Tag archives: Dermatomyositis

In the first part of this examination of risk assessment and genetic testing, I dissected the concept of risk.  Although relative risk is incomplete without the perspective provided by absolute risk, logistical constraints within veterinary research often limit this perspective.  There is still value to these tests. In this next entry, I want to look at specific genetic tests where the result is functionally a risk assessment.  Hopefully, you will better understand how to use the information provided by these tests with the goal of producing better dogs with each generation.    

Genetic testing for dermatomyositis (DMS) is a true risk assessment test. Results from this test place a dog in risk categories of low, medium, high, and unknown.  This type of risk assessment is uncomplicated.  For each possible genotype listed in the report, the percentage of affected dogs in that group has been determined. Based on the genotype, the likelihood of an individual dog developing DMS is classified as low (0% - 5%), moderate (33% – 50%), or high (90% – 100%).  These percentages correlate with the absolute risk for these dogs. With this test result, decisions about breeding a dog can be made ...

As of January 2021, Paw Print Genetics (PPG) is proud to offer 44 new inherited disease tests for the canine health and breeding community. While these new tests are associated with diseases identified in dozens of breeds, the population size of each breed and the relative frequency of these mutations in those populations mean that some of these diseases are much more likely to be seen in clinical veterinary practice than others. Here we will highlight five diseases from the recent PPG test additions that are among those most likely to be diagnosed in the veterinary hospital setting.

Cerebellar Degeneration- Old English Sheepdog and Gordon Setter¹

A genetic mutation in the canine RAB24 gene is associated with a juvenile-onset, autosomal recessive form of cerebellar degeneration (CD) in two seemingly disparate breeds, the Old English Sheepdog (OES) and Gordon Setter (GS). Also referred to as hereditary ataxia or cerebellar abiotrophy (CA), CD presents between 6 months and 4 years of age with progressive neurological dysfunction due to degeneration of cerebellar neurons, especially Purkinje neurons. Coordinated movement becomes progressively more difficult as the disease progresses and can include intention tremors, ataxia, and a stiff, high-stepping gait (hypermetria). Affected dogs are often ...

Dermatomyositis (DMS), also known as Juvenile Dermatomyositis or Canine Familial Dermatomyositis is an inflammatory disease of the skin and muscles caused by an over reactive immune system¹. This disease has consistently plagued Shetland Sheepdogs and Collies of all varieties.  What makes this condition truly insidious is that although it mostly affects immature dogs, it can flare up seemingly out of nowhere to create issues in dogs of any age².  Although testing for the genetic mutations that pre-dispose certain dogs for this disease has been around for some time, interpreting the results can be complicated often leaving owners confused about the results of this test.  Misunderstanding genetic results may lead to poor breeding decisions.  Let us look closer at DMS, how the disease presents, the complexity of genetic testing, and how to best utilize the results of this test.   

What is Dermatomyositis?

DMS is an inherited disease that causes dramatic inflammation of the skin, blood vessels and muscles in affected dogs.  Lesions often originate and are limited to the skin of the face with the lips with the area around the eyes particularly affected³.  Although the mechanisms of the ...