Avian Flashcards
What are tracts of feathers called?
Pterylae
What are areas without feathers called?
Apteria
Which feathers are vascularized?
Which feathers are empty?
Blood/growing feathers
Mature feathers
What do stress bars on feathers indicate?
Structural damage
What function do downy feathers have?
First feathers
Thermoregulation
Protection
What function do bristle feathers have?
Tactile
Sensory
How is the avian spinal column arranged?
Neck 2.5x longer than mammals
Notarium: dorsal vertebrae fused
1 loose vertebrae
Synsacrum: pelvic and sacral bones fused
What part of the bird is assessed for BCS?
Keel, should be convex in shape (3/5)
Will flushing a pneumatic bone drown a bird?
NO
What is the avian shoulder structure?
Clavicle (wishbone)
Coracoid (connects humerus to sternum)
Scapula
What are three sites for blood collection in birds?
- Elbow joint - wing vein runs parallel to humerus
- Medial metatarsal vein on leg
- R jugular
- Cut line into nail
What is the flap of skin/elastic tissue found across the elbow called?
Patagium
Composed of major and minor ligaments
Which site is often used for intraosseus catheter placement?
Ulna, carpal joint
Where are the nares located?
In the cere, opening in the beak
What is the choana? How is it used clinically?
Palatine fissure (birds do not have soft palate) Connects oral cavity with respiratory system
Best place for respiratory sampling - flush nares and collect at choana
Where are foreign bodies commonly seen in the bird?
Tracheal bifurcation
Dx: endoscopy
What is the syrinx?
Where is it found?
Voicebox, system of membranes that move when air comes in
Found at tracheal bifurcation
Describe the avian air sacs and how they function.
Anterior = cervical, interclavicular, cranial thoracic Posterior = caudal thoracic and abdominal
- No direct role in gas exchange, but serve as bellows to store extra air
- Allow a continuous stream of air to pass through lungs in a one-way flow
- Connect to pneumatic bones and remove excess heat as the bird breathes
Describe the flow of air during gas exchange
Movement of sternum and ribs provide mechanical force for inspiration and expiration
Inspiration - most air to posterior air sacs, some passes into lungs
Expiration - air from posterior air sacs passes into lungs
How are birds typically induced and maintained anesthetically?
Mask (isoflurane) starting at 5%
Takes 30-60 seconds
ETT (uncuffed, Cole) inserted 1-2 inches through tracheal opening
Iso 2-3% maintenance
What anesthetic monitoring is typically used in birds?
- Doppler BP clipped to wing/cloaca
- Temp probe in cloaca
- Pulse ox
* Provide IPPV 2-4 times per minute!
What is air sac cannulation and when is it indicated?
Incision placed caudal to last rib (aim for caudal thoracic or abdominal air sac)
Injected air enters caudal air sacs, gas exchange in lungs, cranial air sac, expelled
Indicated in:
- Emergency (severe dyspnea as in tracheal FB)
- Surgery of oral cavity
- Enucleation
What are the sclerical ossicles?
Ring of interdigitating pneumatic bones that surrounds the eye
Results in limited ocular motility
How is the avian iris different from the mammalian iris?
Why is this clinically significant?
Controlled by striated (not smooth) muscle
Commonly used mydriatics (atropine) won’t work, use general anesthesia instead
How does the avian retina differ from mammals?
- Avascular structure
- Pectens provides nutrients to retinal tissue
- Fovea (circle lateral to pectens) is area of greatest visual acuity
What should be considered when performing avian eye neuro exam?
No indirect PLR present (contralateral pupil will not constrict)
T/F, the large cardiac vessels can be visualized radiographically
True, visualized within heart on V/D
What is unique about avian RBCs?
Nucleated, nucleus lightens with age (less densely packed)
How much blood can safely be sampled from a bird?
10% of blood volume (which is 10% of BW)
eg) 500g bird, 5mL can be collected
How is liver function assessed in the bird?
Bile acids
What condition can cause blunting of the papillae on the palantine cleft?
Hypovitaminosis A
Where is the crop located?
R of trachea
What are the enzymatic and mechanical components of the avian stomach?
Proventriculus (enzymatic, glandular)
Ventricular (mechanical, muscular)
What are the three normal components of avian feces?
Fecal (brown)
Urate (white)
Urine (clear)
