Quarter Horses and HYPP

Posted on May 10, 2009
Filed Under Home, Social | 1 Comment

Hyperkalemic Periodic Paralysis (HYPP), is a genetic disease that effects the entire equine industry, dating as far back as the American Quarter Horse stallion, Impressive.

For those who don’t know, Impressive was a very famous halter-horse, that performed in numerous competitions and received numerous awards and prizes, including the title of world champion aged stallion. Despite being such a high quality and high performing quarter horse, the descendants of Impressive have been afflicted with this disease.

HYPP induces the system with an overly large amount of potassium, often resulting in mild or noticeable muscle twitching, crawling skin, usually in the back flank, paralysis of the hind quarters, yawning in excess and in some cases heart attacks and other fatal conditions. Needless to say a quarter horse with this disease is quite disadvantaged compared to one without.

The issue is compounded further by the fact that HYPP is a genetic and dominant disease. If at least one of the parents of the quarter horse has the disease, even if it displays none of the symptoms, there is a possibility that it will pass the gene on to it’s foal. The odds of this depends on the parents genes: a parent with two HYPP genes (H/H) will always have a foal that has at least one HYPP gene, while a parent with one HYPP gene (H/N) will pass the gene onto to 50% of foals it has with an uninfected horse (N/N), whilst passing one gene on to 50% of the foals of another parent with one HYPP gene, and two genes on to 25%. Though there has been research on methods allowing a HYPP positive quarter horse to breed without passing on the gene, so far there has been little success. In general, it is far safer to test horses and ensure that HYPP positive ones do not breed.

HYPP is a real problem that can seriously debilitate an otherwise excellent quarter horse. Due to inattentive breeding it has become far more common, and it must be emphathized that the best solution is to simply not breed HYPP positive quarter horses.

For more information, visit the most trusted online magazine dedicated to the quarter horse – The Quarter Horse Quarterly

Comments

One Response to “Quarter Horses and HYPP”

  1. Marybeth Jarubas on August 18th, 2009 3:11 pm

    I purchased a beautiful quarter horse called Go Lucky Dare at an auction in November 08. He gave me the eye and I was sold. I wanted him so badly I bid before he even came to auction. I had never heard of HYPP prior. When we went back to look at his card there it was – Descendent of Impressive, may carry the gene for HYPP. I went back talked to my daughter and my friend no one seemed to ever hear of it. Finally asking the owner. No one really gave me a clue. I accepted the fact that the guy would need to be checked anyway and home he went. Not knowing that this horse had the bloodlines of champions from Man o’ War to Impressive and on. Had him checked he turned up N/N. He is mischevous, rude, extremely smart and loving and affectionate. When I got the news he was clear I just sat in amazement. I had researched the mutation, talked to the vet, knew what I was getting into and I even had a 30 day guarantee to return him if he had the disease. But you know what? I wouldn’t of returned him even if he did have it. There was just something about the guy and he is best friends with my ex-race horse Mickey. They are part of my family now!

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