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186 Coccidioidomycosis

○ Negative serologic tests of dogs infected ○ Ketoconazole 5-10 mg/kg PO q 12h; phenytoin, methylprednisolone, or
with Coccidioides spp are uncommon but variably effective depending on absorption. cyclosporine because azole drugs may
VetBooks.ir • An antigen diagnostic test that identifies effects or vomiting/inappetence. Serum Possible Complications
raise serum levels of these medications
Least costly; may produce adverse hepatic
can occur.
substantially.
Coccidioides spp galactomannan antigen in
drug concentrations may be needed to
serum and urine is available. The test shows
poorly tolerated by cats.
cross-reactivity with Histoplasma capsulatum confirm bioavailability. Ketoconazole is If clinically significant respiratory signs are left
and Blastomyces dermatitidis and has low ○ Other azoles such as voriconazole or untreated, systemic spread of illness may occur.
sensitivity. It may be helpful in antibody- posaconazole could be considered for
seronegative coccidioidomycosis. dogs that fail to respond to treatment PROGNOSIS & OUTCOME
• Polymerase chain reaction (PCR) testing: not with itraconazole or fluconazole.
yet widely applied to this disease in dogs and • Deoxycholate amphotericin B 0.5 mg/kg • Prognosis for patients with disease limited
cats IV on a Monday-Wednesday-Friday basis, to the respiratory tract is fair to good.
given over 4-6 hours in 5% dextrose for • Patients with disseminated disease have a
TREATMENT 1 month barring nephrotoxicosis (dogs); guarded to poor prognosis for full recovery,
0.25 mg/kg (cats). Can be used in patients depending on the severity of disease and
Treatment Overview that are not responding to or do not toler- degree of dissemination.
Antifungal therapy (itraconazole, fluconazole, ate azoles (e.g., anorexia, vomiting, hepatic • Patients with CNS involvement have a poor
or ketoconazole) is most commonly employed. dysfunction). Adverse effects include prognosis.
Itraconazole and fluconazole have fewer adverse nephrotoxicosis and perivascular irritation/
effects and greater bioavailability than ketocon- sloughing. Renal parameters should be PEARLS & CONSIDERATIONS
azole. Fluconazole is the treatment of choice assessed before each dose. Lipid forms of
for CNS or ocular involvement. Amphotericin amphotericin B (e.g., 1-3 mg/kg IV, given Comments
B may be required for treatment of severe dis- on a Monday-Wednesday-Friday basis over • Radiographic changes cannot distinguish
seminated disease. 1-2 hours [dogs]; 1 mg/kg IV [cats]) are less bony neoplasia from fungal osteomyelitis;
nephrotoxic but more expensive. biopsy is required.
Acute General Treatment • Surgical treatment by subtotal pericardec- • Fungal culture of Coccidioides should not be
• Supportive care for systemic illness and tomy and epicardial excision has been used attempted in a veterinary practice because the
respiratory distress as warranted successfully for relief of right-sided heart mycelial form that produces arthroconidia
○ Oxygen supplementation (p. 1146) failure in dogs with effusive-constrictive in culture is highly infectious.
○ Treatment of systemic hypotension pericarditis.
• Mild respiratory cases may resolve without Prevention
treatment, but antifungal therapy is often Chronic Treatment To minimize the risk of infection in endemic
instituted to avoid dissemination. Avoid • The decision to stop antifungal therapy areas, keep animals away from desert soil and
broad-spectrum antibiotics and immunosup- should be based on resolution of clinical locations where soil is disrupted (e.g., construc-
pressive medications. signs, radiographic lesions, and serologic tion sites), and discourage digging.
• Azole antifungal drugs: if using generic azole titers. Therapy should continue for at least
preparations, obtain only from a reliable 2 months beyond resolution of clinical signs Technician Tips
source. Liver enzyme activities ± serum and radiographic abnormalities, which may • Bandages used for covering cutaneous drain-
drug levels should be monitored periodically be > 12 months with disseminated disease ing tracts for prolonged periods have the
during therapy. (especially if there is bone involvement). potential to become infectious to humans
○ Fluconazole 5-10 mg/kg PO q 12h (dogs); Depending on the severity of disseminated if the lesion is due to Coccidioides infection.
10 mg/kg PO q 12h (25-50 mg/CAT PO disease and the immune competence of the Bandages should be avoided in such situa-
q 12-24h) (cats). Penetrates better than patient, treatment may be lifelong. tions, or if indispensable, they should be
itraconazole into the eye, prostate, and • Rising titers suggest an inadequate response changed on a daily basis and disinfected or
CNS tissues to therapy, although decreasing titers destroyed (autoclaved) immediately when
○ Itraconazole 5 mg/kg PO q 12h for 1 are not necessarily predictive of a good removed.
week, then 5 mg/kg PO q 24h thereafter response. • If a needlestick injury occurs (e.g., during
(dogs); 3-5 mg/kg q 12h for 1 week, then fine-needle aspiration of affected tissues),
5 mg/kg PO q 24h thereafter (cats). Name Drug Interactions medical advice should be sought immediately.
brand is costly, but compounded formula- • Some patients receiving azole drugs can
tions may not be efficacious. Unless develop liver dysfunction, vomiting or diar- SUGGESTED READING
significant inflammation is present, it may rhea, thrombocytopenia, and skin reactions. Sykes JE: Coccidioidomycosis. In Sykes JE, editor:
not penetrate the eye and CNS. Capsules • Compatibility of other medications with Canine and feline infectious diseases, St. Louis,
should be administered with food but the antifungal agents should be investigated 2014, Elsevier, pp 613-623.
solution can be administered on an empty before use. AUTHORS: Jane E. Sykes, BVSc, PhD, DACVIM; Sharon
stomach. Serum drug concentrations may • Caution should be taken in patients receiving M. Dial, DVM, PhD, DACVP
be needed to confirm bioavailability. o,p′-DDD, warfarin, digoxin, phenobarbital, EDITOR: Joseph Taboada, DVM, DACVIM

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