Horses and eye problems

Any condition involving the eye is potentially serious and should be investigated as soon as possible, says Kim Dyson.

This mare sustained a minor scratch to the eye, which subsequently became infected, then cancerous. Attempts were made to save the eye, but it was eventually removed after seven months. The procedure saved the mare, and despite this handicap, she lives an entirely normal life.
Photo: Kim Dyson

In the horse, most infections of the eye are usually caused by dust or other foreign material entering the eye and causing damage to the cornea. Very often, the initial problem will progress to a secondary infection that can be either bacterial or fungal. I was once called out to see a client about a foal that had suddenly gone blind. After examining its eyes I realised that the foal had been standing under the teff net and seeds had falled into its eyes.

The most common cause of eye irritation and consequent infection is the placing of teff nets too high. When the teff net is placed above eye level the seeds fall into the eye. The constant scratching of these seeds can cause blindness.
When empty, the bottom of the net should be about 60cm off the ground. This prevents horses getting tangled up in an empty net. The tie-up point needs to be at eye level.

The best method is to loop the long string of the net through the hook on the wall and then through the base of the net.
Always hang a teff net on a carabina clip or baling twin so that it is easy to release in case of an emergency. Another cause of problems is a turned-in eyelid. This causes the eyelashes to irritate the eye, which can eventually lead to chronic infection and blindness. Unfortunately, even a small injury, if left untreated, can lead to a severe eye infection, an abscess and the loss of an eye. Eye blinkers repaired with wire are the most common cause of this severe damage.

Early investigation pays off
Blindness can also be a result of the viral herpes infection and the occasional stomach worm. Very rarely cancerous cells may invade the skin around the eye. If your horse is showing signs of pain, excessive tear flow, light sensitivity, eyelid swelling and more serious signs of ulceration, contact your vet. Chronic infection of the cornea results in a blue-white colouration of the eye. If growths around the eye are investigated early, they will have a much better chance of healing. The outcome depends on a correct diagnosis of the cause of the irritation. A flourescein test will determine whether the surface of the cornea has ulcerated.

Castor oil
If there is a foreign object in the eye, use clean castor oil to float it to the surface so that it can be removed. Make a herbal wash from calendula, Golden Seal and Bach Rescue Remedy to soothe sore and swollen eyes and minor infections. Apply to the outside of the eye. The dilution of the calendula and Hypericum should be one in 10 and applied three times a day until improvement is seen.

For hot, puffy, tender tissue around the eye, try 10 drops of Ledum Palustre 200c in the bottom lid four times a day for three days. If the cornea has not been damaged, apply Euphrasia eye lotion directly to the affected eye to ease the profuse weeping. Dilute 1:20 in boiled cooled water; administer three times a day for three to five days. Your vet may recommend antibacterial eye ointment.

Ointments containing cortisone should not be used unless there is no ulceration of the cornea. Non-responsive or deep-seated infections that have led to abscess formation may require surgical removal of the eye. Horses can live a healthy, normal life with only one eye. But prevention is best!