Draw It Out® Horse Health Care News
HYPP in Horses: Signs, Genetics, Testing, and Daily Management
Hyperkalemic periodic paralysis is an inherited muscle disorder caused by a sodium-channel mutation. Affected horses can experience episodes of muscle twitching, weakness, collapse, and upper-airway breathing noise.
Quick answer: Confirm status through genetic testing and build an individual veterinary plan. Severe weakness, collapse, breathing difficulty, or inability to stand is an emergency. Do not use electrolytes, liniment, or feed-room guesses as treatment.
What HYPP means
HYPP is inherited in an autosomal dominant pattern. AQHA designations include N/N, N/H, and H/H. Horses with one or two copies can pass the mutation, while H/H horses are more likely to have severe signs. AQHA identifies the mutation with the Impressive bloodline and requires testing in relevant descendants.
Signs of an episode
- Muscle twitching, trembling, or cramping.
- Weakness, staggering, collapse, or difficulty standing.
- Prolapse of the third eyelid in some cases.
- Loud or difficult breathing from upper-airway muscle involvement.
- Episodes that vary greatly between individuals.
Testing and records
Use an approved genetic test and keep the result with registration, veterinary, emergency, feeding, and boarding records. Tell veterinarians about HYPP status before anesthesia or sedation.
Daily management is individualized
Work with a veterinarian and qualified equine nutrition professional on forage and feed analysis, meal timing, potassium intake, salt and water, turnout, exercise, travel, stress, and an emergency plan. Avoiding long fasting periods and large dietary swings may be part of the plan, but exact feed recommendations belong to the individual horse.
Products do not manage HYPP
Hydro-Lyte®, other electrolytes, liniments, and supplements do not diagnose, cure, or independently manage HYPP. Electrolyte composition matters, and potassium should never be guessed. Read the AQHA HYPP guidance and follow the attending veterinarian.
Frequently asked questions
Can an N/H horse show signs?
Yes. Severity varies, and a horse with one copy may experience episodes.
Can an H/H horse be registered with AQHA?
AQHA states that H/H horses are ineligible for registration.
What should I do during a severe episode?
Use the veterinarian's emergency plan and seek immediate help for collapse, breathing difficulty, or severe weakness. Protect people from a falling horse.
Educational content only. This article does not replace veterinary, farrier, medical, saddle-fitting, training, or other qualified professional guidance.
