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Heart murmers are very common in OTTBs. My horse has one. Basically they are so fit due to their racing training, their hearts pump more blood than a "normal" horse and it weakens the valves. My vet showed me exactly where to put the stethescope to hear it. I'm surprised your did not do the same since you really should keep tabs on it to make sure it does not get worse with age.

All a heart murmer is, is leaky heart valves which creates some backflow as the blood passes through the 4 (I think) chambers of the heart. Depending on how severe it is, the amount of blood going backwards can reduce the amount that is going in the correct direction to the point of affecting the horse's normal blood flow to his body. Less blood flow equals less oxygen and results in easily tired horse.

Heart murmers are rated from stage 1 to stage 6. 1 is the mildest and affects the horse's performance hardly at all. 6 is the other end of the spectrum and you'd pretty much have a pasture ornament at that point. My TB is a stage 2 and he is not affected by it at all.

My suggestion to you would be to buy a stethescope and try to find the murmer. Instead of the normal lub/dub sound, you'll hear lub/dub/gush. Honestly, if you cannot locate it, it's probably on the low end of the scale which is good. If you want to see how much your horse is affected by his, there's a simple test you can do. Before exercise, take his heart rate. Listen for a minute and count the beats. Go for your ride and then listen again within 2 minutes of dismounting. That rate should be quite a bit quicker. Then take it again in 5 minutes. In the period between 2 and 5 minutes, his heart rate should return to where it was before you rode. If it stays higher, your horse probably has a higher grade murmer and it may affect his ability to do strenuous work. Do this for a week so you can make sure you have consistent results.

The only way you can tell for sure how much he is affected is to get him an EKG. They cost about $350. For me it was piece of mind and money well spent. Don't worry too much about it. They are very common in OTTBs.
 

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My suggestion to you would be to buy a stethescope and try to find the murmer. Instead of the normal lub/dub sound, you'll hear lub/dub/gush.
Really great info but I just wanted to clear up a few things for you guys. As MyBoyPuck already said, you should invest in a stethoscope (good to have to listen to the heart and the gut). To find the heart put your stethoscope behind the left front leg just above the point of the elbow and as close to the leg as you can get once you find the sound you can move the stethoscope around to hear the noise better. There will be 2 separate noises that both belong to one heart beat (lub/dub) but if there is a murmur it can be when the heart contracts (systolic) or when the heart relaxes (diastolic). If it is during contraction there will be a gush that connects the lub and the dub while if it is during relaxation it will be the lub/dub/gush that MyBoyPuck mentioned. If the gush sound is quieter than the lub/dub then it is a low grade murmur (probably a 2).

The only way you can tell for sure how much he is affected is to get him an EKG. They cost about $350. For me it was piece of mind and money well spent. Don't worry too much about it. They are very common in OTTBs.
An EKG (or ECG same thing) only measures the electrical activity of the heart so although it is a very useful tool for diagnosing rhythm problems that can arise due to a murmur it tells you nothing about the murmur itself. An echocardiogram (an ultrasound of the heart) is what can show you the degree to which a murmur might affect the horse. It shows you exactly what is happening inside the heart and with the fancy ones you can see the backflow of blood as a color change inside the chamber. An echo will also let you know why there is a murmur in the first place (could be thickened valves, stretched heart chambers, congenital deformations). Hope that explains things clearly :D
 

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Thanks for cleaning up my info. It's been a few years since my horse was diagnosed, so the terms have gotten foggy. My horse did get an echo. It was pretty cool to see all the colors. The vet said it's also a good baseline in case we ever need to see if it's getting worse as he ages.
 

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The vet said it's also a good baseline in case we ever need to see if it's getting worse as he ages.
Exactly :D Everything else you said was perfect, really good info.
Yes the colors are fascinating to watch and seeing the heart beat in real time is just too cool!!
 

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I ad a horse with a heart problem in the past. As myboypuck said about the lub/dub....my horse HAD no dub to follow the lub...if that makes any sense.
Not sure what had happened, how he was alive, and how hes still alive today. He got REALLY "sick" when that happened. I listened to it myself. I was also told he had a slight murmor as well that I could barely hear.
Ever since then I check most things having to do with a murmor and I have never heard of another horse having that problem before.
 

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I ad a horse with a heart problem in the past. As myboypuck said about the lub/dub....my horse HAD no dub to follow the lub...if that makes any sense.
Actually makes perfect sense and your description is spot on!! It is called 2nd degree atrioventricular heart block (or AV block). So it is actually alot more complex than this but think of the lub as the top half of the heart contracting and the dub as the bottom of the heart contracting. So basically with 2nd degree av block, the top(atria) contract but the bottom(ventricles) do not. The reason he is still alive is because it only does this "skipped beat" every three or four beats and those missed beats will go away when his heart rate increases (so you can jog him to make his heart go back to normal beats). This problem usually doesn't bother them at all and is only due to the strong natural stimulation from the horses parasympathetic system.
Can you explain more about him getting sick because of it though? As I said this issue normally does not cause any problems and you would never know it was happening until you listened.
 

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Masquerade, you seem to know alot about murmers. Do you know if a grade 2 tends to stay a grade 2 over a lifetime, or can you expect them to get worse with age? My boy was diagnosed at age 6, so I do worry about the long term implications.
 

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This is actually great cause I am supposed to be studying for my vet school final exams but you guys are letting me study and be on the forum at the same time!!
Anyways... back to your horse. Sometimes murmurs will progress but many times if the murmur is a low grade (less than 3) and it has not changed for quite awhile it is probably a physiologic murmur which does not affect them or their performance. Hopefully that is what your guy has.
 

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Thanks! Good luck on your finals. Sound like you know your stuff, so I'm sure you'll ace them.
 

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Yeah, the vet was in awww with what happened to him. We both called specialists in the west side of the state to see if they had seen or heard of anything. His heart wasnt pumping the blood at all, his limps had no circulation so I had to put 3 blankets on him. Of course it happened in winter. It didnt pump right for a little over a day and when the vet called the next day to offer his condulances(he REALLY shouldnt have lived), he was amazed he was able to walk more then a step or 2.
I even got videos if it, he would shake his head up and down, the vets all said to try and help teh blood circulate to his ears since he couldnt feel them. I couldnt find info ANYWHERE on this problem we were having with him. I dont know why it happened, or how he made it through it, but hes back to being a riding horse again and hasnt had any issues since. I say god works in mysterious ways, no vet had any other explination.
 
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