Equine Recurrent Uveitis



Equine recurrent uveitis (ERU), also known as moon blindness or periodic ophthalmia, is one of the most common eye conditions in horses and the leading cause of blindness in horses. Dr. Deborah Y. Strauss D.V.M. has a special interest in the treatment of ERU in horses. ERU is an immune mediated disease. In an immune mediated disease, the body’s immune system attacks its own tissue. In ERU, the immune system of the horse attacks its own tissues in the eye. The exact cause of the disease has yet to be discovered, and no cure exists. Due to these facts, this disease is a challenge to owners and veterinarians. Dr. Deborah Strauss teaches owners how to treat this condition in order to attempt to preserve what vision is remaining in the effected horse.

It is estimated that 10% to 25% of horses suffer from ERU. The Appaloosa breed of horse is 8.3 times more likely to develop uveitis (of any type) than all other breeds combined. The Appaloosa breed is 4 times more likely to go blind as a result of equine recurrent uveitis. It has also been shown that leopard appaloosas are more at risk than those with blankets or dark, solid type patterns. Paint horses, draft breed horses, and warmbloods have also been reported to have a slightly higher risk of developing ERU. It has also been reported that Standardbreds and thoroughbreds appear to be less effected by ERU. The very special interest by Dr. Deborah Y. Strauss D.V.M. in the treatment of ERU comes from the fact that one of her own horses, an Appaloosa, suffers from this disease. Her horse has suffered from this disease for the past 10 years. As a result, Dr. Deborah Strauss has the unique experience of not only experiencing this disease from the veterinarians point of view, but she has also experienced what every owner goes through when attempting to maintain the vision of a horse suffering from ERU. No horse, regardless of age or breed, is safe from this disease. 



 16 (1)The first symptom that an owner will probably notice is their horse squinting or holding the effected eye shut in response to pain and sensitivity to light. There may also be excessive tearing. There may be a blueish or cloudy appearance to the cornea, the white portion of the eye (the sclera) may look blood shot. The pupil may be smaller than normal. When an owner sees these signs, it is time to call a veterinarian. A veterinarian, who is trained to examine eyes, will be able to detect more specific clinical signs during a complete ophthalmologic exam. Detecting this condition as soon as possible is the goal of Dr. Deborah Strauss.  

Diagnosing ERU can be difficult in the beginning because it cannot easily be differentiated from other causes of uveitis. A definitive diagnosis of ERU is typically only made after the horse has had several recurrent episodes of uveitis in one or both eyes. Immediate detection of this disease is essential to the preservation of vision of the horse.

11 (1)There is no cure for equine recurrent uveitis. The goal is to control this disease to maintain vision, if possible. Dr. Deborah Y. Strauss D.V.M.’s treatment for active uveitis is aimed at decreasing inflammation in the eye, controlling the horses’ pain, minimizing the damage to the structures of the eye, and delaying the onset of blindness. Each horse and situation is unique. Treatment of ERU is labor intensive and requires a very dedicated owner. Treatments of active ERU episodes typically require 4 to 6 weeks. In some cases daily treatment is required for the entire life of the horse. Dr. Deborah Strauss’s horse is an example of equine recurrent uveitis that requires daily life time treatment.


Dr. Deborah Y. Strauss D.V.M. has been a fully licensed veterinarian since 1998 and practices in the state of Iowa. She graduated from the Iowa State School of Veterinary Medicine. Dr. Deborah Strauss is available to travel throughout the state of Iowa to treat horses suffering from equine recurrent uveitis (ERU). If an owner believes their horse may be suffering from ERU, Dr. Deborah Strauss can be contacted at 319/521-1099. Dr. Deborah Strauss also treats other ophthalmic (eye) problems in horses.