Considerations for an HYPP N/H Horse
December 10, 2012
When it comes to buying a horse who’s an HYPP carrier, there are some things to consider.
Question:
I am looking at a horse to purchase. He is HYPP N/H. What special considerations should I look at, as he has never had an episode and is now 6 years old? What are the chances that he will eventually show signs? I am looking at this horse for a 10-year-old rider.
For the answer to this question, the American Association of Equine Practitioners consulted Dr. Kerry Beckman.
Answer:
Possible results of HYPP testing are H/H (double positive), N/H (heterozygous) or N/N (normal). N/H horses are also referred to as HYPP “carriers,” because they carry the disease in their genes but don’t always exhibit symptoms. Usually, a horse will shows signs of HYPP during the first few years of life, especially when training is intense. However, there are documented cases of horses showing signs of their first HYPP attack late in life. There is no way to predict if a N/H horse will show signs of HYPP during his or her lifetime.
I recommend that all American Quarter Horses be managed as if they have a tendency toward having HYPP attacks. Dietary management is extremely important in the management of affected horses. Dietary adjustments include:
- Avoiding high potassium feeds such as alfalfa hay, brome hay, canola oil, soybean meal or oil, and sugar molasses and beet molasses, and replacing them with Timothy or Bermuda grass hay, grains such as oats, corn, wheat and barley, and beet pulp.
- Feeding several times a day.
- Exercising regularly and/or being allowed frequent access to a large paddock. If an attack has been documented, treatment of the horse with acetazolamide (under veterinary supervision) can also be helpful.
You are wise to investigate the potential health problems of a horse before you purchase him. You may also consider screening the horse for other genetic diseases. AQHA offers a five-panel genetic disease screening test through the University of California-Davis Veterinary Genetics Laboratory.
The test will screen for five potentially fatal genetic diseases often found in Quarter Horses:
- Glycogen branching enzyme deficiency (GBED);
- Hereditary equine regional dermal asthenia (HERDA);
- Hyperkalemic periodic paralysis (HYPP);
- Malignant hyperthermia (MH); and
- Polysaccharide storage myopathy (PSSM).
The five-panel test is $85 for AQHA members and $125 for nonmembers. Call AQHA at (806) 376-4811 to secure your test for your horse.
– Dr. Kerry Beckman, member of the American Association of Equine Practitioners
Comments
4 Comments on “Considerations for an HYPP N/H Horse”
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December 12th, 2012 at 9:16 am
I own an N/H horse that is 5 years old. She has exibited only a few ‘muscle rippling’ events in her lifetime which were easily managed with clear Karo syrup. (The release of insulin in response to the glucose triggers the sodium/potassium ‘pump’ mechanism in cells and pushes the potassium back where it belongs!) Our vet has given us a few doses of acetazolamide to keep on hand in case a major event were to occur, but she’s never had one.
We feed her exactly as this article recommends and she gets lots of riding and pasture time. Most of the time I forget she’s N/H until I see an article about HYPP! Of course, I’ll never breed her, but she’s going to live a useful life and be enjoyed. I worry much more about her bowing a tendon in her rough pasture than I do having an HYPP attack.
Don’t pass over a wonderful horse with N/H if it is asymptomatic. Do your homework and be prepared, and then enjoy your horse with your 10 year old!
December 13th, 2012 at 7:46 am
I had an N/H filly born on my place. I trained her and rode her on trails until she was 7 years old. She had one episode (that I am aware of) when she was about 3 where she seemed to have a problem with her hindquarters. She seemed unsteady and went down. I ran for the phone to call the vet for some perspective and by the time I got back outside she was up and moving, only slightly unsteady. I can only guess that this was due to HYPP but not positive. Other than that she was a great horse for us and a joy to ride. I sold her to a good friend who wanted a solid trail mount. She still has her and has had no Hypp issues.
I also have a friend who deliberately bred for N/H horses and he never had a problem with any of them. He used them for trail riding.
I will not breed an N/H horse but would consider another one if it was at least 5 and asymptomatic.
December 13th, 2012 at 7:59 am
I agree with all of the above comments IF you were buying this horse for your self as an adult . However since you are referring to using this horse for a 10 year old child I would keep looking for a horse with out the added potential for either a fall with the child, or heightened episodes that might render the horse unsafe. A child may not be able to handle the episodes as well, not to mention the heartache if the horse cannot be managed by diet or medication.
Just my opinion as a mother and riding instructor. All the best with whatever you decide.
December 13th, 2012 at 11:32 pm
Very well written article, and was amazed to see it was not negative toward HYPP and Impressive horses, which seems to be the norm these days!! HYPP can be managed, and is less of an impact than HERDA or other diseases. I have shown and ridden HYPP N/H horses since before they knew what the disease was. Have yet to have a life threatening problem with an N/H horse, and I would have to say I have more N/H than N/N. I prefer it. If the horse is suitable, buy it and enjoy it with your child. HYPP is NOT a death sentence like most people who are uneducated are led to believe. Enjoy!!