Red eye (Conjunctivitis)
Conjunctivitis, sometimes called red or pink eye, is an inflammation of the conjunctival membrane that covers the back of the eyelids and the surface of the eyeball, up to the cornea. It is one of the most common eye problems in dogs.
The classic signs of conjunctivitis are a red eye with discharge. Conjunctivitis is not usually painful.
The eye discharge in conjunctivitis may be clear (serous), mucus-like (mucoid), or pus-like (purulent). A stringy, mucoid discharge suggest the dog may have inadequate tear volume, a problem associated with ketratoconjunctivitis sicca.
Serous Conjunctivitis is a mild condition in which the membranes look pink and somewhat swollen. The discharge is clear and watery. Allergic conjunctivitis is often accompanied by itching and the dog will rub his face. Some viral agents will cause a clear discharge as well.
Follicular (mucoid) Conjunctivitis is a condition in which the small mucous glands (follicles) on the under side of the nictitating membrane react to an eye irritant or infection by forming a rough, cobblestone surface that irritates the eye and produces a mucoid discharge. After the inciting factor has been treated, the follicles may persist and the rough surface acts as a chronic irritant.
Purulent Conjunctivitis is serous conjunctivitis that becomes infected. The usual culprits are the bacteria Streptococcus and Staphylococcus. The conjunctiva is red and swollen. The eye discharge contains mucus and pus. Thick secretions may crust the eyelids.
The most common cause of conjunctivitis in dogs is inadequate tear volume.
Serous Conjunctivitis is caused by physical irritants such as wind, cold, dust, and various allergens such as those that cause allergic blepharitis.
If the eye is red and the dog is squinting and shutting the eye, consider the possibility of keratitis, uveititis, or glaucoma. Any delay in treating these conditions can lead to blindness.
When the discharge involves both eyes, suspect an allergy or possibly a systemic disease such as distemper. When it involves only one eye, consider a local predisposing (To make susceptible to a disease) cause such as a foreign body in the eye or hair rubbing on the eye.
Bacterial culture and sensitivity tests are indicated if the conjunctivitis does not improve after treatment.
Any underlying cause of conjunctivitis should be corrected. Dogs with recurrent or persistent conjunctivitis should be tested for keratoconjunctivitis sicca.
Serous conjunctivitis can be treated at home. Flush the eye 3 or 4 times a day with an over-the-counter sterile saline eyewash or artificial tears. Notify your vet if the eye appears to be getting worse.
Mils cases of follicular conjunctivitis respond to antibiotic and corticoseroid eye ointments prescribed by your vet. In resistant cases, the follicles may need to be destroyed by chemical cauterization.
Purulent conjunctivitis requires veterinary examination and treatment. It is important to remove mucus and pus from the eyes, as well as puss and crusts that adhere to the eyelids. Moisten a cotton ball with sterile eyewash and gently cleanse the eye. Warm, moist packs may help to loosen crusts. Repeat as necessary and apply topical antibiotics as prescribed by your vet. Continue topical antibiotics for several days beyond apparent cure.
NOTE: Corticosteroids and eye medications containing corticosteroids should not be used on dogs with purulent conjunctivitis because they impair the local inflammatory response that fights infection.
Regular grooming can help prevent eye irritations before they get started. Hair in your pet's eyes can cause irritation that can lead to conjunctivitis if it is matted up around the corner of the eye. Brushing the hair back away from the eyes, or getting a groomer to cut excess hair can help prevent conjunctivitis.
When traveling in the car, don't let your pet cruise with his head out the window. Debris can get in the eye, and the eye becomes more prone to infection.
Please contact your veterinarian with questions regarding this condition.
Show Sources & Contributors +
Dog Owners Home Veterinary Handbook
Publisher: Wiley Publishing, 2007
Authors: Debra M. Eldredge, Liisa D. Carlson, Delbert G. Carlson, James M. Giffen MD
The Doctors Book of Home Remedies for Dogs and Cats
Publisher: Bantam Dell Publishing, 1996
Authors: Matthew Hoffman, Laura Catalano, Maryanne Dell