Brain damage from seizures in dogs is a possibility and the main reason why dog owners should seek veterinary assistance when their dogs are suffering from frequent or prolonged seizures. Long lasting seizures have the potential to cause brain cell death, but fortunately, this is not a common occurrence. Although it may take some time for a dog to recover from a seizure, the good news is that most seizures do not have such a detrimental effect on the dog's brain. Knowing what to do when a dog has a seizure that is lasting longer than usual is key to preventing brain damage from seizures in dogs.
Effect of Seizures on the Body
Seizures are temporary disturbances of the normal electrical activity of the brain. Basically, for reasons not yet fully understood, certain sensitive neurons in the dog's brain gets stuck into a pattern of repeatedly firing.
Seizures in dogs may have several causes including exposure to toxins, infections, certain metabolic diseases, tumors in the brain (especially in older dogs), congenital liver disease (porto-systemic shunt), low blood sugar and idiopathic epilepsy ( seizures of unknown cause) to just name a few.
As mentioned, fortunately, most seizures are self-limiting events, with no long-term harmful effects. Soon, after the seizure, there is a spontaneous return to normal baseline neurological function.
However, problems may occur with continuous seizure activity, a condition known as status epilepticus, or the occurrence of multiple seizures in dogs without presence of recovery of baseline neurological function in between the episodes (cluster seizures, which may progress to status epilepticus).
In these prolonged seizures, a cascading chain of events take places potentially leading to several complications such as elevated body temperatures, heart arrhythmia, inadequate blood supply to tissues, aspiration pneumonia, accumulation of fluid in the lungs, rapid destruction of skeletal muscle causing leakage of the muscle protein (myoglobin) into the urine, kidney failure, neural edema (fluid build-up in the brain), brain swelling, neuronal damage and consequent brain damage. On top of brain damage from seizures in dogs, death may occur if the seizures are not quickly stopped.
Brain Damage From Seizures in Dogs
According to Jonathan Bach, a board-certified veterinarian specializing in internal medicine, neuronal damage and brain injury occur after seizures lasting 30 to 45 minutes.
If your dog's seizure is lasting more than 5 minutes, you will need to become proactive and start worrying about your dog overheating potentially paving the path for other complications such as brain damage setting in.
There is unfortunately nothing you can do at home to stop a seizure that is lasting long. Emergency treatment should be sought right away. While you are on your way to the vet, it's important to try to keep your dog as calm as possible.
As mentioned, one main concern in dogs suffering from prolonged or multiple seizures is overheating. Dogs suffering from multiple seizures may at times reach temperatures as high as 107 or 108 (normal temperature in dogs is between 101 and 102.5). Such high temperatures may cause brain damage and even become life threatening.
To prevent overheating, you can place a cool, wet towel on your dog, but avoid anything too cold as this can cause shock, warns veterinarian Dr. Christian K. If you are able to maintain body temperature below 103.5 with the help of towels (while somebody drives you and the dog to vet), that will help. Placing some alcohol on the dog's foot pads may also help cooling down as it evaporates, further adds Dr. Christian.
"If she has a seizure lasting or longer than 4-5 minutes (of active seizing) then you must get her to a veterinarian to prevent brain damage as when the body is seizing the body temperature sky rockets and they can fry their brains if their body temperature remains high for too long." Dr. Meghan Denney
At the Vet's Office
Once you reach the vet's office, vet and staff will work quickly on stopping the seizure activity.
Seizures are usually stopped by giving the dog a a benzodiazepine drug such as diazepam (Valium) either through an IV, intranasally or rectally, followed by the anticonvulsant drug such as phenobarbital for longer-term control.
For severe cases that do not respond to such approach, the vet may administer drugs meant to induce general anesthesia (propofol, pentobarbital).
Pentobarbital,on top of stopping seizures, also offers the advantage of having neuroprotective effects (protecting the brain) in dogs with status epilepticus explains Dr. Christopher L. Mariani, a board-certified vet specializing in internal medicine
In the case of brain damage from seizures in dogs such as brain swelling, increases in intracranial pressure, and neuronal damage, the vet may provide oxygen therapy, mannitol ( to reduce pressure in the brain) and furosemide (water pill) to address and correct these complications.
Once the seizure is under control and your dog is stable and on his way to recovering, your vet may run some diagnostics to find out whether there is an underlying cause that needs addressed. Addressing any underlying cause can help prevent the onset of future seizures. As mentioned though, in many cases the underlying cause of seizures is never found (idiopathic epilepsy).
To reduce the risk for further seizures, your vet will want to keep your dog on long term anti-seizure medications. Seizures can fortunately be controlled well with potassium bromide or phenobarbital. For future emergencies, your vet may also provide you with emergency Valium suppositories that can be quickly administered rectally.
A Word About Post-Seizure Behavior
Following a seizure, the dog may appear sleepy and confused. Some dogs may be wobbly, pacing, panting and walking in a drunk-like state.
Other dogs may suffer from temporary vision impairment which may cause them to bump into objects. Some others may appear depressed, excited or even aggressive. Many dog owners worry about these symptoms and wonder whether these are signs of brain damage from seizures in dogs.
Instead, most likely these signs are part of the post-seizure phase, medically referred to as "post-ictal phase." This is a simply a temporary phase during which there are abnormalities in brain function.
The post-ictal phase may last from a few minutes to hours. In some cases it may even last for a day or more. It's always a good idea to report to the vet should the dog's post-ictal period appear to be prolonged or unusual.
"The post ictal phase may last from minutes to days and the length may not bear any relationship to the length of the seizure episode."~Georgina Child
- Vet Pathol. 1983 Mar;20(2):160-9.Brain damage in the epileptic beagle dog. Montgomery DL, Lee AC
- DVM360: Neurological emergencies (Proceedings)May 01, 2011 By Scott P. Shaw, DVM, DACVECC
- DVM360: Treatment of cluster seizures and status epilepticus (Proceedings)
May 01, 2011 By Christopher L. Mariani, DVM, PhD, DACVIM