By Jay McDonnell, DVM, MS, Diplomate ACVIM (Neurology)
1. Why is my dog trembling or shaking? Could it be a seizure?
There are many reasons your dog may be shaking or trembling including stress or anxiety, cold, pain, muscular weakness, a neurological problems, chronic kidney disease and Generalized Tremor Syndrome (GTS). GTS is a condition that was first seen in small, white dogs such as Maltese and West Highland white terriers, but it can occur in dogs of any size, breed or color. The cause of GTS isn't known, but it is treatable with corticosteroids like prednisone.
It is unlikely that your dog's trembling or shaking is a seizure, but if you are unsure of the cause, it's best to have your dog checked by your veterinarian.
2. What are the symptoms of a seizure in dogs?
A seizure can have several manifestations, from a far-away look or twitching in one part of the face to a dog falling on its side barking, clenching and unclenching its teeth, urinating, defecating and paddling all four limbs. Seizures can vary in time between seconds to hours.
3. What should I do if my dog is having a seizure?
First, do not panic. When a dog is having a seizure, he is unconscious and is not “suffering.” Keep your dog as quiet as possible and prevent him from hurting himself. Loud or sharp noises may prolong the seizure or make it worse.
Other animals in the household may be frightened or threatened by the seizuring dog. Remove them from the immediate area if this is a concern.
If you speak to your dog while he is experiencing a seizure, it may comfort him and may smooth the recovery period. Never put your hands near the dog’s mouth as he may involuntarily bite you. Remember: Your dog is unconscious and may do things he would not normally do.
Always have your veterinarian or emergency veterinary center phone numbers available. Call if your dog has a seizure that lasts more than five minutes. If the seizure lasts more than thirty minutes, permanent brain damage may occur if the seizures are not stopped.
4. Are all seizures or convulsions in dogs epilepsy?
No. A dog may have an isolated seizure unrelated to epilepsy. However, even if your dog has just one seizure, a complete physical and neurological examinations are still in order. If no abnormalities are found, you should watch for further seizures. Your vet may not prescribe treatment unless your dog has additional seizures.
5. Are there different types of seizures in dogs?
Yes—and if you believe your dog is having a seizure, it's important to note all the details so that you may accurately describe them to your veterinarian.
- Generalized Seizure: This type of seizure can be grand mal or mild. The grand mal seizure is also known as a tonic-clonic seizure because typically has two phases; tonic and clonic. In the tonic phase, which typically lasts 10-30 seconds, dog falls, loses consciousness and extends his limbs rigidly. Respiration also stops (apnea). It is followed by the clonic phase, in which the dog may paddling his legs and/or appear to be chewing. Other signs that appear during the tonic or clonic phase are dilation of the pupils, salivation, urination and defecation. The mild seizure involves little or no paddling or extension of limbs, and usually no loss of consciousness. Generalized seizures are usually associated with primary epilepsy.
- Partial Seizures: Movements are restricted to one area of the body, such as muscle jerking, movement of one limb, turning the head or bending the trunk to one side, or facial twitches. A partial seizure can progress to—and be mistaken for—a generalized grand mal seizure, but if the seizure starts with one specific area of the body, it's a partial seizure. Partial seizures are usually associated with secondary epilepsy.
- Complex Partial Seizures (Psychomotor or Behavioral): These seizures are associated with bizarre or complex behaviors that are repeated during each seizure. People with complex partial seizures experience distortions of thought, perception or emotion (usually fear), sometimes with unusual sensations of sound, smell, hallucinations or taste. If dogs experience the same things, it may explain the lip-smacking, chewing, fly biting, aggression, vocalization, hysterical running, cowering or hiding in otherwise normal animals. Vomiting, diarrhea, abdominal distress, salivation, blindness, unusual thirst or appetite and flank biting are other signs. There is an obvious lack of awareness, though usually not a lack of consciousness. Abnormal behaviors may last minutes or hours and can be followed by a generalized seizure. Complex partial seizures are usually associated with secondary epilepsy.
- Cluster Seizures: These are multiple seizures within a short period of time with only brief periods of consciousness in between. There may be as few as two seizures in a 30-minute period. The time between seizures may be as brief as 5 to 10 seconds or as long as 4 to 6 hours. They may be confused with status epilepticus.
- Status Epilepticus: Status can occur as one continuous seizure lasting 30 minutes or more, or a series of multiple seizures in a short time with no periods of normal consciousness. It can be difficult to distinguish status epilepticus from frequent cluster seizures, but both are life-threatening emergencies.Most status patients usually suffer from generalized tonic-clonic seizures. Though status epilepticus can occur with either primary or secondary epilepsy, it may also suddenly arise in dogs with no previous history of seizures, especially in cases of traumatic brain injury, toxins or disease.
- Petit Mal Seizure (Absence Seizure): This type of seizure is rare in dogs; the term “petit mal” should not be used to described a partial or mild generalized seizure in dogs. A dog having a petit mal seizure may tremble, arch his back or shake his head, have difficulty standing, and/or drool.
6. What's the difference between primary and secondary epilepsy?
Primary epilepsy is also known as idiopathic, genetic, inherited or true epilepsy. There is no test for primary epilepsy; instead your vet must rule out every other possibility.
The first seizure in a dog with primary epilepsy usually occurs between the ages of 6 months and 5 years. While primary epilepsy may be genetic (inherited), a diagnosis of primary epilepsy is not proof of a genetic defect; only careful breeding studies could prove that. The breed, age and the history may suggest a genetic basis for primary epilepsy if there is a familial history of seizures.
In secondary epilepsy, the cause can be determined—and there are many causes. In dogs less than a year old, the most commonly-found causes of seizures are degenerative diseases, developmental issues, toxic (poisoning), infectious diseases (such as distemper), metabolic disorders, nutritional issues, or traumatic injury.
7. What are the causes of epilepsy in dogs? And what are the causes of seizures in puppies?
In dogs 1-3 years of age, a genetic factor is typically suspected. In dogs 5 years and older, most seizures are metabolic (related to issues such as hypoglycemia, cardiovascular arrhythmia or cirrhosis) or neoplastic (related to brain tumors).
8. Are some breeds of dogs more prone to seizures?
Epilepsy is found in all dog breeds including mixed breeds. Approximately 2% to 5% of all dogs have epilepsy.
The breeds for which a genetic factor is either proved or highly suspected include the Beagle, Belgian Tervuren, Dachshund, German Shepherd Dog, Alsatian and Keeshond. A high incidence of seizure disorders is also found in Boxers, Cocker Spaniels, Collies, Golden Retrievers, Irish Setters, Labrador Retrievers, Miniature Schnauzers, Poodles, Saint Bernards, Siberian Huskies, and Wire-Haired Terriers.
9. What are the treatments for epilepsy (seizures) in dogs?
A seizure log is the first step in treating and monitoring a seizure disorder. Note the time that the seizure began so that you can determine how long the seizure lasts. Note on your seizure log when the seizure occurred (day, time of day) and how long it lasted (exact minutes are essential). If possible, note any abnormal behavior before or after the seizure. If you suspect your dog has had a seizure but you didn’t see it, list it as a question mark on your seizure log.
Treatment is generally advised for dogs who have one or more seizures within six weeks. (Dogs who have cluster seizures or go into status epilepticus may be treated even if the rate of incidence is less than once every six weeks.) Successful drug therapy depends upon the owner’s dedication to delivering the drug exactly as prescribed, with absolutely NO changes in the dose or type of medication without veterinary consultation. Haphazard drug administration or abrupt changes in medication is worse than no treatment at all, and may cause status epilepticus.
A number of drugs and some alternative therapies—such as acupuncture, herbs, diet changes, homeopathy and vitamins—may be used to control epilepsy. Phenobarbital and potassium bromide are the most widely used anti-convulsant drugs, but others are used, as well.
10. Will treatment help prevent my dog from having seizures?
Epilepsy is a chronic disease that can be managed in most cases. The goal of treatment is to decrease the frequency and severity of seizures and avoid unacceptable side effects. It usually is not possible to stop the seizures altogether.
It's important to keep in mind that, whether your dog is experiencing mild or severe seizures, there is help for both of you. Work with a veterinary professional with whom you feel a good rapport, and educate yourself on seizures and their treatment. Follow the vet's instructions; never change medication or dosages without a consultation; be observant; have drug serum levels tested as recommended by your vet; and have patience and be willing to try another form of treatment if that seems indicated. New therapies are bringing more options and more hope to epileptic dogs and their humans.