Conjunctivitis in dogs, or canine pink eye, is the most common eye infection suffered by dogs. It occurs when the membrane covering the inside of the eyelid and the front of the eye becomes inflamed. It can affect one or both eyes and may be the result of viruses, bacteria, parasites or allergies.
Causes of Canine Conjunctivitis
Canine conjunctivitis can occur for a number of reasons. Often, it's the result of chronic irritation, deformity of the eyelids or abnormal eyelash growth. Chemicals, dust and wind can cause the irritation of conjunctivitis in dogs. Bacterial, viral or parasitic infection may be at fault, as well as allergies.
Conjunctivitis shouldn't affect your dog's vision, but he may experience mild to moderate levels of discomfort and pain. However, if the infection or irritation is left untreated, your dog runs the risk of impaired vision. Sometimes, conjunctivitis in dogs is a symptom of serious illness like canine distemper, so if your dog develops symptoms he should see a vet right away.
Symptoms of Canine Conjunctivitis
Conjunctivitis symptoms in dogs will vary depending on the cause of the condition. Allergies and infections will cause a lot of inflammation and swelling of the conjunctiva, or mucous membrane, that covers the eye. This will cause the white of your dog's eye to look pink, which is the reason why many people refer to conjunctivitis as 'pink eye'.
If allergies or infection are the cause of your dog's conjunctivitis, then there may be some discharge from the affected eye; often, this discharge will change in color and consistency depending on the cause of your dog's pink eye. If the infection is severe, the discharge may become so thick that your dog's eyelids will stick together and need to be washed gently with warm water. This usually occurs in the case of bacterial, viral or fungal infection, while allergic reactions cause a much thinner and often largely colorless discharge.
If your dog is suffering from conjunctivitis, no matter the cause, you'll be able to tell there's something wrong with the eye or eyes. He'll squint perpetually and may rub the eye with his paw or try to scratch it on carpets or furniture. The third eyelid inside your dog's eye will swell and remain partially closed. Even after your dog recovers from conjunctivitis, this eyelid may remain partially closed and visible below the outer eyelids, but that shouldn't cause your dog any discomfort or loss of vision.
Treating Canine Conjunctivitis
Though conjunctivitis in dogs isn't a serious or life threatening condition, and though it doesn't impair your dog's vision, it could damage your dog's eyesight if you don't treat it right away. Conjunctivitis could also be a symptom of a serious illness, so your dog should see a vet if he displays conjunctivitis symptoms.
If your dog's eye is infected, your vet will prescribe medicated eye drops and ointments. If allergies are at fault, your vet will prescribe allergy medications, usually hydrocortisone. If the infection is severe, your dog may need oral antibiotics.