Dermatomyositis (DMS)


Turnaround: 3-5 days

US: $45.00 | UK: £40.00

Breeds: Collie, Rough Collie, Shetland Sheepdog, Smooth Collie, Scotch Collie


Dermatomyositis (DMS) is a genetic disorder in which dogs’ skin, muscles, and blood vessels become inflamed. Dogs become weakened, develop skin lesions, and have an enlarged throat. Symptoms typically appear before the dog is six months old. There is no known cure for dermatomyositis, however, the effects of the disease can be lessened with proper management. 

Dermatomyositis is an autosomal dominant disorder. This means that the mutated gene can be inherited from either parent (the disorder is not sex-linked) and only one copy of the gene is needed in order for symptoms to present themselves. Symptoms include:

  • loss of muscle mass
  • swelling of the esophagus 
  • skin lesions (especially around the face and tip of tail)
  • skin ulcers (in extreme cases)
  • dandruff/scaling skin due to skin irritation
  • abnormal gait
  • problems eating, drinking, and swallowing
  • more prone to contracting pneumonia

Although there is no cure, dermatomyositis can be managed. Avoid letting your dog into bright sunlight, as ultraviolet rays can worsen skin lesions. A veterinarian may prescribe hypoallergenic shampoos, steroids to reduce inflammation, and vitamin-enriched special foods to improve skin health. 

Detailed explanation of testing and test results from American Shetland Sheepdog Association (ASSA)


Beyond the MHC: A canine model of dermatomyositis shows a complex pattern of genetic risk involving novel loci.

Evans JM, Noorai RE, Tsai KL, Starr-Moss AN, Hill CM, Anderson KJ, Famula TR, Clark LA. PLoS Genet. 2017 Feb 3;13(2):e1006604. doi: 10.1371/journal.pgen.1006604. eCollection 2017 Feb. [PMID: 28158183]