When you think of horses foundering, you think of them breaking into the feed room and eating an entire bag or grain or lush pasture in the spring.
Dr. Bob Judd, host of Texas Vet News on the Texas Farm Bureau (TFB) Radio Network, reports that horses can founder in those situations, especially in the spring grass.
Now that we’re through the hot dry summer and the grass is turning brown, horse owners may be thinking it is okay to turn the horse that has foundered before, and is already overweight, out on fall pasture. After all, most grass looks dead anyway.
“This dead-appearing grass can store large amounts of carbohydrates, which can still lead to laminitis and founder,” Dr. Judd said. “As the grass turns brown, it actually becomes dormant.”
Kentucky Equine Research indicates this seasonal change triggers the plants to produce and store carbohydrates.
“Decreasing day length, cool night temperatures, overgrazing, mowing or several dry days followed by rainfall, can all lead to increased carbohydrate intake for your grazing horse,” Dr. Judd said.
When your horse ingests an excessive amount of nonstructural carbohydrates, the horse’s digestive track is upset, leading to the release of endotoxins that can contribute to laminitis or founder.
In the fall, horses also usually have higher levels of a hormone that causes an increase in cortisol to prepare horses for the coming winter weather.
“In normal horses, this is not a problem; however, in horses that have equine metabolic syndrome, or may just be overweight, this increase in cortisol can contribute to insulin resistance. Increased levels of insulin have been shown to cause laminitis in horses.”
If you have an overweight horse, or a horse diagnosed with insulin resistance, Dr. Judd reports it’s not a good idea to turn them out on fall pastures regardless of the dead appearance of the grass.
Dr. Judd’s full report can be heard here: http://bit.ly/1R0Qky6.