Ask the Vet: Exploring strokes in pets
By Matthew Kearns, DVM
Can a dog or cat have a stroke? That is an interesting question. In humans, strokes are the third most common cause of death (after heart disease and cancer). In dogs and cats, strokes (also known as cerebrovascular accidents) are much less common but do happen. Just as in humans, a vascular accident occurs as the result of a emboli (blood clot) or bleeding.
Circumstances that could cause a cerebrovascular accident are: conditions that could lead to a hypercoagulable state, conditions that could cause bleeding in the brain, atherosclerosis (plaque buildup in the vessel), or conditions that cause systemic hypertension. Hypercoagulable states include: Cushing’s disease (hyperadrenocorticism), immune mediated hemolytic anemia, sepsis, cancer and some others. Conditions that cause bleeding include: trauma, certain infections, congenital malformations of blood vessels in the brain, tumors, etc. Lastly, hypertension can be caused by kidney failure, heart conditions, etc.
Depending on the portion of the brain affected, the symptoms will follow. The cerebral cortex is an area where higher functions take place so we would see a decreased alertness, weakness, circling, head pressing in corners, and possible seizures. The thalmus or midbrain would affect balance and eye movement. The cerebellum controls movement so a lesion there would lead to hypermetric (jerky) movement, slowed reflexes and generalized weakness.
The best way to diagnose what type of cerebrovascular accident is with either a CT scan, or an MRI. This is tricky because there is limited availability for these tests, they are expensive, and require general anesthesia. Sometimes the patient is not stable enough for anesthesia. Most times a workup to include bloodwork, x-rays, and sometimes ultrasound will help to rule in or out concurrent diseases to help with a prognosis and to see if a CT/MRI is safe to perform or would make a difference in treatment.
Treatment usually includes supportive care (fluids, oxygen, antibiotics if indicated, etc), as well as treating any underlying/concurrent disease. Medications to prevent additional bleeding or emboli are also used. Physical therapy is performed but many times by the owners after the patient is discharged due to expense.
Prognosis depends on the area of the brain that is affected and how severe the event was. The good news is that symptoms did not usually worsen after 24-48 hours (for those pets that lived that long) so, if your pet is not too severely affected and does not worsen after the first 24-48 hours they have a chance of a longer survival period.
In conclusion, pets do have strokes. On the positive side, strokes are much less common in pets than humans. On the negative side, strokes are usually secondary to serious underlying disease which affects the short and long-term prognosis.
Dr. Kearns practices veterinary medicine from his Port Jefferson office and is pictured with his son Matthew and his dog Jasmine.