Exam 2 Notes PDF

Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Rumin...

Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Ruminant Nematodes Strongylida Trichostrongyloidea (Trichostrongyles) ○ General Life cycle – direct ROI – ingestion of L3 ○ L1-L3 – in environment ○ L3 on pasture – infective disease ○ L4, adults → cause disease PPP – 3 weeks Eggs – thin shell wall, developing morula, shed in feces ○ Haemonchus spp. – barber pole worm Environment – high humidity, warm weather Larvae – abomasal tissues Adults – barber pole worm (eggs and blood in female) Blood feeders Clinical signs Hemorrhagic anemia from adults feeding on blood Hypoproteinemia → edema (bottle jaw) Weight loss or failure to gain weight Death Diagnosis FAMACHA – assess level of anemia based on mucous membrane color Examples H. placeia ± H. contortus – cattle H. contortus – sheep, goats ○ Ostertagia/Teladorsagia spp. – brown stomach worm Juveniles – gastric glands Hypobiotic within glands when environmental conditions are poor ○ Summer in the south Adults – abomasal surface Clinical signs Juveniles – chronic abomasitis in young cattle ○ Emerging larvae destroy gastric glands White, pinhead to pea-sized nodules Maldigestion, parasitic gastroenteritis (PGE) Morocco leather Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Profuse, watery diarrhea Adults – feed small amounts of blood (minor clinical significance) Type I Ostertagiasis – infected with this year’s larvae ○ Animals on pasture for first time that year ○ Larvae slowly acquire from pasture ○ Juvenile worms mature to adults without passing through hypobiosis ○ Disease seen at end of favorable grazing season (winter) ○ High morbidity, low mortality → mild widespread clinical disease ○ Symptoms – thin body condition, rough haircoat, watery diarrhea Type II Ostertagiasis – larvae acquired from pasture grazed last season that went into hypobiotic state ○ Synchronous emergence of many inhibited (hypobiotic) juveniles ○ Disease seen at beginning of favorable grazing season End of hypobiotic period (fall) ○ Low morbidity, high mortality → a few animals severely affected ○ Symptoms – submandibular edema, diarrhea Ostertagia ostertagi – cattle Teladorsagia circumcincta – sheep, goats ○ Trichostrongylus axei – stomach hair worm Contributes to PGE Habitats – cattle, small ruminants, pigs, horses Co-graze → can be seen in other species Abomasum ○ Trichostrongylus spp., Cooperia spp., Nematodirus spp. Location – small intestine Clinical signs – don’t cause a specific disease alone Contributes to PGE when larvae penetrate small intestinal mucosa ○ Anorexia, diarrhea (scours) ○ Cooperia spp. Immatures burrow into gut wall, may become arrested before developing into adults Environment – worldwide Clinical signs Not considered a primary pathogen Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Contributes to PGE Treatment Rate-limiting parasite for dose determination of macrocyclic lactones ○ Hardest worm to kill ○ Most prevalent parasites in cow/calf operations in the US C. curticei – sheep, goats C. onchophora – cattle C. pectinata – cattle C. puntata – cattle C. surnabada – cattle, sheep ○ Nematodirus spp. – thread-necked worm Life cycle Larvae retained within egg as molt Synchronous larval hatch to infect susceptible lambs N. battus, N. filicollis – must be subjected to prolonged cold periods before becoming infective (lambing time) Location – small intestines Eggs – much bigger than Trichostrongyles Clinical signs – infectious well tolerated N. battus – larvae may damage small intestine wall lining in sheep ○ Severe and debilitating diarrhea (scours), 30% mortality N. helvetianus – cattle N. spathiger – cattle, sheep, goats N. battus – sheep, goats N. filicollis – sheep, goats ○ Dictyocaulus spp. Life cycle – direct ROI – L3 ingestion PPP – 5 weeks Environment – worldwide, temperate areas L1 passes in feces → mature to L3 → dispersed by Pilobulus fungi → L3 ingested, penetrate intestinal mucosa → L4 to lungs via blood, lymph → break capillaries, enter alveoli → migrate to bronchioles, mature to adults Location – trachea, bronchi, bronchioles Clinical signs – due to migration Alveolitis, bronchiolitis, bronchitis ○ Intermittent coughing (deep, harsh) Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ○ Labored breathing ○ Pneumonia, death Diagnosis L1 – feces via Baermann exam Adults – necropsy Clinical signs, history Examples D. viviparus – cattle D. filaria – sheep, goats Strongyloidea ○ General characteristics Life cycle – direct ○ Oesophagostomum spp. – nodular worm Hosts – ruminants, pigs Location Juveniles – encapsulated in small and large intestines (sausage) Adults – cecum, colon Diagnosis Quantitative fecal exam (FEC) ○ Cattle – Wisconsin (concentrate) ○ Small ruminant – McMaster’s (dilution) Metastrongyloidea – lungworms ○ General characteristics Life cycle – indirect (snails, slugs) Location – lungs Migration Larvae – L1 Adults – small, bursate ○ Protostrongylus spp., Muellerius capillaris DH – small ruminants Life cycle – snails ingest L1 in feces ROI – ingest infected snails, slugs IH Juveniles Females lay eggs with oviparous in bronchioles → hatch → coughed up → swallowed → feces Adults Reside in lung parenchyma Muellerius capillaris – kinked tail Clinical signs Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Mild chronic bronchitis Dependent on infective dose, immune status, location Disease likelihood – Dictyocaulus > Muellerius > Protostrongylus Diagnosis – Baermann exam – first-stage larvae (motile, live) Treatment – benzimidazoles, macrocyclic lactones Protostrongylus – small ruminants ○ Parelaphostrongylus tenuis (Brainworm/Meningeal Worm) – not in lungs Life cycle ROI – ingesting infected IH Hosts DH – white-tailed deer AH – sheep, goats, llamas, camels, cattle ○ Won’t pass larvae in feces IH – terrestrial snails, slugs Site of infection WTD – meninges AH – neural tissue Disease – neurologic, often fatal Rear leg weakness, ataxia, circling, incoordination Diagnosis – presumptive, will not pass larvae in feces Treatment – often fatal (guarded prognosis) Prophylactic ivermectin or fenbendazole If hospitalized – repetitive anthelmintic, supportive care (steroids), physical therapy Ancyclostomatoidea – hookworms ○ Bunostomum spp. – southeastern US Life cycle – direct Cutting plates, large buccal cavity Ascaridida Toxocara vitulorum ○ Life cycle – direct (cattle) ROI Ingestion of larvated eggs Transmammary transmission – cow ingests larvated eggs → hypobiotic in somatic tissues → activated → mammary tissue → nursing → fetus ingests larvae Environment – worldwide distribution More widespread than previously thought Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ○ Site of infection Adults – small intestines Visceral larval migrans in calves – non-pathogenic ○ Disease Small to moderate infections may be subclinical Diarrhea, weight loss, death in heavy infections ○ Treatment – macrocyclic lactones, fenbendazole Oxyurida Skrjabinema spp. – pinworms ○ Cecum – sheep, goats, wild ruminants, camelids ○ Eggs rarely seen in routine fecal exams ○ Clinically insignificant → treatment rarely necessary Rhabditida General characteristics ○ Life cycle – direct ○ Free-living in soil, few genera of medical importance ○ Small in size ○ Rhabditiform esophagus – corpus, isthmus, bulb Strongyloides papillosus – threadworm ○ Life cycle – direct (ruminants [calves], camelids) Larvated eggs passed in feces → Free-living stage in soil (non-parasitic) Homogonic cycle ROI (L3) – skin penetration, ingestion, transmammary transmission Environment – tropical to subtropical, southern US ○ Juveniles – various tissues ○ Females – small intestines Only one that is parasitic Reproduce parthenogenetically (asexually) ○ Clinical signs – diarrhea ○ Diagnosis – embryonated (larvated) eggs in feces ○ Treatment – macrocyclic lactones Spirurida General characteristics – require IH arthropods Thelazia spp. – eye worm ○ Life cycle – indirect (face fly) Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum PPP – 3-6 weeks ROI Fly ingests larvae while feeding on lacrimal secretions → larvae mature in IH → fly deposits L3 on DH skin Zoonotic ○ Location – surface of eye, lacrimal ducts, conjunctival sacs under nictitating membrane ○ Treatment – rare, physical removal ○ Prevention – fly control ○ T. skrjabini – cattle, horses ○ T. gulosa – cattle ○ T. californiensis – dog, sheep, ± wild animals Gongylonema spp. – gullet worm ○ Life cycle DH – cattle, sheep, goats IH – dung beetle, cockroach ROI – ingestion ○ Eggs – ellipsoidal, larvated, bipolar opercula, rarely in floats (heavy) ○ Clinical signs – harmless unless seen in large numbers ○ Treatment – rare ○ G. pulchrum – esophagus Woven sinusoidal tract in mucous membrane of host’s esophagus ○ G. verrucosum – rumen Elaeophora schneideri – filarid, arterial worm, sorehead ○ Life cycle Hosts DH – sheep, goats, wild cervids IH – horse flies Environment – western, southwestern US ○ Adults – carotid, iliac, mesenteric arteries ○ Microfilariae – skin of head ○ Clinical signs Mule, black-tailed deer – minimal Abnormal hosts – blindness, deafness, circling Moist exudative dermatitis with crust formation on polls and face ○ Treatment – none ○ Prevention – fly control, restrict movement of infected animals Stephanofilaria stilesi – filarid, brisket worm ○ Life cycle Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ROI MF ingested by horn fly when feeding on a lesion → infection passed back to fly when infected horn fly bites a susceptible host along ventral midline Hosts DH – cattle (beef) IH – Haematobia irritans (horn fly) PPP – 6-8 weeks Environment – throughout USA < western ranges and irrigated areas ○ Location – adults and MF in epithelium of ventral abdomen ○ Clinical signs – dermatitis along ventral midline between brisket and navel Enoplida Trichinelloidea ○ Trichuris spp. Eggs Barrel-shaped, symmetrical Bipolar plugs with striations Brown with smooth shell wall Adults Anterior end – long, thin, burrows into mucosa Posterior end – thick, contains reproductive organs Location Adults – cecum, colon Clinical signs – diarrhea (rare) Treatment – fenbendazole T. discolor – cattle T. ovis – sheep, goats, cattle ○ Capillaria – Aonchotheca spp. Life cycle – direct ROI – ingestion of eggs from environment Eggs – smaller, asymmetrical along midline, lighter in color SOI – small intestinal mucosa Clinically significant but can be confused with Trichuris A. bovis – cattle A. longipes – sheep Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Control of Ruminant Nematodes Tests Qualitative ○ Fecal float – centrifugal with sugar solution Quantitative ○ McMaster (dilution) – small ruminants ○ Wisconsin (concentration) – cattle Assessing Anthelmintic Efficacy FECRT – preferred method ○ Before and 10-14 days after ○ Must collect from multiple animals (10-15) if herd ○ Recommended every 2-3 years ○ Results > 90% – effective 80-90% – equivocal; repeat < 80 – resistance FAMACHA – followed by repeat FEC (McMaster) ○ Effective if animal improves Non-Drug Strategies Reduce parasite exposure ○ Animal management Nutrition – ↑ immunity ↑ Parasites if deficient in protein, energy, or minerals Protein supplementation Cobalt, selenium deficiency → ↑ parasite burden Electrolytes Vitamin supplementation ○ B – ↑ liver function, protein utilization ○ K – blood clotting Careful breeding programs Remove/cull animals with chronic parasites ○ High FEC (sheep) ○ High FAMACHA scores Some breeds are resistant to parasites ○ Barbados Blackbelly ○ St. Croix Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ○ Bos indicus (Brahman, Brangus, Beefmaster) Ewes/does that produce more lambs/kids → higher shedders ○ Pasture management Scheduled disruptions of parasite life cycle Mow or harrow pasture → break up feces → expose eggs/larvae to environment Remove, compost feces Pasture rotation/rotational grazing ○ Moving animals to parasite-free pasture ○ Clean pasture – few larvae on pasture Length of time – temperature, humidity dependent Ideal – 1 year rest ○ Temperate regions – parasites last longer Reality – 60 days rest ○ Hay/plow and reseed or burn early in season to ↓ larvae Grazing management Mixed species grazing – other species (PH) ingesting parasites ○ Exception – small ruminants, cattle Trichostrongylus axei Haemonchus contortus – cows, sheep, goats ○ Ideal Ruminants with non-ruminants Animal categories of same species Ruminant adults and yearlings together ○ Successive grazing (pasture flip) – different host species Prevent overgrazing/overbrowsing → forage higher → less likely to contact infectious stages Provide forage that reduces parasites – high tannin foliage → combat parasites ○ For over-browsers (goats > sheeps) ○ Screen new arrivals Aggressively deworm with 3 anthelmintics from different drug classes Moxidectin, levamisole, albendazole ○ Potential to select for multiple resistance Quarantine – 10-14 days Only introduce when eggs not found in feces Selectively deworm Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ○ FAMACHA ○ FEC Anthelmintic Types Therapeutic – treat disease and current infection Prophylactic – routine ○ Pros – prevents clinical disease or subclinical effects ○ Cons – expensive, resistance selection, interfere with acquired immunity, vet expertise may not be required Strategic – combine prevention with knowledge of life cycle ○ Targeted (certain times of year) and selective (certain animals) approaches Kill adults before they pass eggs Don’t deworm during transmission seasons Insecticides in feces kill fly larvae and dung beetles ○ Haematobia irritans – Stephanofilaria stilesi ○ Musca autumnalis – Thalazia spp. ○ Dung beetles – break up feces, good thing Gongylonema spp. ○ Tabanids (horse flies) – Elaeophora schneideri ○ Insecticides – pyrethroid pour-ons, avermectins (ivermectin, eprinomectin, doramectin) Host physiology ○ Duration of drug availability dependent on flow-rate of digesta in rumen ○ ↓ Digesta transit → ↑ drug availability, efficacy ○ Restrict feed intake 12-24 hours before treatment Parasites Primary targets ○ Ostertagia ostertagi – focus of control programs Destroy gastric glands → maldigestion, poor feed conversion, anorexia, ↓ feed intake ○ Cooperia spp. – dose-limiting parasite (hardest to kill → developed resistance) ○ PGE complex – Nematodirus, Trichostrongylus, Oesophagostomum, Haemonchus Deworming Recommendations for Cattle Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Nursing beef calves – susceptible, acquire few worms until grazing starts ○ Deworm once 2-3 weeks before weaning ○ ↓ Stress at weaning Stocker calves/replacement heifers (4-9 months) ○ Fall – treat mothers midsummer ○ First year on pasture – highly susceptible Largest risk for production loss and disease Feedlot ○ Treated upon arrival with broad-spectrum ○ Macrocyclic lactones ± flukicide Kill arrested larvae to prevent Type II Kills internal and external parasites ○ Parasite prior to arrival important Mature cows – once per year with macrocyclic lactones ± benzimidazole ○ If showing illness or resistance history ○ Treat near freshening, maximize milk production ○ Additional treatments may be needed Southern cows or poor condition Herd bulls – more susceptible ○ Treat prior to breeding season ○ Repeat mid-summer (south) ○ With group in fall/winter if stocking density on pasture is high Dairy cattle – replacement heifers ○ 9-24 months old First graze – often raised in confinement → no acquired immunity Once on pasture → minimally managed Strategy – once a year North – treat at turn-out to spring pastures South – no established programs ○ Drier areas don’t need to as frequently ○ > 2 years old – no consensus ○ Macrocyclic lactones withdrawal times Dairy cattle say pour on ME Moxidectin Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Eprinomectin Resistance ○ Haemonchus contortus – ivermectin, moxidectin, doramectin, eprinomectin ○ If severely infected, deworm with 2 dewormers (macrocyclic lactone + benzimidazole) Deworming Recommendations for Small Ruminants Dosing – double sheep dose for goat Common extra-label use All given orally regardless of formulation Goal – manage parasites, not eradicate Haemonchus contortus – dominant parasite ○ Any goat/sheep with anemia has haemonchosis until proven otherwise ○ Choices Ivermectin, fenbendazole – most resistance → least effective Albendazole – improve efficacy by restricting feed Teratogenic – first 3 weeks of pregnancy Moxidectin – treatment of choice for rescue/salvage deworming with a single drug Combined with albendazole or levamisole Levamisole – lowest prevalence of resistance Toxicity –1.5X sheep dose (must weigh first) Teratogenic in late pregnancy ○ When to treat Periparturient period – 2 weeks before and 8 weeks after Nutrient partitioning → immune suppression → ↑ worm burden ○ Can partially reverse with protein supplementation Weaning period – stressful Can partially protect with protein supplement Geographic differences North ○ Treat in winter to kill hypobiotic larvae ○ Leave good BCS animals untreated South – year-round transmission → FEC/FAMACHA Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ○ Combination deworming for severely affected Moxidectin or combination of dewormers with moxidectin Combination – additive effect with each drug class used Move to safe pasture, barn, or drylot Administering combined treatments ○ Don’t physically mix dewormers ○ Purchase and administer separately ○ Give one after another ○ Observe longest withdrawal time ○ Selective treatment for south – only treating a select group to significantly increase population in refugia Highest FEC – McMaster FAMACHA – degree of anemia determines when to treat Keep 3’s in a pen ○ Treat all 3’s if > of herd score 4 or 5 Kids/lambs, periparturient ewes/does, thin/emaciated/debilitated animals Treat any animals with other evidence Limitations ○ Must check animals every 2 weeks in Haemonchus season 4-6 weeks if cooler ○ Other problems cause pale/red eyes ○ Not a standalone or replacement for other control strategies FEC, BCS, pasture, common sense ○ Need veterinarian involved Resistance – genetic mutation of the parasite population selected for over time via successive anthelmintic treatments; natural biological consequence of drug treatment ○ Parasite was susceptible in the past ○ Occurs within drug classes – resistance to one drug → resistance to all others within the class Exceptions due to relative potency – short-lived ○ Some species are more likely to develop resistance due to short, direct life cycles ○ Not all individuals in the population are resistant ○ Prevent resistance/↓ rate of selection Targeted treatment – certain time of year Targeted selective treatment – certain individuals Increase refugia Other non-drug strategies – pasture rotation, mixed species grazing, selective breeding, high tannin forage, Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Quarantine new animals until fecal negative ○ Can still be managed Anthelmintics can still be used Greater focus on pasture management and other strategies ○ Suspected when FEC remain high or clinical signs persist after treatment Consider treatment or diagnostic failure ○ Determine resistance on a farm every 2-3 years FECRT DrenchRite (small ruminants) – determines susceptibility to ML, BZ, levamisole Only one test required – single, pooled fecal sample Procedure – isolate eggs → wells have different [drug] → incubate for 7 days → wells examined PCR identification – not commercially available We don’t know all the genes still Cooperia spp. – dose-limiting parasite for macrocyclic lactones in ruminants Refugia – proportion of parasite population that hasn’t been exposed to the drug → no selection for resistance ○ Untreated animals, larvae on pasture (in environment), stages in animal not affected by drug treatment ○ Any parasites in refuge from drug treatment Ruminant Platyhelminthes Cestoda (Tapeworms) General characteristics ○ Life cycle – indirect (+1 IH) ○ Anatomy Dorsoventrally flattened Hermaphroditic No alimentary tract – nutrients absorbed across tegument Scolex – body segments, anchor (hold fast organ) Strobila – body segments Mature in proglottid (male and female anatomy) ○ Proglottid – segment that is often passed in the feces Gravid – end of proglottid, sac full of eggs Cyclophyllidea ○ Moniezia spp. Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Life cycle IH – oribatid mites DH – ruminants ○ Others – cattle, sheep goats Proglottids passed in feces → IH ingests eggs → embryo grows into metacestode (cysticercoid) → infected within IH → IH, metacestode ingested by DH → metacestode matures to adult Environment – worldwide Eggs – irregular shaped (square or triangular), pyriform apparatus with hexacanth embryo (oncospheres) Clinical signs – don’t harm DH Diagnosis – incidentally see eggs on fecal float or proglottids in feces Heavy eggs, shed intermittently Treatment – albendazole ○ Taenia saginata Life cycle DH – humans IH – ruminants Humans ingest raw or undercooked infected meat → eggs passed in feces → IH ingest eggs while crazing → oncospheres hatch → penetrate intestinal wall → circulate to musculature Clinical signs – due to metacestode maturation and location Muscle – “measly beef” Prevention – pasture contamination with infected human feces must be eliminated Zoonotic ○ Echinococcus granulosus Life cycle DH – canids IH – ungulates Clinical signs – due to metacestode maturation and location Liver, lung Trematoda (Flukes) General characteristics ○ Dorsoventrally flattened, bilaterally symmetrical ○ Functional digestive tract ○ Hermaphroditic ○ Requires 2 hosts – switch between sexual (DH) and asexual (IH) Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ○ Normal IH – molluscs (snails, slugs) Digena ○ Fasciola hepatica (liver fluke) Life cycle DH – cattle, sheep, goats, other ruminants ○ Reservoir for infection – infected cattle IH – aquatic snails Ruminant ingests metacercariae (juveniles) on contaminated pasture → eggs in feces → contact water → develop hatch → miracidium find snail within 24 hours → mature to metacercariae in snail ○ Active transmission requires eggs, water, snails at the same time Environment – Gulf Coats, Western states, Puerto Rico, Oklahoma Snail habitats – neutral solids, high annual rainfall, poorly drained pastures Migration Juveniles – SI → peritoneum → hepatic parenchyma Location Juveniles – through liver parenchyma Adults – bile tracts Eggs – yellow-brown, indistinct operculum Adults 3 cm, leaf-like, brown Broader anterior than posterior Anterior con-eshaped projection with oral sucker Clinical signs Acute – necrosis, anemia due to migration and feeding of immature flukes through liver parenchyma ○ No eggs in fecal ○ Migration can allow replication of Clostridium novyi Chronic – thickening → calcification of bile ducts (pipe stem liver) ○ Long-term damage to liver → ↓ digestion ○ Production loss Diagnosis Eggs – fecal sedimentation ± Fluke Finder ○ For heavy eggs, using gravity to collect ○ Minimal concentrative ability → low sensitivity ○ Takes a long time for procedure and slide reading Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Juveniles – not in feces Treatment Juveniles – none Adults ○ Clorsulon – trematode specific ○ Albendazole Broad spectrum – nematodes (trichostrongyles), cestodes, trematodes When – after transmission season (when flukes have matured) before snail reemergence (transmission resumes) ○ Gulf coast area Transmission stops in summer All flukes mature by fall Treat in early fall Reasons to treat ○ ↓ Pasture infectivity to protect cattle next transmission cycle ○ ↑ Immediate performance – remove adults → prevent chronic disease Zoonotic – rare Must ingest vegetation with metacercariae Interference with TB testing – inhibits TH1 response → shifts to TH2 response TB tests relies on TH1 response ○ Paramphistomum cervi Life cycle DH – domestic, wild ruminants IH – aquatic snails ROI – ingest metacercariae encysted on vegetation Migration Juveniles – retrograde from duodenum through abomasum to rumen ○ Enteritis Location Adults – rumen Eggs – clear shell wall, large ○ Fascioloides magna – Large American liver fluke, deer fluke Severe disease in sheep, goats → wall off ○ Dicrocoelium dentriticum – Lancet fluke Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Ingested by terrestrial snail (1st IH) → cercariae passed in slime balls → ants eat slime balls (2nd IH) → form metacercariae → ants lock jaw on vegetation → ants ingested by DH Parasite induced trophic transmission (PITT) Ruminant Protozoa Apicomplexans General characteristics ○ Sporozoites – infectious unit ○ Merozoites – asexual, in IH or DH ○ Gametocytes/gametozoites – sexual, haploid, DH only ○ Schizogenous stages causes pathogenesis ○ 2 sporozoites → 1 sporocyst 4 sporocysts → 1 sporulated oocyst (8 sporozoites [infectious units]) ○ May NOT cause clinical signs but WILL most likely be on diagnostics !!! Cryptosporidium spp. ○ Life cycle – direct Sporulated oocysts passed in feces → immediately infectious, damage resistant PPP – 2-7 days Oocyst shedding lasts 3-12 days Clinical signs can occur before shedding ROI – fecal-oral 1° – ingestion (thick-walled oocysts) 2° – autoinfection (thin-walled oocysts) → rupture → reinfection ○ Can lead to hyperinfection ○ Problematic in immune-compromised patients ○ Hosts C. parvum – calves, sheep, goats, horses, humans ○ Pathogenesis Damage to intestinal or gastric epithelium as schizonts rupture Very superficial association with host cells Disruption of nutrient absorption, barrier permeability, secretion ○ Clinical signs – subclinical to severe Profuse watery diarrhea (scours) Dehydration Loss of appetite, failure to gain, anorexia, weakness ○ Diagnosis Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Centrifugal flotation in sugar solution Small – may be aided by acid-fast or fluorescent staining Coproantigen testing – humans, extra-label in ruminants PCR – genetically differentiate species ○ Treatment No drugs FDA-approved for treating ruminants Supportive care – fluids, electrolytes ○ Management Isolate affected animals Reduce stocking density, don’t cohouse young and old animals Adequate sterilization of stalls/hutches – steam cleaning, UV light… Proper PPE ○ Zoonotic – C. parvum Eimeria spp. ○ Life cycle – direct Passed as unsporulated → need 24-48 hours to become sporulated oocysts (infectious) PPP – 2 weeks E. bovis – 16-21 days E. zuernii – 12-14 days ○ ROI – fecal-oral (sporulated oocysts) ○ SOI – small intestine ○ Oocysts – unsporulated – elongated/ovoid, ± micropyle cap ○ Host, site, cell specific – no sharing of species with other animals ○ Primary pathogens associated with disease ○ Factors leading to coccidiosis – age, stress, genetic susceptibility ○ Clinical signs in cattle Animals < 2 years old, precipitated by stress Severe diarrhea ± blood (depends how deep they are) Winter coccidiosis – stressful conditions Nervous coccidiosis – neurologic signs NW US after rain, cold ○ Treatment, management Goals – minimize clinical disease Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ↓ Exposure to infective sporulated oocysts ↓ Stress Prophylactic coccidiostats – start before stress ○ Cattle – amprolium, decoquinate, monensin, lasalocid, sulfa drugs ○ Goats – decoquinate, monensin ○ Sheep – decoquinate, lasalocid, sulfaquinoxaline Treatment of clinically ill animals relies on isolation and supportive care ○ Zoonotic – none Toxoplasma gondii ○ Life cycle – indirect DH – felids IH – all warm-blooded animals ○ ROI Ingestion of sporulated oocysts from feline feces Transplacental infection Ingestion of tissue cysts ○ Pathogenesis Driven by tissue invasion by tachyzoites → inflammation Tachyzoites can form tissue cysts in any tissue, especially muscle and neurological tissues ○ Clinical signs More common in transplacental and immunocompromised patients Abortion, fetal mummification in small ruminants if doe/ewe infected during gestation Potential cause of bovine abortion ○ Diagnosis Antemortem Serology test – serum (not enough to confirm) Postmortem – histopathology ± PCR testing ○ Treatment – no drug effectively eliminates tissue stages from infected hosts Cull positive animals with history of abortion ○ Prevention/control Avoid feed/pasture contamination with cat feces Vaccination (Toxovax) – Europe, New England Prevents abortion, not infection ○ Zoonotic – cook all animal tissues before consumption Neospora caninum Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ○ Life cycle DH – wild, domestic canids IH – cattle (dairy) ○ ROI Ingest sporulated oocysts from canine feces Transplacental infection ○ Clinical signs Major cause of bovine abortion, fetal mummification Incidence peaks at 5-6 months Surviving infected calves can have neurological deficits Potential cause of abortion in small animals Suspected to ↓ milk production in dairy cows Most infected adult cattle are clinically important ○ Diagnosis Antemortem Serology test – serum (not enough to confirm), bulk milk Postmortem – histopathology ± PCR testing ○ Treatment – no drug effectively eliminates tissue stages from infected hosts Cull positive animals with history of abortion ○ Prevention/control Avoid feed/pasture contamination with canine feces Don’t allow canids to consume uncooked or aborted ruminant tissues ○ Zoonotic – none Tritrichomonas foetus Flagellate parasite Life cycle – direct ○ Motile trophozoites in cattle reproductive tract ROI – sexually transmitted (live cover > AI), preputial fluid ○ Potentially through AI if semen is contaminated with infected preputial fluid Clinical signs – beef cows > dairy cows ○ Heifers Mild vaginitis Breeding failure or early-term abortion (< 3 months) Widespread breeding failure among herd Long calving interval Pyometra ○ Bulls – none, all infected bills are chronic asymptomatic carriers Diagnosis Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ○ Microscopic examination of male or female samples ○ PCR detection from samples ○ Sensitivity – ↑ through culturing samples in Diamond’s Medium (InPouch TF) before testing Treatment ○ No drugs will effectively clear cattle, no FDA-approved drug ○ Infected cows – sexual rest, cull ○ Infected bulls – cull Management/control ○ Vaccination (TrichGuard) for cows ○ Use younger, less experienced bull ○ Use negative-tested bulls ○ AI > live cover ○ Cull infected animals ○ ↓ Length of breeding season Regulation – state laws ○ Testing accepted by OK Law 3 negative culture tests at weekly intervals OR 1 negative PCR test ○ Any bulls being sold over 12 months old, potentially exposed females, any breeding bull entering OK Buxtonella sulcata Ciliate parasite Life cycle – direct (2 life stages) ○ Motile trophozoite – cecum Large ○ Cyst – passed in feces Kidney-shaped macronucleus ROI – fecal-oral of cysts Clinical signs ○ Many are clinically normal – commensal organism ○ Diarrhea in weaning calves Diagnosis ○ Identify cysts ○ Sedimentation – floatation with salt solution ○ Morphologically indistinguishable from Neobalantidium coli Treatment – rare, no FDA-approved drugs Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Ruminant Arthropoda Arachnida Acarina – ticks, mites ○ General characteristics Anatomy Fusion of head, thorax, abdomen ○ Idiosoma – body, main portion ○ Mouthparts – basis capitulum, palpa, chelicera, hypostome (feeding) Long – longer > wide Short – wide > longer No antennae, no mandible Adults – 4 pairs of legs Female – larger, scutum only covers part of the body to allow engorgement (require more blood) and egg production ○ Produce 5,000-10,000 eggs Male – scutum covers entire dorsal body Stages Eggs → larva → nymph → adults (male, female) ○ Larva – 6 legs ○ Nymphs – 8 legs ○ Adult – genital aperture All are parasites – food source is blood Quest – search for hosts at preferred times based on temperature, humidity, availability of hosts… Conditions – irritation, pruritus, 2° infections at bite wounds, anemia, transmit disease agents and tick paralysis (regurgitation), production loss (↓ weight gain, damage to hide), difficult to control Ticks Ixodidae – hard ticks ○ General characteristics Anatomy Mouthpartis visible from dorsal surface Scutum present – complete on male, anterior on female Life cycle 1, 2, or 3 hosts Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ○ 1 – larvae remain on host, become adults after 2 molts ○ 2 – molts in environment (nymph → adult) ○ 3 – host for every life stage More effective at transmitting disease Diapause – ↓ metabolism/activity when conditions are poor Time to complete life cycle depends on environmental conditions, host availability ○ Amblyomma spp. General characteristics Long mouthparts, ornate scutum A. americanum – Lone Star Tick Hosts – deer, domestic animals, humans Scutum – white dot for females, white along posterior for males Hunter/predator tick – chases Distribution – Eastern, Central US, southeastern, south-central US Clinical signs – damage to hides Vector Ehrlichia spp. Most common tick in southeastern, south-central US A. maculatum – Gulf Coast tick Hosts – domestic animals with preference for large animals Scutum – white lace pattern Distribution – Gulf Coast, Atlantic coast Clinical signs ○ Damage hides – aggressive biters ○ Gotch ear – ruminants Edema, crusting, alopecia of pinna Dropping ears Vector Ehrlichia ruminantium A. cajennense – Cayenne Tick Distribution – Florida, Texas Vector Theileria equi to horses ○ Dermacentor spp. General characteristics Short mouthparts, rectangular basis capitulum 3 host D. andersoni – Rocky Mountain wood tick D. variabilis – American dog tick Hosts – domestic animals, humans Vector Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ○ Anaplasma marginale ○ Vector EP (Theileria equi, Babesia caballi) to horses 1 host D. albipictus – winter tick ○ Scutum – inornate or ornate ○ Hosts – large domestic animals, humans (rare) All motile stages on large domestic animals, rarely on humans ○ Distribution – most of North America ○ Vector for Anaplasma marginale ○ Heavily infested domestic animals show loss of production D. nitens – Tropical Horse Tick ○ Scutum – inornate ○ Hosts – prefers horses ○ Distribution – Southern Florida, Texas ○ Vector EP agents (Theileria equi, Babesia caballi) ○ Ixodes spp. Adults – long mouthparts, inornate, arch above anus I. scapularis – Eastern Blacklegged Tick (deer tick) I. pacificus – Western Blacklegged Tick More active in temperate areas, cooler times of the year Hosts – white-tailed deer (reservoir), many hosts, humans Transmit Borrelia burgdorferi (Lyme), Anaplasma phagocytophilum to horses ○ Haemaphysalis longicornis – Longhorn tick, bush tick Hosts – indiscriminate feeder, all stages will infest livestock Short mouthparts, inornate scutum, flared palpal segment, rectangular basis capitulum Females reproduce through parthenogenesis – don’t need a male to reproduce Stress on animals, ↓ growth/production Vector of Theileria orientalis to cattle ○ Rhipocephalus (Boophilus) spp. – reportable Life cycle – one-host tick Short mouthparts, inornate, flared basis capitulum Rhipocephalus (Boophilus) annulatus (Cattle Tick, Cattle Fever Tick) Rhipocephalus (Boophilus) microplus (Southern Cattle Tick) Vector Anaplasma marginale Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Babesia bovis (smaller), Babesia bigemina – redwater disease, Texas cattle fever ○ Anemia, hemoglobinuria, fever, death (acute phase) ○ Piroplasms in RBCs ○ Control ticks and cull infected animals Argasidae – soft ticks ○ General characteristics Anatomy Anterior mouthparts – mouthparts not visible from dorsal surface No distinct scutum Life cycle – multi-host Different stage at every single host ○ Otobius megnini – spinose ear tick Hosts – cattle, horses, mules, sheep, goats Distribution – Southwest US, arid or semi-arid Life cycle – muli-host Larvae, nymphs feed in the ear canal of hosts Adults are free-living – not parasitic ○ Larvae are the only part that are parasitic Nymphs leave host → molt to adults in external environment Clinical signs – irritation, otitis externa, 2° infections Anaplasma Marginale Obligate intracellular bacteria → bovine anaplasmosis Clinical signs – lethargy, abortion, weight loss, icterus, anemia, fever, death ○ Cattle build immunity post-infection, become carriers of agent ○ Most severe losses when new cattle introduced to herd Transmitted to cattle through ticks (Dermacentor spp. > Rhipocephalus (Boophilus) spp.) ○ Mechanical (iatrogenic) → fomites – uncleaned tools Diagnosis – organisms (inclusions) in RBCs, serology for detection of Abs, PCR Treatment – tetracyclines Control ○ Chlorotetracycline in medicated feed or block ○ Limit contact with tick and mechanical vectors ○ Vaccination Theileria Orientalis Tick-borne protozoa (apicomplexa) – emerging bovine theileriosis in US Subtypes – Ikeda (most disease, death), Ketose (minor signs) Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Clinical signs – lethargy, pale mucous membranes, abortion, death ○ Clinical abnormalities – anemia, fever ○ Cattle that survive become carriers for life Diagnosis – piroplasms in RBCs (smear) or lymph node spears, PCR (differentiate from anaplasmosis) Treatment – no approved treatments in US Control – limit contact with tick vectors, infected reservoir cattle, contaminated fomites Integrated Tick Control Large animals ○ In environment Field management – cut grass, remove leaf litter, controlled burns Fencing Exclude wildlife Acaricides ○ On hosts Acaricides Tick vaccines – not available yet Cattle breed resistance – Hereford < Brahman Horses ○ Difficult – persistency of control is disappointing ○ Pyrethrins /pyrethroids – repel flies better than thicks ○ 45-65% spot-ons ○ Organophosphates (malathion, coumaphos) – older drugs ○ Avoid amitraz – toxic to horses (neurotoxicity) Cattle ○ Application methods – sprays, dips, pour-ons, spot-ons, dusts, injectable, feed/mineral additives, impregnated ear tags, baits, boluses ○ Acaricides Pyrethrins/pyrethroids – permethrin, cyfluthrin, β-cyfluthrin, λ-cyhalothrin, Ζ-cypermethrin Organophosphates, carbamates – treat them, put them out Dichlorvos, coumaphos, diazinon, phosmet Macrocyclic lactones – ELDU for cattle due to efficacy Mites General characteristics ○ Microscopic, stay on host, smaller mouthparts relative to body size, feed on host tissue/cellular debris Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ○ Life cycle – generalized to specialized Metamorphosis – simple (each stage looks similar) Transmission – direct Sites of infection Burrowing – Sarcoptes spp., Demodex spp. Non-burrowing – Psoroptes ovis, Chorioptes spp. Signs – variable (subclinical to fatal) Alopecia, ± pruritus, location of dermatitis ○ Diagnosis – skin scrapes Look at body shape, features of anterior legs Astigmata ○ Sarcoptes scabiei – reportable Burrowing – head, neck, shoulder Intense pruritus, papules → crusts Survive off host for only a few hours to a few days off hosts Hosts – host specific Cattle (bovis), sheep (ovis), goats (caprae), horses (equi) Zoonotic – infestation is transient and atypical Diagnosis – longer, unjointed pedicel ○ Psoroptes ovis – reportable Hosts – sheep, goats, cattle, horses, rabbits Pierce host tissue, feed on serum, crusting Non-burrowing – backs, flanks Devastating for wool Can survive off host for over 2 weeks Diagnosis – longer, jointed pedicel ○ Chorioptes spp. – not reportable Clinical signs – leg mange, foot and tail mange, symbiotic mange, barn itch Direct effects of mite feeting Tolerated by some animals Lower leg dermatitis – superficial, mildly pruritic, flaky ○ Winter-time Spontaneous regression during summer Diagnosis – shorter, unjointed pedicel Horses – heavily haired areas on legs (feathered area of fetlocks) ○ Hypersensitivity → heavy crusting Prostigmata ○ Demodex – not reportable, not zoonotic Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Hosts – each host as its own species Cattle, goats, sheep, horses Clinical signs – demodectic mange, follicular mange, bovine demodicosis D. bovis – most common Clinical signs – follicular papules and nodules over topline (withers, neck, back), flanks Treatment ○ Assume other animals have it if 1 animal is diagnosis ○ Retreat in 10-12 days to get recently hatched mites ○ Isolate new individuals for +1 week before introduction to herd ○ Products – pour-ons, injectables, dips, sprays… Macrocyclic lactones – ivermectin, moxidectin, doramectin, eprinomectin Pyrethroids – permethrin Organophosphates – coumaphos Lime sulfur dips Insecta General characteristics ○ Anatomy – head, thorax, abdomen, 6 legs ○ Molting – hypodermis secretes new cuticle Egg → L1 → L2 → L3 → L4 → pupa → adult (imago) ○ Complex metamorphosis – stages look different from adult Flies, fleas Diptera ○ Nematocera – require water for life cycle, females are blood feeders Culicidae – mosquitoes Life cycle – requires stagnant water Anatomy ○ Biting mouthparts – females feed morning and evening ○ Long proboscis ○ Scaled wings Anopheles spp., Aedes spp., Culex spp. Pathogenesis ○ Nuisance – painful bites, persistent feeders, loss of production Hypersensitivity reactions ○ Anemia – exsanguination Vector for equine encephalitis viruses Simmulidae – blackflies Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Anatomy – small antennae with many segments Life cycle ○ Require fast running water to lay eggs ○ Larvae attach to rocks and other debris Distribution – northern North America from mid-May-July Pathogenesis ○ Painful bite, annoying ○ Anemia ○ Hypersensitivity reaction to saliva Vector Onchocerca spp. Simulium spp. Ceratopogonidae – midges Life cycle ○ Breed in tree holes, stagnant water ○ Eggs in damp, marshy ground or decaying vegetation ○ Larvae around lakes, rivers, mud holes Pathogenesis ○ Painful bites – females are blood feeders Hypersensitivity – “sweet itch” ○ Seasonal equine pruritic dermatitis ○ Pruritic, crusting alopecia ○ Tail, mane > ears, poll, face, chest, ventral abdomen Vector ○ Bluetongue virus, epizootic hemorrhagic disease ○ African horse sickness ○ Filariidae (Onchocerca spp.) Culicoides spp. – biting midge ○ Crepuscular, nocturnal ○ Very small fly ○ Brachycera – require water for life cycle, females are blood feeders Anatomy – short antennae (3 segments), patterns on wings, proboscis, stylets Tabanidae Life cycle – emerge late spring/early summer, peak June-September ○ Lay eggs around pond edges under vegetation ○ Larvae burrow into moist mud, feed on other insects ○ Larvae pupate, adults emerge Pathogenesis Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ○ Bite – persistent, messy, interrupted feeders ↓ Production, hide damage Prefer darker animals, feed ○ High on the body (back), legs Vector ○ Mechanical – Trypanosomiasis, Anthrax, tularemia, Bovine anaplasmosis, EIA ○ Biological – Elaeophora schneideri (arterial sorehead) MF → L3 Tabanus spp. – horseflies Chrysops spp. – deer flies ○ Cyclorrhapha General characteristics Apex of dipteran evolution Breed in decaying plant and animal tissue, manure, carrion Larvae ○ 3 stages, prominent respiratory openings (spiracles) ○ Maggots – slender larvae from Muscidae, Sarcophagidae, Calliphoridae ○ Bots/grubs – stout larvae from Oestridae Muscidae Musca autumnalis – face fly ○ Lay eggs, larvae on fresh feces ○ Anatomy – sponge mouthparts, medium-sized ○ Females feed on eyes, mouth, muzzle wound secretions ○ Difficult to control ○ Vector Moraxella bovis (pinkeye) Bovine rhinotracheitis (IBR) Thelazia (eyeworm) Musca domestica – house flies ○ Filth fly ○ Biological vector – Draschia megastoma, Habronema muscae ○ Sponging mouthparts (labella) Stomoxys – stable flies ○ Larvae breed on decaying matter ○ 2-3 blood meals/day Only visits hosts to feed, mostly off animal Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ○ Economic injury – 5 flies/front leg ○ Hosts – cattle, horses, dogs Prefer indoor environments ○ Vector Habronema microstoma in horses Haematobia irritans – horn flies ○ Stay on animals – cattle on pasture ± horses nearby Half the size of stable flies ○ Lay eggs in fresh cow feces ○ Vector Stephanofilaria stilesi (Brisket worm) – alopecia on cattle ventral abdomen ○ ↓ Weaning rate, milk production ○ Infestation levels Treatment threshold – 50-100 flies/animal Economic injury level – 200 flies/animal ○ Control Capture flies Insecticides Hippoboscidae – keds Melophagus ovinus – sheep ked, louse fly ○ Life cycle – peaks in winter Spends entire life on sheep Larvae retained in females until pupation Pupal cases glued to wool ○ Anatomy Dorsoventrally flattened Wingless ○ Control Treat after shearing Pupa not affected by insecticides → treat every 3-4 weeks or use insecticide with residual activity ○ Location – neck, shoulder, underbelly ○ Pathogenesis Blood feeding → anemia Inflammation → loss of wool and production ○ Vector Trypanosoma melophagium (nonpathogenic) Bluetongue virus Myiasis – invasion of living vertebrate animal tissue by fly larvae Types Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ○ Obligate – flies involved are always parasitic, require host Bot flies, primary screwworms ○ Facultative – opportunistic Blow fly larvae invade open sores but normally feed on carrion ○ Accidental – not normally parasitic Ingest food with fly eggs or larvae General characteristics ○ Life cycle – lay eggs in decaying organic matter, necrotic tissue, carrion ○ Clinical signs – depression, anorexia, irritation, maggots ○ Treatment – remove wool, maggots, spot treatment, act quickly Calliphoridae – blow flies, bottle flies ○ Phaenicia spp., Phormia spp., Lucilia spp., Calliphora spp. ○ Cochliomyia macellaria – secondary screwworm fly ○ Cochliomyia hominivorax – primary screwworm Anatomy – tracks along thorax Life cycle – males not blood feeders, females only mate once, obligate myiasis Lay eggs on mucous membranes, orifices, in wounds Larvae feed on any tissue for 4-12 days 2-3 week cycle from egg to tegg Eradicated in the US by releasing sterilized males Threat of reintroduction → reportable Sarcophagidae – flesh flies ○ Sarcophaga spp., Wolfhartia spp. Oestridae – botflies ○ Anatomy Adults Resemble bumble bees Vestigial mouthparts → don't feed Free-living, short-lived, irritate animal ○ Larvae are parasitic – large, round Feed on ingesta, secretions, host tissue ○ Oestrus ovis – sheep (goats) nasal bot fly Life cycle Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum L1 in nasal passages → L2 → migrate to frontal sinus → L3 → migrate to nostrils → fall out → pupae in soil → adult Adults emerge in summer but can overwinter via arrested L1 larvae or pupae in soil ○ Pathogenesis Adults – annoying Larvae – irritate nasal mucosa Sneezing, nasal discharge, erode bone, asphyxiation ○ Treatment – ivermectin (PO or SQ) for all larval stages Hypoderma spp. – cattle grubs, warbles, heel flies, gadflies ○ Subcutis → migrate to dorsal back → form warbles by L3 putting spiracles to breathe → mature → fall to ground → pupate ○ H. bovis – Northern cattle grub L1 in spinal canal in epidural fat 8 months ○ H. lineatum – common cattle grub L1 in esophagus mucosa 5 months after emerging from egg, stays for 3 months ○ Pathogenesis Irritation Creeping subcutaneous myiasis Host reaction to toxin release from dead larvae → anaphylaxis, esophageal stricture, drooling, stiffness, ataxia ○ Treatment – macrocyclic lactones Avoid when larvae are in esophagus or spinal column Gasterophilus spp. – horses ○ Eggs on hairs → ingestion → L1 develop in oral, pharyngeal tissue → L3 → migrate to stomach or small intestine → mature over 10-12 months → feces → burrow into soil → pupae ○ Pathogenesis Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Annoyance, tongue ulceration, stomatitis Stomach – nodules, papillae, ulcers, pyloric stricture, rupture stomach, peritonitis Minimal pathogenicity → treatment is rare ○ Control – flies Minimize breeding sites Fly traps Insecticides Cattle ○ Ear tags, dusts ○ Backrubbers, facerubbers Pyrethroids/pyrethrins Organophosphates Carbamates Macrocyclic lactones Feed-through Insect growth regulators (larvae) – diflubenzuron, methoprene, cyromazine Daily – oral → top-dress on feed, blocks, tubes Prevent house, stable fly development in animal feces Most effective when administered before populations establish Trichoptera – Caddishflies ○ Vector – Potomac Horse Fever (Neorickettsia risticii)→ colitis Harbor metacestode Death within water cups → ingestion of caddishfly Phthiraptera – lice (plural) ○ General characteristics Very host specific Same louse species not found on two different host species Simple life cycle – egg → 1st nymph → 2nd nymph → 3rd lymph → adults Immature stages resemble adults Entirely on host – no environmental stages Pediculosis – infestation with lice Transmission – direct Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Contact with infected animals Contact with materials used on infested animals Most often problems in sick or immunocompromised animals Seasonal Found year-round, numbers ↓ in spring, summer Winter-time problem in crowded animals Disease Alopecia, pruritus ○ Dull, matted coat, self-trauma ○ Rubbing vigorously on fencing → excoriations ↓ Production – weight loss, ↓ milk production Severe – sucking lice → anemia Diagnosis Presence of clinical signs Presence of eggs (nits) Presence of adults Host type, location Treatment application Large operations – dips, vats, sprays, powder dusting Single animals – hand-applied, spot-treatment Must repeat treatment in 12-14 days ○ Must kill any recently emerged nymphs – protected from treatment while in egg ○ Mallophagan – chewing lice Feeds on skin, occasional blood meal Anatomy – head wider than thorax Large animals – Damalinia spp. Cattle – topline of back Treatment Permethrin-based products ↓ Stocking density – ↑ space between animals ↑ Facility hygiene ○ Anapluron – sucking lice Feeds on tissue, fluids, blood Anatomy – head narrower than thorax Large animals Linognathus spp. – little claws on 1st pair of legs ○ Goats, sheep – can share ○ Cattle – back, shoulder, neck, dewlap (face) Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum Haematopinus spp. – body builder legs ○ Cattle – top of neck, dewlap, brisket, ears Certain species Last 18 inches of tail Florida, Gulf Coast states ○ Horses Solenoptes spp. – small guy ○ Cattle – ace (muzzle, cheek, eye) Treatment – take in a blood meal Macrocyclic lactones – ivermectin, moxidectin ○ Not approved → ELDU → WDT Siphonaptera – fleas Hemiptera – bugs Pig Parasites Stomach Hyostrongylus rubidus (Red stomach worm) ○ Superfamily – Trichostrongylidae ○ Life cycle – direct ○ Egg – looks like hookworm ○ Site of infection Stomach – juveniles in gastric glands ○ Eggs in feces ○ Pathogenesis Similar to Ostertagia spp. – nodules in stomach → destruction of tissue → maldigestion Different – pigs can vomit → chronic vomiting due to ulcerative gastritis ○ Treatment – macrocyclic lactone, fenbendazole Small Intestine Ascaris suum (Roundworm) ○ Life cycle ROI – ingestion of infective eggs No transplacental or transmammary Hepatotracheal migration Paratenic hosts – earthworms, dung beetles No development PPP – 6-8 weeks Life cycle (ROI, PPP, habitats, environment), eggs, adults, clinical signs, diagnosis, treatment, prevention, zoonotic implications, examples  Phylum → Class (-a) → Order (-ida) → Superfamily (-oidea) → family → Genera → species Bolded → in gold/red on slides Haemonchus, Ostertagia, Teladorsagia, Trichostrongylus, Cooperia, Oesophagostomum ○ Distribution – common, pigs raised outdoors Access to soil → assume parasite is present Eggs persist in environment ○ Pathogenesis Migrating juveniles Mechanical destruction of tissue – early infection ○ Initial focal hemorrhages ○ Respiratory distress in young pigs (2-5 months old) – thumps Interstitial pneumonia Bronchiolitis Alveolar edema ○ Hypersensitivity