Vanessa Schmidt

Proliferative, lymphocytic, infundibular mural folliculitis and dermatitis have been reported in six female Labrador retrievers from North America. This is the first report of the disease outside North America, describing the clinical and histopathological diagnosis and dermoscopic aspect of the verrucous plaques, treatment and co‐morbidities in a female Labrador retriever dog.

Canine cutaneous mastocytosis (CM) is rare in contrast to canine mast cell tumours. In humans, CM commonly affects children and is usually indolent with possible spontaneous resolution. Systemic mastocytosis (SM) with bone marrow involvement typically affects adults, can have a poor outcome, and often includes skin lesions. ‘Mastocytosis in the skin’ (MIS) is the preferred term of skin lesions, if bone marrow evaluations are not available, which is often the cases in dogs. In human SM and CM, KIT mutations are often detected. The veterinary literature suggests clinical resemblances between human and canine MIS, but data is limited, and KIT mutations are rarely assessed. This retrospective study describes clinicopathological findings, treatment and outcome of 11 dogs with suspected MIS. Dogs with multiple mast cell tumours were excluded. Histopathology reports ( n = 5) or slides ( n = 6) were reviewed. KIT mutation analysis including exons 8, 9, 11, 14 and 17 were analysed in eight dogs. Median age at diagnosis was 4 years (range, 1–12). Typical clinical signs included multifocal to generalised nodules and papules. Histologically, skin lesions were characterised by dermal infiltration of well‐differentiated mast cells. KIT mutations were detected in 3/8 dogs (exon 9: n = 2; exon 11: n = 1). One dog had mastocytaemia suggesting possible SM. Glucocorticoids were mostly successful with lesion improvement in all treated dogs ( n = 8). This cohort highlights resemblances between human and canine MIS. Further studies are required to confirm these findings and establish diagnostic criteria for CM and MIS associated with SM in dogs.

A captive‐bred polar bear was presented for investigation of a non‐healing wound, suspected to be traumatic in nature. Histopathological examination of cutaneous samples, taken while the bear was under general anaesthesia, was compatible with dermatophytic furunculosis. The bear was treated with systemic itraconazole (5 mg/kg once daily) for 3 months, alongside topical 2% miconazole nitrate and 2% chlorhexidine gluconate twice weekly. Environmental decontamination of concrete flooring and metal handling facilities was performed with a detergent to remove organic matter, followed by 1:10 dilution of 5% sodium hypochlorite solution at least twice weekly and between the use of the facilities by different bears. Within 4 months, the ulceration had resolved, and the lesion had reduced to a 10 cm diameter patch of complete alopecia.