CASE REPORT Focal metatarsal sinus tracts in a Weimaraner successfully managed with ciclosporin 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. A. M. OLIVEIRA, M. J. OBWOLO*, A. H. M. VAN DEN BROEK AND K. L. THODAY Journal of Small Animal Practice (2007) 48, 161–164 DOI: 10.1111/j.1748-5827.2006.00147.x INTRODUCTION Focal metatarsal sinus tract formation (‘fistulation’) is an uncommon condition, which has only been reported in German shepherd dogs (GSD) or their crosses (Scott and others 2001). It has a peculiar and a highly suggestive clinical present- ation characterised by symmetrical sinuses on the lower plantar surface of the meta- tarsi or, less commonly, metacarpi. One or several limbs can be affected (Kristensen 1997). The cause is unknown, but the exudate obtained from closed lesions is sterile (Scott and others 2001). Treat- ments described in the literature include systemic prednisolone, vitamin E or surg- ical removal of affected tissues (Kunkle and others 1993, Paterson 1995). Ciclosporin is a potent inhibitor of T-cell induction and proliferation and has a wide variety of anti-inflammatory and anti-proliferative effects (Robson 2003). It has been used in the treatment of a                                                  number of dermatological conditions in the dog, most notably atopic dermatitis (Olivry and others 2002) and perianal sinus tract formation (‘fistulation’) (Hardie and others 2005). To the authors knowledge, this study describes the first reported case of focal metatarsal sinus tracts in a Weimaraner and the first controlled with ciclosporin.                                                                                                         CASE HISTORY A six-year-old, entire male Weimaraner was referred with a five-month history of sinus tracts affecting both hindlimbs (Fig 1A and B). During this period, the lesions had been in the same position shown the same macroscopic appearance and had not progressed to other parts of the body. The owner reported that the animal had been otherwise healthy and that there had been no signs of pruritus, discomfort or lameness. Skin biopsy, performed by the referring veterinary sur- geon, revealed a hyperplastic and ulcerated epidermis with serocellular debris present over parts of the ulcerated areas. There was a severe inflammatory reaction within the dermal collagen, which was characterised by the presence of neutrophils, macro- phages, lymphocytes, plasma cells and multi-nucleated giant cells, together with some micro-pustule formation (Fig 2). Fibrosis was evident in some areas, partic- ularly at the edges of the lesion. Hair follicles, sebaceous glands, and sweat glands were unremarkable. Previous treatment with amoxycillin/ clavulanic acid and carprofen had been unsuccessful. Prednisolone administration had resulted in resolution of the clinical signs, but had produced adverse effects of marked polyuria and polydipsia and relapse was noted shortly after the drug was stopped. At this point, the case was referred to the Dermatology Service of the Royal (Dick) School of Veterinary Studies, at the University of Edinburgh. General physical examination revealed no significant abnormalities. Dermatological University of Edinburgh, Dermatology Unit, Division of Veterinary Clinical Sciences, The Royal (Dick) School of Veterinary Studies, The Hospital for Small Animals, Easter Bush Veterinary Centre, Roslin, Midlothian EH25 9RG *IDEXX Laboratories, Grange House, Sandbeck Way, Wetherby LS22 7DN Journal of Small Animal Practice Á Vol 48 Á March 2007 Á Ó 2006 British Small Animal Veterinary Association 161