New research from the University of London’s Royal Veterinary College (RVC) may shed light on why some dogs respond to anti-epilepsy treatments, and become seizure-free, while others continue to have seizures long-term.
Anti-epileptic drugs (AEDs) are the most common treatment for canine epilepsy, according to the college. But in some cases, the side effects of drug treatment can impact upon quality of life as much, if not more than, a dog’s seizures, the college further noted. Past studies have also found that in a third of dogs, current drug treatments failed to reduce the number of seizures they experience by 50 percent.
“Canine epilepsy is a complex condition and can be very distressing for the dog and their owner,” said Holger Volk, DVM, Ph.D., clinical director of the RVC’s Small Animal Referral Hospital. “Drug treatments can be successful in reducing seizures, but it is important to note that consistent remission is difficult to attain.”
This new study analyzed patient data from six years of medical history taken from the epilepsy clinic at the RVC’s Small Animal Referral Hospital. At the point of follow up, only 14 percent of dogs studied were in seizure-free remission.
It turns out that seizure density (how close together seizures occur) rather than the number of seizures a dog has is a more telling sign of achieving remission in canine epilepsy, according to the study.
Similar results have previously been found in human epilepsy, highlighting the dog as a natural occurring model of this disorder, RVC noted.
In human medicine, epilepsy patients are traditionally treated with AEDs immediately after the onset of the condition. RVC’s study found that time to treatment after diagnosis, or the number of seizures experienced before treatment, did not affect the likelihood of achieving remission.
The study also found that the sex of the dog was an important risk factor with male animals less likely to go into remission than female dogs receiving AED treatments.
Other studies into canine epilepsy have focused on a specific dog breed. RVC noted that its study was able to look at how epilepsy affects a wider section of dog types. The results found Border Collies and German Shepherds are at a significantly higher risk of not responding to anti-epileptic drugs than other breeds.
“In its worst form, canine epilepsy can be life threatening to dogs, but it is a dog’s long term quality of life that is most affected,” said Rowena Packer, Ph.D., co-author of the study and clinical investigations research assistant at RVC. “It can also take a toll on the owners who have to manage this unpredictable, uncontrollable condition.
“Therefore, it is important to manage owners’ expectations with regards to drug treatments. Studies like this are important and can have wider implications for the treatment of epilepsy in humans as well as dogs.”
The study was published in PLoS One on Aug. 25.