Dog Seizures & Life Expectancy: When to Consider Euthanasia

This article was updated on May 1st, 2023

Caring for an old dog with seizures can be challenging, not to mention the distress it can cause for both the dog and the owner.

There are many possible causes of seizures and some are more manageable than others. However, as a dog gets older, the underlying cause for their seizures may get worse resulting in more frequent or more intense seizures.

Owners only want what is best for their beloved companion. As a result, they may consider putting their seizuring dog to sleep to put an end to their companion’s suffering. However, making this decision remains a difficult one.

This article will help owners in understanding the underlying causes of seizures in older dogs and the best time for euthanasia.

How Many Seizures Can Dogs Have Before Dying?

The frequency and length of seizures will have a huge impact on your dog’s prognosis. Seizures that last long enough can be immediately life threatening as the blood and energy supply to the brain is cut off.

If your dog’s seizures last for more than 5 minutes or if they have multiple seizures (more than 2-3) within a 24-hour period, then the brain could eventually be starved of energy and shut down. Therefore, these situations are an emergency, and your dog should be seen by a veterinarian immediately.

How Long Can a Senior Dog Live After Seizures?

The survival time for a dog that is having frequent seizures will depend on many factors, including what is causing the seizures and how well they are controlled. Dogs with idiopathic epilepsy have an estimated survival time of about 66 months according to this study; if poorly controlled then the survival time is usually shorter.

However, if seizures are occurring due to a brain lesion such as a tumor, then the median survival time will be dramatically reduced to closer to 8 months. It is therefore crucial to try and determine the cause of seizures and to start your dog on medication if necessary.

Let’s look now at the most frequent medical conditions causing seizures in dogs.

Most Frequent Conditions Causing Seizures, Life Expectancy & When It May Be Time To Euthanize Your Dog

1. Liver Disease

If your senior dog has liver disease, or is in liver failure, it’s possible that it could cause them to have seizures. However, there are many other symptoms of liver problems that are likely to show up before a seizure does. The first one is usually a loss of appetite. Abdominal swelling, digestive upsets (vomiting, diarrhea, or constipation), dark orange urine, and a yellow tint to the skin, gums, and mucus membranes are also symptoms of liver problems. These are also likely to be obvious well before the risk of seizure occurs.

Life expectancy: Dogs with liver disease can have a variable life expectancy depending on the underlying cause of the disease. Some liver diseases are more slowly progressive such as chronic hepatitis whereas other forms of liver disease progress much faster such as liver cancer. Because of this, the life expectancy for a dog with liver disease can range from months to years.

When it is time to consider euthanasia: However, if your dog is obviously very unwell and having seizures on a regular basis such as multiple seizures every week then it’s likely time to consider euthanasia.

2. Cancer

Tumors (also known as neoplasia) are much more common in senior dogs than they are in younger ones. Some tumors are benign, others cancerous. A brain tumor can cause seizures as well as other neurological symptoms. A cancer that starts off in another part of the body can metastasize (spread) to other parts of your dog’s body, including the brain, and cause similar problems.

Life expectancy: The life expectancy of dogs with brain tumors will vary depending on the type of cancer present and the speed at which it progresses. However, in many cases, the prognosis is poor with a median survival time of two months.

When it is time to consider euthanasia: Treatment may be able to extend this period but often not by much. If your dog is displaying other neurological symptoms other than seizures such as incoordination, confusion, and an inability to walk properly, then it’s time to consider euthanasia. Having your dog euthanized is also recommended if your dog is having multiple seizures a week that cannot be controlled with medication.

3. Kidney Disease

If your older dog has kidney disease or kidney failure, toxins build up in their bloodstream and can’t be excreted the way they would normally be. This buildup of toxins in the blood can cause seizures in senior dogs. Other symptoms are much more likely to show up first. Including increased thirst and urination, lethargy, weight loss, and nausea. Seizures or a coma don’t usually happen until the disease is very advanced.

Life expectancy: The life expectancy of dogs with kidney disease will depend on the stage of kidney failure they are in. Seizures will usually only occur in very late-stage renal failure; this is described as stage 4 kidney disease and the medial survival time for dogs in this category is between 14-80 days according to the international renal interest society (IRIS).

When it is time to consider euthanasia: Dogs in stage 4 renal failure are likely to be very unwell and so euthanasia may be in their best interests, especially if they are losing weight, vomiting, and having regular seizures.

4. Diabetes

Dogs with extreme diabetes can enter a state known as diabetic ketoacidosis. This results in electrolyte disturbances within the blood and seizures may follow. It’s also possible for seizures to occur as a result of overtreating diabetes -they could have a seizure if they develop hypoglycemia because of accidentally receiving too much insulin.

Life expectancy: The general median survival time for dogs with diabetes left untreated is 60 days. Treated and controlled diabetics may live full life spans. However, if your dog is having seizures or displaying other unusual neurological activity, then they are likely in a much later stage of the disease (See my article on Final Stages of Dog Diabetes). Take your dog to the vet immediately as prompt treatment may be able to reverse the seizures.

When it is time to consider euthanasia: If your dog has been having seizures for a while, and their diabetes is getting more difficult to control then euthanasia may be an option. Learn more in our article signs that your dog may be dying from diabetes.

5. Hypoglycemia

Hypoglycemia happens when your dog’s blood sugar plummets. The brain needs glucose in order to function properly, and if the supply of that drops then, seizures can happen. This condition is most often seen in small or tiny breeds (and puppies) as they have more difficulty regulating their blood sugar levels, however, it can also be seen in active dogs, dogs with pancreatic cancer, and diabetic dogs, as already discussed. Seizures or coma are the most severe results of hypoglycemia; other signs can usually be seen first, including:

• Lethargy

• Loss of coordination
• Trembling
• Restlessness
• Collapse

Most causes of hypoglycemia can be easily reversed through veterinary treatment. However, in some cases where there is a more serious underlying cause, the prognosis might be poorer.

When it is time to consider euthanasia: If your dog keeps experiencing seizures despite veterinary intervention, then euthanasia might be in their best interests.

6. Adverse Reaction to Medication

All medications (and also, to a lesser degree, natural remedies) can have side effects. Many are mild and can include vomiting, diarrhea, and reduced appetite. Other severe reactions are less common, but definitely do happen. Seizures in dogs can be one fairly rare, but serious, side effect of certain medications.

7. Environmental Toxins

There are several things in our dog’s environment that can potentially cause seizures.

These include:

• Rodent poison
• Antifreeze
• Insecticides
• Garden weedkiller
• Insect poisons
• Lead paint
• Black mold

You may not even know that things like black mold, or lead paint are in your home. If your dog has unexplained seizures, having your ductwork and heating/ac and any old paintwork checked out is a good idea. Blood tests can determine lead levels too.

8. Trauma or Injury

An injury to the brain can cause a seizure in dogs of any age. Older dogs are more prone to falling than younger ones, and a fall down some steps resulting in a blow to the head could cause brain damage or bleeding. If your dog shows any signs of illness, strokes, or seizures after falling or injuring himself (even if you didn’t see them hit their head), take them to be examined by a veterinarian asap.

Read more about dog seizures:

Can Seizures Be Fatal to Dogs?

Best Food for Dogs with Seizures

Final Words

While making the decision to euthanize your pet is an extremely difficult one, watching them suffer is something no owner wants to experience. Seizures are very distressing for both you and your dog, and they are likely to feel very disorientated between episodes. Seizures are never normal, and if they are occurring on a frequent basis, then veterinary attention is required. If your dog continues to seize on a weekly or even daily basis then it is not fair to keep them alive; often the kindest thing is to have them humanely euthanized.