Page 395 - Problem-Based Feline Medicine

19 – THE PYREXIC CAT 387

Respiratory signs such as coughing and wheezing are
COCCIDIODES IMMITIS
less common in cats and occur in approximately 25%
of cases.
Classical signs
Musculoskeletal signs such as lameness, with or with-
● Skin lesions.
out painful bone swelling, were reported in 19% of
● Respiratory signs.
cats.
● Ocular lesions.
● Fever, anorexia, depression. Ocular lesions are seen infrequently and include chori-
oretinitis and anterior uveitis. Ocular or CNS signs
were reported in 19% of cats.
Pathogenesis
Most cats have clinical signs for less than 4 weeks
The geographical distribution includes south-west
prior to diagnosis.
USA, Central America and South America in areas
that have sandy soil with low rainfall and high tem-
peratures. Diagnosis
Soil is the reservoir for infection, and the highest fre- Hyperproteinemia is present in approximately 50% of
quency of cases occur when the soil is dry and dusty, cats.
and organisms are disseminated in the wind.
Definitive diagnosis is by identification of the organism
Most humans and animals in endemic areas become via biopsy of lesions.
infected, but the majority of infections are subclinical
or cause only mild, transient clinical signs. Antibody detection is available using latex agglutina-
tion (IgM), AGID (IgM) or ELISA (IgM or IgG).
Cats are more resistant to infection and signs are less
common than in dogs. Tube precipitin (TP) for IgM and complement fixation
(CP) for IgG were previously thought to be less reliable
Infection is contracted via inhalation, and only a few in cats, but have been subsequently demonstrated to
organisms are required to produce signs, which occur detect feline infections.
after 1–3 weeks.
Initial infection is confined to the respiratory tract,
Treatment
but dissemination may occur resulting in chronic dis-
ease over months or years with signs referable to bones, Itraconazole (10 mg/kg PO if possible, q 24 h or 5
eyes, central nervous system and abdominal organs. mg/kg q 12 h) is the treatment of choice. Treatment is
required for 4–6 months and must be continued for at
Localized infection following a penetrating skin wound
least 2 months after all signs have resolved.
appears to be rare.
● Some cats develop anorexia, and less commonly
vomiting or diarrhea. Stop the drug for a few days
Clinical signs until the cat is eating, and then restart at 1/2 the
dose for 7–10 days, before increasing back to the
Cats appear to be resistant to clinical disease.
full dose, which is usually then tolerated.
Skin lesions are the most frequent types of infection in
Amphoteracin B is also effective (0.25 mg/kg in 30 ml
cats and were reported in 56% of cats in one study.
dextrose 5% IV over 15 minutes q 48 h or given subcuta-
● Lesions begin as small bumps and progress to
neously) – see page 26, for Cyptococcosis in The Cat
abscesses, ulcers or draining tracts.
With Signs of Chronic Nasal Disease. Continue ampho-
● In cats, underlying bone involvement is uncommon.
tericin B therapy until a cumulative dose of 4 mg/kg is
Systemic signs such as fever, anorexia and depres- given or until BUN > 17.9 mmol/L (50 mg/dl).
sion are commonly reported (44% of cats) and can be Amphotericin has the disadvantage of requiring frequent
seen with skin lesions. parenteral or subcutaneous administration and causes sig-
nificant nephrotoxicity.