February 27, 2020 – Morris Animal Foundation-funded researcher Dr. Fiona James at the University of Guelph, Canada, is working to find new ways to reduce seizures in dogs with epilepsy. Her team is collecting baseline data on a wearable wireless collar device that she hopes may one day help decrease frequency and severity of seizures in canine patients.
“Epilepsy is a common disorder in dogs,” said Dr. James. “And while treatments are available, for up to 30% of epileptic dogs these treatments simply don’t work. These dogs have what is called drug-resistant epilepsy. My team is working on identifying a noninvasive and nonpharmaceutical therapy that we hope will increase treatment options for these patients.”
Vagus Nerve Stimulation
Dr. James’ team is evaluating a device mounted on a collar that is designed to send mild pulses of electrical energy to the brain via the vagus nerve. Just like in humans, dogs have two vagus nerves, one on each side of the body, running from the brainstem through the neck to the heart and other organs. The electrical device works somewhat like a pacemaker that uses electricity to regulate the heartbeat. With vagus nerve stimulation, sending an electrical signal to the brain may help prevent or limit electrical bursts that cause seizures. If successful, findings from Dr. James study will help inform future clinical trials in epileptic dogs.
In human medicine, the FDA has approved similar devices that are either implanted under the skin in the chest or directly implanted in the skull. Although similar surgeries have been tried in dogs, Dr. James is concerned that these kinds of surgeries don’t always work and they’re cost prohibitive for most owners. And like all surgeries, invasive procedures come with complications. Dr. James is looking for an easier and more affordable option for owners caring for epileptic dogs.
Finding the Right Frequency
One of the main goals of Dr. James’ study is to find out what is the optimal stimulation and frequency needed for dogs to achieve successful results. To answer these questions, her team is collecting baseline data on brain activity and heart rate using electrodes. This noninvasive procedure is similar to attaching electrodes to a person when getting an electrocardiogram to measure heart electrical activity.
“We will be measuring any changes before and after vagus nerve stimulation in a few healthy dogs,” said Dr. James. “If we notice any positive changes, the next step will be to try the device in epileptic dogs and monitor the response. If our first attempts don’t work, it may mean we need to try higher settings to achieve our desired results. It’s all about finding the right frequency to stimulate the dog’s brain which might be a very different frequency from the one that works in humans with epilepsy.”
If the vagus nerve stimulation works in dogs, it may open doors to other avenues of research. In humans, vagus nerve stimulation is used not only in epileptic patients but also in patients with behavior abnormalities, tremors and migraines.
“Some dogs with epilepsy can be moody,” said Dr. James. “But right now, it’s hard to know if this mood disorder is just piggybacking on epilepsy because the dog isn’t feeling well or if it is directly associated with the disease. It will be interesting in future studies to see if vagus nerve stimulation can help us answer these questions, too.”
The Value of Pilot Studies
Dr. James’ project is a pilot study. Pilot studies are smaller in scope and designed to test if a project’s hypothesis is worth further investigation. At the Foundation, we often refer to pilot studies as the high-risk stock of our research portfolio. For about $11,000 (a tiny amount of funding for the research world), a successful pilot study can have a big impact on animal health that is lasting and transformative.
“Researchers need preliminary data to support large-scale projects,” said Dr. James. “However, resources for pilot studies are rare and desperately needed. Thanks to Morris Animal Foundation, investigators like me have the support we need to get a glimpse into the potential novel pathways of research that we can build upon to find answers to pressing health concerns like epilepsy in animals.”