(616) 897-7877
 

Ophthalmology

Thornwood Equine

Complaints from horse owners regarding their horses eyes are relatively common for us at Thornwood Equine. Fortunately for horses, most eye injuries and diseases are relatively easy to diagnose and treat if identified and treated in a timely manner. Most equine veterinarians would classify eye injuries as an “almost” emergency situation. The reason being is that if some eye conditions are left untreated even for 24 hours, they can rapidly deteriorate to a point where it becomes difficult to salvage the eye and its visual function. So be prepared if you call describing symptoms of eye problems, we will most likely be recommending an appointment that day just to be on the safe side.

Symptoms of eye problems are relatively straight forward and obvious to the average horse owner. The following lists some of the common signs of eye problems: Squinting, swollen eyelids, tearing, pus-like discharge, cloudy cornea (the surface of the eyeball), rubbing the eye, lacerated eyelids, drooping eyelid assymetrical appearance of the eyes or eyelids. Specific eye conditions can share many symptoms with other conditions, so it is impossible for veterinarians to know what the diagnosis is without examing the eye and its surrounding tissues. For instance, a horse with a scratched cornea can display identical symptoms as a horse with Moon Blindness; the treatments are drastically different and therefore it is critical to differentiate the two before prescribing treatments.

The most common eye injury would most definitely be a corneal ulcer, or scratched eye. As many of you know, this can be an extremely painful condition to the point of not being able to sleep. Horses demonstrate extremely powerful squinting and often have tearing and can be very reluctant to have their eyelids handled. The veterinarian often has to tranquilize the horse and numb the eyelids in order to examine the eye thoroughly and effectively. Then special stains are used to identify the scratch and to help delineate the entire extent of the ulcerated cornea. Checking for small foreign bodies within the cornea is also a crucial step for the veterinarian to perform. Ulcers can range from tiny scratches that are difficult to even see with the naked eye to large “crater-like” defects that are at risk of perforating the full thickness of the cornea. Treatment strategies vary depending on the severity of the lesion but largely revolve around frequent application of antibiotic ophthalmic preparations and anti-inflammatory medications to help control infection and pain.

Another common eye condition is blocked nasolacrimal ducts, or tear ducts. The usual complaint from the owner is that the horse has chronic tearing from one or both eyes, but acts and looks perfectly normal otherwise. On occasion, blocked tear ducts can cause mild swelling of the eyelids. This typically is not an urgent situation to resolve because it does not harm the eye(s) if left untreated temporarily. The horse has a tear duct that runs from its upper and lower eyelid to a lacrimal gland that is located on the inside lower corner of each eye. From the gland, the lacrimal duct descends to its respective nostril where there is a small opening located on the floor of the nasal cavity. To diagnose the condition, your veterinarian will likely place a special dye into each eye and observe the nasal opening of the lacrimal duct 3-5 minutes later to determine the presence of dye at the nostril. If the dye does not trickle down from the eye to the nasolacrimal opening, then the duct is considered blocked. To relieve the blockage, a catheter or special syringe in carefully placed into the nasal opening and saline is flushed up into duct thereby pushing the blockage up and out through the opening at the eyelid. Usually the actual blockage is not seen but relief is evident to the horse owner by the following day when the tearing has ceased.

Other common eye conditions are equine recurrent uveitis (Moon Blindness) and trauma to the eyeball and periorbital facial bones. Check back at a later date as we will be adding more information to this article. Dr. Duane Fitzgerald 6-02-2009