Stroke in dogs and cats happens less frequently than it does in people, but when it does occur, it’s a very serious situation.
Stroke is caused when a blood vessel in the brain either becomes blocked or ruptures. In both cases, blood flow to the brain is interrupted. Since blood carries oxygen and glucose, which are critical nutrients the brain needs to survive, this lack of blood flow causes brain cells to die.
Most strokes are caused by a blood clot, called an “embolus”, that develops somewhere in the body and travels to the brain. The clot then becomes lodged in a vessel and blocks it. There are usually no warning signs when a dog or cat is about to suffer a stroke. Most strokes happen suddenly, and they require immediate veterinary attention. Once stroke occurs, serious damage can happen within hours if treatment is not provided.
Although older pets are affected more frequently than younger ones, stroke can afflict any dog or cat at any time.
Types of Stroke In Dogs And Cats
There are 3 major types of stroke that can happen in dogs and cats:
This is when the brain gets too little blood. It usually happens when a blood clot or other material lodges in a blood vessel, and blood supply is either greatly reduced or cut off. This is the most common type of stroke in dogs and cats.
This is when the brain gets too much blood, usually caused when a vessel ruptures and bleeds out into the brain. Brain cells can then become damaged, either because the extra blood puts pressure on surrounding brain cells, or the hemoglobin in the blood damages specialized cells in the brain called neurons.
FCE (fibrocartilaginous embolism)
This occurs in dogs when a small piece of disc material in the spine breaks off and migrates into the spinal cord. FCE happens very quickly, usually when a dog is playing, jumping, or running. It’s extremely rare in cats.
Risk Factors For Stroke
Although most strokes happen in elderly dogs and cats, stroke can also be associated with the following conditions:
- Genetically weak blood vessels
- Cushing’s disease
- Heart disease
- Kidney disease
- High blood pressure
- Thyroid disease (hypothyroidism in dogs, hyperthyroidism in cats)
- Brain tumors
- Head injury
- Poison exposure
- Internal parasites
- Blood clotting disorders
- Rocky Mountain Spotted Fever
Sometimes, however, stroke happens for no apparent reason, and the actual cause of the stroke is never found.
Symptoms of Stroke In Dogs And Cats
All stroke symptoms are caused by the same thing: a lack of oxygen and glucose to the brain. However, there can be many different symptoms based on where the blood vessel damage occurred and how severe the damage was.
Symptoms of stroke almost always come on suddenly. They can include:
- Tilting of the head to one side
- Loss of balance
- Difficulty walking and lack of coordination
- Walking in circles, or turning the wrong way when called
- Paralysis (usually on one side of the body)
- Extreme sluggishness
- Unequally-sized pupils in the eye (called “anisocoria”)
- Sudden loss of vision
- Loss of bladder and/or bowel control
- Dark red gum color
- Irregular heartbeat
- Abrupt behavioral changes
Some pets may suddenly show signs of stroke, but recover from them in a few hours. In these cases, the incident may be what’s called a transient ischemic attack (TIA), which generally doesn’t involve permanent brain damage. However, if your pet is exhibiting any of these signs, it’s best to get him to a veterinarian as quickly as possible.
The most definitive way to diagnose stroke (and to identify which type has occurred) is with brain imaging scans such as computed tomography (CT) or magnetic resonance imaging (MRI). Unfortunately, x-rays don’t always provide enough detail to see whether a stroke has taken place. Not all veterinarians have brain imaging equipment on site, so a referral to a veterinary specialist may be necessary.
Veterinarians may also recommend other tests to try to determine the underlying cause of the stroke. These can include routine blood work, blood pressure testing, an electrocardiogram (to detect any problems with heart rhythm), and specialized blood tests to look for certain diseases or clotting disorders.
Treatment and Prognosis
Treatment for stroke in dogs and cats is largely supportive, and will depend on which type of stroke the pet suffered. Patients are usually hospitalized so they can be given IV fluid therapy, nursing care and constant monitoring, anti-inflammatories to control swelling, anti-nausea medication, anticonvulsant medication (to control seizures), and oxygen therapy (if needed). Initial physical therapy can also be started.
Treatment also focuses on managing the underlying cause of the stroke (if one is known). For example, if the stroke was caused by Cushing’s disease, diabetes, heart disease, or thyroid problems, medication can be started immediately to help get the illness under control as quickly as possible.
Pets who receive early diagnosis and treatment have the best chance of making a full recovery. With strong supportive care, treatment of any underlying disease, and physical therapy, prognosis for stroke in dogs and cats is good, and many patients can return to normal. However, some may suffer long-term permanent damage. One good thing for pets, however, is that the part of the brain controlling voluntary movement is located in a different area than where it’s located for humans, so strokes in pets usually don’t cause permanent paralysis like they can in people.
Once a pet who’s suffered a stroke comes home, he or she will need continuous monitoring while they are recovering. Many people who are unable to stay home during the day use alternative care (such as a neighbor or professional pet sitter) to check on their dog or cat while they are away.
Immediate Action Is Key
Although there is no known way to prevent stroke in dogs and cats, and it can be fatal, the good news is that if it’s caught early and treated immediately, prognosis for a full recovery is good – even if the stroke was a severe one. Recovering from a stroke can be a slow process, and can take from weeks up to several months, but complete recovery can be experienced by many dogs and cats.
Mild strokes in pets may often go unnoticed, or can be simply written off as behavioral changes due to old age, so knowing the signs and risk factors can allow you to act quickly if you suspect your dog or cat is experiencing a stroke.
Has your dog or cat ever had a stroke? If so, what was the outcome? Please share your story with us in the comments below!
1 Photo Credit: Thank you to Megan Day, WagHab