can a gene defect in dogs help treat epilepsy?
Epilepsy in dogs and cats is one of the most frightening – and frustrating – diseases veterinarians confront.
Treatment is a challenge: delicately balancing anti-seizure medications with their potentially severe side effects in an effort to restore some semblance of normalcy to affected pets.
Making matters worse, we don’t know why most people or animals develop epilepsy in the first place—but we’re getting closer to an answer: A genetic defect recently identified by an international team of veterinary researchers appears to be responsible for one form of canine and human epilepsy. This groundbreaking discovery may pave the way for better tests and treatments.
Can a gene defect in dogs help treat epilepsy?
Rhodesian Ridgebacks are extraordinary dogs with an unenviable list of medical maladies. Bred for strength, stamina, intelligence, loyalty, and to be good with children, Ridgebacks are also notorious for inherited deafness, a devastating neurological condition called degenerative myelopathy, bloat, and epilepsy among them.
It is Ridgeback’s predilection for early-age seizures that caught these researchers’ investigative attention. Ridgebacks are known to develop juvenile epilepsy as early as six weeks to six months of age.
Uncontrollable muscle twitching and jerks, even when sleeping, are typically the first signs of juvenile myoclonic epilepsy. The canine version is remarkably similar to human juvenile myoclonic syndrome.
Veterinary scientists wanted to find out why dogs developed this form of epilepsy and if that information could benefit people. But first, they had to figure out a way to track seizures in a large number of dogs quickly and affordably.
How the test was conducted
Most dogs don’t enjoy being hooked up to a halo of wires or confined in claustrophobic MRI machines. To precisely record brainwaves in dogs, you’d either have to sedate them, altering neurological activity, restrain them in often uncomfortable positions for long periods, or specially train them over a period of months.
Those methods were more costly and difficult to scale for researchers. But veterinarian Fiona James of the University of Guelph Ontario Veterinary College had a breakthrough: she developed a special backpack for dogs that tracks their brainwaves while they go about their day.
James and her colleagues quickly optimized the new technology and tested 600 Rhodesian Ridgebacks plus another 1,000 dogs with epilepsy. Once they documented the dog was experiencing juvenile myoclonic epilepsy on EEG, they began evaluating the DNA for clues.
With such a large cohort of study dogs, they quickly identified a defect in the DIRAS1 gene in epileptic Ridgebacks.
This research provides veterinarians with a simple tool to test for the DIRAS1 defect in Rhodesian Ridgebacks. It’s currently estimated about 15% of all Ridgebacks carry the defect (research into other breeds is underway). The test can be performed before breeding to reduce future generations of epileptic puppies.
The DIRAS1 gene is also being studied in humans, and treatments aimed at this new clinical pathway are being investigated.
Man’s best friend proves once again to be man’s best health ally. A group of very clever veterinarians solved a diagnostic dilemma that may eventually lead to a cure to epilepsy in animals and humans.
If you share your home with a Ridgeback and want to help with the DNA study, share this website with your veterinarian: https://www.koirangeenit.fi/english/participate