Concurrent hyperadrenocorticism in a minature schnauzer with severe Trichophyton mentagrophytes infection

Abstract

A 4‐year‐old intact female schnauzer dog was presented with a history greater than 1 year of alopecia, thick crusting and secondary seborrhea with mild pruritus. The dog was diagnosed pituitary‐dependant hyperadrenocorticism (PDH) concurrent with severe Trichophyton mentagrophytes infection. The dog showed generalized alopecia, enlarged pendulous abdomen, mild polydipsia, polyuria and polyphagia. Liver enzymes alanine aminotransferase (ALT) and alkaline phosphatase (ALKP) were normal. ACTH stimulation and low‐dose dexamethasone suppression tests were performed prior to therapy. The concentrations of serum cortisol were determined by radioimmunoassay (RIA) and direct enzyme immunoassay (EIA) methods. The results of both assay systems indicated PDH. Fungal cultures showed T. mentagrophytes infection in 4 days. Histological examination of a skin biopsy specimen revealed severe irregular acanthosis accompanied by compact hyperkeratosis, and numerous dermatophytic spores and hyphae heavily colonized in the keratin layer. After 3 months of oral terbinafine (25 mg kg−1, once daily) and mitotane therapy, the hair regrew and the result of an ACTH stimulation test were normal. Three sets of biweekly fungal cultures were negative after 6 months. In this case, terbinafine was given concurrently with mitotane without detectable adverse effects (no abnormal clinical signs were observed and liver enzymes remained within normal ranges). Thus, the combination of terbinafine and mitotane appears to be a safe therapeutic protocol in treatment of PDH with dermatophytosis. This study was supported by The Association of Veterinary Dermatology, Taipei.