Oral voriconazole therapy in cats with histoplasmosis yielded mild side effects and a favorable outcome.

OBJECTIVE

Infection by Histoplasma organisms most commonly results in disseminated systemic infection in cats. Relapse during therapy with itraconazole and fluconazole has been reported. The aim of this study was to report the clinical response, duration of therapy, side effects, and outcome in cats with histoplasmosis that were treated with voriconazole.

ANIMALS: 6 client-owned cats.

CLINICAL PRESENTATION: Medical records were reviewed of cats with confirmed histoplasmosis that presented to the Kansas State University Veterinary Health Center and received voriconazole therapy (n = 6 cats).

RESULTS

4 cats were switched to voriconazole from fluconazole (n = 2), itraconazole (1), or both (1), and 2 cats received voriconazole as initial therapy. Median starting dosage was 3.51 mg/kg PO every 72 hours. Two cats required a change in dosing interval from every 72 hours to every 96 hours due to hyporexia (n = 2) and an elevated ALT (1). Remission was documented in all 6 cats with a median time to a negative urine antigen of 256 days (range, 94 to 494 days).

CLINICAL RELEVANCE: Voriconazole therapy in 6 cats with histoplasmosis yielded mild side effects and a favorable outcome. Reported dosages provide a feasible alternative to daily dosing for owners of feline patients.