Eye diseases can threaten your pet’s vision and can be a source of acute or chronic pain or discomfort. Although your pet’s eyes work similarly to your own, the eye disorders that affect your pet may be different and unfamiliar. The Valley Center Veterinary Clinic team shares the most common eye diseases in dogs and cats.

#1: Conjunctivitis in pets

The conjunctiva is the tissue that lines the inside of the eyelids and the eye’s white portions (i.e., sclera). Conjunctivitis, or conjunctival inflammation, is also called “pink eye,” because the eye has a pink or red appearance. In cats, feline herpesvirus or a bacterial infection are the most common causes, while in dogs, allergies or immune system problems are most common. Eye drops or ointments usually clear up the problem in a few days or weeks, although some types may require long-term medications. 

#2: Corneal ulcers in pets

The cornea, which is the clear tissue covering the eye front, is composed of layers, similar to skin. Corneal injuries or irritation from another eye disease can abrade the top layer, causing a painful ulcer. Signs include squinting, watery discharge, and rubbing at the injured eye. Thick, yellow, or green discharge can indicate an infected ulcer. Most ulcers heal in a few days with antibiotic eye drops, but in severe cases, they may require repair with grafting surgery. 

#3: Entropion in pets

Entropion occurs when the upper or lower eyelids are too long, the extra skin rolls inward, and the eyelashes rub on the cornea, which can lead to recurring corneal ulcers, corneal inflammation, and scarring. A few puppies or kittens are born with and can outgrow the condition, but most need surgery to restore the eyelids to their normal position. 

#4: Cherry eye in pets

Dogs and cats have a third eyelid that rises from the inner eye corner (i.e., medial canthus), with a tear-producing gland attached to the base. In some young dogs, the third eyelid gland can pop out of its normal position and appear as a red or pink lump. Although the condition is rarely uncomfortable for the pet, reduced tear production and subsequent inflammation can occur over time. Surgery to replace and tack the gland into place is usually curative.

#5: Distichiasis in pets

Distichiae are extra eyelashes that often grow toward and rub on the cornea. Typically, multiple hairs grow from a single hair follicle, but they are found incidentally and never cause a problem. In other pets, however, coarse hairs cause chronic tearing, squinting, ulcers, and discomfort. Treatment with cryosurgery (i.e., freezing) is recommended for problematic hairs.

#6: Dry eye disease in pets

Dry eye disease occurs in dogs following auto-immune tear gland destruction and reduced tear production. When a less watery tear film layer is produced, the mucous layer takes over and causes profuse, sticky, yellow-green discharge and the eyes appear dull, red, and sometimes pigmented or scarred. Dry eye disease requires life-long treatment with daily immune-suppressing and anti-inflammatory eye drops or ointments.

#7: Cataracts in pets

The eye’s lens sits behind the pupil and iris and helps focus light on the retina. A cataract is a lens hardening and opaque white coloration, and the more the cataract covers the lens, the more severely the pet’s vision is impacted. An oral supplement called Ocu-Glo may help slow progression, but definitive treatment requires surgical removal. Cataract surgery is extremely specialized and can be expensive, so may not be appropriate for all pets. Long-term anti-inflammatory eye drops are recommended to prevent secondary complications, such as glaucoma.

#8: Uveitis in pets

Uveitis is inflammation inside the eye that usually occurs from a systemic disease or illness, such as a tick-borne infection, fungal infection, cancer, parasite, or auto-immune disease. Signs include redness, cloudiness, bleeding or pus inside the eye, iris color changes, and squinting. Uveitis treatments include aggressive anti-inflammatories, testing to find the underlying cause, and targeted medical therapies based on test results.

#9: Glaucoma in pets

Glaucoma is elevated eye pressure caused by a primary genetic defect or secondary to another eye disease. Glaucoma is usually primary in dogs, but often secondary in cats, with cataracts, infections, trauma, and uveitis the most common causes. Glaucoma signs include redness, a bluish color change, eye bulging, blindness, and pain. Eye drops or surgery are sometimes effective for controlling glaucoma, but eventual blindness often results. Eye removal surgery is recommended if a pet’s glaucomatous eye becomes blind and painful.

Addressing new problems with your pet’s eyes promptly can help avoid potential vision loss and reduce discomfort or pain. Contact the Valley Center Veterinary Clinic team if you notice eye disease signs in your pet, or to learn more about diagnosing and managing common ocular issues in dogs and cats.