Monday, June 11, 2007

Selenium toxicity and Laminitis Possible Side Effects of Drought-Damaged Hay

Received via press release from the University of Missouri today

COLUMBIA, Mo. — While much of the Midwest has recovered from the drought that parched the area last year, horses are continuing to experience effects from the hot dry summer of 2006. Due to a bad hay crop, University of Missouri-Columbia veterinarians are reporting an increased number of horses with chronic selenosis and vitamin E deficiency, problems that can be fatal.

“Last year’s drought meant that Missouri’s hay crop, which is usually balanced very well for a horse’s nutrition, was much poorer than usual,” said Philip Johnson, professor of veterinary medicine and surgery. “Because of the poor Missouri hay crop, horse owners imported hay from other states nearby and possibly fed their horses hay that was too high in selenium. This can have very grave consequences for horses.”

Selenium is a naturally occurring element and is an essential part of horse diets. However, too much or too little can create problems for a horse. When chronic selenosis, or selenium poisoning, occurs from eating too much of the element, horses can lose the hair in the mane and tail and develop a form of laminitis, a painful condition that affects the hoof. If left untreated for too long, a horse with chronic selenosis may require euthanasia as a result of severe laminitis.

Johnson said that the amount of selenium in hay can vary by county throughout the nation, but that Missouri hay typically has just the right amount of the essential element. For a small fee, horse owners can have their hay tested to determine if it has the right amount of selenium in it.

“Usually, by the time the horse is showing symptoms, it may be too late to reverse the disease completely,” Johnson said. “However, if a horse owner has other horses that are feeding from the same food source, it’s important to have those animals treated before the damage is permanent.”

Photo of Dr. Johnson provided by University of Missouri. Dr. Johnson will speak on his important research on the subject of laminitis and represent his university at the Fourth International Equine Conference on Laminitis and Diseases of the Foot, a gathering of the world's leading researchers and field practitioners in West Palm Beach, Florida in November.