If a friend or a family member has ever had a stroke, you know how devastating and life changing it can be. In humans, it is the fifth-leading cause of death in the United States. Every year, 800,000 people will experience a stroke; in the majority of cases it will be the first time. Every four minutes, someone will die from a stroke; in people, 80 percent of these deaths are preventable.
You should not be surprised to learn that both dogs and cats can also have a stroke, and it can be serious or even life threatening.
Today, there is an increase in the availability of both MRI and CT scans in veterinary medicine, and these deep neurological events are being diagnosed more often, confirming our suspicion that stroke, or CerebroVascular Accident (CVA), is not uncommon in pets. Consequently, understanding the causes, symptoms and treatment of strokes in pets will help you recognize it and get help sooner.
In simple terms a stroke is a “brain attack.” It is the sudden loss of brain function that results from one of two things –- and that is also how a stroke is categorized.
The first type of stroke is an ischemic stroke, which is a sudden interruption of blood flowing to various parts of the brain. This is usually caused by a clot that forms elsewhere in the body and flows to the vessels of the brain. The clot lodges there, causing the stoppage of vital blood flow to that part of the brain.
The other cause and category of a stroke is a hemorrhagic stroke, where there is a rupture of a blood vessel in the brain. This causes leakage of blood into the area, and that causes damage to the delicate nerve cells.
Strokes can happen to any age of a pet and at any time. No matter which of the two main types has caused the stroke, when the blood flow gets interrupted to the brain, the brain cells become deprived of oxygen and cause cell death. The result of a stroke is complex and the symptoms can vary greatly, and are determined by what part of the brain has been affected.
A stroke can be mild and symptoms can be minimal and not even noticeable. I believe we often don’t know this type of stroke has happened in pets because they cannot report to us mild changes or deficits in their senses. However, in serious cases, a stroke can be completely debilitating, and symptoms are very sudden and obvious. In rare cases, they can cause sudden death.
What does a stroke look like in a dog?
Because animals don’t show slurred speech or loss of memory, their signs of stroke are usually only seen when the effects are much greater.
Symptoms of strokes in dogs can include the rapid onset of the following:
- Inability to walk, or walking with an uncoordinated gait
- Head tilt or walking in a circle
- Abnormal eye movements, side to side or rotary
- Abnormal eye positioning
- Loss of consciousness
- Abnormal behavior
- Falling to one side
- Sudden blindness
Causes of strokes in dogs
Strokes are usually seen with diseases that can increase the risk of clots or bleeding. I often see them secondary to a large tumor mass, where the blood flow is sluggish and clots are more likely to form.
Some of the underlying diseases that can cause strokes in dogs include kidney disease, Cushing’s disease (hyperadrenocorticism), hypertension, diabetes, heart disease, bleeding disorders, hypothyroidism, cancer; and, in some cases, high doses of steroids like prednisone can lead to a stroke. No one breed is more likely to have a stroke, unless your dog’s breed is predisposed to some of the aforementioned diseases.
Treatment begins with diagnosis
Getting a correct diagnosis is the most important part of treating strokes in dogs. A fainting spell (sometimes called syncope) that might look like a stroke can be caused by abnormal heart rhythm. Your veterinarian can distinguish a stroke from a fainting spell by doing a good cardiac workup. Tests may include an electrocardiogram, chest X-rays and possibly a cardiac ultrasound.
If the heart is normal, the brain will be examined by a good neurological exam that checks reflexes and reactions to various stimuli. Often, that is all that is needed and there is no need to head to the more expensive tests. But when they are needed, it is nice to know that an MRI or CAT scan can be done. These tests can cost over $2,000, another reason why pet health insurance is so important. Other tests, such as a blood panel and urinalysis, can look for an underlying disease that could cause a blood clot.
Once the cause is determined, treatment will focus on that. Some common treatments for a stroke include blood thinners or high blood pressure medications — hypertension is a common cause of a stroke in pets, just as with humans.
Dr. Jim Humphries is a veterinarian in Colorado Springs and also serves as a visiting professor at the College of Veterinary Medicine at Texas A&M University. He provides hospice and end of life care for pets. He lives in Falcon with his wife, horses and Great Danes. www.HomeWithDignity.com