Survey of ocular abnormalities in draft horses.

This research article investigates the prevalence of eye diseases in working breeds of horses in the United States. The study uses different tests and examinations to identify any abnormalities, and concludes that although minor cataracts are relatively common in this horse population, they usually do not threaten their vision.

Research Method

The article describes the method used to investigate eye health in draft horses. This included:

• A non-dilated ophthalmic examination to study the horse’s eye health. This involved the use of a slit lamp microscope and an indirect ophthalmoscope. These tests provide important details about the horse’s eye, including its size, shape, and any abnormalities detected.
• Measurements of intraocular pressure in the horses’ eyes. This pressure can indicate conditions such as glaucoma, and can reflect the overall health of the horse’s eye.

Study Sample

The study focused on 165 draft horses, ranging in age from 10 days to 33 years old, and included different breeds of horses. The gender distribution of the horses was noted, with geldings (neutered male horses) making up the majority of the sample.

Results

Among the horses examined, 9 (or 5.5%) were found to be suffering from serious eye conditions that could potentially threaten their vision. These conditions included cataracts, uveitis and secondary glaucoma, optic nerve atrophy which occurred post-trauma, retinal detachment, large chorioretinal scars, and phthisis bulbi – a condition characterized by a shrunken or atrophied eyeball.

A slightly larger group of horses, or 33.9%, were identified as having non-vision-threatening eye conditions. These included various conditions such as corpora nigra cyst, eyelid trauma or notch defect, corneal scars, asteroid hyalosis, keratitis, and “bullethole” chorioretinal scars.

Conclusions

The study concluded that minor cataracts were fairly common among the horses studied, but these were not usually vision-threatening. Furthermore, the survey found a higher prevalence of a condition known as linear keratopathy in draft horses, which was not typically associated with concurrent eye disease.