My HYPP Experience
In 2008 I acquired an almost 2 year old AQHA stallion named “DS Always Dressed.” A friend of mine told me about him and knew that I am a bleeding heart for animals that need help. She told me that he was owned by a woman who shows and breeds halter horses. Classic (the name I gave him) was born with contracted tendons and HYPP(N/H). Due to the fact that his owner showed halter and knew that he would never be showable, she decided not to help him and just turned him out. He received the basics but minimal care. He was in good physical condition but as far as his feet go, he was a mess. And due to the fact that he was left till he was almost 2, he will always be a mess.
HYPP stands for Hyperkalemic periodic paralysis. A horse can be N/N (negative), N/H (negative on one side and positive on the other) or N/N (which is positive on both sides). An N/H or H/H horse can either show or not show symptoms. I could get more in depth with this part of the disease, but it gets confusing even to me! But this tells you in a nutshell what it is and what the symbols stand for. It is an inherited disorder that affects sodium channels (potassium) in muscle cells and the ability to regulate potassium levels in the blood. Equine hyperkalaemic periodic paralysis occurs in 1 in 50 quarter horses and can be traced to a single ancestor, a stallion named Impressive.
Classic was my first HYPP horse, which made me do some extensive research on the disease. I realized that by what I read every horse with the disease was different. Some may never show signs and some may show signs with triggers as minimal as stress or weather change. So I decided to treat him like all the other horses until he gave me reason to do otherwise. The main triggers are alfalfa and any feeds high in potassium, so I just stayed away from those as a precaution.
I did not have any problems with Classic until he was about 4 years old. I hauled hay for a living back and forth to south Florida from Georgia. I had just recently hauled a load of alfalfa and there was about a flake left on the bed of my truck. I was out in the pasture doing some work and before I realized it, Classic had cleaned up all the alfalfa! I was mortified, but because I had never had an issue with him, I just had to wait and see. And boy did I see! The next day I was out in the pasture and noticed he was what I thought twitching from flies. But as I watched it was too rhythmic to be that; he was having a fit. It started as just minor muscle spasms and went into a full blown fit. Stiff legged walking, yawning, eyes rolled back in his head, twitching uncontrollably. I was scared to death. I immediately remember that the first thing I should do is administer Karo syrup, so I did. In the meantime I quickly got my vet on the phone. She said Banamine will help stop the fit and help with the pain he will have from all the spasms. I gave it promptly. Within 15 minutes he was slowing down and all that remained was small muscle tremors. He was now very sedate, tired I would imagine, as his fit lasted about 45 minutes. Within an hour it was pretty much over. I asked my vet what to do after this point and all she said to watch him and if he continues to have them after this that we may have to consider medications daily. I was sure hoping that was not the case, but all I could do was wait and see.
The next day he did have a very small one that I was able to control with syrup. After that it was back to normal for quite some time. I really have to watch his feed intake now that he is older and done growing. I feed him a diet of whole oats and a very small amount of Safe Choice pellets. This seems to keep him on a pretty even keel with no fits in about a year. After the initial big fit, the rest have been very small, some almost unnoticeable unless you know what to look for. It really can look just like a fly twitch, except it stays for a longer period of time or stays consistent through the episode. From my experience the younger horses do not have too much of a problem until they are done growing, and their body is not utilizing the potassium as readily. That is just an observation I have made over the years of having Classic and seeing a few others that did the same transition with age.
Always remember that each HYPP horse is an individual, but that treatment starts with a good feeding program and knowledge of the disease. This disease can be deadly if left untreated. As natural as possible is good for diet, natural grazing and little to no alfalfa. Although some HYPP horses do okay on alfalfa, mine on the other hand cannot even sniff it. So each is its own case and should be treated as so. I hope this spreads a little light on this disease. I know I did not get too far into the technical stuff, but sometimes this makes it easier for people who have no knowledge of it, to understand. Thanks for reading and voting!!
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