It’s likely that you know someone who has experienced a stroke and have witnessed the significant impact it can have on their life. As a devoted pet owner, you may be surprised to discover that strokes can also affect dogs, although they occur much less frequently compared to humans.
According to Dr. Brett Levitzke, the medical director of the Veterinary Emergency and Referral Group in Brooklyn, N.Y., the increased availability of MRI and CT scans for pets has led to more frequent diagnoses of strokes in dogs. Understanding the causes, symptoms, and treatment options for strokes in dogs will empower you to be a knowledgeable and proactive pet parent.
What Is a Stroke?
Dr. Virginia Sinnott from the Massachusetts Society for the Prevention of Cruelty to Animals Angell Medical Center explains that a stroke in dogs is characterized by a loss of blood flow to certain areas of the brain, leading to tissue damage and neurological abnormalities.
There are two primary mechanisms that can cause strokes in dogs:
- Ischemic strokes, which occur due to obstructions in blood vessels. These obstructions are often caused by factors such as blood clots, tumors, inflammation, and infections.
- Hemorrhagic strokes, which result from the rupture of blood vessels or blood clotting disorders, leading to bleeding in the brain.
Ischemic strokes are more frequently observed in dogs compared to hemorrhagic strokes.
Symptoms
Signs of strokes in animals can mirror those observed in humans, although animals don’t exhibit obvious symptoms like slurred speech or memory loss. Dr. Levitzke notes that symptoms vary depending on the specific location in the brain where the stroke occurs.
“Even in humans, these signs can be subtle, and since animals can’t verbally communicate feelings such as dizziness or loss of vision in one eye,” adds Dr. Sinnott, “subtle strokes in animals may go unnoticed.”
Dr. Sinnott also mentions that while massive strokes are more common in dogs, pet parents may sometimes mistake fainting spells (syncope) for strokes. “Both conditions are extremely serious and necessitate immediate veterinary attention,” Dr. Sinnott emphasizes.
Symptoms of strokes in dogs may include:
- Difficulty walking or uncoordinated gait
- Head tilt
- Abnormal eye movements, such as side-to-side or rotary (nystagmus)
- Irregular eye positioning (strabismus)
- Loss of consciousness
- Altered behavior
- Falling to one side
- Blindness
- Rapid onset of symptoms
“Typically, owners report that their pet was fine one moment, and suddenly they are unable to stand up. These symptoms may persist for a few minutes or extend for a longer duration, ranging from hours to days,” says Dr. Sinnott.
It’s essential to recognize, however, that many of these symptoms overlap with other more common conditions in dogs, including idiopathic vestibular disease, which frequently affects older dogs, and even severe ear infections.
Causes
Dr. Sinnott mentions that veterinarians typically encounter only a few cases of strokes in dogs each year, and when they do occur, they often affect very elderly dogs with preexisting conditions that can elevate the risk of clotting or bleeding.
“The symptoms can be alarming and may cause discomfort for the dog, prompting some owners to opt for euthanasia for their pets,” Dr. Sinnott explains, especially in cases of severe strokes in geriatric dogs.
The underlying conditions that can predispose dogs to strokes include:
- Kidney disease
- Cushing’s disease (hyperadrenocorticism)
- Hypertension
- Diabetes
- Heart disease
- Bleeding disorders
- Hypothyroidism
- Cancer
Additionally, in some instances, high doses of steroids like prednisone can contribute to the risk of stroke.
Dr. Levitzke adds that while no particular breed is more susceptible to strokes than others, certain breeds are prone to the underlying conditions that can lead to strokes. For example, Cavalier King Charles Spaniels have a higher incidence of heart disease, which is a common precursor to strokes.
Diagnosis
Accurate diagnosis stands as the cornerstone of treating strokes in dogs. What might seem like a stroke-induced fainting spell could actually stem from an irregular heart rhythm, posing a severe threat to your pet’s life. Through a thorough physical examination, your veterinarian can differentiate a stroke from other conditions with similar symptoms, including assessing your dog’s heart function to eliminate the possibility of a cardiac issue triggering fainting. Diagnostic measures may involve an electrocardiogram (ECG), chest X-rays, and potentially a cardiac ultrasound, as outlined by Dr. Sinnott.
In cases where the heart appears normal, further evaluation of the brain becomes imperative, often through an MRI or CAT scan. Additionally, your vet may conduct additional tests to uncover underlying diseases that could precipitate a blood clot, such as hormone testing, bloodwork, and urinalysis.
Treatment
Once the cause is identified, treatment focuses on addressing it, according to Dr. Levitzke. For instance, if a clot triggers the stroke, blood thinners may be prescribed. In cases where hypertension is the culprit, medications to lower blood pressure might be utilized.
“The neurological symptoms associated with a stroke typically resolve as the body restores blood flow to the affected area and swelling diminishes. Medications such as steroids, mannitol, and hypertonic saline can aid in reducing brain swelling,” explains Dr. Levitzke.
Providing supplemental oxygen is fundamental in treatment to enhance oxygen delivery to damaged tissues and facilitate healing.
In addition, managing urination and defecation, ensuring proper nutrition, and engaging in physical therapy (including massage and passive range of motion exercises for limbs if necessary) play pivotal roles in the recovery process. “The brain demonstrates remarkable resilience, although recovery may require patience,” notes Dr. Levitzke.
Prevention
Dr. Levitzke emphasizes that since strokes in dogs frequently coincide with underlying health issues, regular veterinary check-ups and screening blood work can detect potential causes that can be addressed preemptively. Maintaining consistent wellness care as dogs grow older is crucial for their overall health and well-being.