syn w/ stress **Prevent**: 18h grazing/day, small vol more frequent, X high starch, ↓ stress **W5 Approach to equine diarrhoea** **Hindgut:** store &absorb water, bac & protozoal flora ferment eaten fibre → VFAs, prots & vits, ↑undigested sugar =disturbed **Foal**: foal heat diarrhoea, rotavirus, Rhodococcus equi **ALL** -- toxins **Salmonellosis** (*enterica*)-G-ve fac anaerobe-faecal oral- subclin usual, mild=fever, anorexia depressed (FAD), recover fast Acute enterocolitis = FAD + gastric reflux Septicaemia -- endotoxaemia/SIRS Chronic **Dx**: bac culture, PCR, lat flow **Clostridiosis** (perfringens/difficile) -- G+ve anaerobic spore-forming bac- faecal-oral- opportunistic - veg growth X inhibited = toxins A -- enterotoxin B -- cytotoxin Can [ELISA] toxin for dx **Equine coronavirus (ECoV) --** enveloped ssRNA - faecal oral -- most self limit -- co-infection = serious **Larval cyathostomins:** small redworm, nema -- problem when mass emergence of encysted cyathostomin larvae from LI walls (young/old horse, late winter/early spring). [Serum ELISA] shows [exposure] but X current infection [Faecal test bad] **CHO overload:** eat too much = CHO overflow to LI → ↑ VFAs & lactic acid = ↓ pH → normal flora disturbed, bac overgrowth & endotoxin release from dying bac **NSAID toxicity**: no cytoprotective prostaglandins (COX1) that produce mucus lining & no inflamm prostaglandins (COX2) - EGUS & R dorsal colitis **Tx**: misoprostol **Lawsonia intracellularis:** obligate IC G-ve =\> proliferative enteropathy -- weanlings & young yearlings Aug-\> Feb Prolif of crypt epi cells in intestine = immature epi cells w/ no microvilli -\> malabsorption -\> PLE **Clinical findings**: dehydration (total body water loss), protein loss (= peripheral/pul oedema), SIRS **SIRS**: endotoxemia, sepsis, multi-organ dysfunc syndrome = tachycardia/pnoea, pyrexia, ↓ CRT, cold extremities **Chronic diarrhoea:** lasting \> few weeks, maintain hydration. **Signs**: dirty hind, weight loss **Infiltrative bowel disease:** IBD, lymphoma -- weight loss -- US see [↑ mural thickness]. Tx w/ steroids **Labs:** PCV/TP high due to haemoconcentration, high lactate = dehydrated, ↓ WBCs w/ acute, ↑ WBCs w/ chronic **Dx**: imaging & sand sedimentation test for sand enteropathy, US, faecal PCR +/- bac culture **Management**: fluid therapy -- isotonic to rehydrate, hypertonic if want fluid circulated quickly, not for PLE (= oedema) **W5 Investigating liver disease** **Hep insufficiency signs:** lethargy, weight loss, colic -- \>70% func mass affected, irreversible path likely, bad prognosis **↑** AP, AST, GGT & GLDH **↑** globulins, bile acids, bilirubin **↓** urea (syn in liver) **Monitor case** -- ID & eliminate cause, likely to see other horses in herd affected **Hep encephalopathy signs**: depressed, circling, blind **Tx**: hypertonic saline (anti-oedema) **Hep encephalopathy pathophysiology**: disturbed NTs, ↑ cerebral conc of benzodiazepine-like substances, **Hepatopathy outbreaks**: toxicity (pyrrolizidine alkaloids, iron, mycotoxins), infectious disease (EHV, F. hepatica) **US**; dx info, find site & ↓ risk of biopsy **Biopsy**: confirm liver disease present, choose spec therapy, indicates prognosis **Biopsy adverse effects**: aim to do in early stage liver disease, late = bleeding risk **Biopsy score**: fibrosis, irreversible cytopathy, inflam infiltrate, haemosiderin accumulation, biliary hyperplasia **Tx**: prednisolone glucocorticoid, vit E antioxidant, severe haemosiderin accumulation = remove 1.5% BW blood q1-2wks **W5 Approach to coelomic disorders assoc w/ GIT & liver** **GIT**: Chick (0-7d) -- gizzard impaction, starve out, young bird (7-40d) -- coccidiosis, (necrotic) enteritis, gizzard ulceration adult (trichomonas, crop impaction, PGE) **Hepatic**: chick -- bac hepatitis, young -- bac hep, inclusion body hep, adult -- histomoniasis (blackhead), bac hep **Signs**: hunched, tail down, penguin stance, emaciated, ↓growth. **Pet**: full hx, clinical exam, faecal smear & culture, bloods **Commercial**: PME -- localise lesion in intestine -\> microscopy/histo/virus isolation **Wet litter**: ↑ moisture -- environmental or (intestinal/caecal) diarrhoea **Crop distension:** bad prognosis **Crop impaction** -- metoclopramide, lactulose + warm water, fluids **Crop candidiasis**: itraconazole, surgical drain/flush **Trichomonas** (canker): motile protozoa, plaques in upper GIT → scrapes & microscopy **Gizzard ulceration**: mild = trauma/FB, severe = adenovirus/mycotoxin → supportive tx, prevent w/ vacc & nutrition **Coccidiosis**: [non] motile Eimeria protozoa, do intestinal wall scrape + histopath -- tx: nicarb&nara 28d then 2d monensin **Necrotic enteritis***: C. perfringens* commensal overgrowth =\> mainly Type A toxin = severe mucosa necrosis & bloody poo Gamebirds: **spironucleosis** -- motile protozoa, microscopy, no treatment = electrolyte supportive therapy **Histomoniasis -- blackhead** -- motile protozoa -- oregano extract tx -- prevent: keep indoors (earthworm intermediate host) Worms: eggs resistant in enviro, can have intermed host, do FEC then fenbendazole, praziquantel & ivermectin **Nursing**: ↑ litter quality & temp, stim appetite, multivits in water, cull sick birds **Pet** = weigh daily, may feed via crop tube **Egg bound:** oft salpingitis -- **dx** w/ US/xray -- **tx**: drain egg to ↑ risk infection then break it up & remove, ABs if visibly unwell **Peritonitis**: NSAIDs if appear well, NSAIDs **+ ABs** if pyrexia, ab distension & emaciation **Liver disease**: **PME** -- bac culture, histopath, sample for PCR/virus isolation **Vacc** for marek's disease **Inclusion body hep (adenovirus**) = supportive therapy **Bacteria** eg. pasteurellosis = AMs based on C&S **W5 GI conditions related to behavioural disorders** **Positive**: desire seeking, social play, care, lust **Negative**: fear anxiety, frustration, pain, panic grief **Behaviour response** to -ve emotions: appease, avoid, repulse, inhibition X anthropomorphic terms, open qus **Anxiety** = chronic state of stress = ↑ cortisol = ↑ SNS activation, ↑ gut permeability & ↓ absorption **W5 Evidence based practice of minimising risk of gastric ulcers in horse -- nutritional perspective** **↑ risk gastric ulcers**: infrequent feeding, ↓ saliva, X feed before exercise See more in **racehorse** -- fed more concs **Non-glandular stomach** = microbial fermentation -- pH 5 **Saliva buffer** Saliva -- 1ml per chew **Feed 2hrs before exercise**= pH drops less - exercise ↑ab P so acidic stomach content pushed into unprotected upper half **Solutions**: ↑ saliva buffering w/ chaff & hay, forage during travel, feed little & often w/ good quality hay before concs **Don't restrict fibre** -- need bulk + psychologic need to chew -\> stereotypies **Trickle feed** = ↓ exposure of gastric mucosa to acid = X mucosa injury **Surgically treated** horses = ↓ ESGD incidence, **medically managed** fasted longer = ↑ risk ulcers **↑ colic in autumn/winter** - ↑ stabling (↓ motility), ↓ exercise **↑ colic w/ stereotypies** -- uneven teeth wear, ↓saliva & fibre **W5 Approach to distended abdomen** **Signs:** appetite, thirst, V/D, big ab regardless of BCS, ballottement fluid thrill, gas percussion **Apparent distension** -- ab wall rupture (ab muscle/prepubic tendon), ab wall weakness (HAC, DM) **True distension**: pneumoperitoneum, obesity, neoplasia, ascites **Organomegaly**: SUS BLIK -- spleen neoplasia/drug, uterus pyo/preg., stomach dilate/distend, bladder obstruct/neoplasia, liver drug/disease, intestine dilate/obstipated, kidney hydronephrosis/neoplasia **Ascites**: path accumulation of free fluid in ab cav **Abdominocentesis**: 1-5ml **Pure transudate** ascites - \ 3g/dl protein, ab free fluid, supportive tx ![](media/image28.png)**W6 Equine dentistry** **Triadan system**: Cementum around edge, 2ndary dentine @ pulp horns, infundibular maxillary only **Mandibular teeth:** 2 roots (rostral, caudal), no infundibular **Older**: ↑ angled incisor, taller **Permanent teeth eruption times:** 1 2 3 4 canine 5 - wolf 6 7 8 9 10 11 ----- ----- ----- ---------- ---------- ----- --- --- --- ---- ----- 2.5 2.5 4.5 4-5 5-18m 2.5 3 4 1 2 3.5 **Mark**: enamel ring & enclose cement core of infundibulum **Cup**: top part of infundibulum filled w/ food **Star**: transverse cross sec of pulp cavity (filled w/ 2ndary dentin) **Cap**: deciduous teeth that cover permanent teeth **6 cheek teeth** -- 6 & 11 angled = lat excursion to molar occlusion test **Teeth erupt** \~2mm/yr **Gaps** = change diet **Shear mouth** - \>45° angle of occlusion -- ↓ side to side chewing - pain/diet **Excessive transverse ridges (ETR)** -- ridge normal (↑ SA), if too big, reduce **Sharp buccal & lingual points (BLPs**) -- enamel overgrowth - ↓ to prevent ST trauma **Cheek teeth displacement** -- common inn mini breeds -- overcrowding -- best tx = extraction **Routine dental**: annual, severe resolved findings = 6-9m, severe unresolved finding = 3m **Power tools**: ↓ tiring & time, ↑ heat, ↑ potential for ST damage, ↑ precise **W6 Approach to pig GI diseases** **Oral cavity lesions**: FMD, vesicular stomatitis, uraemia from kidney failure, teeth clipping, eat toxin **Transition diet**: ↑ constipation, ↑ risk stillborns. Prevent w/ **fibre rich diet** = ↑ bulk = ↑ gut fill = ↑ full **Colostrum**: within 3hrs. Longer = ↑ risk death. Milk replacers only as supp not replacement -- [crude fat lower] **↑ colostrum intake**: **milking sow** -- role to produce milk **Split sucking**: piglets compete for access to mum's teats **Creep feeding: ↑** weaning weight, smoother transition, help start villi development = ↑ completely digestion = ↑ risk D+ **↓ weaning challenged**: X eat = stomach empty in 3hrs, feed porridge to stim feed intake, cosy kennel, 3:1 water:feed, hospitalise compromised piglets, wean piglets in batches of similar sizes **[Young (0-7d)] --** RECC- rotavirus, E.coli, campylobacter, C. perfringens **[7d→weaning]:** SEC: S. enterica, E. coli, coccidiosis **Sample** faeces. **PME** -- intestine -- superficial = PCR, contents = C&S, histopath. Virology = lung & spleen **Tx**: broad spec AM, electrolytes, clean out pen, heat pen **Prevent**: ✓ colostrum, hygiene, vacc dam, biosecurity **[Weaned pig]**: Vit E deficiency **Ascarid nematode**: tx w/ fenbendazole/ivermectin **Salmonellosis:** C gut content/faeces **Brachyspira**: *hyodysenteriae* = dysentery (bloody D+), *pilosicoli* = watery D+ -- culture gut content/faeces -- tx w/ tylosin **Post-weaning multisys. wasting syn**. (PMWS)- porcine circovirus T2= pallor, dyspnoea, jaundice, ↑ mortality = [vacc] young **[Adult pig]:** C. novyi, salmonella, swine dysentery, gastric ulcers, swine fever (CSF/ASF) = depression & anorexia -- notifiable Lawsonia intracellularis =\> ileitis -- [porcine i adenomatosis] (thick mucosa, ulcer, necrotic enteritis) = D+, PCR, MZN scrape **Feed**: ↑ fibre for motility, wet meal **Vacc**: clostridia (novyi), salmonella. L. intracellularis, PCV2 **Liver disease**: gross path, PCR -- ascarid larvae migrate through liver, Aspergillus poisoning, C. novyi = aero chocolate liver **W6 Lameness in companion animals** **Hx:** which limbs, severity, onset, trauma, continuous, improvement, lying/sitting, exercise, other issues, travel **Distant observation**: NWB, weak, hard to sit/stand, plantigrade stance (entire food contact w/ ground when stand/walk) **Ortho exam**: lame limb last -- pain/crepitus, ROM, integrity of supporting strucs, anatomical deformities/displacement **Lameness grades**: 0=none, 1=inconsistent, 2=minor head movement/pelvic tilt, 3=obvious, 4=some NWB, 5=always NWB **Cat**: pat.lux, avasc. necrosis of femoral head, CCLD **All** = CCLD **CCLD**: **acute** = sudden NWB, **chronic** = WB lameness assoc w/OA, **partial tear** = lame mild, WB w/ exercise, improve w/ rest **→ Exam**: +ve sit test = RH displaced laterally, offload affected limb, stifle joint effusion & pain when hyperextend, \ surgery for bigger dog (\>15kg) -- arthrotomy & tibial plateau levelling osteotomy **Patella luxation:** intermittent WB lameness, ¼ have concurrent CCLD -- luxation assoc w/ popping sensation **Xray**: ortho views -- **CrCd** - ID patella location, **lat & flexed view** - ID joint effusion & degen changes **Tx: physio/hydrotherapy** for grade 1&2 **Surgical treatment**: grade 3&4 or painful/lame grade 2 **Bone tumour:** osteosarcoma- most in appendicular skeleton esp forelimbs - severe lameness, poor response to analgesia **DJD**: old dog or cat. **Hx**: lame, slow onset, worse after rest, improve w/ exercise, hard to jump, change in behaviour **Exam**: stiff, muscular atrophy, \ laxity & inadequate coverage of fem. head & acetabulum **Cause**: genetics + enviro Laxity -\> sublux -\> microf\#s -\> sharpey fibres tear -\> cartilage degen -\> synovitis -\> pain **Young dog**: exercise intolerance, reluctant to jump/climb stairs, bunny hop **Tx**: good BCS, exercise, analgesia **Old dog**: DJD, ↓ active, shoulder muscle hypertrophy (cranial weight shift) **Tx**: fem head + neck excision **Ortolani test:** examine hip laxity in lat recumbency -- rarely +ve in old dog (acetabulum shallow & joint capsule fibrosis) **Xray**: lateral & hip extended VD view, extend femurs parallel to each other, patella centred on femoral condyles **Signs of remodelling**: acetabular rim blunt, femoral head flat & thick, subluxation **Joint laxity** -- fem. head centre to cranial acetab. - Norberg angle \>105° normal \>50% femoral head coverage normal **Elbow dysplasia:** group of developmental diseases w/ genetic & enviro comp that overtime leads to DJD -- MOURI **Signs**: lame, worse post-exercise, weird gait, \ primary ossification centres 2. Osteoblasts encased in matrix =\> osteocytes **Endochondral ossification** -- form bone from cartilage precursor -- vertebrae/ribs/pelvis & long bones 1. Form cartilage template → replaced by mesenchymal stem cells, chondrocytes, osteoclasts+blasts & endo. cells 2. SECONDARY CENTRES: in epiphyseal areas = joint cartilage & bone shaped locally -- separate blood supply **Wolff's law:** bone responds to loads placed on it Stress = electrical currents inducted = Piezoelectric effect **F\#**: E delivered to bone greater than E it can absorb. Larger E transfer = greater structural damage **Oblique** = compression/shearing **Transverse** = distraction/tension **Spiral** = torsion **Comminuted** = multidirectional **Monotonic**: supramaximal loading → failure **Pathological**: weakened by eg. osteomyelitis, neoplasia, osteoporosis **Stress** **f\#:** rate of accumulation of fatigue damage surpasses body's ability to remodel → weakening → f\# **F\# classification**: DLONDS **Direction**: transverse, spiral, avulsion (tension), oblique (\>30° to transverse) **Indirect bone healing** -- **callus formation**: inflamm phase (haemorrhage, n.phils, GFs), reparative phase (gran tissue, chondrogenesis, gradual mineralisation), remodelling phase (woven -\> lamellar bone) **Direct bone healing** -- 1° bone union -- rigid fixation -- contact healing (\15%, gran tissue 100% **F\# repair:** reconstruction to meet func. requirements, fixation for enough immobilisation till healing, mobilisation of joints **Methods**: conservative (nothing), rigid external fixation, closed reduction w/ external OR internal fixation, open reduction w/o rigid fixation OR w/ internal fixation **Surgical fixation**: integrity of weight bearing axis lost, pelvis canal \>50% narrowed, acetabular f\# **Casts & splints:** inherently stable ff\#, paired bones BUT P sores, patient interference, joint stiff, cost **External rigid fixation**: linear & circular, dynamic repair, biochemically strong BUT owner compliance, drainage tract **Plates**: neutralisation (overcome forces at site), compression, buttress (prevent collapse in unstable f\#), bridging for gaps **Wire**: cerclage wire encircles bone (long oblique f\#) BUT may slip, loose = affects blood supply, X use alone in long bone f\# Tension band wire applied to neutralise avulsion forces **Pins:** cheap, simple, diaphyseal long bone f\# BUT only neutralise [bending] forces = need interlocking nails/external fixators **Problems w/ healing**: mechanical/bio failure (blood supply, ST coverage, disease), poor compliance **F\# complication**: delayed union (taking longer), non union (not healing, need to intervene) **Viable non-union** -- Hypertrophic (elephant's foot, xs motion), mod hypertrophic horses hoof (less callus, xs motion) **Non-viable non union** -- biologically inactive -- dystrophic (no living bone), necrotic (sequestrum prevent healing), defect (gap at site), atrophic (all above) **W6 Bone & joint disease** **Causes** VITAMIN D **Categories: C MINT CD** - Congenital **Metabolic bone disease**- hypervit A -- cat eats only liver = stiff neck & exostoses on cervical spine -fibrous osteodystrophy **Infection**: osteomyelitis -- haemat. spread after f\# repair **Neoplasia**: osteosarcoma -- 1° bone tumours X cross joints **Trauma**: f\#, periosteal rxn **Chondrodysplasia**: dwarfism **Developmental**: short ulnar (growth plate damaged), pat. lux **Marie's disease aka** hypertrophic [osteo]pathy -- assoc w/ chest mass, periosteal rxn of distal bones, metac/t **Hypertrophic osteo[dys]trophy aka** metaphyseal osteopathy -- large 4-6m old dog, pyrexia, vit C deficient **Craniomandibular osteopathy** -- WHWT, 3-7m old, pain & pyrexia, cant open jaw, prednisolone tx **Bone biopsy**: do for def neoplasia dx (histo), or for osteomyelitis (C&S for tx) -- lesion centre & transition zone samples **Joint disease: predisposition**: ageing wear & tear, exercise, conformation, sepsis, genetics, obesity 1. Inflamm in synovium, cartilage, joint capsule or subchondral boe 2. Initiates inflamm mediator cascade from primary tissue of insult **3.** Inflamm process into 2ndary tissues **4.** 2ndary tissues release inflamm mediators **5.** Enzymatic degradation of cartilage **Septic arthritis**: any age -inflamm → fibrin clot traps bac → cartilage destroyed & extend to subch. bone -- can =\> degen OA **Tx**: joint lavage to remove bac & inflamm mediators, joint capsule sample for C&S, arthroscopy debride & lavage best **Immune-med polyarthritis**: young dog, multilimb, pyrexia, **Non-erosive** = n.phils on cyt. & joint effusion Glucocorticoids **Diagnostics**: **synoviocentesis** (abnormal -- serosanguinous, turbid, less viscous, \>90% n.phils, high TP) **Management**: analgesia, control articular inflamm & cartilage damage, arthroscopic removal of cartilage flap for OCD **W6 Therapeutics for MSK system** **Neuromuscular blocking agents** -- NMBAs -- induce paralysis **Dantrolene**: ryanodine receptor (RYR1) antagonist -- release Ca2+ from SR of striated muscle = X muscle contract -- tx RER **1.** **Inflam mediators released**: production [blocked] by: **Nutraceuticals** -- glucosamine, chondroitin sulphate, antioxs, EFAs **2**. **Nociceptors triggered** -- firing blocked by anti-NGF monoclonal Abs -- bedinvetmab, frunevetmab **3. Pain signal transmitted across afferent neurons** -- transmission blocked by LAs -- bupivacaine, lidocaine **4. Pain perceived in CNS** -- perception blocked by opioids (tramadol), GABA agonists (gabapentin), glutamate & NMDA receptor antagonists (ketamine, amantadine) **W7 Production animal lameness** **Healthy feet**: low infection P, good shape & digital cushion, early detection & prompt treatment, low forces on feet **All diseases**: NSAIDs, nursing care (loose straw bedding, reg cleaning, easy food & water access, close to parlour), trim & examine foot **Digital dermatitis**: daily topical tx (oxytet AB OR salicylic acid), footbath, underfoot conditions, infectious issue **White line disease**: hoof block reexamine in 2-4wks, 5 Fs management: friend, farmer, food (enough biotin?), floor feet **Sole ulcer**: hoof block reexamine in 2-4wks -- time standing, BCS (thin = ↓ fat pad), bedding **Surgical interventions**: partial or complete (more oft) P3 amputation **Sheep**: CODD, foot rot, scald (interdigital dermatitis) - examine foot & clean (AVOID TRIMMING), ABs (topics/systemic oxytet), NSAIDs **Manage flock**: cull, avoid spread, treatment (\50% improvement, [partial] 50-75%. Negative \50% fluorescence **FNA**: solitary lesions, depends on exfoliating capacity **Fungal culture**: sterile toothbrush to get hair → culture medium → evaluate daily for 2-3wks **Biopsy**: take multiple samples, representative area, include normal haired skin **Allergy testing**: dx atopic dermatitis -- **intradermal** is cold standard **Therapeutic**: Elimination diet or insect control trial **W7 Approach to atopic dermatitis** **Allergic skin disease causes:** atopy, FAD, food allergy **Atopic-like dermatitis**: no detectable IgE **Atopic dermatitis**: genetically predisposed inflamm & pruritic allergic skin disease w/ features asooc w/IgE, most commonly directed against environmental allergens **Predisposition**: WHWT, sharpei, pug, \ cutaneous & GIT signs **Allergies**: develop due to prior exposure of allergic = Abs **Allergens**: 15-40kDa, beef most common Nutrient intolerance: ID w/ elimination trial -- **6-8wks** -- 2 skin cycles (22-30d/cycle) **Novel protein**: ✓ cheap, ↓ processing X need detailed hx, hard to find suitable diet, longer = ↓ compliance **Hydrolysed diet**: ✓ shorter = ↑ compliance, easier, ↓ risk AFR to diet X expensive, ↓ wet options, ↓ palatable **W8 Approach to skin conditions of production animals** **Biosecurity** for all: closed herds, quarantine treatments, fencing **Sheep scab** -- Psoroptes ovis -- notifiable in Scotland, chorioptes bovis (rams)= pruritic, fleece loss, 1+ animal= [biosecurity] **Cattle mites** -- Chorioptes bovis -- pruritic, hair loss, pustular/crusty skin **Dx**: skin scape, microscopy **Sheep lice**: Bovicola ovis (chew) --winter/outdoor=pruritis & fleece loss. **Tx (& ↓):** pour on m.cyclic lactone (X fully fleeced) **Cattle lice**: Bovicola bovis (chew) -- winter/indoors = pruritis, hair loss, rough skin → bruise → wound → 2° infection **Blowfly strike/cutaneous myiasis-** green/black/bluebottle flies -summer- isolated from flock, discoloured wool, maggots **Cattle warble fly** -- hypoderma -- notifiable in Scotland -- 2mm soft painful swelling on back -- ID larvae - inject ivermectin **Ticks** -- Ixodes ricinus -- swelling over bites -- ID ticks -- avoid grazing pasture w/ known tick burden, anti-parasitic spot on **FMD**: notifiable -- pathognomonic lesions -- ID w/ swab & PCR -- dx = X movement, cull whole herd, vacc in endemic areas **Vesicular stomatitis**: notifiable -- hypersalivation -- mouth ulcers -- dx w/ virus isolation & serology **BTV**: notifiable -- Culicoides midge vector -- oedema/crust on muzzle -- dx w/ virus isolation, serology, PME **Lumpy skin disease**: notifiable - milk ↓, fever, skin nodules -- dx/ swab & PCR -- vacc if endemic, vector/movement control **BVDV mucosal disease**: ulcerated erythematous lesions -- dx w/ isolation of cytopathic BVD on swabs -- no tx -- vacc **Malignant catarrhal fever** -- ovine herpes - 40°C+ pyrexia, depressed, painful muzzle crusting -- dx w/ viral PCR or Ab ELISA -- no tx - prevent by avoiding co-grazing w/ sheep **Papillomavirus**: warts on teats/penis/neck -- characteristic lesion -- self-limits, disinfect at milking **Bovine herpes mammillitis**: BHV-2 -- ulcerative teat lesions - PCR for virus- symptomatic tx, stop milking -- parlour hygiene **Contagious pustular dermatitis**: ORF -- zoonotic -- lamb nose/mouth skin lesions -- PCR -- no tx -- vacc & ↓ mismothering **Digital dermatitis**: Treponema spp -- slurry to feet -- 50% lame -- topical AM tx -- prevent w/ footbaths, biosecurity **Rain scald** -- Dermatophilus congolensis -- affect dorsum after long wet weather -- symptomatic tx **Abscesses**: F. necrophorum, T. pyogenes - walled off infection -- FNA dx -- drain & flush **Scrapie**: prion -- notifiable - pruritis **Ringworm**: Trichophyton verrucosum -- zoonotic - pathognomic lesions -- antifungal tx (limited efficacy) **Photosensitisation**: primary = eat photodynamic agent (X liver path). Secondary = hep dysfunc (dx w/ liver biochem) **W8 Approach to pruritis** **Pruritis threshold**: different tolerances to pruritis w/o exhibiting signs **Puritis ddx**: PAIN Parasites - SLOFD -- Sarcoptic mange, lice, otodectes, fleas, demodicosis Allergy/autotimmune -- F ACAP -- FAD, atopic dermatitis, contact dermatitis, AFR, pemphigus foliaceus Infection -- bacterial [pyoderma], Malassezia dermatitis, dermatophytosis Neoplasia/neurogenic -- cutaneous lymphoma, feline psychogenic alopecia, acral lick granuloma **W8 Therapeutics for skin** **β- lactam ABs:** amoxicillin & cefalexin for deep & superficial pyoderma **Oxytetracycline**: foot rot in sheep **Lincosamide**: clindamycin for infected wounds/abscesses in oral cav -- NOT for rum/hose/rabbit/hamster/GP/ chinchilla **Fusidic acid**: X prot syn, bacstatic -- G+ve bac **Polymyxin B**: binds to phospholipids to disrupt memb -- cidal- G-ve bac **Miconazole & nystatin** -- antiyeast/fungal -- X ergosterol put into cells memb = ↑ cell wall permeability & cell content leak **Fipronil --** inhibit GABA complex. Binds to Cl channels = uncontrolled CAN activity & death -- NOT RABBITS **Imidacloprid** - ↑affinity for PS nicotinic ACh receptors = paralysis & death **Amitraz**: ↑ nervous activity in synapses = death -- demodicosis tx **Permethrin**: Na channels = excitement→ paralysis& death **Methoprene**: insect growth regulator- affect developing stages Selamectin = stronghold Imidacloprid + moxidectin = advocate Isoxazoline = Bravecto Fipronil = Frontline **Ciclosporin**- atopica -- chronic AD -- calcineurin inhibitor- impair IL-2 production= X activation of T-lymphocytes on Ag stim **Oclatinib** -- Apoquel -- skin allergy/pruritis -- janus kinase inhibitor = proinflamm cytokines inhibited **Lokivetmab** -- cytopoint -- dog AD -- monoclonal Ab targeting IL-31 cytokines **Chlorphenamine** -- antihistamine -- antagonise histamine binding to cellular receptors (esp H1) **W8 Approach to sinus formation, abscesses, popular & pustular dermatoses** **Sinus tract**: draining tract open to skin surface- expel unwanted material via pus formation **(**WBCs, liquefied tissue exudate) **Abscess**: localised collection of purulent material -- fibrous capsule around infection site -- none = septicaemia **Tx:** open, drain, flush, remove nidus (focal point of infection) if poss, debride, ABs IF BAC, pain relief, C&S if not open **Abscess/sinus tract causes**: TINIS -- traumatic (penetrating trauma/FB), inflamm (bac), neoplasia (dog mammary tumour), iatrogenic, 2ndary infection of primary skin disease (folliculitis, furunculosis, panniculitis is SC fat inflamm) **Abscess causes**: **1°** = penetrating trauma, FB, feline leprosy, **2ndary =** deep pyoderma (acral lick granuloma, demodex) **Anal sac disease**: anal gland impaction = 2ndary infection = abscess in perianal region, erythema, draining sinus **Feline leprosy**: Mycobacterium lepraemurium -- rodent vector -- coastal/temperate areas. \ pustules -\> epi collarettes -\> healing cols. **Staph pseudointermedius**: EATSS -- enterotoxin, adhere to keratinocytes, toxic shock protein, [SUPERANTIGEN] **1°** = pyogenic bac w/ no underlying cause -- esp in GSD **2°**: allergic, ectoparasite, hormonal, ket. disorder, idiopathic **Surface pyoderma:** bac infection of epidermal skin layers -- INTERTRIGO aka [skin fold dermatitis] -- staph or malassezia **Superficial pyoderma**: pustule forms in epidermis or hair follicle -- IMPETIGO - common in puppies -- crust adheres to skin **Deep pyoderma**: bac infection of fermis & subcut tissues -- ulcerative crusty lesion w/ purulent haemorrhagic exudate **Pustular diseases**: pemphigus foliaceous -- cat, dog 7+yrs old -- idiopathic cause target DSG-1 antigen = [acantholysis] (separation & breakdown of skin cells due to intercellular Ab deposits) **W9 Skin diseases in NTCA** **Bird:** self-mutilation from pain, smoke, mange, psittacine beak & feather disease (PBFD), endoparasites, fungal, neoplasia **Dysecdysis**: abnormal shedding in reptiles **Management**: housing space, humidity/temp/ventilation, stress-free bathing, good hygiene, know normal eating patterns **W8 Approach to crust, scale, environmental & endocrine dermatosis Crust**: cells & dried exudate **Scales**: accumulation of loose fragments of horny later (cornified cells) of skin -only visible to naked eye when abnormal **Pruritis =** parasites, allergy, pyoderma - Psoroptes cuniculi**:** rabbit -- mites irritate lining of ear =\> serum & thick brown crust **Non/variably pruritic**:SZMELLDN-seb adenitis & sterile pustular disease, Zn responsive dermatosis, malasezia, erythema multiforme complex & endocrine disease, lethal acrodermatitis, leishmaniasis, dermatophytosis & drug rxn, neoplasia - Hard to tx **Drug rxns**: seen within 2 wks of admin **Scaling in young =** seb adenitis, Zn responsive dermatosis **Scaling in old** = epitheliotropic lymphoma **Environmental dermatosis**: solar dermatitis: chronic sun damage from UV radiation **Endocrine dermatosis**: **Hypothyroidism**: middle aged, big dog -- causes: pit/thyroid neoplasia, lymphocytic thyroiditis, congenital **HAC**: **Pit dependent** most common (pit adenoma): 7-9yrs small dog -- xs ACTH =\> adrenal hyperplasia & xs cortisol **Adrenal dependent** -- old big dog -- unilateral adrenal adenoma/carcinoma **Signs**: PPP, BBB **Dx**: ↑ AP, ALT, glucose & cholesterol, ↓ urea & creatinine, ↓ lymphocytes & eosinophils **USG** LESS THAN 1.015 **Steroids** = ↓ total & free T4 **ACTH stim test**: 2hrs - +ve test if **no cortisol ↑** **Low dose dexamethasone test** -- 8hrs -- dexamethasone should suppress cortisol - ID xs cortisol -- get false +ves **High dose test**: 10x higher -- diff between **PDH** (cortisol/ACTH [suppressed]) & **ADH** (cortisol [X suppressed]) **Tx:** PDH = pit irradiation w/ trilostane synthetic steroid -- [risk] of hypoadrenocorticism, adrenal necrosis & hyperK **Alopecia X**: arrested follicle cycle - 2-5yr poodle - 1° hair lost1^st^ - SYMMETRICAL loss over trunk & caudal thighs **W9 Approach to nodular dermatoses/neoplasia** **Feline cutaneous tumours**: basal cell tumour, mast cell tumour (small, discrete, well circumscribed, not encapsulated) **Canine mast cell tumour:** large diffuse, oedematous, swollen, unclear marigns - ↑likely mets, ↑ risk w/ age & obesity **Measure longest single dimension** w/ calliper **Pre-op biopsy**: establish dx w/ FNA, diff quick staning **FNA**: pincushion/cap technique: stab w/ needle, ✓ exfoliative tumours, ↓ distortion cell morphology Aspiration w/ -ve P: only if \^ doesn't work - ✓ dense tumours **Primary criteria**: high nuclear:cytoplasmic ratio, anisokaryosis (varied nucleus size), nuclear pleomorphism **Secondary criteria**: multinucleation, basophilic cytoplasm, ↑ mitotic index **Malignant neoplasia:** Epi tumour**:** round cells, ↑ cellularity, central nucleus, LN & lung mets Mesenchymal: spindle cells, ↓ cellularity, eccentric nucleus, lung mets Round cell: ↑ cellularity, no clusters, LN mets **Papilloma**: young dog typically resolve, older dogs = sx **Histiocytoma**: \ R→L atria via internodal paths -\> AV node -\> bundle of His -\> R+L branches -\> Purkinje fibres -\> ventricles **Normal foetal strucs**: ductus arteriosus & foramen ovale (R-\>L shunts), ductus venosus (hep portal shunt), umbilical a &v **R parasternal short axis**: rotate transducer 90 clockwise from long view -- beam perpendicular to long axis of ventricles **Cardiac murmurs**: I -- intense listen, 2→4 -- S1 & 2 sound, 5 - palpable thrill, 6 -- still hear w/o stethoscope **S3 -- lub dup ud** -- early ventricle filling in early diastole **S4 -- ooh lub dup** -- late diastolic filling **Harsh ejection** murmur assoc w/ **stenosis** of SL valves **Soft blowing** murmur assoc w/ **valvular** regurgitation **Innocent murmur**: 6-15wk old puppy/kitten -- often louder w/ excitement -- disappear by 4-5m **W9 Diseases of CVS II Congenital diseases** **Vol overload**: L→R shunt: PDA, VSD, ASD, mitral/tricuspid valve dysplasia, **P overload**: valvular pulmonic, subvalvular aortic stenosis **Cyanotic**: large PDA/VSD/ASD w/ R→L shunt, tetralogy of fallot **PDA**: ductus arteriosus connects pul a → aorta -- after birth, lungs open = ↓ pul vasc resistance → DA flow reversed to L→R → ↑ oxy blood through DA = X local prostaglandin release = smooth muscle constricts & DA closes **Reverse PDA =** R→L shunting -- v large PDA, oft NO murmur -- differential cyanosis -- cranial pink mm, caudal cyanotic mm **Pulmonic stenosis**: RVOT obstruction-- valvular most common -- [Type A] = ↓ opening size, [Type B] = ↓ opening & hypoplastic **Subvalvular aortic stenosis**: LVOT obstruction -- large breed -- same path and signs as just on LHS **ASD**: lower ASD = ostium premium, high ASH = ostium secundum -- soft/no murmur -- larger = ↑ R vol overload = RHS CHF **VSD**: most common congenital cardiac disase in **cat --** almost always high septal -- murmur over R apex -- large = LHS CHF **W9 Diseases of CVS III Cardiomyopathies & valvular disease** **DCM** -- large dog -- systolic dysfunc & eccentric hypert. of L ventricle- **Doberman** autosomal dominant, **great dane** X linked **HCM** - cat - 1° myocardial disease -- concentric hypert. of L ventricular walls -- **ragdoll** substitution mutation in MyBPC3 **RCM** -- cat -- diastolic dysfunction w/ impaired ventricular filling due to ↑ myocardial stiffness **Arrhythmogenic right ventricular cardiomyopathy** (ARVC)-- boxers -- autosomal dominant = syncope **Myxomatous mitral valve disease** (MMVD): small male dog (CKCS, chihuahua) **W9 Diseases of CVS IV Diseases of peripheral vasculature** **Dirofilariasis -- heartworm --** infestation of **pul a** (+ R heart) by Dirofilaria immitus (mosquito-borne nem) -- dog/fox host **Aortic thromboembolism aka saddle thrombus --** cat -- oft caused by heart disease (HCM, LA enlargement, heart failure) **Systemic hypertension:** old male dog **-** sustained elevation in systolic BP - MAP \>100mmHg, 150/90 systolic/diastolic **W9 Failing Heart I** **Preload**: amount of blood returning to ventricles: ventricular EDV **Afterload**: force acting on ventricular wall myocytes after onset of shortening **Frank starling law**: ↑ blood in ventricles = ↑ contractile strength = ↑ stroke volume -- more cross bridges = ↑ Ca2+ **Heart failure**: pathophysiological state when unable to function to meet requirements -- neuroendocrine & biomechanical **Myocardial failure**: impaired contractility (primary = DCM, secondary -- taurine deficiency, doxorubicin, neoplasia) **Vol overload**: valvular insufficiency, shunts **XS afterload/ P overload:** chronic = ↓ myocardial contractility, hypertension **Inadequate preload** (pericarditis, pericardial effusion) **=\> diastolic dysfunction** (myocardial fibrosis, RCM) = ↑ vent EDV **Signs**: WCS VODCA - **Weakness, exercise intolerance & weight loss:** often w/ **R** sided heart failure & cardiac cachexia **Clas

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