For owners, experiencing your dog have a seizure for the first time is both scary and disturbing. Dogs may experience collapse, involuntary movement and commonly loss of consciousness. Subsequent disorientation and unusual behaviour may be observed. It is a medical emergency if your dog seizures continuously for more than about 5 minutes.
What is a seizure and what does it look like?
A seizure generally results from increased electrical activity in the front part of the brain. The patient will usually lose consciousness, fall over and may become very stiff then start paddling limbs and/or tremor, but there are many variations. If your dog experiences abnormal behaviour it is often good to capture it with a smart phone to show your veterinarian. Seizures may be classed into several categories.
Generalised (Grand Mal) Seizures
With the most commonly observed seizure in small animals the body is involved in stiffness and then possibly cycles of contractions of the body and limbs. Urination and defaecation are common during or afterwards.
Focal seizures involve involuntary activity in only on part of the body, with consciousness only sometimes impaired. “Gum chewing” seizures may be associated with infection from canine distemper, where the animal appears to have a gum chewing action without the presence of food in the mouth.
These seizures are focal seizures that appear to be an episode of abnormal behaviour rather than convulsions. The pet may be interpreted to be hallucinating or in an altered mental state. Rage or aggression may be evident and even people familiar to the animal may be the target. Alternatively, a simple period of disorientation or ‘spacing out’ may be evident.
Seizures should be differentiated from fainting spells as the two often have very different causes. Seizures in humans are often associated with an aura of special feeling associated with the impending seizure, however in animals, nothing abnormal may be noticed and the seizure may arrive unexpectedly. Seizures are commonly followed by a post-ictal (or post-seizure) period where the animal may continue to be disoriented or perform unusual behaviours. The duration of this period can vary from a few minutes to hours. Fainting animals on the other hand will often have normal return to function very quickly.
Causes of Seizures and Diagnostics
The canine brain may be affected by different causes of seizures including: toxins, tumours, genetic diseases, infections, and possibly even brain dysfunction from previous trauma. Dogs of different ages and breeds are more likely to have seizures caused by particular inciting agents. This may have an impact on which diagnostic test is going to be the most appropriate for a dog presenting with a seizure.
Dogs less than 6 months of age are more likely to have seizures caused by infections. These dogs may best be assessed by collecting fluid around the spinal cord to look for evidence of common infections. Alternatively, a blood test may be performed depending on which infection is most highly suspected.
Animals between 6 months and 6 years of age may be more likely to have canine epilepsy. This diagnosis is concluded when no other cause can be identified, or when all other causes of seizures have been ruled out. Blood work and possibly imaging of the brain may be undertaken to rule out other possible causes. Schnauzers, Basset Hounds, Collies and Cocker Spaniels tend to be over-represented. Labrador Retrievers and Golden Retrievers are predisposed but often start their seizures later, around 5 years old.
Animals older than 5 years old are more likely to have an organic brain problem such as a brain tumour or a vascular accident. Advanced imaging of the brain is often required to reach these diagnoses.
When to Begin Treatment
Treating seizures in dogs may be undertaken, if they fall into one or more of the following categories:
- When seizures occur in "clusters," that is, more than 3 seizures within a 24-hour period.
- When two or more isolated seizures occur within a six-month period.
- If a seizure has lasted 5 minutes or more.
- If the seizures or their post-ictal disorientation periods are particularly severe.
- If the dog has a visible structural lesion on a CT, MRI or even a radiograph.
- If the dog has a history of brain injury or trauma.
- German Shepherd dog, Border collie, Australian shepherd, Golden retriever, Irish setter, and Saint Bernard breeds are notorious for difficulty in seizure control. It is best not to wait for frequent seizures in these cases as each seizure makes the next more difficult to control. Often medication is started in these individuals after the first seizure.
There a several good medications used to treat seizures in dogs and, at Vet-O, we are happy to discuss these with clients in order to help control seizure disorders. In general, if a dog has a seizure at home the key things are to prevent any harm coming to your pet and avoid getting bitten during the seizure or in the post-ictal period. If a dog has cluster seizures or the seizure continues for longer than 5 minutes, this is an emergency situation and your pet should be taken straight to an emergency centre.
Reference: Veterinary Partner