Conjunctivitis: cause and treatment

Learn more about eye problems in horses

Conjunctivitis occurs when the pink lining of the eyelids — the conjunctiva — becomes inflamed.

It is the most common disease affecting the equine eye and it always causes it to weep.

Conjunctivitis can be a disease in its own right, or as a follow-on from another eye disease such as uveitis.

Some common causes of conjunctivitis:

• Bacterial infections
• Irritants, such as wind, dust, flies and chemical irritants
• Allergens, such as pollen
• Trauma
• Foreign bodies
• Eyelid deformities, for example when a wound leaves a gap in the eyelid
• Parasites, such as habronema, which cause sores and are common in sunny summers
• Tumours

Treatment of conjunctivitis will depend on the cause.

With the common bacterial conjunctivitis, antibiotics are frequently prescribed as an ointment, gel or drop to be placed in the eye.

To apply rest your hand on the horse’s cheek and gently turn out the lower eyelid so you can squeeze the medicine into the exposed conjunctival sac.

Medication is often easiest to apply at the inner (medial) corner of the eye.

Find out more about eye problems in horses