Bingo – likes to make me worry – Page 5

Keymaster

Vally,

This is an interesting and puzzling (and frightening) thing happening to Bingo.

Let me tell you about Chance and see if this sounds familiar to you. After he recovered from treatment for his bone marrow failure he returned to relatively normal life. For about 2.5 years he was fine but then he started having similar symptoms. He started “tipping over” while walking. He would act a little dizzy and then down he would go. He would sometimes paddle his feet and cry out.

Of course I started with my local vet. The chest x-ray showed an enlarged heart. Immediately we saw the specialist. He did a variety of tests on the heart, including an echocardiogram. He was diagnosed with a mitral value deficiency and an arrhythmia. This would eventually worsen and would lead to congestive heart failure. He put Chance on several heart medications and he improved significantly.

Over several visits, and with more information from me, the specialist and I talked about these collapses. I had taken a video showing Chance doing this and he confirmed what I also felt, though this looked like it could be a seizure, it was not.

I described that I had noticed this seemed to be preceded by several things, one of which was taking a large drink of cold water. Then he would cough or gag and then a short while later he would collapse, just as you describe. He would also set himself off by barking.

So the specialist gave me a veterinary research paper that described the effect that the vagus nerve can have on a dog’s heart. This large nerve runs through the neck. In particular, with the anatomy of a dog, this nerve runs more horizontal than it does in a human, under the neck of the dog, where it can be compressed. Coughing (or eating) can lead to more pronounced pressure on this nerve. This stimulates this nerve in a variety of ways.

“Vasovagal syncope occurs in response to a trigger, with a corresponding malfunction in the parts of the nervous system that regulate heart rate and blood pressure. When heart rate slows, blood pressure drops, and the resulting lack of blood to the brain causes fainting and confusion” (This is simply describing fainting!)

There is a significant list of things that can trigger this response. But one in particular of note is “Violent coughing.” We discussed Chance drinking cold water, followed by coughing or gagging or perhaps his barking and how that could be causing this vasovagal syncope.

There is a significant difference between seizures and syncope. A seizure takes longer to start, during this time the dog seems less alert. During the seizure the dog is most likely not alert at all. They may take a long time to recover after a seizure. A dog that has a syncope can be walking along fine, begin to wobble and down they go. They can paddle or vocalize (which may happen in seizures) but if you look in their face you see they they are conscious. After only a brief time they will recover, get up and continue on as if nothing happened. This was Chance. Down in an instant and a few minutes later trotting home again like nothing had happened.

We agreed that this was the most likely cause of his irregular heart rate and the reason why he was having these frightening episodes. I was also approached by one of the vets at my clinic who explained that she had this condition and she had to be careful herself about compressing this nerve or she would go down in a heap.

The dog’s heart is quite close to the throat and when it enlarges, it can actually compress the neck and that is why coughing is one of the first signs of canine heart conditions.

So our goal was to treat the fluid buildup around the heart, helping it to reduce size to normal. I also started giving Chance tepid water, no more cold drinks. I also reduced the amount of water he could get at one drink. Giants can drink an incredible amount of water!

You are right on about the use of a harness. If this is what is happening with Bingo, it probably reduces the compression of the neck as well.

So it might be a wise thing to have your vet do a bit of a heart workup in the office to see if everything sounds good.

Even without a heart problem, a dog’s anatomy can cause abnormal compression of the neck. It might be good to reduce the amount of water and food he can get at one time so there isn’t a lot of gulping and stimulation of the neck. If this were me, I might try to slightly elevate the food bowl to avoid severe forward bending of the neck.

There is no specific test, only using a 24 hour Holter Monitor can possibly pinpoint this because the owner keeps a diary of each activity and can note when there was a collapse. We used this with Chance but he didn’t have an episode during the time he had the vest on.

If you want to read about it:

http://en.wikipedia.org/wiki/Vasovagal_response

This is a somewhat complex paper about this condition in small dogs:

http://www.cliniciansbrief.com/sites/default/files/sites/cliniciansbrief.com/files/0404_whattakehome.pdf

Read this article directed towards owners:

http://www.vetspecialistsofsfl.com/cardiology_articles_Syncope.html

If any of this sounds like it could be the issue, take these papers with you to your vet so that they can see you understand this condition. They may be able to say one way or another whether this is the case with Bingo. They can help you treat any possible conditions that are contributing to this.

my best, patrice

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