Idiopathic or “Old Dog” Vestibular Disease: Vestibular signs in dogs are often incorrectly referred to as “a stroke”
A fairly common reason for a veterinary visit is the concern by pet parents that their dog is “having a stroke.” More sadly than this, I have heard of times when people have made the decision to euthanize their pet because they thought that their dog had a brain tumor as the source of these signs. Well, I wanted to shed some light on a much more common cause of “stroke-like” signs in case it is something you ever experience with your own geriatric dog.
This is a condition known as Idiopathic (meaning, unknown… think: idiot) Vestibular Disease and is syndrome that looks really, really bad, but usually gets better all on its own with little or no treatment.
The vestibular system is composed of portions of the brain and ear and is responsible for maintaining a sense of balance. When something goes wrong with this system, it’s like being drunk on a rocky boat. Dogs with idiopathic vestibular disease have some combination of the following signs:
- A head tilt
- An unsteady gait, loss of balance, or falling over
- Circling in one direction
- Eyes rapidly moving from side to side, known as nystagmus
- Sudden vomiting
Now for the caveat: these clinical signs are unfortunately not unique, or diagnostic for, idiopathic vestibular disease and other things can cause this same presentation. This can include (yes) a brain tumor, an inner ear infection, inflammatory disease, or sudden bleeds into the brain to name a few of the more common causes. But with that said, when the symptoms seemingly appear out of nowhere in an older dog, I always recommend a “wait and see approach” and treat symptomatically and supportively.
These are the steps and discussion I would have with a pet parent if their dog were showing the above described signs: I generally recommend blood work to make sure there is no other obvious disease and I discuss the availability of an MRI to evaluate the inner ear and brain. Although an MRI allows for the best evaluation of disease, it is often not pursued due to cost (about $1,500.00 here in the Bay Area). An ear exam is also performed, and if an infection is suspected, I discuss antibiotic therapy to “cover all the bases.” The difficulty with assessing the presence of infection is that infection must occur in the inner ear to cause disease; this is something you cannot see during an exam because the eardrum obscures the view to the inner ear. However, if there is a nasty looking middle ear and an inflamed eardrum, there is a chance that inner ear disease could be present as well.
If the dog’s clinical signs are so severe that they cannot walk, I then recommend supportive care with IV fluids and injectable anti nausea medications. Urinary catheters are sometimes placed for hygienic reasons. If clinical signs are mild, pets can often be managed at home with over-the-counter meclizine (for “motion sickness”) and instructions to protect from falls along with general nursing care.
The conversation ends with discussing a very loose rule of thumb: if there is gradual or complete improvement within 72 hours, it is likely idiopathic vestibular disease and additional diagnostic testing is not necessary; if there is no improvement or progression of signs, it is likely something much more serious such as a tumor, and an MRI would be recommended to reach a definitive diagnosis. With idiopathic vestibular disease, marked improvement is usually evident in this time frame, with the pet returning to normal in 7 to 14 days (although in some dogs, a head tilt will still persist).
It should also be noted that this is not a painful condition, and my recommendations stem from the fact that euthanasia is a permanent decision, so why not wait and see, giving time a chance? There is a high likelihood that improvement will be seen and the difficult decision of euthanasia can always be made at a later date if there is no improvement or if there is a change in your pet’s quality of life. I feel there is reason to hold out hope, and be cautiously optimistic, as idiopathic vestibular disease is the most common form of vestibular disease in dogs. It is the direction I would take if it were my own boy experiencing this.
Please note: there are times, however, when a physical exam points undeniably to a brain tumor, but these neurological exam findings are beyond the scope of discussion, so feel free to ask me any questions!