Page 68 - Problem-Based Feline Medicine

60 PART 2 CAT WITH LOWER RESPIRATORY TRACT OR CARDIAC SIGNS

hours) to moderate doses (300 IU/kg SQ q 8 h) have Clinical signs
been published, with no clear advantages of any one
Nasal tumors are most commonly squamous cell car-
protocol.
cinoma of the nasal planum, solid nasal carcinomas and
Coumadin is a more potent anti-thrombotic agent in nasal lymphoma.
the cat. Having an oral liquid suspension compounded
Nasal obstruction produces stridor, stertor or open-
makes the titration of the dosage much more reliable in
mouth breathing, uni- or bilateral nasal discharge and
the cat. Doses of 0.1 mg/kg PO q 24 h are a recommended
coughing from post-nasal drip. Anosmia may lead to
starting point. Monitoring the prothrombin time (PT) and
inappetance.
the INR (international normalization ratio), with a treat-
ment endpoint of an INR of 2.0–3.0, may help to prevent Squamous cell carcinomas of the tonsil are common
overdosage, although trials in cats are lacking. pharyngeal masses, along with benign nasopharyngeal
polyps.
Fluid therapy must be used judiciously, due to the
predisposition of right-sided heart failure. Pharyngeal masses produce dysphagia, stertorous
dyspnea and voice changes. Fetid halitosis is also
reported.
Prognosis
Tracheal tumors consist of lymphoma, squamous cell
Prognosis is directly proportionate to the severity carcinoma, leiomyosarcoma and osteochondral tumors
of the lesion, as well as to the underlying cause. from the tracheal rings. Adenocarcinomas have
Resolvable causes (i.e., trauma or catheter-induced) increased prevalence in Siamese cats.
have a better long-term prognosis that do patients
Tracheal tumors cause fixed obstruction, leading to
with irreversible causes (i.e., renal amyloidosis).
both inspiratory and expiratory dyspnea. A harsh, dry
cough is common.
Prevention
Treat underlying risk factors early in the disease course,
Diagnosis
for example, protein-losing nephropathies and
enteropathies. Diagnosis is by rhinoscopy, pharyngoscopy or tra-
cheoscopy with biopsy. It is possible to image soft tis-
Acetylsalicylic acid or heparin theoretically may help
sue masses radiographically, but endoscopy is still
prevent further thrombus formation, although there are
advised for biopsy.
no studies demonstrating efficacy in cats.
Differential diagnosis
AIRWAY TUMORS
Inhaled and penetrating foreign bodies, and benign or
Classical signs parasitic granulomas of the airways may mimic neo-
plastic masses. Foreign bodies result in acute onset of
● Nasal obstruction produces stridor and
signs and often distress, compared to chronic signs in
open-mouth breathing.
neoplasia and granulomas. Visualization and biopsy
● Pharyngeal obstruction results in
will differentiate these diseases.
dysphagia, stertor and voice changes.
● Tracheal tumors produce fixed obstruction
with inspiratory and expiratory dyspnea, Treatment
and often coughing.
Solid nasal tumors respond well to external beam
See main reference on pages 41 and 24 for details (The radiotherapy, with survival times of 20–27 months.
Cat With Stridor, and The Cat With Signs of Chronic Rhinotomy with turbinatectomy has been reported to
Nasal Disease). be successful.