A seizure is one of the scariest things to watch a dog go through, but what about events that look like seizures? I have many cases where patients come in that have “fainted.” They often become stiff and fall to the ground which can easily look like a seizure. After a complete physical exam, a thorough history, and diagnostics, the veterinarian diagnoses the patient as having a syncopal episode.

What is syncope?

Syncope is a sudden loss of consciousness that can look like fainting or passing out. It is caused by a temporary lack of blood flow or oxygen delivery to the brain. Hypotension or low blood pressure is most commonly the underlying cause of the disruption of blood flow however there could be other reasons. Some of those reasons include heart disease, emotional stress or anxiety, low blood sugar, abnormalities in blood electrolyte levels, as well as specific actions such as coughing, urinating, or defecating.

How is syncope different from seizures?

When trying to differentiate between a seizure and syncope, the clinician evaluates 3 main factors: Actions prior to the event, what the episode looked like, and how quickly the patient recovered.

  • Actions prior to the event: If your pet was doing some sort of activity such as running, excessively barking, coughing, urinating, or defecating, it could be a syncopal episode. Syncope is typically triggered by activity. Seizures can happen during activity or rest, but are typically not triggered by anything specific. Seizures are also typically preceded with whining or anxiety, which can be part of the pre-ictal phase (ictal=seizure). Syncopal episodes typically happen quickly with no warning.
  •  What did the episode look like?: Sometimes it is difficult to determine the different between the actions during a syncopal episode and a seizure, even for an experienced clinician. One main component that we evaluate include movement. If your pet goes limp, it is more likely a seizure. Sometimes patients that try to get up after a syncopal episode have so much trouble that their legs flop around in an uncoordinated fashion. Seizures also create movement of the legs, but typically these movement s include rhythmic paddling or stiffness and tremoring.
  • How quickly did the patient recover?: Patients that experience a syncopal episode recover almost immediately. The whole episode lasts seconds. A dog that experiences a seizure often shows prolonged disorientation or lethargy after an episode (named the post-ictal phase).

How do you treat syncope?

It is imperative to find the underlying cause of syncope, so it can be treated appropriately. Heart disease is the most common underlying issue. Unfortunately, if your pet is in heart failure, medications can be started to slow down the progression of the disease, but it will not fix the heart failure. The syncopal episodes will therefore be managed and possibly slow down. If your patient’s heart failure is quickly progressive, the syncopal episodes may even become more frequent.

Hopefully you will never have to witness this in your pet but if you do, now you have some more information that may make the event a little less scary. Of course if you think you have seen a seizure or a syncopal event (or you are not sure which one it was), please call your primary care veterinarian or us if it is after hours. It is very important to diagnose and treat the underlying cause.