By Jennifer Coates, DVM
Epilepsy is a disease that is characterized by recurring seizures. Some dogs have sporadic and mild seizures, while others have severe seizures that last a long time and occur frequently. Because seizures come in so many forms and can be caused by a number of diseases, it can be hard to determine whether or not a dog has epilepsy. Recognizing the four primary signs of epilepsy can help.
Seizures can take many forms but all are caused by abnormal, involuntary electrical activity within the brain. A generalized or “grand mal” seizure is the most dramatic because a large portion of the brain is affected. Dogs undergoing generalized seizures will fall down, paddle or stretch out their legs, may urinate and/or defecate, and are totally unaware of their surroundings. A smaller portion of the brain is affected when dogs have partial seizures (also called focal or petite mal seizures). Dogs who are having a focal seizure are usually aware of their surroundings and their unusual movements are limited to a specific part of their body (e.g., one leg will kick out repeatedly). Seizures of any type can last for just a few seconds or continue for many minutes.
Before dogs have a seizure, they often act restless or behave in an abnormal way. This is called the aura, or pre-ictal stage. We don’t know exactly what dogs are experiencing during this time, but people with epilepsy describe a variety of symptoms, including seeing bright lights or spots, hearing strange sounds, smelling odd odors, or experiencing a feeling of tingling, numbness, nausea, or anxiety.
The aura typically lasts anywhere from a few seconds to several minutes but a dog’s behavioral changes may be subtle enough that it is difficult to identify this stage until you recognize what you are seeing.
The post-ictal phase occurs immediately after a seizure. Dogs often appear confused, behave in abnormal ways, and have difficulty walking. This stage may continue for a few minutes or for several hours, after which dogs completely return to normal—unless a lengthy seizure has caused permanent neurologic damage.
Many different diseases can cause seizures. Before a dog can be diagnosed with epilepsy, other conditions like low blood sugar, hypothyroidism, liver disease, kidney failure, toxic exposures, infections, trauma, and tumors or inflammation of the brain need to be ruled out. To do this, a veterinarian will perform a thorough history and physical and neurological exam, and usually will order blood work, a urinalysis, and a fecal exam. Sometimes analysis of a sample of cerebrospinal fluid or an MRI or CT scan will also be necessary to reach a definitive diagnosis.
While scary to watch, most seizures are not in and of themselves all that dangerous to the dog who experiences them. In extreme cases, however, seizures can be life threatening. When dogs experience any of the following, they should immediately be taken to the nearest veterinarian:
- A seizure lasts longer than five minutes (not including the aura and post-ictal phase)
- When seizures come in clusters so that the dog cannot fully recover between episodes
- A dog experiences more than three seizures within 24 hours