A “stroke” is a term commonly applied to people who have suffered a cerebrovascular accident, commonly abbreviated as CVA, caused by cerebrovascular disease. It was once thought to be very uncommon in cats and dogs but is now known to occur.
A stroke is caused by the disruption of blood supply to the brain that results in failure of nerve impulses to be transmitted from the brain to the rest of the body.
Neurologic symptoms develop that can be temporary or permanent. If the symptoms persist for over 24 hours, the condition is categorized as a stroke. If the symptoms persist for fewer 24 hours, the event is categorized as a transient ischemic attack or “TIA”.
There are two types of strokes. They include:
- Hemorrhagic stroke – This type of stroke results from hemorrhage (bleeding) into or around the brain. This can be caused by bleeding from toxins such as rat poison, vascular abnormalities, and secondary to brain tumors, high blood pressure (hypertension), inflammatory disease of the blood vessels (vasculitis).
- Ischemic stroke – Ischemia is a term that means there is an inadequate blood supply to a part of the body or organ. Therefore an ischemic stroke results from a blockage of blood flow to the brain. This can be caused by parasite migration (Cuterebra), migration of cancer cells to the brain, high blood pressure (hypertension) secondary to hyperthyroidism, heart disease, or chronic kidney disease.
Signs of a Stroke in Cats
Whatever type of stroke a cat has, the symptoms that develop are determined by how much brain tissue is affected, how severely it is affected, and where in the brain it is located. Possible signs of a stroke in cats include:
- Altered mental status e.g. disorientation
- Circling in one direction
- Falling over to one side
- Head pressing
- Head tilt to one side or another
- Stumbling or drunken walking
- Not using the legs normally (sometimes on one side of the body)
- Unequal pupil sizes and/or abnormal eye reflexes
Diagnosis of Stroke in Cats
Stroke in cats can affect an animal very suddenly. A very important point is that many owners may mistake a stroke for a different condition called Vestibular Disease. Learn more about Vestibular Disease in Cats.
Other disorders that result in signs similar to strokes include inner ear infections, thiamine deficiency, head trauma, middle ear polyps, middle ear cancer, brain tumors, and/or metronidazole (antibiotic) toxicity.
Diagnostic tests are needed to determine the presence of an underlying disease or cause for the stroke and to differentiate between other disorders that may be affecting the balance system of the body.
Tests may include:
- Your veterinarian will take a complete medical history and perform a thorough physical examination including a complete neurologic examination and complete examination of the ear canal.
- Laboratory tests may be recommended to determine your pet’s general health and the presence of an underlying disease that may be causing the vestibular disease. Recommended tests may include:
- Blood tests may include a complete blood count (CBC or hemogram), serum biochemistry tests to evaluate blood glucose, liver and kidney function and electrolytes, and thyroid test to evaluate for hyperthyroidism.
- Urinalysis to help evaluate kidney function.
- Blood clotting times (PT and PTT) may be recommended if there is suspicion of toxin exposure such as to rat poison. Read more at Anti-coagulant rodenticide.
- Blood pressure to evaluate for hypertension.
- Radiographs (x-rays) of the chest and abdomen may be recommended to evaluate for major diseases affecting the heart, lungs or abdominal organs.
- Cardiac evaluation: In cases where the heart is suspected to be the problem on the basis of the physical examination and initial evaluations, a cardiac evaluation including an echocardiogram (ultrasound of the heart) and an electrocardiogram (ECG) may be recommended.
- Other diagnostic tests may be recommended based on the results of the history, physical examination and initial laboratory tests such as spinal tap, CT, MRI or skull x-rays.
Treatment of Stroke in Cats
The treatment for strokes in cats is largely supportive. The first 24 hours is most difficult as the symptoms are worst, providing there is not progression.
- Management will be recommended to treat any underlying conditions. For example:
- Blood pressure medications to treat hypertension
- Heart medications to treat the underlying heart disease
- Thyroid medications to treat hyperthyroidism
- Maintaining hydration with fluid therapy
- Encourage adequate nutrition
- Oxygen therapy to improve oxygen delivery
- Nursing care as needed to keep the eyes lubricated, rotating pets that are not moving from side to side, constant cleaning urine and feces, and/or warm environment to provide optimal comfort
Some cats can recover completely from stokes and others will have permanent neurological abnormalities. Little research has been done to determine the overall prognosis for strokes in cats. The prognosis is largely dependent on the underlying cause and the ability to adequately treat those causes.
Home Care and Prevention
Call your veterinarian promptly if your pet is showing signs of a stroke. This is a frightening experience for your cat so speak calmly and soothingly. Make sure he does not injure himself and please make sure you do not get bit. Cats that are frightened or in pain may bite.
Home care should include giving all prescribed medications, protecting your cat from injury if he or she is weak, encouraging your cat to eat and drink well and follow-up with your veterinarian for all rechecks.
Resources & References for Strokes in Cats:
- Plumb’s Veterinary Handbook by Donald C. Plumb, 9th Edition
- Blackwell’s Five-Minute Veterinary Consult: Canine and Feline, Tilley and Smith, 5th edition
- Textbook of Veterinary Internal Medicine, Ettinger & Felman
- Current Veterinary Therapy XIV, Bonagura, and Twedt
- Current Veterinary Therapy XV, Bonagura, and Twedt
- ASPCA Pet Poison Hotline
- Pet Poison Helpline