Seizures can often be an indication of canine epilepsy. However, it's uncommon for epilepsy to appear in senior dogs if they didn't already have the condition when they were younger. Therefore, if your senior dog starts getting seizures, he may have a different condition.
Some common causes of seizures in senior dogs
Brain tumor. Some older dogs develop brain tumors that can put pressure on the brain as it grows, resulting in a seizure. Other symptoms to be on the lookout for include a loss of vision and motor coordination. If your vet suspects your dog has a brain tumor, he will most likely recommend diagnostic tests like an MRI (magnetic resonance imaging) or CAT (computed axial topography) scan.
Kidney disease. Dogs that have a buildup of toxins in the blood or high levels of acidity due to kidney disease can also experience seizures.
Diabetes. If a dog with diabetes has a seizure, it's usually due to an insulin overdose, not because the condition has been left untreated. Diabetes that is left untreated will cause stupor or coma, not seizures.
Cushing's Disease. Though Cushing's Disease (also known as hyperadrenocorticism) is not typically a direct cause of seizures, some of the circumstances surrounding the condition can lead to seizures. In most cases, Cushing's Disease is caused by a tumor in the pituitary gland at the base of the brain. The majority of these tumors are microscopic in size. However, there are cases where larger tumors have become big enough to put pressure on the brain and cause seizures.
What to do if your dog has a seizure
First and foremost, you need to prevent your dog from injuring himself. Dogs can either experience a single convulsion (usually lasting for a minute or two, and that doesn't happen again for at least 24 hours) or multiple, continuous convulsions. The latter is most serious and requires immediate veterinary attention.
In the case of continuous convulsions, you should gently restrain your dog by placing a towel over him. This will help prevent him from injuring himself. When a dog is having a seizure, don't put your hand on, in, or near its mouth because you may get bitten. Once you've restrained your dog, take him to the vet immediately.