Conjunctivitis is defined as inflammation of the conjunctiva, which is the delicate, well-vascularized mucous membrane lining the upper and lower eyelids and covering the outermost parts of the eyeball. It is one of the most common eye disorders in dogs.
How Conjunctivitis Affects Dogs
Conjunctivitis is also called "red eye" for obvious reasons. It is painful and irritating to affected dogs and frustrating for their owners. Clinical signs of conjunctivitis include swollen and sticky eyelids, excessive tearing, pawing at the eyes, squinting, pronounced redness and inflammation. It can occur in one eye or in both and often is accompanied by a profuse, thick ocular discharge. Left untreated, chronic conjunctivitis can permanently damage the cornea and other surrounding ocular tissues.
Causes of Conjunctivitis in Dogs
There are many causes of conjunctivitis. They include trauma, allergies, foreign body intrusion, bacterial or viral infection, neoplasia and immune-mediated conditions. Certain breeds are predisposed to developing conjunctivitis, especially those with long narrow skulls, deeply set eyes and inadequate tear drainage(Afghan hounds, Dobermans, Poodles).
Preventing Conjunctivitis in Dogs
Dogs chronically affected by conjunctivitis – especially if it is due to a structural or conformational breed predisposition – probably should not be bred. Dogs with an immune-mediated cause of conjunctivitis may require lifelong oral or topical prescription therapy.
Medicated eye drops can be quite helpful for dogs suffering from conjunctivitis. In troublesome cases, owners may be referred to a specialized veterinary ophthalmologist for advanced diagnostic testing and treatment. While chronic conjunctivitis can be frustrating for owners, it usually can be treated effectively once the cause is determined.
Conjunctivitis ("red eye") refers to inflammation of the delicate, well-vascularized membrane lining the eyelids and covering parts of the eyeball (called the "conjunctiva"). There are many causes of conjunctivitis, including trauma, allergies, foreign body intrusion and bacterial or viral infection. Treating conjunctivitis requires extensive testing to determine its underlying cause. Of course, any treatment protocol must be tailored to the cause of conjunctivitis in that particular dog.
The goals of treating conjunctivitis are to resolve the underlying cause, eliminate any bacterial, viral or fungal infection and eliminate ocular pain associated with the condition. A thorough ophthalmic examination must be done, including assessment of all conjunctival surfaces, taking samples for bacterial and fungal cultures, examination of conjunctival cells microscopically for infection or other disorder, applying fluorescein dye to examine internal eye structures, assessing tear production via a Schirmer tear test and testing intraocular pressure.
In most cases, topical, broad-spectrum antibiotics in the form of prescription eye drops will resolve conjunctivitis caused by bacterial infection in dogs. These drops also sooth and wash over the eyes, promoting healing. Topical steroid eye drops may be added to the protocol to reduce inflammation.
If eye drops are not effective and a more chronic condition develops, further investigation into the cause of the condition is necessary. Normally, this will include referral to a specialized veterinary ophthalmologist for advanced diagnostic testing. These tests will check for foreign objects or parasites which may be contributing to eye irritation. The veterinarian will examine and sample cells of the irritated eye tissue to determine whether any viral components or resistant bacteria are involved. If a foreign object or parasitic infection is found, surgical removal may be necessary. If a virus is detected, anti-viral eye drops may be prescribed. If an especially resistant bacteria is suspected, samples will be cultured to determine which particular antibiotic, or combination of antibiotics, will effectively eliminate the infection. Dogs experiencing chronic conjunctivitis due to seasonal allergies can be given prescription eye drops, especially during the seasons in which the condition is worse. A number of oral medications are available as well, particularly if the eye redness is secondary to some other underlying condition.
While chronic conjunctivitis can be frustrating for owners, it usually can be treated effectively once the cause is determined. In most cases, it is best to consult with a veterinarian who has advanced training in ophthalmology in order to resolve chronic eye conditions.