Diagnosing dizzy dogs
For anyone who has experienced the unpleasant syndrome of vertigo, it may come as a surprise that we humans are not alone. As it happens, both dogs and cats experience a similar malady. When a pet is experiencing vertigo, it is not only upsetting and frightening for the pet, but the pet owner as well.
This month’s esteemed guest author is Dr. Katherine Crook. Dr. Crook is a board certified neurologist/neurosurgeon at CVRC. She describes the symptoms, causes and treatments of vestibular disease in dogs and cats.
One common reason for veterinary emergency visits is loss of balance, which is more accurately described as vestibular disease. When loss of balance occurs it can be very sudden and very dramatic. Patients are often rolling or circling to one side with their heads profoundly tilting — their world is literally spinning. Although these signs can be shocking, leaving people to fear the worst for their pets, they commonly are due to very benign causes and resolve with time and some tender loving care.
The vestibular system is the part of the body that regulates balance and it is made up of two parts. The first part is known as the peripheral vestibular system and includes the structures in the inner ear that are responsible for sensing where the body is in space. The second part is known as the central vestibular system and includes the areas of the brain that coordinate and integrate that sensory information. Dysfunction of either the central or peripheral portions of the vestibular system can cause very similar signs.
Sensory information from the vestibular system allows dogs and cats to sense where they are in space. It is literally how they perceive the difference between up and down. Therefore when dysfunction of the vestibular system occurs, it results in a loss of balance. Common signs that a dog is experiencing a problem with their vestibular system include a head tilt (one ear is held closer to the ground than the other), leaning or rolling to one side, walking in circles, incoordination, spontaneous and involuntary eye movements, a wide-based stance and, sometimes, vomiting.
The good news is that when vestibular dysfunction occurs in pets, it is most often associated with the peripheral portion of the vestibular system. The most common peripheral cause is usually of unknown (idiopathic) origin. Some less common peripheral causes of vestibular disease include middle and inner ear infections, trauma, underactive thyroid glands, or, rarely, tumors affecting the inner ear.
Idiopathic peripheral vestibular disease is also commonly referred to as “old dog” vestibular disease. This typically causes a sudden loss of balance, which does not worsen once it begins. It can occur in dogs of any age however it is most commonly seen in middle aged to older dogs, hence the descriptor “old dog.” Dogs afflicted with this disease typically show signs of improvement within a few days, steadily getting better over the next two to four weeks, though they may keep a slight head tilt. Treatment for the disease involves supportive and nursing care while they slowly regain their coordination. The care they need may include intravenous fluids if they are vomiting, confining a dog to a well-padded area if it is falling, or medications to control vomiting and dizziness. Luckily dogs with this disease get better if they are provided with the support they need and this disease rarely occurs a second time.
If your dog does show signs of vestibular disease, I recommend bringing him or her to your primary care veterinarian for a physical exam, a blood pressure check and some blood work. This exam may indicate a cause of the vestibular signs, such as an ear infection or low thyroid levels. “Old dog” vestibular is ultimately diagnosed by excluding other causes of both peripheral and central vestibular disease. Therefore, if a dog displays signs of another problem or does not show improvement within a few days, additional testing or referral to a veterinary neurologist may be recommended to rule out other causes of vestibular disease.
A neurologist can offer more advanced testing such as an MRI and of the brain possibly a spinal tap to rule out central causes of vestibular disease such as a brain tumor, stroke or meningitis. In general, treatment of vestibular disease depends on the specific cause, but fortunately many of the common causes of vestibular signs can and will improve with time and nursing care.
Charleston Veterinary Referral Center is a specialty referral and 24-hour, seven-day-a-week emergency and critical care veterinary hospital. Dr. Crook leads CVRC’s Neurology Department. Information may be found at http://www.charlestonvrc.com or on Facebook at facebook.com/charlestonvrc or (843) 614-VETS (8387).