Canine Seizure vs. Stroke

A seizure is caused by an electrical storm in the brain, which happens when too many neurons become overexcited. It's difficult to know what causes such a storm. They can be caused by a brain injury, toxic substances, and certain other metabolic and electrolite disturbances, but seizures can also be genetic.

During a generalized, or grand mal, seizure, dogs' muscles become stiff all over, usually with the legs stiff and the head back. The eyes may remain open, but the dog is unconscious during this phase, known as the "tonic" phase. It typically lasts about 30 seconds before transitioning into the "clonic" phase, during which the dog may jerk his limbs, make chomping motions with his jaw or move his head from side to side. Typically, this type of seizure can last several minutes, but if it lasts more than five minutes, the dog is considered to be in status epilepticus, or prolonged seizure.

A focal, or partial, seizure affects a small area of the brain, and can be simple or complex. Simple focal seizures usually result in facial twitches, excessive blinking, making paddling motions with one limb, or jerking the head. Complex focal seizures occur in areas of the brain responsible for emotion and behavior and can result in altered, even bizarre, behavior such as uncharacteristic aggression. Focal seizures may be a symptom of brain damage, or the presence of a brain tumor, but can also have some of the same causes of more generalized seizures.

Canine strokes are much less common than seizures, and also occur less often than strokes in humans. While a stroke can resemble a type of seizure, it has a different root cause. Strokes are caused by either a blocked artery preventing blood from flowing to the brain or by bleeding in the brain caused by a burst blood vessel. The root cause can be high blood pressure, heart, kidney or thyroid disease, Cushing's disease, diabetes, or even a brain tumor.

Common canine stroke symptoms can include walking in circles, tilting the head from side to side, acting confused, lethargic or unbalanced, blindness, eating out of only one side of his dish, or loss of bowel and bladder control. Circling and head tilting can also be related to disorders of the inner and middle ear, however, so it is important to seek medical attention to try to determine whether the dog has had a stroke or seizure, the possible causes, and treatments.

If your dog appears to be having a seizure, make sure he's in a safe place where he can't harm himself if he starts thrashing, then give him space during the seizure and as he recovers. Many dogs are confused and fearful after a seizure and may bite if you touch them. Speak softly and calmly, but use the dog's behavior as your cue as to what to do. Some dogs want to sleep; others may seek you for comfort.

If this is his first seizure, try to time it and jot down any details to help your vet determine its cause. If he has a history of seizures or has been diagnosed as epileptic, note in a journal the time, date and length of each seizure, and any other details, to help your vet know whether medication should be adjusted.

Blood work will help show if toxicity caused the seizure. For epileptic diagnoses, your vet will determine whether anti-seizure medication is advisable. If a stroke is suspected, your vet will run tests to verify the stroke, determine its root cause, and prescribe treatment to help prevent further strokes and to reduce brain swelling. With treatment, dogs can recover quickly from strokes, although, depending on the degree of brain damage, some changes might be permanent.