Q. My veterinarian has diagnosed my horse with classic equine recurrent uveitis. My vet has explained that this kind of uveitis tends to come and go with flares that can last a couple of weeks, followed by periods where my horse will be fine for some unknown length of time before another flare occurs. Right now he is on medication that seems to be helping control it, but long-term I am wondering whether there is anything I can do nutritionally that might help keep it under control?

A. Recurrent uveitis is the leading cause of blindness in horses, with a prevalence of 2 to 25% in the United States, making it one of the most common eye diseases. Uveitis is characterized by inflammation in the eye that first impacts the uveal tract. Within this tract lies the vascular tissue that provides nourishment to the eye and ensures proper function.

I’m not aware of any supplements specifically for uveitis; however, because the damage is caused by inflammation, I would look to provide nutrients and supplements known to help support a healthy inflammatory response.

First, as with any horse, I would want to make sure all nutrient requirements are being met and the diet is balanced. From there, I would consider adding an omega-3 fatty acid source, especially if the horse doesn’t have access to good-quality pasture (this might be a seasonal supplement if the horse doesn’t have pasture access during winter). Plant-based sources of omega-3 fatty acids, such as flax and camelina oil, would be a good starting place; however, you might want to offer more potent omega-3 fatty acids such as EPA and DHA found in fish oil and some forms of algae. Anecdotally, some owners have reported that supplementing methylsulfonylmethane (MSM) helps. Resveratrol might also be beneficial, because unrelated research has shown that it supports a healthy inflammatory response.

We commonly give our horses topical or systemic non-steroidal anti-inflammatory (NSAID) drugs to help control inflammation. These can be hard on the gut, so digestive support might help counter NSAID side effects. Gastric ulcers can result from long-term NSAID administration, because these drugs can degrade the natural protective barriers in the stomach’s glandular region, increasing the risk of glandular ulcers. Many supplements have been shown in research to help support gastric health in the face of feed deprivation and reduce the number and severity of gastric ulcers. One ingredient that stands out for glandular ulcers is sea buckthorn berry pulp, which helps mitigate the risk of glandular ulcers during feed deprivation. It is important to note, though, that ingredients found to be beneficial in the face of feed deprivation may not be effective at supporting gastric health in the face of NSAID application.   

With careful management that includes diet as well as fly masks, UV filters, night turnout, and medication as needed, hopefully you can manage this chronic condition and prevent your horse from losing his sight or his eye.