The technical definition of a stroke is a "sudden lack of blood supply to the brain". This can happen in one of two ways: either a blood vessel feeding the brain becomes blocked, often with a clot, or the blood vessel ruptures. Both of these occur more commonly in people; they are actually quite rare in dogs.
The symptoms of a stroke are variable depending on which part of the brain is affected, but the most common are:
- A sudden loss of balance
- Paralysis, which can affect either one side of the body or both
- A head tilt
- Flicking eyes (nystagmus)
- Loss of bowel or bladder control
If your dog displays any of these symptoms, you should take it to your vet immediately. A clinical examination will give your vet a great deal of information, but the only way truly to diagnose a stroke in a dog is to give him an MRI or CT scan. This allows the veterinary staff to look directly into the brain and see exactly where and how the damage has occurred. However, these can be expensive and not every clinic will have immediate access to these imaging tools.
It can also be difficult to distinguish a stroke from another condition called "Vestibular Disease", which is common in older dogs and has very similar symptoms. The treatments are often similar as well, but Vestibular Disease carries a better prognosis.
A dog that has had a stroke and is struggling to stand or eat will need to be admitted into a veterinary hospital for supportive treatment. This will increase and maintain the blood supply to the brain to ensure it is receiving adequate supplies of oxygen and other nutrients. The dog will likely be placed on an intravenous drip, get a deep, conforming bed to ensure they don't develop sores while they are recumbent, and receive various kinds of medication.
The prognosis is variable and the improvement made within the first 48 hours following a stroke is the best indication of how your dog is going to recover. Many make full recoveries and will go on to lead normal lives, while some will be left with permanent issues, such as a head tilt. Unfortunately, some will sadly not improve to a significant degree; for them, euthanasia may be the kindest option.