Vestibular disease affects both dogs and cats, and when it happens, it can look very scary. The important thing to remember is that although the symptoms of vestibular disease look very similar to stroke, these are entirely different conditions altogether.
Unlike stroke, which is caused by an interruption of blood flow to the brain, vestibular disease is caused by a malfunction in the mechanisms of the inner ear. Although stroke can cause permanent damage to the brain, vestibular disease does not.
Vestibular disease is essentially a sudden disturbance of balance. It’s very common in cats, and in dogs it’s often referred to as “old dog vestibular syndrome”. Although it’s more often found in older dogs and cats, all ages can be affected.
But to really understand how vestibular disease affects the body, it’s important to know how the vestibular system works.
The Vital Vestibular System
Our body’s vestibular system is responsible for maintaining normal balance and keeping us in an upright position without falling over. According to Cornell University’s College of Veterinary Medicine, the vestibular system is made up of 2 parts: the vestibular apparatus (located deep within the inner ear), and a second component located in the medulla, an area of the brain located at the base of the skull.
Inside the vestibular apparatus are fluid-filled canals filled with specialized nerve cells and receptors. These receptors are connected to nerves that lead directly to the medulla. As our heads change position, the fluid in these canals shifts and sends signals to the brain, which registers the position of our heads relative to gravity. This tells our brains whether we are motionless or moving, and if so, in what direction.
Just like us, dogs and cats maintain their sense of balance because the vestibular system is able to adjust for changes in position. Whenever an animal turns, signals are sent from his brain to the muscles on one side of his body telling them to make adjustments – and it’s this communication that prevents him from tipping over.
What Causes Vestibular Disease?
Vestibular disease can result from a variety of factors:
- Inflammation of the vestibular nerve located in the inner ear
- Middle ear infections (caused by bacteria or ear mites)
- Head trauma or injury to the ear
- Underactive thyroid gland (hypothyroidism)
- Adverse reaction to certain types of antibiotics (including streptomycin, gentamicin, or metronidazole) or ear flushes containing chlorhexidine (an over-the-counter antiseptic)
- Genetic or inherited factors
- Thiamin (Vitamin B1) deficiency
- Polyps (small growths) or cysts in the middle ear
- Brain tumors
However, most cases of vestibular disease are considered “idiopathic”, which means that no identifiable cause is ever found.
Interestingly, in the northeastern United States, there seem to be more cases of vestibular disease in cats in July and August, which suggests there could also be an environmental cause. I witnessed this when I was in veterinary practice in Ohio – we saw more vestibular disease in cats during the summertime than during any other time of year.
Symptoms of Vestibular Disease
Vestibular disease symptoms tend to come on very suddenly. They can include:
- Head tilt
- Loss of balance and falling over to one side (usually in the direction of the head tilt)
- Ataxia (lack of coordination – stumbling, staggering, wobbling)
- Standing with legs apart in a wide stance
- Head shaking
- Rolling on the floor or walking in circles
- Inability to stand
- Repetitive, involuntary drifting eye movements (“nystagmus”)
- Reluctance to eat and drink
- Avoidance of people or other pets
You can see what nystagmus looks like in the video below:
It’s important to differentiate between vestibular disease, stroke, and brain tumor, as they can all cause similar symptoms. A veterinarian will usually diagnose vestibular disease based on symptoms, blood and urine tests, and an examination of the ears. Stroke and brain tumor can be definitively ruled out with the use of magnetic resonance imaging (MRI), or computed tomography (CT) scans.
If symptoms do not begin to resolve in a few days, the veterinarian may recommend a visit to a veterinary neurologist for a spinal tap.
Treatment For Vestibular Disease
If vestibular disease symptoms have a known cause (such as hypothyroidism, injury, or infection), specific treatment will be started to help resolve that particular condition. However, if no other cause is found and the case is considered idiopathic, unfortunately the only effective treatment is time and supportive care.
In severe cases, if the dog or cat is extremely disoriented, sedatives and anti-nausea medication can be administered. If the patient can’t hold down food or water, he or she may need to be hospitalized for a few days so intravenous (IV) fluids can be given.
Vestibular disease in dogs and cats is usually best treated at home, where they will be less stressed. Keeping them in a quiet place, and as comfortable and still as possible, goes a long way in the recovery process.
If your dog or cat is diagnosed with vestibular disease, you can also help assist in their recovery by:
- Giving them time and space. Vestibular disease is not life-threatening, so although the symptoms may be upsetting, they will often start resolving on their own within a few days.
- Keeping your own stress to a minimum. Since pets are sensitive to the moods of others, keeping your own stress level low will keep your pet from being startled or upset.
- Providing good lighting. This enables your pet to better use visual cues to determine proprioception (where his body is positioned in space).
- Creating proprioceptive support. You can do this by taking a long, thick blanket, rolling it up jellyroll-style, and snuggling it around your pet in a C-shape to provide something for him to press his body against.
- Not carrying your pet around. Since touch sensors in your pet’s paws need to be activated by touching the ground, carrying your pet can make him feel more dizzy and disoriented. Instead, help him learn to walk steadily again by putting your hands on both sides of his body as he walks.
Most patients recover from vestibular disease on their own in about 2-3 weeks, and in most cases, it never comes back. The head tilt is usually the last symptom to resolve, but occasionally it may not fully go away. However, this will not interfere with the dog or cat’s quality of life.
The Mystery of Vestibular Disease
A healthy vestibular system is vital to well-being, for us as well as for our dogs and cats. Without it, we wouldn’t be able to recognize where we are in space, maintain our balance, have good vision, or walk without falling over.
When the vestibular system malfunctions, it can be both frightening and frustrating, especially if there doesn’t appear to be any cause. But the good news is, vestibular disease in dogs and cats usually resolves just as suddenly as it appeared, with no lasting permanent damage. However, if your pet begins to exhibit any of the symptoms of vestibular disease, always take him to your veterinarian to rule out other potentially more serious causes.
Have you ever had a dog or cat with vestibular disease? Please tell us about it in the comments below!