Combination therapy with azathioprine, cyclosporine and ketoconazole in a dog with concurrent pemphigus foliaceus and hyperadrenocorticism - Case report

A 10-year-old, spayed female Shih Tzu dog presented with a history of progressive erythema and multiple crusts developing 85 days previously. The dog had been diagnosed with hyperadrenocorticism (HAC) 55 days prior to presentation and was treated with oral trilostane (2.86 mg/kg, once daily) that was discontinued due to a poor response. In addition to generalised alopecia, erythematous plaques and crusts were noted on the trunk, head and footpads. Lesional impression smears revealed numerous acantholytic cells and non-degenerated neutrophils. Histopathological findings demonstrated subcorneal pustules with acantholytic cells and intact neutrophils. On the basis of these findings, we diagnosed pemphigus foliaceus (PF) with concurrent HAC. We wished to avoid glucocorticoids and, therefore, prescribed oral, once-daily azathioprine (2 mg/kg), modified cyclosporine (7 mg/kg) and ketoconazole (5 mg/kg). By day 71 post-treatment, the erythematous crusts had almost disappeared and the alopecia had improved considerably. However, by the subsequent follow-up examination on day 99, the clinical signs had reappeared due to the tapering of cyclosporine. To the best of our knowledge, this is the first case report describing concurrent PF and HAC in a dog. Combination therapy with azathioprine, modified cyclosporine and ketoconazole was effective, and should be considered for dogs diagnosed with concurrent autoimmune diseases and HAC.