Itraconazole for the Treatment of Histoplasmosis in Cats

Abstract

Eight cats with histoplasmosis were treated with itraconazole at 5 mg/kg per dose PO bid. There were multiple sites of infection, and 2 of the cats had hypercalcemia that was attributed to the histoplasmosis. All 8 cats were eventually cured, but 2 cats experienced recurrences of disease after completion of therapy, requiring 2 to 3 additional months of itraconazole. There were no clinically relevant adverse effects during treatment. Although a limited number of cats were treated, the study suggests that itraconazole is a well-tolerated and effective drug for the treatment of histoplasmosis in the cat.

Antigen Concentrations as an Indicator of Clinical Remission and Disease Relapse in Cats with Histoplasmosis

“…The 6 month recheck was intended to better assess for early disease relapse. Previously reported relapse rates in cats with histoplasmosis are 25 and 40% . In the aforementioned studies, disease relapse occurred from 4 to 74 months after discontinuation of antifungal treatment.…”

“…Previously reported relapse rates in cats with histoplasmosis are 25 and 40%. 1,11 In the aforementioned studies, disease relapse occurred from 4 to 74 months after discontinuation of antifungal treatment. As such, relapse in the future remains possible for cats included in this study.…”

“…9 Itraconazole, fluconazole, and amphotericin B are the most commonly used antifungal agents for the treatment of histoplasmosis. 1,2,10,11 In cats, antifungal treatment is costly for the pet-owner and can require extended treatment duration. 1,2,11 The veterinarian often faces challenges in determining the optimum antifungal treatment endpoint to reduce relapse occurrence while mitigating overall cost of treatment.…”

Antifungal agents of use in animal health – practical applications

“…Long‐term oral itraconazole (5 mg/kg once or twice daily) is effective for treatment of feline cryptococcosis (Medleau et al ., 1990, 1995; Kano et al ., 1997) and histoplasmosis (Hodges et al ., 1994).…”

Fungal Infections

“…Possible (Figure 95-1, B). 18 Antigen detection testing is available for humans (MiraVista Diagnostics, Indianapolis, IN). 12 Serologic tests to diagnose histoplasmosis are unreliable; falsenegative results occur in active disease and false-positive results occur in animals without active disease.…”