The cardiologist and my vet arrived today to asses his heart with an echo cardiogram. An echo cardiogram is an ultrasound of the heart. It allows us to see the shape of his heart, the size of the heart, the condition of the valves, the thickness of his heart muscle, and which direction the blood is flowing in the heart. First, we were able to tell that he does in fact have a mitral valve regurgitation. Of the causes for a murmur this one is the most likely to cause performance issues or even sudden death. Blood in the heart should go one way, if it doesn't then it is having to work extra hard to get blood to pump out to the body. Think of it like trying to get the chickens into the pen after a day of digging in the garden before they are ready. Every time you try to get two chickens in, one of the other chickens gets back out. It takes twice as long and you end up more sweaty than you would have been if all the chickens just went in the first time. If the backflow of blood is resulting in his body not getting enough oxygen then his heart is always doing extra work. If, despite the back flow, his body is still getting the oxygen he needs his heart won't be asked to do double duty.
We can tell if the heart is showing signs of strain by looking at several factors. If the muscles of his heart are enlarged it indicates he has already been working too hard just to keep his cells oxygenated. Larger, thick muscles also make the heart less flexible and able to withstand the increase in oxygen demand that comes with riding. At some point, if the horse's heart cannot compensate for the strain with thicker muscles, the walls of the heart will get thinner and the heart itself will stretch out and pump inefficiently. That is a really simplistic version of what happens when a horse's heart fails but I know not everyone has a medical background so I wanted to keep it simple.
At this point Dickie's heart looks great. There are several areas where the mitral valve doesn't snap shut but his heart is a normal size, his walls are normal thickness, and all the chambers are normal size. We don't know what caused this problem but he was probably born with it. If he had a high parasite load or recently had a serious illness then it might not be congenital. He is a healthy horse with essentially a zero parasite load so nothing points to this being a degenerative illness. The echocardiogram can also measure what is called and ejection fraction and this tells us how efficiently the heart is pumping blood out to the rest of the body. From what he could see it looked fine. However, one of the problems with predicting how well he will do over time is the fact that he hasn't been worked. We don't know if his heart looks great because this problem isn't affecting him or if it is just because his is young and has never been pushed.
We talked at length about his intended use and the cardiologist felt there is a good chance he will hold up. He is not going to drop over dead under saddle but we may at some point see changes in his performance. This could be in 3 years but there is a good chance it won't be until he was retirement age anyway. Both the specialist and my equine vet felt I could go forward using him as planned. He said he recently had to tell someone he wouldn't feel safe with his daughter riding a horse he consulted on. In this case he said he would feel fine if it was his own daughter riding the horse. I will need to get yearly echocardiograms for the next few years. This will tell me how he is holding up to conditioning. The next year should tell me a lot. He won't be doing hard work under saddle for at least a year but I plan on long lining him and ponying him so he will get lots of work in the coming months. After a few annual echos I will have a good idea of how stable his condition is. Having regular check up exams will make me feel better about pushing him. I won't have to wonder if he is being a snot about something because he is uncomfortable or if he is just being naughty. I don't want him to ever feel bad because he is trying for me and his health just won't let him do what I have asked.
I am so happy that we can move forward and start having new adventures together. The happiness is clouded by the fact that I could get a couple years into training and find out he is showing signs of heart failure. It is also hard to know I have another horse with health problems that will require special vet care. However, you could have the healthiest horse in the world who you just paid $10,000 for and it could tear a suspensory from a bad landing. We had one healthy horse who cost us more than the yearly cardio exams will when he went through a phase of letting himself out to gorge on grain. My first horse who was rock solid sound and trained to the hilt died of colic after I owned her for only 2 years. I hope that the future brings good things for us but nothing is ever certain in life. One thing I am certain of is the fact that I have appreciated every second I spent with all of my horses. No matter how long, or short, our time together is Dickie will bring more joy into my life than can be quantified by the passing of time or the exchange of money.