Dermatomyositis in five Shetland sheepdogs in the United Kingdom

Five cases of dermatomyositis in four Shetland sheepdog puppies and one adu lt bitch are described. The dogs all had well-defined patches of scaling, c rusting and alopecia over the muzzle, periorbital skin and distal limbs, an d the tail, perineum and pinnae were affected in some of them. The affected puppies were all sired by the same stud dog. The affected adult bitch was unrelated to the puppies. Three of the four dogs tested had high serum crea tine kinase concentrations and electromyographic abnormalities were detecte d in three of the four dogs tested. The histological changes observed in th e skin of four of the dogs strongly supported the diagnosis of dermatomyosi tis, and in the fifth dog they were compatible with this diagnosis. Two of the puppies were euthanased shortly after being diagnosed. In the other two puppies and the adult the disease remains stable and non-progressive 15 to 18 months after diagnosis. The sire of the four affected puppies has been used extensively because it was considered to be genetically clear of colli e eye anomaly.