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How to Tell the Difference Between Seizures and Syncope in Dogs

Miriam has been a freelance writer since 2013. Born in Whittier, CA, she now lives in Ontario (California) with her husband and family.

Shadow resting quietly.

Shadow resting quietly.

Seizure vs. Syncope: Learning From Experience

Shadow's Episode

Shadow is the 11-year-old male Chiweenie we take care of for my niece. He's been under our care for the past two years, and we fell in love with this little guy.

One day, Shadow was getting ready to take a walk with Jerry (husband) at 8:00 a.m. when all of a sudden Shadow's legs sprawled out to the ground, stiff, looking like he had no control over his body. Then he fell to his side and urinated on himself, looking bewildered and scared.

Shadow was in a daze, or in shock, for some time afterward. After a few hours, he started to act more normal, but he was moving very slowly.

Visit to the Vet

After telling the vet we thought Shadow had a seizure, she checked him out with a stethoscope and found he had a heart murmur. The vet said what happened to him was not a seizure, but something called syncope (pronounced sin-co-pay), a symptom caused from the heart murmur.

She said he was unlikely to have another episode, but if he did, she recommended that we bring him back in and she would prescribe heart medication for him.

Another Episode

Two nights later, when I went to the garage, I left the door ajar so Shadow could come out if he felt like it. After a few minutes, here he was walking in to see me. I talked to him and pet him, and then he started walking away.

He started coughing (like he always does), so I went over to him to keep him calm. I spoke softly to him and pet his neck and back, but it was of no use. His legs started collapsing from under him and his neck seemed stiff; I freaked out.

I saw that he was having another syncope reaction, and I was scared. I tried yelling for Jerry (husband), but he did not come out. It seemed like nobody was home, it was so quiet, and I was crying out for help!

Shadow Helpless to His Own Body

I watched as Shadow flinched from side to side on the floor of the garage and wondered if he was going to be all right. Then, after what felt like a long time (15 to 20 seconds), the episode stopped and Shadow just stayed on the floor—he was afraid to move.

Finally, Jerry and my son, Chester, came running out. I told them what happened, and Jerry picked Shadow up and brought him into the house. Then I called my sister Monica to let her know what happened to Shadow.

Back to the Vet

Monica took Shadow to his vet a couple of days ago, but the doctor also told Monica that she would prescribe Shadow heart medication if he had another episode of syncope, which she said was unlikely.

Heart Meds for Shadow

Monica was able to get the prescriptions filled for Shadow without having to bring him in to see the vet again.

The vet prescribed Shadow half a pill of Furosemide (diuretic) and half a pill of Enalapril maleate (heart medicine), once in the morning and once in the evening.

He is doing well so far, but I also pray for him every night just to be sure.

How to Recognize Syncope From a Seizure

Here are the differences between a syncope and a seizure.


The first time your dog has a seizure or syncope, you will think it is a seizure because it looks as if the dog's body is seizing up on him. However, seizures are produced by irregular brainwave patterns that can be controlled with epilepsy/seizure medication.

If your dog is having a seizure, they might start drooling, but they do not always lose consciousness. Their body will seize-up, becoming rigid, and they will convulse uncontrollably on the floor.

Once you recognize there is something wrong (seizure or syncope), please make sure the dog is not going to fall or bump into anything that they can hurt themselves on. Move large objects away from the area where your dog lies, but do not try to put anything in their mouth—the dog cannot control their movements and could bite your finger off!

Seizures can be very violent and last anywhere from a minute to several minutes. Once it is over, your dog will be tired and in a fog. Seizures have about a four-hour recovery period.


If your dog is having syncope, they will suddenly pass-out (faint) and then quickly regain composure. It is almost like they nodded-off (fell asleep and quickly woke up).

I posted a couple of videos that show what a dog looks like when it has syncope. Some dogs hardly seem phased. The dog just almost falls, then resumes walking as if nothing happened.


In Shadow's case, he did not faint. Jerry was getting ready to take him for a walk, as usual. He was going to the front yard through the back gate, his leash on his collar. All of a sudden he was sprawled out on the ground. Jerry said that after that he rolled onto his side, then he urinated. He was confused and seemed dazed. He just stood there. I petted him and told him he was okay, and after a few hours he was his old self again.

I found out that what Shadow had was "presyncope" because he did not lose consciousness (faint). I hope we got him on medication early enough that he will never faint—and I hope this syncope never happens again. It is pretty scary to watch your dog and not be able to help them!

General Descriptions

My description of what a seizure or syncope might look like is a generalization of some of the symptoms your dog might display during an episode. Some seizures can be worse or less dramatic, and the same goes for syncope episodes.

Do not try to diagnose your dog by yourself, it is best to get professional advice from a veterinarian. They will make a brief physical examination of your dog, including listening to their heart and lungs, before making a diagnosis for your pet. If your dog needs medication, a prescription will be written for your dog that will help their condition.

Call Your Vet ASAP!

If your dog has any type of seizure or syncope episodes call the vet as soon as possible! In some cases seizures or syncope can lead to sudden death so it is vital that you call your vet if your dog exhibits seizure or syncope symptoms.

What to Do During a Seizure or Syncope

If your dog is having a seizure or syncope episode, stay calm so that your dog does not get frightened! (I acted totally wrong by freaking out when Shadow had syncope!)

Do not freak out because this does not help your dog. You should remain calm and talk softly to your dog. "You're going to be okay, Shadow" is what I should have said instead of screaming for help and getting excited.

Other steps to take during your dog's episode:

  • If there are any tables, chairs, or other objects that your dog might hurt him/herself with during the seizure or syncope, please move them away from your dog so they don't hit their head on them.
  • Do not try to put anything in your dog's mouth! A seizure is unpredictable, if you put your hand in their mouth your dog cannot control the outcome and may bite your hand.
  • Seizures can be violent, so wait until the episode is over before approaching and consoling your dog.
  • Syncope episodes are short, but do not approach your dog until it is over, just to be safe.
  • If you remember, take photos of your dog during the episode or video record it. This is very valuable information to your vet!
  • Also, write down exactly what happened, the date and time it occurred, what your dog was doing prior to the episode, and the duration of the episode. Bring this paper with you when you visit your vet.

Graphic Videos Below

Below are two graphic videos of syncope.

Charting the Symptoms of Seizures and Syncope

Charting the Symptoms of Seizures and Syncope --


Has a history of seizures

Triggers: coughing, barking, tugging on collar with leash

Is not initiated by triggers

Pre-symptoms: nausea, blurred vision, headache, dizziness

Has pre-symptoms ("aura")

May be anxious, clingy, or want to hide

Muscles become rigid or stiff

Suddenly loses muscle control. Legs flacid, collapse.

Convulsions begin after dog faints

Convulsions at onset of fainting

Seizure duration 2 minutes +

Episode of short duration: Usually less than 15 seconds, but can be as long as 2 minutes maximum

May drool, bite tongue, urinate and defecate

May urinate

Recovery about 4 hours

Recovery is almost immediate

After seizure: confused, sleepy, headache

After syncope: dog lethargic, but not confused

Handsome Chiweenie, Shadow

Handsome Chiweenie, Shadow

Graphic Video:

Below is another graphic video of what appears to be Syncope.

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

Questions & Answers

Question: my dog is having seizures related to a heart condition. He screamed badly during the last one. Can you explain to me why this happens?

Answer: I don't know why your dog screamed, probably because he didn't know what was going and was scared. My dog, Shadow, died during a seizure, so be sure to have a vet prescribe him something for his heart.

© 2014 Miriam Parker

Please Post Your Comments Below

TriggerTo3s on April 27, 2019:

Did you try measuring her heart?