Secondary Epilepsy in Dogs

Epilepsy is a disorder of recurring seizures that usually become more frequent with time. A seizure is a disruption of nervous system function caused by abnormal electrical activity in the brain. Epilepsy in dogs may be a primary condition but it is often a secondary condition caused by another associated ailment.

Symptoms of Epilepsy in Dogs

During a seizure, the dog's body systems are inactive or involuntary for a period of seconds or minutes. The seizure may begin with what is referred to as an aura phase. During this time the dog may be restless, vocalizing, agitated, staring and seeking privacy or attention. This is followed by 10 to 30 seconds of a grand mal seizure, during which a dog may exhibit:

  • Collapse

  • Extended rigid limbs

  • Unconsciousness

  • Respiratory arrest

  • Uncontrollable paddling of legs

  • Involuntary urination and defecation

  • Abnormal jaw movements

Upon regaining consciousness, the dog 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.

Potential Causes of Secondary Epilepsy

Secondary epilepsy can be caused by sudden injuries or trauma such as:underlying medical conditions. If the dog is not suspected of having suffered a recent injury, then an underlying medical condition may be the cause of epilepsy. Potential injuries or disorders include:

  • Head injury

  • Hypoglycemia

  • Low blood calcium

  • Hypothyroidism

  • Kidney or liver problems

  • Electrical shocks

  • Poisons

  • Milk fever

  • Encephalitis (inflammation of the brain)

  • Hydrocephalus (fluid accumulation in the brain)

  • Heat stroke

  • Brain abscess or tumor

  • Parasitic Infestation

  • Stroke

  • Vaccine reactions

Diagnosis of Secondary Epilepsy and Associated Conditions

If epilepsy is suspected, a record of seizure activity should be kept and then shown to a veterinarian. The veterinarian will recommend laboratory blood work to help determine causes such as hypoglycemia, hypothyroidism or organ disorders. A fecal analysis may be done to rule out parasitic infection as the cause of secondary epilepsy. A CT scan may be recommended if a brain condition, such as encephalitis or hydrocephalus, is suspected. Cerebrospinal fluid analysis is usually only done if another cause is not found or if a viral or bacterial infection is suspected.

Preparation for Seizures and Treatment of Epilepsy

Treatment of secondary epilepsy varies significantly and is dependant upon the primary disorder that is causing it. It is important to be prepared for seizures until the underlying cause of epilepsy can be determined and corrected. Anti-epileptics or anti-convulsants may be prescribed to reduce the occurrence and severity of seizures, but they are not entirely preventative.

A carrier lined with a towel can secure the dog and prevent injury from involuntary movements. The dog should be handled or moved minimally. Dog's cannot swallow their tongue while experiencing 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 in the dog's environment. Stimulation can prolong a seizure or instigate repeated ones. If the dog experiences an observable aura phase, this time can be used to prepare.

Seizures that last longer than five minutes or occur repeatedly, without regained consciousness, are emergencies. The dog's temperature will continue to increase, prompting more seizures. This may result in permanent brain damage or death.