View Full Version : How do heart meds work?

30th June 2011, 01:55 PM
One of my Cavaliers was recently diagnosed with a Grade 2/3 murmur at a heart clinic. I am taking her in today, per the cardiologist's recommendation, for a baseline x-ray to be sure there is no heart enlargement at this point. He didn't seem very concerned with the murmur and we don't need meds at this point, he just recommended the x-ray and to keep an eye on it for now. I was talking to my husband this morning and he asked how the heart meds work. I started to answer him and then realized that I wasn't really sure as this is the first time I have dealt with a murmur with one of my dogs and I am really just learning all about treatment for it. (I can tell you a lot about SM since we have been dealing with that for a while. Luckily, my SM girl is heart clear).

So... how do the heart meds work exactly? I know that Enalapril is the first med, typically.

30th June 2011, 03:43 PM
Our Shih Tzu developed an early stage heart murmur when he got older - maybe twelve or thirteen years old? I freaked out, initially, as the dog had been über healthy all his life. Overtime, I realized it was just one-of-those-things and I gave the meds faithfully and never thought more about it.

The vet had an ultrasound done (I think that's what it was,,, it's been so many years ago) to verify the diagnosis. Enalapril is a human medication, and I was able to "Google" side effects and such, but Alex really never had any. He started to get a little senile around the same time and I always wondered if it was brought on by the Enalapril, but I truly doubt it, as that is not listed anywhere, as a side effect.

We gave him a half-tablet of Enalapril daily, and it worked very well for him, and never had to increase the dose. At the time of his diagnosis, he was being walked a mile or two a day, and our vet encouraged me to continue with that. He said the exercise would keep his heart in good shape and give him a better chance. The heart murmur never got worse and he died at 16 years from old age.

30th June 2011, 03:56 PM
I know the meds typically work well, but my question is more along the lines of what do the various meds actually do in the heart to help it work better? How do the meds work on the Jett?

30th June 2011, 04:41 PM
This might help you - how the heart works



there is a lot of information including how all the drugs work on http://cavalierhealth.org/mitral_valve_disease.htm#Symptoms

30th June 2011, 05:16 PM

This might also help, Brendan Corcoron explanation is very interesting and easy to listen to.

30th June 2011, 10:44 PM
I googled "enalapril for dogs" and this was the first result:
http://www.1800petmeds.com/Enalapril-prod10282.html (http://www.1800petmeds.com/Enalapril-prod10282.html)
Googling may answer a lot of questions, as I learned quite a lot from that one web site today.

2nd July 2011, 01:38 AM
Thank you for the replies. :) I knew I could gooogle, but I thought someone here might have a quick and dirty explanation for me. I stopped by Pat's house (from this board) and she loaned me a copy of one of her canine cardiology texts to look over. I told her I would try but I'm not sure that will make sense to me as it is very technical! :)

2nd July 2011, 09:20 PM
Thank you for the replies. :) I knew I could gooogle, but I thought someone here might have a quick and dirty explanation for me. I stopped by Pat's house (from this board) and she loaned me a copy of one of her canine cardiology texts to look over. I told her I would try but I'm not sure that will make sense to me as it is very technical! :)

Nicki mentioned the symptoms section of the MVD article on http://cavalierhealth.org, and I thank her for that link. I suggest that you also take a look at this section of that article --
http://cavalierhealth.org/mitral_valve_disease.htm#--_moderate -- as it goes into some detail about how particular types of MVD meds work.

The key of these meds is "maintenance" of the affected dog's quality of life. The most an owner may reasonably expect from these drugs is that the deterioration of the dog's heart is slowed and that the dog is able to feel as comfortable as possible. A bonus is that the drug actually reverses the enlargement of the heart, which does occur with some dogs and some of these drugs.

One thing I have noticed about many owners when they first find that their cavaliers have developed MVD murmurs is that the owners expect that they should be giving their dogs drugs immediately. The general rule among cardiologists is to not medicate cavaliers with low-grade MVD murmurs and no other symptoms. So don't jump to the conclusion that when you leave the cardiologist's office after your first visit that he is not doing his job when he doesn't give you a boat-load of drugs, like diruetics, ACE-inhibitors, and even Vetmedin (pimobendan).

If you want to learn just about everything there is currently to know about how to treat cavaliers with MVD, read the 2009 Consensus Statement issued by the ACVIM's board certified veterinary cardiologists: http://cavalierhealth.org/images/acvim_guidelines_ccvhd_2009.pdf Start at the bottom of the first column of page 1144 and read through 1150 and you will learn more than most general practice vets know about treating MVD.

3rd July 2011, 12:18 AM
Wow great document Rod, in the pdf.

Thank you for highlighting the point too that dogs do not need medications simply because they have a murmur. Generally they do not go onto anything until the higher grades but even then they may not need anything for some time. My Lucy was a grade 5 for at least a year before she started to need meds. She could do active long walks up til then, too.

Unfortunately most of us as cavalier owners will get to know one or more of these heart drugs eventually.

3rd July 2011, 12:28 AM
That's timely. I'd just posted looking for this information.

3rd July 2011, 12:35 AM
I've mentioned before that everyone should print that document and keep it in their files. I gave a copy to my GP vet also when it was first published and also cross-posted it to various other canine health groups. I've got to run out but I'll also try to post some other links later.

Also notice in this consensus paper that not all cardiologists agree 100% on when to start meds and which meds to give at each stage. I remember my cardiologist telling me many years ago that there is more "art" involved versus "science" than most clients suspect. There is often a trial and error approach that happens as the best regime is found for each individual dog and this process is a continual one.


3rd July 2011, 01:15 AM
I think that's very true. We tend to forget that trial and error and regular adjustment is the order for humans -- it would likely be the same for our dogs.