Page 396 - Problem-Based Feline Medicine

388 PART 7 SICK CAT WITH SPECIFIC SIGNS

● Because of its quick onset of action, amphoteracin Fever, anorexia, depression, weight loss and lymph-
B in combination with itraconazole is useful in adenopathy are systemic signs associated with dissem-
cats with severe pulmonary signs that are rapidly inated disease.
deteriorating. If the cat survives, after a few weeks
Draining skin lesions may occur and are usually a man-
treatment can be continued with itraconazole alone.
ifestation of systemic disease rather than local disease.
● Lipid-complexed amphoteracin formulations
allow higher dosages with less toxicity, and Neurological signs are associated with CNS involve-
should be used in cats with severe pulmonary signs, ment of the brain or spine and include circling, disori-
although the cost is higher. Dose at 2–3 mg/kg IV 3 entation, anisocoria, paresis, decreased conscious
days per week for a total of 9–12 treatments (cumu- proprioception, or upper motor neuron signs, hyperes-
lative dose of 24–27 mg). Dilute to a concentration thesia and extensor rigidity.
of 1 mg/ml in dextrose 5% and infuse over 1–2
hours.
Diagnosis
If the titer has decreased four-fold and there is a sim-
Definitive diagnosis is by demonstration of an extra-
ilar improvement in physical and radiographic
cellular, broad-based budding yeast in aspirates or
signs, treatment can be stopped after 4–6 months.
biopsies from lymph nodes, draining tracts, bone
Antibodies may persist for long periods and obtaining
lesions or vitreous humor.
a zero titer is not a useful treatment goal.
An antibody detection test is available, but may be
negative.
BLASTOMYCES DERMATIDITIS
(BLASTOMYCOSIS)
Treatment
Classical signs
Itraconazole (10 mg/kg PO if possible, q 24 h or
● Fever. 5 mg/kg q 12 h) is the treatment of choice. Treatment is
● Respiratory signs. required for 4–6 months and must be continued for at
● Ocular signs. least 2 months after all signs have resolved.
● Lymphadenopathy. ● Some cats develop anorexia, and less commonly
vomiting or diarrhea. Stop the drug for a few days
until the cat is eating, and then restart at 1/2 the
Pathogenesis dose for 7–10 days, before increasing back to the
full dose, which is usually then tolerated.
The geographical distribution includes North
America, Central America and Africa. Amphoteracin B is also effective (0.25 mg/kg in 30 ml
dextrose 5% IV over 15 minutes q 48 h or given subcu-
Soil is believed to be the reservoir for infection, and
taneously) – see page 26, for Cyptococcosis in The Cat
living near a lake or river increases the risk of infection
With Signs of Chronic Nasal Disease. Continue ampho-
in dogs.
tericin B therapy until a cumulative dose of 4 mg/kg is
Signs are more common in dogs than in the cats. given or until BUN > 17.9 mmol/L (50 mg/dl).
Amphotericin has the disadvantages of requiring fre-
Disseminated disease is primarily contracted via
quent parenteral or subcutaneous administration and
inhalation.
causing significant nephrotoxicity.
● Because of its quick onset of action, Amphoteracin
Clinical signs B in combination with itraconazole is useful in
cats with severe pulmonary signs that are rapidly
Respiratory signs include coughing, dyspnea and
deteriorating. If the cat survives, after a few weeks
harsh lung sounds.
treatment can be continued with itraconazole alone.
Ocular disease, such as uveitis, glaucoma and retinal ● Lipid-complexed amphoteracin formulations allow
detachment, is a frequent finding. higher dosages with less toxicity, and should be