Page 75 - Problem-Based Feline Medicine

5 – THE DYSPNEIC OR TACHYPNEIC CAT 67

excision of nodules may palliate clinical signs tem- Treatment
porarily.
Corrective surgery for patent ductus arteriosis and
Chemotherapy and radiation have been attempted pulmonic stenosis (rare in cats) is available in special-
in generalized pulmonary neoplasms, with disap- ist centers.
pointing results. Metastases from distant tumors
Most other problems require medical management
carry a grave prognosis, although pulmonary lym-
depending on the presenting signs (see page 140, The Cat
phoma may attain remission with chemotherapy.
With Abnormal Heart Sounds and/or an Enlarged Heart).
General supportive care and nutrition are important.
LARYNGEAL PARALYSIS
Prognosis
Classical signs
Fair to excellent with surgically resectible primary
pulmonary neoplasms without metastasis. ● Inspiratory dyspnea and increased airway
noise.
Grave with metastatic disease or malignant pleural
● Stertorous breathing (snoring).
effusions.
● Stridor (high-pitched whistling =
obstructive).
CONGENITAL HEART DEFECTS ● Voice changes, absence of purring.

Classical signs See main reference page 43 (The Cat With Stridor).
● Reluctance to play or run.
● Anxious, uncomfortable breathing. Clinical signs
● Dyspnea – if present varies from mild to Inspiratory dyspnea.
severe.
Stridor which is worse with excitement or exercise.
● Abnormal heart sounds (murmurs, gallops,
arrhythmias). Occasional stertorous breathing or snoring.
● Signs of pleural effusion – increased chest
Voice changes such as an absent or whisper-like meow,
excursions with little airflow.
or harsh purring sounds.

Diagnosis
Clinical signs
Diagnosis is based on signs of laryngeal stridor, inspi-
Atrioventricular valve dysplasia, septal defects, aortic ratory dyspnea and visualization of the larynx.
and pulmonic stenosis (rare) and patent ductus arterio-
Laryngoscopic inspection under heavy sedation or
sus all lead to pressure and/or volume overload on the
light anesthesia with a rigid laryngoscope and blade
heart, and potentially result in congestive heart failure.
reveals absent or paradoxical motion of the arytenoid
Heart murmurs at various locations (left apex for cartilages. Normally they should abduct on inspiration.
mitral valve dysplasia, right apex for ventricular septal If they close on inspiration, it is paradoxical motion.
defect), and intensities (continuous murmur of patent
Erythema and swelling (“kissing lesions”) of the ary-
ductus arteriosis) occur depending on the type of con-
tenoid mucosa may be evident as a result of repetitive
genital heart defect.
focal impact of the touching surfaces of the corniculate
The cat may be reluctant to play or run, and if pres- processes.
ent, dyspnea varies from mild to severe. Open-mouth
Low-dose ketamine (4–6 mg/kg IV), ketamine/
breathing or cyanosis may occur with severe defects.
diazepam (3–5 mg/kg/0.1–0.2 mg/kg IV) or propofol
Signs of pleural effusion include increased chest excur- (4–6 mg/kg IV) allows visual inspection without
sions with little airflow. diminishing laryngeal function.