Eye Ulcers in Horses

If I could, I would wrap my horse in bubble wrap. One day they are fine, and the next, you may find them squinting, holding their eye tightly shut and tearing, which will cause any horse owner to worry. If this has happened to your horse, it may have sustained an eye injury and/or ulcer, which is actually a pretty common condition and should always be treated as an emergency. The position of the eye, the fact that the horse is a flight animal, and that they like to rub on everything (stable doors, wood posts, trees, troughs etc.) means that they are susceptible to these types of injuries. Most corneal ulcers heal relatively quickly with treatment, although some may become severely infected and require further veterinary treatment. 

When a horse has an ulcer, it typically means that there has been some loss to the most superficial layer of the eye, the cornea. This injury is very painful and irritating, so the horse will try to rub its eye, which may worsen things. Ulceration of the eye can also turn quickly, meaning that secondary infection (fungal or bacterial) can result if the eye is not treated immediately. If veterinary treatment is not sought immediately for corneal ulcers, then there is a possibility of the eye rupturing, and a loss of vision will ensue. Hence, it is imperative to call your vet immediately if you suspect an eye ulcer - the control pain, prevent infection and promote healing. 

Signs of Corneal Ulcers

As mentioned above, corneal ulcers are very painful. One of the earliest signs that an eye may be sore could be that the affected eye’s eyelashes are pointing downwards, and the horse closes its eye tightly if you approach it. Some other signs include:

• The eye is watery and may have varying amounts of discharge;
• The horse is squinting and may keep its eye closed;
• Sensitivity to light;
• Swelling of the eye;
• A blurred appearance or blue hue of the eye;
• Reddened conjunctiva;
• A constricted pupil; and
• head shying

If your horse is experiencing any of these symptoms, it is best practice to call your vet immediately. It is most likely that your vet will thoroughly examine the eye and prescribe pain relief medication, as well as antibiotic eye drops, to control infection. 

If you suspect your horse has an eye ulcer, follow the below steps before your vet’s arrival;

• Do not put anything in your horse’s eye, even if it’s old eye medication you have - wait for the vet’s arrival and assessment
• Put a fly veil on your horse to protect it from light, and monitor your horse to ensure it is not rubbing its eye on anything;
• If there is anything protruding from the eye, don’t try to pull it out - wait for the vet;
• Do not wipe the eye or attempt to open it - wait for the vet; and
• Place your horse in a stable, if possible, to protect it from sunlight, as bright light will make the eye painful.

Prognosis

The majority of corneal ulcers are superficial and will likely resolve within a week. However, many may develop more complicated infections (due to secondary fungal and bacterial infections) and may need more aggressive treatment. If you find that after treatment, your horse’s eye begins to water, there is an increase in pain, or it turns cloudy or develops a blue hue, then remember to call your vet straight away.

It is not uncommon for a horse to experience an eye ulcer in its lifetime. If you suspect an eye ulcer, remember to call your vet immediately. Your vet will then be able to provide you with a treatment plan and have your horse back to its happy and healthy self!