Avian Anatomy.pdf

Course Outline: v8 lectures focusing on Pet Bird Medicine v We meet 2-3 days per week v Clinical techniques: handling, restraint, grooming v Diagnostics: venipuncture, radiographs, ultrasound v Non-infectious v Infectious v Block diseases: feathers, repro, and more diseases: viruses, bacte...

Course Outline: v8 lectures focusing on Pet Bird Medicine v We meet 2-3 days per week v Clinical techniques: handling, restraint, grooming v Diagnostics: venipuncture, radiographs, ultrasound v Non-infectious v Infectious v Block diseases: feathers, repro, and more diseases: viruses, bacterial, fungal exams on syllabus Who is this crazy lady? Heidi Hoefer, DVM, Dipl ABVP-Avian RUSVM graduate 1987 Boarded ABVP Avian 1993 100% Avian and Exotics Practice since 1988 — Birds and other exotics are popular pets — Parrots live a long time and are expensive — — Clinical knowledge makes you marketable - ability to handle emergencies is valuable! Birds are colorful, fun, and cool!! Dr. La’Toya Latney, RUSVM 2007 1. Psittacines “hook-bills” - parrots, parakeets, cockatiels 2. Passerines “straight-bills” - canaries and finches 3. Columbiformes - pigeons and doves 4. Backyard poultry pets - chickens, ducks, geese 5. Raptors: birds of prey New World Birds: South American macaws, amazons, conures Old World: African Species African grey, lovebirds, Senegal parrot Australasian Species cockatoos, eclectus, cockatiels, budgies, wet and dry seasons they may not need to drink for about a month “Locals” — There are over 10,000 different bird species — Incredibly diverse group — There is no generic “bird” prototype — Much anatomy is preserved across species Beaks: — — — — Beaks and tongues = “hands” for the bird Nerves and blood vessels in tip Continue to grow like fingernails Trauma common: very painful and stop eating - beak trims, falls, bird bites the beak is blunt and should not be straight, it should be curved Rhampotheca= keratin overlay — — Tongue adaptations vary with species and diet - psittacines have leathery tongues to open nuts/seeds Choana = natural cleft palate - - connects to nasal cavity - has projections: “papillae” that aid in food movement — Larynx behind tongue, no epiglottis in birds - easy to pass endotracheal tube - easy for mold spores to get inhaled glottis choana black tongue! Birds breathe through nares, into choana and down trachea There is air in the beak and head! Anything that blocks oropharynx can lead to respiratory distress. This includes swellings or masses, infection, mucous, nasal debris * Birds who are struggling to breathe need an oral exam first thing! she said to take note of this; sinus is all over head IO sinus Swelling of the infraorbital sinus is common with bacterial sinusitis SQ emphysema can be anywhere, where as for sinusitis its in one area ying trauma and extreme exertion are the most common cause of ruptured airsacs This is different in appearance to sinusitis which is in a confined space — — — Ancient evolutionary adaptation Avian voice-box, unique to birds! Located at bifurcation of the bronchi - lies below the keel bone, not palpable - thyroid and crop are nearby - disease can lead to voice change thyroid and crop dz can cause a voice change Normal lateral Birds with thyroid enlargement can present with respiratory distress or voice change choana and lower by syrinx are where there can be voice changes — Designed for flight: Ultimate Athletes! — Lungs fixed and embedded in spine — Do not inflate and deflate - hard to auscult lung sounds — airsacs are what makes the work, instead of diaphragm No diaphragm; air-sacs act like bellows - expansion using abdominal muscles — Complete circuit in 2 breaths: - constant unidirectional flow of oxygen - oxygen always presented to lungs — Air capillaries in lungs, not alveoli - very thin blood-gas barrier in birds *Hummingbird wings beat an average 58 per second! Avian lungs are embedded into thoracic spine Endoscopic view thru airsacs View from the dorsum with skin and muscle removed lungs are where the gas-exchange occurs; NOT THE AIR-SACS Normal airsacs aspergillosis lung trachea airsacs Birds have 9 air sacs: two cervicocephalic, an unpaired clavicular, two cranial thoracic, two caudal thoracic, and two abdominal air sacs. Lungs have like honeycomb appearance radiographically Air-sac spreads into medullary cavities The avian body is lined by air-sacs laterally Intra-clavicular air sac into the humeri is most radiographically obvious It takes 2 cycles to complete one respiration ** remember those little factoids** Uni-directional airflow ensures fresh oxygen gets to lungs at each cycle (unlike mammals where air is mixed on each breath) otherwise, air does not come in Skeletal systems: — — — — Designed for flight : thin, hollow bones Air-sac spreads into medullary cavities Fusion of bones, e.g. tibia-tarsus Red muscle rich in myoglobin: O2 Vertebrae: — — — — Large number of cervical vertebrae Freely movable, synovial joints Fused to pelvis: synsacrum Fused to thoracic vertebrae: notarium Avian neck: 2.5x longer than mammals! — Beak and neck replaces forelimbs — Large number of flexible cervical vertebrae — — — Birds have an “S” curve to the neck at rest Trachea needs to be long and rigid no stretch allowed so if you in ate the ET tube you cause pressure necrosis Complete tracheal rings - keeps trachea from collapsing during motion — — — Each side has 3 lobes embedded in the synsacrum Comprised of 80% reptilian nephrons (no Loop of Henle) and 20% mammalian type Uric acid = main nitrogenous waste Sciatic plexus runs through the middle kidney lobe anything that presses on this area results in lameness or paralysis Sciatic nerve is enlarged with Marek’s disease testes are right against cr. pole of the kidney enlarged kidneys will cause pressure on sciatic n. causing lameness — Out-pocketing of esophagus - at thoracic inlet on right side - temporary storage of food — Species variations in size — Hand raised baby birds are fed formula - crop should empty within 4-5 hours — Can gavage feed into crop when anorectic Cloaca Roma — — — — Common exit for 3 systems Repro - Renal – GI tract you can use this for mucus membrane color Feces and urine empty into cloaca No urinary bladder, keeps birds light for flight Cloacal exam Eggbound Polyuria vs diarrhea? the rosette on the right (their left); is the oviduct & thats how you know its a female Bird lying on back sedated. Best view of cloaca The cloaca is the cave that collects everything before expelling — Auditory senses prominent — Small olfactory lobe: no smell! — Anatomically smooth brain - lissencephalic vs gyrencephalic — The eyes are largest of all animals - take up most of the skull — Birds have striated muscle in pupil — No pupillary light reflex – PLR — Blinking with 3rd eyelid - when excited can “pin” pupils No one sees better than a bird! **said to know pecten** Pecten oculi is a comb-like structure unique to birds — Pigmented and vascular, projects into vitreous from retina over the head of the optic nerve — Supplies nutrition to avascular avian retina — Scleral ossicles form a supporting ring surrounding cornea — — — — — — — Most pet birds are not domesticated 1 or 2 generations removed from wild Mentally similar to wild counterparts Flocking for protection Become socially and sexually mature They are loud and messy — — Birds are prey species Masters of disguise - they hide illness until end stage in many cases — Sick bird = free lunch So how do I tell if my bird is sick? — — — — — — — Decreased appetite Sleepy, fluffed Refusing favorite treats Decreased vocalizations Weird droppings Easier to handle Owner’s assessment meaningful - behavior at home most important - adrenaline in the clinic kicks in Adrenaline makes sick birds look well! So don’t “stare ‘em down” during observation in exam room Prey species get intimidated easy and pretend to be OK