I'm stumped

My 10 year old dog was diagnosed with a grade2/3 heart murmur last week. He had been increasingly lethargic and exercise-intolerant, restless at night, and unable to sleep. He doesn't cough. He is lethargic and exercise intolerant.

Vertebral heart score didn't indicate an enlarged heart, but showed soft signs of edema. His blood work was fine, and his NTproBNP score was 500, well below the 900 cutoff.

He's been on 20 mgs of furosemide and 5 mg of fortekor for three days now. There's improvement in his breathing and comfort at night, but he's still lethargic and tires easily on walks.

I'm stumped--how can his tests be relatively normal, but he's obviously sick?

Anyone have experience like this? I should add that he's always been considered a cavi-mix, although he's never had genetic testing.

Hi,
Sorry you're going through this. My Leo was diagnosed with CHF last year. He too was lethargic and his breathing harsh....he was also quite exercise intolerant. Since the meds started he's improved greatly.....he cant walk for hours like he used to, after an hour he slows down....some days are better than others....
Maybe your little guys meds need to be tweeked. Speak to your vet and ask...when is your next heart review? I'd chat then and see if things can be improved.

Good luck

Is the vet/cardio sure it is his heart that is causing the lethargy and disinclination to walk? Could there be another cause for this -- disk disease, possibly syringomyelia, arthritis?

Did a cardio talk through the results and why they might produce symptoms?

Just thinking maybe his heart isn't actually the issue, as some of those symptoms are typical of disk disease, or SM (syringomyelia) as well (possible restlessness, exercise intolerance, lethargy).

So sorry your little guy is ill too. The vet is tweaking his meds next week. He's going down to 20 mgs of furosemide a day. So far he's doing very well, but it's strange that his symptoms don't match his medical testing.

She's not sure at all, as a matter of fact, that it is MVD. She's treating it symptomatically. I don't have the funds to pay for a cardiologist or an ultrasound, unfortunately. He doesn't have physical pain or any signs of arthritis.

It's strange to me that it's all or nothing with canine heart disease: either a dog is asymptomatic with a heart murmur, or if they're symptomatic they're in heart failure. Buddy's NTproBNP test clearly shows he's not in heart failure (thank god), but he is symptomatic. I'm going to do some reading on syringomyelia and see where that takes me. Thanks for the tip.

MVD isn't really all or nothing, though it sure can seem that way because generally, after a long and slow decline, things start to happen that tip the dog closer or into CHF and symptoms become apparent. Then CHF of course tends to progress, creating more symtpoms that seem to come on very fast. But I've had cavaliers that have had asymptomatic murmurs for years and years. As with humans, either genes, or lifestyle, or a mix of both can make progression faster. I've two 10 year olds with barely audible murmurs, who;ve had them for years. The cardiologist considers them to be in excellent health with excellent hearts as the murmur is sol minor. (though worth noting that grade of murmur doesn't always connect to how bad the MVD is or whether a dog is in CHF).

I've one cavalier that held at a grade 4 murmur for three years or so, with no symptoms, then suddenly tipped very quickly into CHF and is now exercise intolerant, etc. But of course all those asymptomatic years he was slowly moving towards this point. The cardio saw him 5 months ago and was very impressed with his stability; so change came very fast. But also, conversely, some dogs just stay at the same level and never really worsen at all. Those ones depend mostly on genes I think!

From your description it sounds like the issue *possibly* may not be his heart. Might be worth just doing a good vet exam looking for signs of pain?

that's the confusing part for me regarding Buddy. He's not in congestive heart failure, according to his blood work. But he's not asymptomatic either.

In other words, can't a dog have a heart problem, be symptomatic, and NOT be in congestive heart failure? That's the case with humans all the time--they have heart disease and tire easily, etc, but they aren't in congestive heart failure.

I think part of the puzzle is that humans can have a greater variety of heart diseases, and with MVD we are talking about one very specific disease.The murmur is early warning that the mitral valve is beginning to wear out and not close completely, so allowing blood to seep into the upper chamber of the heart. So far the heart muscles can still manage to push the regurgitated blood round the body. but some dogs will cope better than others, just as some human bodies cope better with angina than others, for example. Some dogs will get more easily puffed and so find exercise uncomfortable; some may have fluid accumulating in the lungs - but generally the heart is still able to keep on top of the situation. Congestive heart failure occurs when the mitral valve finally becomes useless and so much blood is going where it shouldn't and having to be pushed out and round the body that the heart can't keep up with it and doesn't have enough muscle power to keep the body healthy. That's when drugs are needed to strengthen the heart muscles and keep the heart beating steadily, and to prevent fluid accumulating in the lungs and elsewhere. Grades of murmur are generally indicators of how far the mitral valve has deteriorated - ie how much blood is getting past it - but they can't measure the ability of the heart muscles to cope with this problem, symptoms are indicators of that. Some will cope better and for longer than others. In heart failure the heart stops coping and has to be supported.

That's how I see it anyway (having had 3 of my 5 Cavaliers in heart failure over the years) - if I'm wrong I'm sure someone will put me right! Some vets seem to equate a 3-4 murmur with being in or near heart failure (and many - but not all - dogs with that grade will be heading in that direction) and will start giving heart strengthening drugs much too early, when in fact the heart is still able to cope and strengthening drugs will send it into overdrive and it will wear itself out more quickly.

My Aled went into heart failure 8 weeks ago, with very little warning - the valves on both sides of his heart finally wore out and were fluttering uselessly and the heart was trying desperately to keep things going (heart rate 220 instead of the normal 70-120) and not really succeeding; with other dogs you may be dealing with one symptom and then another, but in general the heart is managing to keep going, though overall it is losing the battle.

There's a very good article on MVD and heart failure on the Cavalier Matters website, which supports your feeling that a dog can have individual symptoms without actually being in total heart failure.

Kate,Oliver and Aled

I'm so sorry about your little Aled. I think all you cavi parents are so wonderful--I don't know that I could deal with this over and over again like you do.

I think my Buddy must be part person--his heart problem more resembles a human problem than a dog problem.

I deal with it, but it makes me very angry. Unlike CM/SM, where the genes are likely to be multiple, the inheritance of heart disease in Cavaliers is fairly straightforward. It should then be relatively easy to breed it out - you have your dogs checked regularly and you don't breed from any dog with a serious murmur (ideally with any murmur at all, but this could have repercussions on the gene pool). This has been recognised for years - and is a recommended protocol of the UK Cavalier Club - but still breeders ignore it. Aled is a rescue from a puppy farm so health didn't come into his breeding at all. He's doing well, gradually taking more exercise and returning to a normal routine, but you can see his heart pumping away like mad, supported only by the drugs that strengthen the heart muscles and regulate the heart beat. It seems so unfair when he had a bad start in life and also has CM/SM, and he is such a nice dog.

Kate, Oliver and Aled