Polymyositis 1 & 2 (PM1 & PM2) – Kooikerhondje

Polymyositis is an inflammatory muscle disease that can cause difficulties with movement, swallowing, and general muscle function. In the Dutch Kooikerhondje, two genetic variants, PM1 and PM2, have been associated with an increased risk of developing the disease.
Current research indicates that only dogs carrying at least one copy of the PM1 variant are at risk of developing polymyositis. Dogs heterozygous for PM1 have an estimated disease risk of approximately 2%, while homozygous PM1 dogs have an estimated risk of approximately 10%.
If a dog carrying the PM1 variant is also heterozygous or homozygous for the PM2 variant, the risk increases further. In these cases, the estimated risk rises to approximately 6% for heterozygous PM1 dogs and up to 30% for homozygous PM1 dogs.
The reported risk estimates are based on the current state of scientific research and may change as additional data and studies become available.