Dermatomyositis - DMS


Dermatomyositis is an inflammatory disease affecting skin as well as muscle, in extreme cases. This is an auto-immune disease and in rare cases can be fatal.

Dermatomyositis (DMS), presents much the same as demodex, with skin lesions starting on the face any time after the age of 7 weeks. However, it is distinct from demodex as lesions can be found on all parts of the body and it attacks the muscles as well.

A test for DMS has been developed. This test will not definitively indicate whether or not a dog will get the disease as DMS has both a genetic as well as an environmental component. Collies whose risk factor is determined to be high may never develop the disease as the genetic risk does not take into account environmental factors.

The risk of developing DMS in UK Collies is rare, but not unknown.

Dr Leigh Clark, Clemson University published a study as below

'We had 6 collies from the UK and all were unaffected controls. 5 of them were Aabb and 1 was aabb. This equates to an allele frequency of 42% for A, one the risk alleles for DMS, and 0% for B, the other risk allele for DMS.

A mating between two Aabb dogs would result in approximately 25% of puppies with the AAbb genotype, which carries a 40% chance of developing DMS.

DMS looks a lot like other skin conditions and is very often misdiagnosed, especially if skin biopsies were not taken.'




This information is not meant to be a substitute for veterinary care. Always follow the advice provided by your veterinarian.