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
Who is the intermediate and accidental/definitive hosts of gapeworms?
- Intermed = earthworm
- Host = poultry and waterfowl (zoo, aviary birds)
- Tx = REMOVE ACCESS to earthworms, dewormers won’t work until then
Diseases and prognosis of syrinx (2)
1) Foreign bodies
2) Fungal infection
- Often extensive, infection grows towards oxygen and blocks the trachea and other bronchi
- POOR prognosis
General tx of tracheal and syringeal disease
- Air sac catheter placement = only TEMPORARY (progresses to air saculitis)
- Nebulization
- Debridement
- Topical treatments
- Resection and anastamosis (usually successful)
Diseases that affect the lungs (5)
- Bacterial and fungal pneumonia
- Rare = viral infection
- Toxins = teflon and PFTE (acute lesions and dyspnea), smoke
- Cardiogenic and pulmonary edema
- Allergic
- Asthma = to chronic environmental allergens
Dx? Cause? Tx? SQ emphysema of the head
> Air sac rupture or hyperinflation
- Occurs secondary to trauma, malnutrition, or laparoscopy
- Acute trauma cases usually resolve
- Tx = aspiration, but usually re-inflates, can try and place stents
Why are the air sacs prone to infection?
- Poorly vascularized
- Low amounts of WBC delivered to the area
- No mucociliary elevator clearance
Dx? Weight loss, lethargy, high WBC counts (chronic nature), exercise intolerance, voice change, tachypnea, dyspnea, hyperinflation and consolidation of air sacs on radiographs
Aspergillosis
- Acute = high spore number inhalation
- Also in immunosuppressed (steroids) or stressed birds = more chronic in nature
Common infectious agent with air sacculitis
Fungal = Aspergillosis
Which species are highly susceptible to fungal aspergillosis?
- African gray parrots
- Pionus parrots
- Other = falcon, snowy owl, swans, penguins (cool temps, not usually exposed but infected when you bring them to captivity)
> Less = cockatiel, macaw
True or false - aspergillosis is contained to the air sac and lungs
False - can spread to the trachea, syrinx, or nasal cavities (diffuse or local)
Main diagnostics of Aspergillosis
- Endoscopy = most sensitive
- Cytology
- Biopsy
- Fungal culture
- PE and history (signalment)
- CBC
- Less sensitive = auscultation, radiographs
Risk factors for developing Aspergillosis (2)
1) Straw bedding
2) Peanut ingestion with aflatoxins
Tx of aspergillosis
- Depends on if local or diffuse
- Systemic antifungals = intracon, terbianfine, voriconazole ($$), ampho B
- Nebulization with antifungals or antimicrobials
- Topical tx with ampho B and debridement
- Antibiotics if you suspect concurrent bacterial infection
- Vit-A supplementation = supplement mucosal healing
- Nutritional support
- Weeks to months of tx
- Prognosis = guarded to poor, relapses are common, keep checking WBC’s
Normal and abnormal avian bacterial flora (GI, respiratory)
- Normal = gram positive
- Pathologic = gram negative (E. coli, Pseudomonas, Salmonella, Chlamydophila, etc)
- Mycobacterial infections can occur
Diagnostics for GI and respiratory bacterial disease
- Non-specific cytology of feces, choana, or crop
- C&S of feces, choanal slit, or crop
- Direct organ mass aspirate
- Blood culture
- Anaerobes, Mycobacteria, and Mycoplasma may be difficult to grown –> may try PCR
E. coli (colibacillosis) infection - when do we treat?
- Large numbers in fecal culture are usually significant - LOOK AT YOUR CLINICAL PICTURE (diarrhea?)
- May lead to chronic granulomatous disease or septicemia
- Control = prevent fecal contamination
- More of a problem in poultry and wild birds, but can occur in pet birds
Dx? Septicemia and polyarthritis in pigeons and chickens (not a problem in psittacines)
Salmonella
*Treat based on culture and sensitivity
Dx? Opportunistic respiratory infections
Pasteurella
Pseudomonas
Klebsiella
*Treat based on culture and sensitivity
True or false - is Chlamydophila gram negative intracellular bacteria
True
Transmission and clinical signs of chlamydophila
- Shed in feces and respiratory tract
- Cockatiels = classic species, may be asymptomatic carriers
+ Lethargy, diarrhea, fluffed appearance, conjunctivitis
