Efficacy of oral administration of itraconazole to cats with dermatophytosis caused by Microsporum canis.

OBJECTIVE

To determine efficacy of orally administered itraconazole in cats with dermatophytosis caused by Microsporum canis.

DESIGN

Uncontrolled clinical trial.

ANIMALS

15 cats with dermatophytosis caused by M canis.

PROCEDURE

All cats were treated with itraconazole (1.5 to 3.0 mg/kg [0.7 to 1.4 mg/lb] of body weight, PO, q 24 h, for 15 days). Six cats had been treated with griseofulvin (10 mg/kg [4.5 mg/lb], PO, q 24 h) during a 60-day period, but their clinical condition had not improved. Five cats treated at the highest dosage of itraconazole vomited or became anorectic. Consequently, dosages were progressively decreased for each cat until adverse effects were not evident. After treatment, samples of hair were submitted for fungal cultures, and if appropriate, treatment was repeated when culture results were positive.

RESULTS

8 cats treated with itraconazole recovered completely, as indicated by resolution of lesions and negative results of fungal cultures. Six of these 8 cats received a single 15-day course of treatment, whereas the remaining 2 cats needed prolonged treatment (two 15-day courses of treatment and three 15-day courses of treatment). In 4 other cats that became clinically normal, M canis was isolated from hair samples obtained at the completion of treatment, even though only 1 colony or a small number of colonies was isolated. In the other 3 cats, itraconazole did not cause clinical improvement, and culture results remained positive.

CLINICAL IMPLICATIONS

Oral administration of itraconazole at dosages of 1.5 to 3.0 mg/kg may be useful for the treatment of cats with dermatophytosis attributable to M canis infections.