Page 110 - Problem-Based Feline Medicine

102 PART 2 CAT WITH LOWER RESPIRATORY TRACT OR CARDIAC SIGNS

strangulation from neck collars), excessive vocalization way obstruction such as tracheal collapse, are differen-
(senility, sexual behavior), or other laryngeal disease tiated with laryngotracheobronchoscopy.
(laryngeal paralysis).
Laryngeal trauma may directly inflame the larynx, or Treatment
may cause nerve damage, secondary laryngeal paraly-
Anti-inflammatories, especially glucocorticoids, are
sis and subsequent mucosal edema from abnormal ary-
used to diminish the local inflammation.
tenoid cartilage motion.
● Dexamethasone (0.1–0.25 mg/kg IV or IM), or
Aspiration of lavage solutions from dental prophy- prednisone (0.5–1.0 mg/kg PO q 12–24 h).
laxis or endodontics may be caustic to the laryngeal ● Little is known about the application of NSAIDs in
mucosa, creating significant edema. laryngeal edema.
Laryngeal edema may occur as part of a type I hyper- Antibiotics are only indicated if there is evidence of
sensitivity reaction to insect stings or vaccination. bacterial infection.
Inflammatory diseases like eosinophilic laryngeal granu- Antitussives may be indicated when the cough has
loma can cause edema (see The Cat With Stridor, page 45). become protracted and debilitating, and lower respira-
tory disease has been ruled out.
Coughing may occur from irritation of the laryngeal
● Butorphanol (0.2 mg/kg SQ q 6 h or 1 mg/cat PO
cough receptors, or from aspiration of food, water or
q 6–8 hours prn) may be effective.
saliva due to laryngeal paresis.
Prognosis
Clinical signs
Fair to excellent.
The cough is usually non-productive, but is typically
harsh and may stimulate a gag reflex and expectoration
of pharyngeal contents. Prevention
Inspiratory dyspnea and stridor, which is worse with Use of break-away neck collars on outdoor cats may
excitement or exercise, may be evident. significantly decrease strangulation injury to the larynx
and the laryngeal nerves.
Dysphonia or voice change, often a whisper-like or
hoarse sound, is frequently observed in cats. Avoidance of insect stings is helpful.

Neutering tom cats helps to prevent both fighting and
Diagnosis mating behaviors such as excessive vocalization.
Laryngoscopy requires deep sedation or anesthesia and
a rigid laryngoscope and blade, and often reveals ery- TRACHEOBRONCHIAL COLLAPSE
thema and edema of the laryngeal mucosa.
Classical signs
Samples of abnormal tissue may be taken for cytology
and histology. Culture of the larynx is of questionable ● Harsh, honking cough.
value. ● Dynamic airflow limitation on inspiration if
cervical segment, and expiratory if
If biopsies are taken, this may worsen edema. Post-
intrathoracic segment involved.
operative steroids may decrease iatrogenic edema.
● Very rare in cats.
Occasionally, temporary tracheostomy may be required
after biopsy.
Clinical signs
Differential diagnosis
The cough is often harsh, non-productive and paroxys-
Laryngeal mass lesion or foreign bodies are differenti- mal, ending in a gagging episode which may appear to
ated visually and by biopsy. Other causes of upper air- be productive.