Breeding Away from Epilepsy in the Belgian Tervuren

Updated November 2024

Understanding the genetic variations that influence disease risk has many benefits. It may lead to the development of more accurate diagnostic tests or point to new ways to treat the disease. The AKC Canine Health Foundation (CHF) has funded many studies exploring the genetics of canine disease. For example, CHF-funded investigators at the University of California, Davis explored several genetic variants associated with idiopathic epilepsy in the Belgian Sheepdog and Belgian Tervuren (CHF Grant 02936: Validating Genetic Variants Underlying Canine Idiopathic Epilepsy and Exploring Their Functional Roles in the Belgian Sheepdog and Tervuren). They confirmed the presence of variants on chromosomes 37 and 14 which increase the risk for epilepsy in these breeds.

With increased awareness of idiopathic epilepsy in the Belgian Tervuren breed, Principal Investigator Dr. Anita Oberbauer followed up on her research to determine if the disease prevalence in this breed has decreased over time. Comparing the frequency of epilepsy risk variants in Belgian Tervurens born 1985-1999 to those born 2000-2015 yielded interesting results. There was no significant change in the frequency of these two risk variants combined. Similarly, the frequency of the chromosome 14 risk variant remained unchanged. However, the chromosome 37 risk variant frequency decreased in epileptic dogs but increased in healthy dogs. Finally, the prevalence of idiopathic epilepsy in Belgian Tervurens appears to be higher than it was decades ago - calculated at 27.1%, compared to the 18% prevalence reported from an owner survey in the 1980’s.

Prevalence: the number of cases of a disease in a specific population at a particular point in time or over a specified period of time.

Given the increased awareness of epilepsy and its genetic risk factors, why is epilepsy more common in the Belgian Tervuren now than it was before? There are several potential reasons for this trend.

• Environmental factors such as stress, weather, and more can trigger seizures. Have these environmental factors become more frequent over time? How do genetic and environmental factors interact to trigger seizures in dogs?

• Additional genetic risk variants may have developed over time. Genetic testing for risk variants will only be helpful if all variants that influence disease risk are understood.

This study highlights the complexity of fighting heritable disease in dogs. Ongoing research is needed to understand the influence of genetic and other factors on disease risk. Dog breeders, dog owners, and veterinary professionals must remain informed and proactive, relying on scientific evidence to guide their decisions. CHF and its donors remain committed to funding studies that seek to answer these challenging questions and advance the health of all dogs. Learn more about the Foundation’s commitment to understanding canine epilepsy at www.akcchf.org/epilepsy.