Mycobacterium avium subspecies hominissuis infection in a dog from Germany with multifocal alopecia, exfoliative dermatitis, hypercalcaemia and subsequent sebaceous atrophy

Mycobacterium avium subspecies hominissuis belongs to the M avium complex and infections with this agent are reported rarely in the dog. A nine-year-old intact female Elo dog was presented with widespread hypotrichosis, erythema and exfoliation. Other clinical signs were polyuria/polydipsia and severe weight loss. No other animals or humans in the household showed any dermatological abnormalities. Multiple skin biopsies identified a pyogranulomatous dermatitis but no causative agent could be detected. Skin tissue culture and PCR revealed M avium subspecies hominissuis. Hypercalcaemia (ionised calcium) was initially present. All other serum biochemistry parameters, chest radiographs, abdominal ultrasound, parathyroid hormone and parathyroid hormone-related protein were within the reference interval. Subsequent to therapy with rifampicin, pradofloxacin and oral fatty acids the pyogranulomatous dermatitis resolved and mycobacteria could not be detected but sebaceous glands were lost histopathologically. This is the first report describing a dog infected with M avium subspecies hominissuis successfully treated with antibiotic therapy and with no zoonotic transmission.