Syncope vs. Seizures

Let me start by saying I’m not a veterinarian or any sort of medical professional. This is not medical advice; please, always talk to your vet if you think your dog has had a syncope or seizure event!

Indy recently had several episodes where he lost consciousness, and I mistakenly assumed they were seizures. However, since he definitely has congestive heart failure and pulmonary hypertension, syncope is way more likely.

Roxy, my other dog, has had seizures intermittently since 2015. You would think I’d be good at identifying them by now, but it’s not that simple.

Roxy’s seizures are—I think—partial seizures. She doesn’t entirely lose consciousness, but her body goes rigid. Typically one of her front legs contorts and is raised by her face while her head twists and pulls back. There’s not really any convulsing, she doesn’t seem to have any pre-seizure warning behaviors, and post-seizure, she seems completely normal within minutes. Her first seizure was after a head trauma during dog agility, and she has one or two per year since then. As much as she loved agility, we retired after her injury.

What happened with Indy was very different. In the first two recent incidents, he was sleeping on the sofa while I watched tv. I heard a strange-sounding bark from Indy, and when I looked over, he was limp and twitching (maybe?). The twitching stopped quickly, and he seemed a bit out of it for 10-30 minutes. The third was very similar, except it was just as we were waking up one morning.

Indy with his head on a blue stuffed toy.

The most recent two were unlike the others. These are the ones that I think are more obviously identifiable as syncope events. In both cases, we were getting ready for a walk. This is usually one of Indy’s most favorite things, so he gets very excited. In both incidents, he was wobbly and had trouble walking/standing. Before I could reach him, he fell over. I picked him up, and it seemed like he was twitching, but I now think he was just limp and flopping about a bit. Both times he urinated just after I picked him up, then let out a strange bark. Shortly after, he was back but dazed.

Seizures or syncope, either way, are pretty scary to witness!

And, in retrospect, Indy has fainted before! Once when he was a puppy and another dog pounced on him, and again about seven months ago while we were on a walk.

How Can You Tell?

Syncope is not a common term, at least outside of medical use. I wasn’t even sure what the vet meant when she asked if I was sure it was a seizure and not syncope. A syncope event means fainting or a sudden temporary loss of consciousness., often due to a lack of oxygen to the brain.

Seizures, on the other hand, result from abnormal electrical activity in the brain and often present as a loss of consciousness accompanied by convulsions.

Here’s where it gets tricky – not all seizures cause convulsions, and some syncope events can present with jerking movements that mimic convulsions. A fainted fallen dog might also paddle their legs while trying to get back up, which can look very much like convulsions. When Indy fainted on a walk, the leg paddling made me think it might have been a seizure, but it’s more likely he was trying to get back up after fainting.

Vocalizations, urinary incontinence, and other symptoms can accompany seizures or syncope events. Seizures can also be partial seizures without a total loss of consciousness, and these can be a lot different from full (tonic-clonic or grand mal) seizures. What this means is that it’s really hard to be sure what’s happening if your dog has any or all of these symptoms.

What About Indy?

So, why do I think Indy’s episodes are syncope? Well, he has CHF and pulmonary hypertension. Comet had CHF, and one of the first symptoms was that he fainted one morning while pooping. (This may sound funny, but again, seriously scary when your dog falls over suddenly for no apparent reason.)

Indy on the way home from the hospital.

Also, in the last two events, Indy was clearly wobbly, lost control of his legs, and then went completely limp and fell over. This is not consistent with seizures where a primary identifying characteristic is a stiff or rigid body.

The confusing bits were the barking, twitching, urination, and how long he was dazed after. However, none of this rules out syncope.

One of the biggest things that stood out to me was the thought that, clinically, we should default to assuming syncope over seizures (especially for intermittent episodes) until proven otherwise. Syncopes usually indicate an underlying disease that needs immediate treatment. Epileptical seizures, however, won’t cause much harm if a diagnosis is delayed.

I found these articles very useful in my research:

For now, Indy is waiting on a follow-up with his cardiologist, taking some heart medications. And, until we rule out seizures, he has an upcoming consult with a neurologist.

Indy is happy to be out of the hospital!

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