Senior Dog Syncope, Seizures, Stroke, and Heart Attack Part 1

Dog During Syncope

Last night, or should I say this morning, at around 5:30am, Jet had a syncopal episode.

Jet has had this happen before, it’s a direct result of his heart disease. Last night’s episode was the worst yet, though.

As I sat with him, comforting him, I remembered the first time that it happened and how confused we both were. So today, I wanted to address syncope in senior dogs and other concerns that are often confused with syncope – seizures, stroke, and heart attack.


Tired Senior Dog


What is Syncope?


Let’s begin by taking a look at syncope.

Syncope is a loss of consciousness that is most frequently caused by a drop in heart rate or blood pressure that causes insufficient blood flow to the brain. It can happen in humans and in our pets. Syncope in dogs is sometimes referred to as “fainting.”

Syncope in dogs is sometimes referred to as “fainting.” It is a SYMPTOM and not a disease.


What Causes Syncope?


There are a few different causes of syncope, ultimately anything that causes a sudden drop in heart rate or blood pressure and insufficient blood flow to the brain. The two main categories of illness that cause syncope are neurological or cardiological in origin.


Neurological Causes of Syncope


Neurological illnesses that can cause syncope in dogs include:


  • Epilepsy
  • Any abnormal brain activity


Cardiological Causes of Syncope

Cardiological illnesses that can cause syncope in dogs include:

  • Ventricular fibrillation
  • A-V block
  • Abnormal heart rhythm
  • Ventricular tachycardia


Other Causes of Syncope


In some situations, syncope can also be prompted by other events including:


  • Coughing
  • Pulling on the collar


What Happens During a Syncopic Episode?


When a dog experiences syncope, blood flow to the brain is insufficient. Most often this happens in older dogs with heart disease or abnormal heart rhythms. The alteration in heart function results in an alteration of the blood flowing to the brain which results in an alteration of the amount of oxygen being provided to the brain. This can result in episodes of syncope.

Syncopic episodes last from seconds to minutes and dogs spontaneously recover following them.

Syncope is NOT a very common occurrence in dogs, but when it is seen 2/3 of patients also have heart disease. It is estimated that around .15% of dogs experience syncope – the only problem with this figure is that owners often confuse syncope episodes with “simple” fainting, seizures, or other similar symptoms.


What Does a Syncopic Episode Look Like?


When Jet had his first syncopic episode I thought it was a stroke.

I knew it wasn’t a seizure because I have experience witnessing canine seizures.

When he has a syncopic episode, Jet usually coughs once or twice. Then he takes a couple of deep breaths in through his nose and as he breathes out, his lips puff out. If he is standing or sitting, he falls onto one side. Sometimes his legs will flail, sometimes he will lay there. He then leans his head back just slightly. His front legs stiffen out straight and then his back becomes rigid. His head arches back, creating a prominent curve in his neck.

If you have ever seen Jurassic Park or have experience in paleontology, this pose is similar to the “death pose” of many fossilized remains. (You can read more about it here at the American Museum of Natural History.)

Here is an image of a dog during a syncopic episode. The dog’s name is Teddy.


Dog During Syncope


Jet stays in this curved neck pose for a few seconds most of the time while breathing deeply. You can hear each breath coming in through his nose as if he were sleeping heavily. His eyes tend to fixate and blank out while still open. After a few seconds, his neck will start to relax and his front legs will unstiffen as he “comes to.”

Last night for the first time during a syncopal episode Jet cried out. He whimpered in an almost squealing pitch three times before his body unstiffened.

After unstiffening, Jet will be tired. For around fifteen minutes his breathing will be shallower than normal and then he will get back to normal breathing. He will then sleep hard for a few hours and upon waking up he will be back to his normal self. Once in a while, Jet will jump right up from a syncopal episode and act like nothing happened.


See a syncopal episode in “action” in this video that Teddy’s owner posted to YouTube.



If your dog experiences syncope, you should visit your vet as soon as possible. In most instances, if your dog’s syncope is the result of an existing condition that is being treated, your vet will re-evaluate your dog’s condition to determine if any changes in treatment need to be made. If your dog has not been diagnosed with a condition already, the first thing that your vet is likely to check is your dog’s heart health.


What Should You Do When Your Dog Experiences Syncope?


When your dog experiences syncope your first instinct is likely going to be shock or fear.

Since syncope episodes tend to be quite short, you probably still be panicking when your dog has regained consciousness.

If you are able to maintain your composure, however, you should first reassure your dog. Let them know in a calming voice that you are there and if you feel comfortable, you can stroke them gently. You should also try to get a general idea of your dog’s heart rate during their syncope episode. You don’t have to count the beats of their heart, but you should try to determine whether your dog’s heart is beating very quickly or very slowly, this information will help your vet in making a diagnosis.

If you are able, you should also try to take a brief video of your dog during their syncope episode. This is going to provide accurate documentation of your dog’s episode so that your vet can make a more educated diagnosis of your dog’s condition.


Most importantly, when your dog experiences syncope, you should stay with them until they regain consciousness and are breathing normally. Once this happens, you should contact your vet as soon as possible to arrange for diagnosis or treatment.


So how does syncope compare to seizure activity? Stay tuned for part 2 of this article series tomorrow!

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Next Senior Dog Syncope, Seizures, Stroke, and Heart Attack Part 2


  1. Chelsie C
    July 29, 2019

    Thank you for posting this. My 9 year old Shih Tzu experiences syncope episodes from Myxomatous Valvular Degeneration and it’s a hard thing to watch. This article helped me in learning more about the episodes!

  2. Beth
    October 16, 2018

    This page was such a blessing to find. I have been taking my dog to a cardiologist for years to monitor his heart. I talked with them about his “screaming episodes” and they never took me seriously. Since I found this page, I was able to call another vet to get me in sooner. Buddy is 15 year old Llhasa and when I told them about the increase in his episodes they were able to evaluate his previous echo-caridograms and agreed to see him tommorow. This posting may very well helped to save my dogs life. Thank you.

  3. Jen
    July 23, 2018

    Our 12 yr old Jack Russell has syncope episodes. Scares me every single time. She has been diagnosed with Congestive Heart Failure. She also has had a heart murmur for years. It got worse nearly overnight. I’m devastated. She is on meds but still having a few episodes here and there.

  4. Bernadette
    March 13, 2018

    My Great dane is experiencing exactly the same things, as the dog above. We took him to the vet and he said that he is too old to get a pace maker. He’s 8 now. He had an episode this morning again and his heart is beating quite fast during the episode. Must we put him down or just sit and wait for him to die? Is there absolutely no alternative meds for this condition? The doctor said that the heart size is normal and the blood tests also came back normal, but if he was younger, he would be a candidate for a pace maker unfortunately not at such a high age.

    • Stacey
      April 13, 2018

      My 14.5 year old Pomeranian started experiencing this just about 2 years ago. He was evaluated by a cardiologist and put on pimobendan, enalapril, lasix, and norvasc. In addition to mitral valve disease he had a pericardial effusion, which has since resolved. At first he had them for a few days in a row, I thought they were seizures, but his cardiologist confirmed it was due to his heart issues. Since then the episodes have decreased significantly to about once every 3 months or so and typically in the very early hours of the morning. My dog was also not a candidate for a pacemaker, but is still enjoying a good quality of life.

    • Jason
      June 26, 2018

      Who is your vet? Doesn’t sound like he is an actual animal doctor, sounds more like a moron. Yes, for your dog at age 8 he is old, however, what does this have anything to do with having a pacemaker put in? You don’t need to be a candidate for a pacemaker in a pet you own, this makes absolutely no sense at all. This is something you would say to a human being who needs a heart transplant but because he is 80 years old, he unfortunately is not eligible, thus not a candidate for the operation. Its important to note that the 80 year old man in my example is only eneligible for this procedure because he is not eligible to receive an organ from a donor at that age.

      So, regarding your old dog, that needs a pacemaker, you just tell your vet, I don’t care if this only helps him for a month I want a pacemaker put into him. Again, this is your dog and a pet, the doctor isn’t getting your dog an organ from a donor, he is putting in a pacemaker that you are paying for, along with his fee for surgery. Your Vet should make you aware that your dog may die in surgery and obviously you will need to understand the risk, however if your dog is going to drop dead from an out of sync heart, there is no risk, he may die in surgery, but at least he would die in no pain and also with you doing everything possible to prolong his life.

    • August 6, 2018

      My apologies for getting back to you so late, I hope that I can still be of use in answering your questions.
      Syncope can happen for a number of reasons and it’s important to find out why. What causes the sudden loss of consciousness is a sudden drop in blood pressure but a variety of things can cause this to happen. Some causes include blood loss, low body temperature, a disease of the heart muscle, anaphylaxis, sepsis, high body temperature, medication side effects, and severe dehydration. The medication recommended will depend on the cause of your boy’s syncope.
      I’m curious why a pacemaker is being considered if there is no abnormality of his heart? If the size is normal and function is normal for his age, I wouldn’t consider anything so drastic. My advice would be to keep pushing for answers to find out why your boy is having these episodes.

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