Page 114 - Problem-Based Feline Medicine

106 PART 2 CAT WITH LOWER RESPIRATORY TRACT OR CARDIAC SIGNS

● Adulticide therapy is not recommended as Dyspnea and exercise intolerance, evidenced as
there is a high risk (25–30%) of mortality, lethargy, physical inactivity, reluctance to play or weak-
mostly from pulmonary thromboembolism within ness, may occur.
the first 5 days. The death rate following treat-
Weight loss, poor coat and ill-thrift may be evident.
ment is at least as high as the death rate in
untreated cats. Vomiting sometimes occurs with feline heartworm dis-
● Manual removal of worms by a specialist is ease.
associated with a lower mortality rate than killing
the worms with parasiticides. This technique is
only recommended in symptomatic cats with Diagnosis
worms visible in the right heart and main pul-
Feline heartworm disease – peripheral basophilia,
monary arteries on ultrasound. Shock-like signs
positive heartworm antibody testing, dilated and
and death may occur if the worms are damaged
blunted pulmonary arteries and patchy pulmonary infil-
during extraction.
trates on radiographs, and evidence of heartworms on
ultrasound (see page 105 for details).
Prevention
Lungworm infection with Capillaria aerophilia is
The currently available drugs licensed for prevention diagnosed by finding eggs in the stools or lung wash,
of heartworm in cats are ivermectin (24 μg/kg once and with Aelurostrongylus abstrussus by finding lar-
®
monthly) and selamectin (Revolution , Pfizer Animal vae in the lung wash or fecal Baermann.
Health, 6 mg/kg once every 30 days). Milbemycine
Lung flukes (Paragonimus kellicotti) produce opercu-
oxime (Interceptor®, Novartis Animal Health, 500
lated eggs in the stool.
μg/kg once monthly) is effective but not licensed for
use in cats. Toxoplasmosis rarely produces clinical disease in cats.
Mixed fluffy interstitial and alveolar patterns are typi-
Imidacloprid and moxidectin (Feline Advantage
cally evident on radiographs. Tachyzoites may occa-
®
Heart , Bayer Health Care) topical solution as monthly
sionally be recovered on lung wash.
treatment for prevention of heartworm infection in cats.
As indoor cats are as likely to be infected as outdoor
cats, restricting the cat to indoors is not effective pre- Differential diagnosis
vention.
Other forms of pneumonia, namely bacterial, viral, fun-
gal, inflammatory and neoplasia need to be considered
PARASITIC PNEUMONIA if no larvae or ova are found in the stool or lung wash.

Classical signs
● Variable cough. Treatment
● +/- Eosinophilia.
Feline heartworm disease, see page 105 for main reference.
● +/- Larva/ova in stool.
Lungworm – Capillaria aerophilia and Aelurost-
rongylus abstrussus – fenbendazole (50 mg/kg PO q
Clinical signs 24 h for 3 days) or ivermectin (400 μg/kg PO, SQ).

Etiological agents include heartworm disease, lung- Lung flukes – Paragonimus kellicotti, fenbendazole
worm (Capillaria aerophilia or Aelurostrongylus (50 mg/kg PO q 24 h for 3 days), or praziquantel (25
obstrussus), lung flukes (Paragonimus kellicotti), mg/kg PO q 8 h for 2 days).
migrating nematodes and toxoplasmosis.
Toxoplasmosis – clindamycin (12.5 mg/kg PO q 12 h),
Coughing may be present, and is typically harsh and potentiated sulfa (trimethoprim or ormetoprim), or
productive. azithromycin (7–15 mg/kg PO q 12 h).