Canine Strokes Explained

The effects of a canine stroke, such as sudden blindness and loss of balance, can be alarming for dog owners. Fortunately, most dogs that have strokes can recover with time and care. Dr. Beth Boudreau, clinical assistant professor at the Texas A&M College of Veterinary Medicine & Biomedical Sciences, explained the different types of canine strokes and how they occur.

“As in human medicine, the word ‘stroke’ is used in veterinary medicine to mean a sudden loss of blood supply to a region of the nervous system,” Boudreau said. “We most often recognize strokes occurring in the brain of dogs, where they can be either ischemic — caused by a blockage of a blood vessel — or hemorrhagic — caused by a bleeding blood vessel.”

“However, dogs can also have ischemic strokes affecting their spinal cord. In the brain, ischemic strokes may be due to damage to blood vessel walls, a circulating clot that lodges in the brain, or less commonly to blockage secondary to cancer or infection,” Boudreau continued. “In the spinal cord, ischemic strokes are often related to blockage of a blood vessel by a piece of connective tissue that may have originated from the intervertebral disc. Hemorrhagic strokes can occur because of a malformation of blood vessels, cancer affecting the blood vessels, or certain infectious diseases. Sometimes, no cause is found for a stroke.”

Although we would like to protect our dogs from a potential stroke, there are typically no warning signs before a stroke occurs. In fact, Boudreau said in spinal cord strokes, owners often report that their dog was running or playing when the event occurred.

“The signs associated with a stroke depend on the part of the nervous system affected,” Boudreau said. “Strokes can occur anywhere in the brain or spinal cord. In the brain, strokes may cause sudden loss of balance, blindness, or seizures. In the spinal cord, strokes can cause sudden weakness or paralysis of one or more limbs.” Other nervous system diseases can cause these signs as well, but are typically more generalized, take longer to progress, and worsen over time. “The real key to recognizing a stroke is the rapidity and non-progressive nature of these signs,” Boudreau said.

All dogs can experience a stroke, but some may be more susceptible. For example, young adult large-breed dogs that are otherwise healthy may have a higher chance of a spinal cord stroke. In strokes affecting the brain, older adult dogs may be at higher risk. Additionally, dogs with underlying problems that could increase their risk for blood clots or spontaneous bleeding could be also be predisposed. “For any dog diagnosed with a stroke, tests for an underlying cause should be completed,” Boudreau said. “Appropriate treatment of these conditions by a veterinarian may reduce the risk for future strokes.”

If you think your dog has had a stroke, it is essential to have your dog evaluated by a veterinarian as soon as possible. After initial evaluation by a veterinarian, a referral to a neurologist may be recommended. Additionally, an MRI may be needed to confirm a stroke is the cause of your dog’s signs.

“It is important to remember that while a sudden occurrence of a new neurological problem is characteristic of a stroke, there are other causes of these types of signs,” Boudreau said. “The good news is that most dogs that have strokes can recover with time and care.”

Photo of Biggie Smalls submitted by Angela Esparza