Conjunctivitis is one of the most common causes of red eyes in dogs. But when people refer to ‘conjunctivitis’ in dogs, they usually just mean their dog has a red eye for one reason or another. There are actually many causes of red eyes in dogs that are not related to inflammation of the conjunctiva, which is the literal translation of ‘conjunctivitis’. The conjunctiva is a thin lining of tissue covering the inside of the eyelids and the surface of the white part of the eye.

signs of Conjunctivitis in dogs

The most common sign of conjunctivitis in dogs is redness of the eye. There can also be discharge from the eye that can be cloudy, yellow/green or bloody. Masses or thickening of the conjunctiva can also be seen.

Causes of Conjunctivitis in dogs

1. Infectious – Bacteria, viruses of parasites can cause conjunctivitis. Repeated episodes of bacterial conjunctivitis in dogs should lead to a broader investigation for an underlying disease process.
2. Allergic – The conjunctiva has a large amount of active immune cells within it. Pollens and other allergens can trigger allergic conjunctivitis.
3. Immune mediated – The immune system can sometimes attack the conjunctiva resulting in swelling and redness of it. This can look like little bumps on the inside of the eyelids or on the third eyelid.
4. Injury – Trauma to the eye or objects behind the third eyelid or stuck in the deeper recesses of the eye can result in conjunctivitis.

testing for conjunctivitis in dogs

Your veterinarian may advise you to test the tear production of the eye, stain the eye for damage to the cornea, look behind the third eyelid and measure the pressure of the eye. More advanced testing or referral to a veterinary ophthalmologist may be advised.

treatment for conjunctivitis in dogs

Treatment for conjunctivitis in dogs can be as simple as an antibiotic eye drop for a week or may involve lifelong treatment with topical steroids or other immunosuppressive drugs. This is why it is important to contacta veterinarian near youif you think your dog might have conjunctivitis in one or both of his eyes.

Yours in health,

Dr. Kent Morley