Case Study: Equine Recurrent Uveitis

Vision in the horse is a critical factor.  Without it, they are vulnerable to attack in the wild, have a hard time navigating and encounter difficulties in training and competition.  The eye in the horse also tells us a lot in regards to personality and demeanor, often allowing us to see into the spirit of the animal. It is large and obvious, often one of the first things we notice about a horse. Considering the placement of each eye in the horse, as compared to humans or even pets, their range of vision is limited and they are dependent on two functional and healthy eyes.  When the health of the eye is impacted, the health and safety of the horse is likewise compromised.  The equine eye is subject to a variety of conditions including corneal scratches and lacerations, but one of the most debiliating is equine recurrent uveitis or ERU, which is becoming more common place in the equine industry.  What used to be a condition primarily impacting Paint breeds, Appaloosa and even fair skinned Quarter Horses, is now affecting many other breeds.  The exact cause is unknown and despite the best efforts with therapy, these cases can be frustrating and financially draining for the horse owner. Our horses are our companions and given this, it is hard to see them in constant discomfort.  Often, we need to step back and analyze these situations and apply what we have learned from research, to improve comfort and aid in management.

“Reggie” is a 7 y.o Oldenburg gelding that was noted one morning to have a small blue spot in his eye.  Out of concern, his owner called out her local veterinarian for an evaluation.  The exact diagnosis was not able to be determined, but obvious problems such as a corneal scratch or ulcer had been ruled out.  Reggie seemed to be fine otherwise with no major discomfort or even eye drainage.   The blue spot was determined to be an area of localized corneal edema, which was fluid accumulation within the cornea.  This can happen as a result of direct injury or scratch to the eye, but these causes had been ruled out.  Reggie’s veterinarian prescribed a topical anti-inflammatory along with a medication to help resolve the fluid accumulation.  

Over the next month, Reggie’s condition continued to progress and worsen.  What started as a localized blue spot on his cornea had now progressed to where the entire surface of his eye was impacted.  After another veterinary examination, his dose and frequency of medications were increased on a daily basis.  Reggie also now had clinical signs of glaucoma, which is excessive fluid accumulation within the eye, so additional medications were added to his regimen to reduce inflammation and control ocular pressures.  Despite the increase in medications and persistence of his owner, Reggie’s condition continued to deteriorate rapidly.  The only viable option for him, considering his lack of clinical response, was surgical removal of the eye.

Equine Recurrent Uveitis is a strong inflammatory process of unknown cause with associated immune system dysfunction.  In some cases, there is possible trauma as the source or even infection, but in most the condition seems to pop up out of nowhere.  In some breeds, there is a possible hereditary link and predisposition to development of ERU, but considering that multiple breeds are being impacted, it makes us wonder as to the true cause.  Typical therapies for ERU include topical steroidal anti-inflammatory medications along with injectable or oral anti-inflammatories.  In early stages, these medications do provide relief but cases of ERU are prone to frequent relapses or flare ups, which do not seem to be managed well with these routes.  Another option, in early stage disease, is the use of a Cyclosporine implant which is placed surgically.  The goal with Cyclosporine is to help control the inflammatory response and even modify the immune response, which again can be helpful, but is often limited due to the stage of the disease when presented.  

The key issue with ERU is that not only can it be hard to manage, but there are frequent flare ups and with each flare, there is potentially more damage done to the eye.  In early stages, horses with ERU can present with mild eye drainage or cloudiness, impacting one eye or both.  As the condition worsens, the cloudiness progresses, pain increases, drainage increases and often the affected eye is closed a large percent of the time due to discomfort.  In uncontrolled cases, total vision can be lost due to cornea damage, cataract formation, iris changes and even damage to the retina.  Sometimes the cases can progress very quickly and often, the only means of restoring comfort is surgical removal of the eye.

Clinical research data tells us that uncontrolled inflammation plays a major role in ERU, contributing to a dysfunctional immune response and production of damaging pro-inflammatory proteins. Again, the exact cause of this uncontrolled inflammatory response is not known, but despite this, all of our treatments attempts are focused on controlling the inflammation which is the consequence.  The problem, as I see it as a veterinarian, is that our current therapies are well intentioned but limited in their scope of action against inflammation.  The inflammatory response is very complex and these therapies are only impacting a small aspect of that process.  We could increase the dose of these medications to accomplish more of an impact, but with that, we likely encounter serious side effects and risk adding more insult to the patient.  In those situations or cases of ERU that are difficult to manage or fail to respond, we need to look for other options to use either with our current therapies or as stand alone options for better managment.

Reggie was started on the Cur-OST® Pure EQ®  formulation, providing the highest levels of Curcumin and Boswellia for support and balancing of the inflammation response.  In addition, this formula also provides a high level of Vitamin C and CoQ10, which may provide critical antioxidant support against free radicals.  Curcumin and Boswellia have been demonstrated in research studies to help control inflammation at a higher and more broader reaching level than many typical therapies with minimal to no side effects on the body.  In many instances in the patients that I see, the condition is not as critical when presented and I opt for use of the Cur-OST® EQ Total Support® EQ Total Support for long term support and management.  Given the rapid progression of Reggie’s condition, he would likely benefit from a more target approach to inflammation in conjunction to his current therapies. In many of our patients, we will also add in the Cur-OST® EQ Immune  formula to help support balance in the immune response, which I feel adds to easier management and better recovery for the patient.

After 6 weeks of support, the owner began to notice a reduction in the blue coloration at the top of the eye.  Reggie seemed to be doing better and overall was comfortable.  Here is a photo of his eye after 6 weeks of supportive therapy.  You can see in this photo that the top part of the cornea is clearing and we are able to see parts of the iris (pupil) or internal components of the eye.  This also means that vision is more than likely improved as long as there is no other damage inside of the eye.

Reggie’s owner continued her relentless support and pursuit for recovery.  After 6 months of daily supportive care, Reggie has done well! The overall cloudiness to the cornea has reduced by over 50% and is mainly impacting the lower part of the cornea.  His daily comfort has been improved and vision seems to be restored to a moderate degree.  His 6 month photo is to the right and below.

Equine Reccurent Uveitis is a difficult condition to manage, even in the best of scenarios.  There is no ‘cure’ for this condition and many horses succumb to chronic eye damage over time due to frequent flare ups. Considering the high percentage of horses that require ongoing therapy or even surgery, the high morbidity rate and the ongoing financial expense, we need to seek out all options to improve the outcome.  I do believe, as a veterinarian, that use of specific herbs can assist us in managing the ongoing inflammation within these animals, which helps us to improve management and quality of life.  The sad reality is that many of these cases are ongoing, often over several years, and with this comes repeated and accumulative damage to the eye which cannot be reversed.  Overall, the goal is never to ‘cure’ them of this condition but instead, we should focus on better means of controlling it, reducing flare ups and improving quality of life. This, I believe, can be done in a high percentage of cases.

Thank you to Reggie’s owner for allowing us to relay his information to guide others.

All my best,

Tom Schell, D.V.M.

Nouvelle Research, Inc.

www.curost.com

 

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