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Moon Blindness in horses

Equine Recurrent Uveitis or ERU

What is it?

Equine Recurrent Uveitis or better known as Moon Blindness is a chronic, painful eye disease, and it’s the most common cause of blindness in horses with an estimated prevalence of 2-25% in the United States. Equine recurrent uveitis is characterized by inflammation occurring inside the eye, first impacting the uveal tract (termed uveitis). The uveal tract consists of vascular tissues inside the eye essential to proper nourishment and function of the eye.  It was so named during the 1600s because people thought recurring attacks were related to phases of the moon. This eye disease might be one of the first veterinary diseases ever documented. It is one of the most common diseases of the equine eye.

The cause of the inflammation is not always determined but should always be investigated. Three known general causes of uveitis in horses: ocular, systemic, and immune-mediated (ERU). Ocular causes include trauma, corneal ulcers, lens-induced uveitis, or immune-mediated uveitis. Essentially any insult to the eye may result in a reflex inflammatory response within the globe itself. Systemic causes include any infectious bacterial, viral, parasitic, or associated disease that results in systemic illness. ERU is an immune-mediated uveitis that is characterized by intermittent episodes of intraocular inflammation. Contrary to ocular and systemic manifestations of uveitis, ERU is a syndrome with documented chronic recurrence of inflammatory episodes. Any horse may be affected but the Appaloosa breed seems to be predisposed to ERU.

signs & symptons

  • Sensitivity to light, horses will squint or hold eyelid only half open.

  • Swollen eyelids.

  • Watery, teary eyes.

  • Excessive blinking.

  • Spasms of the eye muscles.

  • Constricted pupils (small pupils).

  • Cloudy eye.

traditional medicinal treatment

Majority of treatments consists of topical and systemic (oral) anti-inflammatory (NSAIDs) medications such as Prednisone which is the most commonly used prescription drug. If there is a suspicion of bacterial infection, some veterinarians will additionally prescribe an antibiotic. There are also alternative therapies for ERU; one option available in the United States and offered here at KSU is a cyclosporine implant. A small disc-shaped implant filled with a medication called cyclosporine is surgically implanted within the white layer (sclera) of the eye. The implant then slowly releases the medication, which is an anti-inflammatory/immune-modulatory drug. A major goal of the cyclosporine implant is to reduce the requirement of topical and oral medications in horses treated with this procedure.

Unfortunately, the long term prognosis for the eye (maintaining vision and comfort) in horses diagnosed with ERU is guarded. Some horses respond favorably to treatment, while others develop secondary problems related to the inflammation inside the eye. These include cataract (cloudiness or opacity of the lens), glaucoma (elevation of eye pressure), shrinkage of the eye, and retinal damage, all of which result in blindness and are difficult to treat. Early recognition and treatment intervention are important in an effort to maximize the amount of time a horse retains vision and comfort of the affected eye(s).


It is important that a veterinarian evaluate your horse prior to initiating any treatment to ensure a proper diagnosis.

how serraquin es15™ can help?

Serraquin ES15 is an a one-of-a-kind alternative therapy to fighting inflammation, of which is a major contributing factor in dealing with Moon Blindness. Composed of a very unique blend of systemic enzymes Serraquin ES15  plays a fundamental role in balancing the immune system.  For example, if the horse's immune system is overactive the body will attack itself creating further issues and obviously if it's underactive the body will incur the same issues. Serraquin ES15 insures the horse can get back to it's natural state of homeostasis which creates a healthier and much more balanced immune system.

Serrapeptase is the fundamental ingredient in Serraquin and has been thoroughly researched worldwide for its numerous and diverse effects on inflammation, pain, infection and healing. Unlike NSAID’s, Serrapeptase does not block Cox enzymes to suppress inflammation but rather digests the pro-inflammatory prostaglandin responsible for causing inflammation. By breaking down the old cellular debris, the blood circulation can be improved in the affected area, allowing vital nutrients and building blocks to nourish new cells allowing the natural healing process to work faster.

The most common treatment for most horses with Moon Blindness is Prednisone, which does help but comes with many unwanted side effects and is not recommended for long term use. Serraquin ES15 has no side effects whatsoever and can be given to the horse for the entire duration of it's life if needed. Serraquin ES15 can also be used for any type of inflammation in the horse due to injury, over exertion, wound healing, and to breakdown old scar tissue. 

We are offering this product with decades of experience & positive results with a similar product for people with auto-immune and inflammatory conditions and personally guarantee you & your horse will be happy with the results you will see and they will feel!


"There are three choices in life:  Give Up.  Give In.
Or Give it All You Got!"

our testimonial & results ~ our barn to yours

alternative treatment for moon blindness ~resultsndness 


This is TR Big Hope Badger, an AQHA gelding, better known as Iceman. He's one of my good rope horses and very special to us. Iceman came up with the condition called Moon Blindness which we really had no knowledge of until 3 years ago in which we followed the typical veterinary protocol of Prednisone, Bute and a steroidal eye cream. We were fortunate enough to be in an industry that allowed us access to some very unique formulas that helped countless people suffering from severe inflammatory conditions. Until recently we had been using Prednisone, an anti-inflammatory drug that does help but not something we wanted to use long term as we knew the side effects. So we decided to use what we knew best, systemic enzymes! No side effects and it works along with many other benefits it provides! We have been dealing with systemic enzymes for decades for human use and know it's many uses for inflammation and scar tissue. As you can see, Day 1 his eye is very painful and watery. Day 2 he starts to be able to open his eye but still a lot of redness and a little watery. By day 4 we knew it was working as his eye was opened and the redness was turned into a light pink. Day 17,  his eye is fuller and not as sunken in above his eyelid and even noticed a diminishing of the blue(inflammation) around and on his pupil. We are going to keep documenting this with the use of Serraquin ES15 and cannot wait to see the long term results! We just wished we had this product to use earlier on as we feel it would of kept this condition from progressing to where it is now. Feel free to give us a call with any questions you may have! We would love to share our story and the many successes this product has had over the many years. You may contact us via e-mail or phone @ 1-877-378-1178 or

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