Focal metatarsal sinus tracts ('fistulation') are, to the authors knowledge, reported for the first time in a Weimaraner. The six-year- old, entire male had a five-month history of two symmetrical, well-demarcated sinuses on the plantar aspect of each metatarsus. The area surrounding each pair of sinuses was slightly fluctuant and a serosanguineous discharge could be expressed. Cytological examination of the discharge was characteristic of pyogranulomatous inflammation. Bacterial culture showed the material to be sterile. Examination of a skin biopsy revealed a severe inflammatory reaction involving the dermal collagen, with an infiltrate of neutrophils, macrophages, lymphocytes, plasma cells and multi-nucleated giant cells, with some micro-pustule formation. Treatment with ciclosporin induced total remission. Reduction of the dose of ciclosporin resulted in recurrence of the physical signs with further remission on re-introduction of the original dosage. This is the first report of the use of ciclosporin to control this condition.