A seizure is a disruption of nervous system function caused by abnormal electrical activity in the brain. During these episodes the body systems are inactive or involuntary for a period of seconds or minutes. Epilepsy refers to a disorder of recurring seizures that usually become more frequent with time and may be idiopathic (with no known cause).
Signs and Symptoms
Canine behavioral signals of an oncoming seizure are called an aura phase in which the dog can be restless, vocalizing, agitated, staring and seeking privacy or attention. This is followed by approximately 10 to 30 seconds of what is referred to as a grand mal seizure, during which a dog will exhibit:
- Collapse
- Extended rigid limbs
- Unconsciousness
- Respiratory arrest
- Uncontrollable 'paddling' of legs
- Involuntary urination and defecation
- Abnormal jaw movements
Upon regaining consciousness, a dog in a post-seizure state may be disorientated and unstable for minutes or hours. Not all phases of a seizure may be observed and some dogs may experience phases while sleeping.
Causes of Seizures
Causes of seizures can vary from sudden injuries to underlying medical conditions, or have no known cause. Potential causes include:
- Head injury
- Hypoglycemia
- Low blood calcium
- Kidney or liver problems
- Electrical shocks
- Poisons
- Milk fever
- Encephalitis
- Heat stroke
- Brain abscess or tumor
- Stroke
- Vaccine reactions
Preparation and Treatments
A carrier that is lined with a towel or blanket can secure the dog and prevent injury from involuntary movements. The dog should be handled or moved minimally and only for safety, particularly if a head injury is suspected. A seizure that occurs at the time of a head injury can increase skull pressure and compromise circulation, worsening the injury. Dogs cannot swallow their tongues, so do not attempt to hold the tongue during a seizure.
A seizure burns a significant amount of calories and a dog can overheat quickly, so ice packs should be applied to the groin and neck. Reduce noises, bright light, movement and touch, because stimulation can prolong a seizure or instigate repeated ones. If the dog experiences an observable aura phase, this time can be used to prepare.
If hypoglycemia is suspected, karo syrup or honey can be applied to the gums at doses of 1 to 3 teaspoons, depending on size, during the seizure. The seizure will not stop until the blood sugar is normalized. If poisoning is suspected, 3% hydrogen peroxide can be administered. However, vomiting can worsen the effects of some poisons, so it's important to call a veterinary emergency clinic for instruction on immediate treatment.
Status epilepticus seizures that last longer than five consecutive minutes and cluster seizures that occur repeatedly without regained consciousness are both emergencies that require immediate veterinary attention. The dog's temperature will continue to increase, prompting more seizures, and may result in brain damage or death.
Anti-epileptics or anti-convulsants such as phenobarbitol, clonazepam, potassium bromide and clorazepate or the Valium diazepam may be prescribed to reduce the occurrence and severity of seizures, but they are not entirely preventative. Dosage and effectiveness is variable and stopping medication suddenly or administering the incorrect dosage can prompt seizures. Regular laboratory blood work is necessary to monitor drug levels for appropriate effectiveness and to avoid toxicity.