As this winter nears its end, many people are looking forward to the riddance of the year’s heavy snow accumulation. But for horse owners, the arrival of fresh spring grass means increased measures of precaution as their horses roam the outdoors.
The dangers of cold spring grass are no secret to horse owners, and the potential for winter laminitis can be specifically problematic for horses with a history of endocrine problems.
“Horses and ponies with insulin resistance can founder in the winter months with seemingly no identifiable predisposing factor,” says Kentucky Equine Research nutritionist Dr. Kathleen Crandell.
Information published by the Kentucky Equine Research's newsletter assures that although laminitis affects a wide range of horses, not much research has been conducted on winter laminitis compared to other equine diseases. Important symptoms to look out for in horses thought to have winter laminitis are the classic sawhorse stance and decreased mobility that is present in horses with pasture- and endocrine-associated laminitis. It is also worth paying close attention to horses with insulin sensitivity or metabolic syndrome, as scientists have suggested that equines with these issues could have an increased risk of the disease.
When a susceptible horse with insulin problems is exposed to the cold ground for extended periods of time, the shunts between the arterial and venous blood vessels in the foot contract in an irregular way and decrease blood supply to the foot. In contrast, the dilating blood vessels of a healthy horse maintain regular circulation to the foot’s lamellae.
“This paradoxical response to cold is believed to be due, at least in part, to the failure of endothelin-1 receptors in the walls of blood vessels to dilate,” says Crandell.
Insulin levels also seem to grow higher and more inconsistent as the weather becomes colder, which may be another factor of the abnormal circulation of blood in the feet.
“In terms of treatment, horses with winter laminitis typically do not respond to anti-inflammatory drugs such as phenylbutazone, known as bute. In fact, experts in this field report that winter laminitis doesn’t respond to many traditional treatments,” says Crandell.
Steps such as corrective trimming and dietary management have been shown to help, but it won’t offer lasting results if the lower limbs of the horse are not kept warm. A simple way to do this is to use lined hoof boots or even shipping wraps. To effectively maintain a horse’s good health year-round, Crandell recommends a supplement of biotin, methionine, iodine and zinc. The benefit of these ingredients is that they have been linked to faster hoof growth and support normal development, especially after a case of laminitis.
An end to shoveling might seem to be just around the corner, but the impacts of winter will last just a bit longer for horse owners. To read more about winter laminitis and how you can better protect your horse this spring, click here.
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