Epilepsy causing recurrent seizures affects around 0.5-1 percent of dogs, with significant welfare impacts from the seizures themselves, interictal behavioral changes, and medication side effects.
Seizures themselves cause significant welfare harm. The clonic phase of a generalized seizure involves violent involuntary muscle contractions, loss of bladder and bowel control, and apparent unconsciousness. The post-ictal phase causes confusion, blindness, exhaustion, and anxiety that may last hours. Frequent seizures cause cumulative brain damage and progressive cognitive decline. The chronic unpredictability of seizures causes anxiety in both dogs and owners, with dogs becoming fearful of situations associated with previous seizure occurrence. Status epilepticus causes severe metabolic disruption including hyperthermia, hypoglycemia, and lactic acidosis that can be fatal or cause permanent neurological damage.