Use of prednisolone as monotherapy in the treatment of feline pemphigus foliaceus: a retrospective study of 37 cats.

Background: Prednisone doses of up to 8 mg/kg/day have been used to treat feline pemphigus foliaceus (PF). Oral prednisolone has more favourable pharmacokinetics in cats than prednisone; therefore, lower doses of prednisolone may be effective in treating feline PF.

Hypothesis/objectives: To assess the dose of prednisolone required to induce and maintain remission of PF in cats.

Animals: Thirty-seven client-owned cats with a diagnosis of PF treated with prednisolone monotherapy for induction of remission.

Methods: A retrospective analysis of records of a veterinary dermatology referral practice between the years of 1995 and 2013 was carried out. History, clinical signs, cytological and/or histopathological findings, lack of response to antimicrobials, absence of fungal hyphae on periodic acid Schiff staining and/or negative fungal culture and positive response to immunosuppressive therapy were used to confirm the diagnosis. Cats were included in the study if prednisolone was used as the monotherapy induction protocol.

Results: Complete remission was achieved within 8 weeks in 97% of cats with a median induction dose of 2 mg/kg prednisolone daily. In cats requiring ongoing treatment, 67% were maintained in remission with prednisolone monotherapy. The median maintenance dose was 1.2 mg/kg/week. In 14% of cats, medication was eventually discontinued.

Conclusions And Clinical Importance: Daily prednisolone at 2 mg/kg is an effective dose for inducing remission of PF in cats. Adverse effects were uncommon with this dose. In a small population, permanent remission may be induced. Secondary bacterial overgrowth and exudate in claw folds resolved in all cases with immunosuppressive therapy; therefore, antimicrobial therapy may be unnecessary.