“I have a yearling QH gelding that is growing at an alarming rate. He grew 5″ in 20 days…”

We are dealing with major muscle cramps. When he lays down it is very difficult for him to get up cause his muscles cramp up & appear to fall asleep on him. I have had 3 vets out to look at him.

Dr. Jack Sales’ Answer:

Hi Amy,
There is no question that your yearling is experiencing a serious growing problem. The fact that the muscles seem to be involved makes it even more alarming. First of all, I would want to make sure that this colt is not a descendant of the QH sire Impressive, as a grand sire or on the Mare’s side of the pedigree. HYPP is a genetic disease that is found in the Quarter Horse population that involves muscle cramping, and sometimes muscle paralysis. It could also be associated with a primary muscle disease and this would usually show up on blood tests as an elevation of Muscle enzymes like CPK levels, SGOT levels, and/or LDH levels. Were these blood levels out of line? Serum chemistry needs to be done to determine these blood levels. The levels that you described as being high or low were not far enough from the normal ranges to be worried about these levels except the ph level does indicate that muscle damage may be taking place.
Vitamin E and Selenium are usually very helpful as a supplement when muscle problems are found. This supplement can also be supplied on a daily basis in the feed. Ask your Vet about this. Keep working with your Vet, the reduction in total calories in the diet is going to be helpful in the reversing of the symptoms.

HYPP Gene