Page 45 - Problem-Based Feline Medicine

4 – THE CAT WITH STRIDOR OR STERTOR 37

Clinical signs Classical signs—Cont’d

Sneezing, snuffling, stridor or stertor and chronic nasal ● Chronic non-responsive otitis, head tilt and
discharge are most common with cryptococcosis. Horner’s syndrome.
Nasal discharge may be unilateral or bilateral, and
serous, mucopurulent or hemorrhagic.
Clinical signs
Distortion and swelling over the bridge of nose, or a
polyp-like mass projecting from the nasal cavity are Nasopharyngeal polyps are thought to occur second-
present in 70% of cats with the respiratory form of ary to chronic upper respiratory tract inflammation
cryptococcosis. as they consist of inflammatory tissue covered by
Depression, anorexia or inappetence and weight loss are epithelium. They are thought to arise from the
often present with nasal or CNS involvement. Eustachian tube or bulla.

Mandibular lymph nodes are often enlarged. They are a relatively common cause of stridor and
dyspnea, and typically occur in young cats (average
Vestibular disease has been reported associated with age 1 ⁄2 years old), and most begin to exhibit signs
1
cryptococcal infection. before they are 1 year of age. Abyssinians may be pre-
Aspergillus, Penicillium, Sporothrix and some other disposed.
fungi are very rare causes of chronic nasal disease. Chronic mucopurulent nasal discharge and congestion
is common, but may be absent.
Diagnosis
Inspiratory noises, usually stridor, but sometimes ster-
Cytological identification of the organism in nasal tor, along with dyspnea and open-mouth breathing have
discharge, exudate from skin lesions, lymph node aspi- been reported.
rate, cerebrospinal fluid (CSF), or ocular aspirate is
diagnostic. Note that very occasionally small numbers Signs of ear disease, including chronic discharge, head
of organisms may be cultured from the nasal exudate of tilt and possibly Horner’s syndrome on the affected
normal cats. side, may be present.
Serology to detect cryptococcal capsular antigen in
blood, CSF, or urine is sensitive and specific.
Diagnosis
Tissue biopsy of the granulomatous mass or skin lesion,
and histological identification of the organism may be Radiographs or CT may show a soft tissue mass lesion
required if cytology is negative. in the nasopharynx
PCR (polymerase chain reaction) assays are now avail- Rhinoscopy and otoscopy are valuable in visualizing
able to detect cryptococcal antigens in biopsy material. the mass and obtaining biopsy material. The polyp may
be visualized directly or with a dental mirror. The ros-
Fungal isolation with culture is rarely required tral soft palate may bulge down into the oral cavity with
for diagnosis, but is useful for sensitivity testing. pressure from the polyp. Pull the soft palate rostrally
Radiographs often reveal turbinate lysis and opacity for an improved view.
of the nasal cavity (soft tissue density). Sinus involve-
ment is common.
Differential diagnosis
NASOPHARYNGEAL POLYP
Tracheitis from feline rhinotracheitis virus is generally
Classical signs associated with other upper respiratory signs.
● Nasal discharge and congestion. Laryngeal paralysis or edema, tracheal foreign
● Inspiratory dyspnea and stridor. body, and tracheobronchial neoplasm can be differ-
entiated endoscopically.