Avian Exam Pt.4 - Respiratory Dz Flashcards
Organs included in the URT and LRT
- Upper respiratory = nares, nasal cavity, sinuses, nasopharynx, trachea, syrinx
- Lower respiratory = primary and secondary bronchi, parabronchi, lungs, air sacs
What structure lies in the upper beak? Anatomy?
> Sinus diverticulum of the infraorbital sinus
- Extends into upper beak
- Surrounds eye
- Psittacines = left and right sinuses are connected
- Passerines, columbidae = left and right sinuses are separated
Where do the sinuses reach in the head?
- Beak
- Behind the eye
- Down the neck to the cervical air sac
Etiology for swellings around the eye in birds
Not ophthalmic, but RESPIRATORY (infraorbital sinusitis)
True or false - the nasal cavity connects with the oral cavity
TRUE - choanae, slit, glands (salivary glands), may see drainage out the mouth from the nasal cavities
- Can breathe through their nose or mouth
- Nasal discharge = serious respiratory disease
What is unique about the larynx in birds?
> Sits at the base of the tongue
- Not a true larynx or glottis
- Not covered by an epiglottis = physiologic resting position of the laryngeal cartilages is closed, needs to be opened if they want to inspire
What does having closed tracheal rings mean for birds?
NEVER use a cuffed tube for intubation
Fun anatomic differences in birds
- Cervical trachea = highly mobile
- Coiled in whooping cranes and trumpeter swans (allows them to vocalize)
- Penguins = medial septum with compete separation
Location, purpose, and problems with the syrinx
- Location = bifurcation of trachea (at heart base), where primary bronchi start
- Comprised of modified tracheobronchial cartilages
- Functions as the “voice box”
- Vibrating membranes regulated by syringeal musculature = voice on expiration
- Clavicular air sacs = act as a resonance body
- Problem = narrowed diameter, prone to OBSTRUCTION
What is an osseous bulla and who has it?
Ossified syrinx seen on radiographs with male ducks
Anatomy of avian lungs
- More rigid = don’t collapse
- No pleural space
- Primary bronchi run through the whole lung
- Secondary and parabronchi
- No alveoli
- Large lung volume that doesn’t change with respiration = lung air sacs push air through the system
Anatomy of air sacs
- FOR VENTILATION and air movement and storage only
- Thin, transparent, distensible simple squamous epithelium
- Poorly perfused = plays no role in gas exchange
- Cervical, clavicular, 2x cranial and caudal thoracic, 2x abdominal air sacs
- Pneumatized humerus and femur = diverticula of air sacs
Do birds have a diaphragm?
No
What problem does having a long/wide trachea cause?
More dead space
True or false - birds have a highly efficient gas exchange system
TRUE
Where do these signs localize you to? Sneezing, nasal discharge, nasal swelling, sinus/periocular swelling, head shaking, stridor
URT = nasal and sinus
Where do these signs localize you to? Dyspnea, exercise intolerance, voice change, open mouth breathing
Trachea and syrinx
Where do these signs localize you to? Tail bobbing, loss or change of voice, dyspnea, exercise intolerance, “coughing”, sounds on auscultation
Lower airway tract
What non-respiratory structures may cause respiratory like disease?
- Heart failure and pulmonary edema
- Air sac compresssion due to ascites, coelomitis, organomegaly (neoplasia, liver), obesity
DDx: nasal discharge, granulomas, rhinoliths (3)
1) Hypovitaminosis A
2) Secondary fungal or bacterial infection
3) Choanal atresia and drainage problems
DDx: sinusitis, ocular swelling (6)
1) Hypovitaminosis A
2) Neoplasia
3) Foreign bodies
4) Drainage problem with choanal atresia
5) Primary and secondary bacterial = Pasteurella and E. coli (poultry), Chlamydophila (+conj), Mycoplasma (finches + conj)
6) Fungal = Aspergillus
Diagnostics and treatments for nasal infection
- Dx = nasal flush = upside down to avoid aspiration, rehydrates mucosa = cytology (WBC’s, high bacterial counts), +/- culture (contaminated through mouth)
- Tx = surgical + medical = best outcome (medical only = isolated infection), can try to repeatedly flush, open up and instill antibiotics
Diseases of the trachea
1) Obstruction = foreign body (acutely dyspneic), post-intubation stenosis if cuffed (B+G macaws have anatomic tapering)
* Don’t move the ET tube once placed
2) Tracheitis = toxins (NH3), bacterial, fungal, viral = pox, amazon tracheitis virus (herpes)
3) Parasites
Dx? Tx? Clicking noise from finch or canary, ADR
> Tracheal mite
- Affects finches and canaries
- Irritates trachea with excess mucus production
- Dx = wash (difficult), response to tx
- Tx = ivermectin
