What Causes Eye Infections in Pets?
Eye infections are caused by bacteria, fungi, viruses, or parasites that enter your pet's eye. These microorganisms begin growing in the eye, causing one or more of these symptoms:
Redness. Does the white part of your pet's eye look red? Both infections and allergies can inflame the eye, causing redness. Your veterinarian can determine why your pet's eyes are red and offer appropriate treatment.
Squinting. Your pet may not be able to tell you it has eye pain, but can show you by squinting or blinking.
Discharge. Watery discharge or white, yellow, or green mucus around the eyes may mean your pet has an eye infection.
Swelling. The tissues around your pet's eye may look puffy and swollen.
Rubbing. Your pet may rub its face against furniture or paw at its eye in an attempt to relieve pain or itching.
Tearing. Infections can cause the eye to water constantly.
Crusts. The fur around your pet's eyes may become crusty due to constant discharge.
Light Sensitivity. Eye infections can cause sensitivity to bright light. If your pet suddenly prefers staying indoors, light sensitivity could be the problem.
Tear Stains. Tear stains around the eyes or wet fur around the eyes are possible signs of infection.
Visible Third Eyelid. The third eyelid at the corner of your dog or cat's eye may be more noticeable if an infection is present.
Eye infections have many causes. A stray branch or speck of dirt or dust could scratch the surface of your pet's eye, allowing bacteria, fungi, or viruses to enter. Allergies, blocked tear ducts, dry eyes, or a weak immune system could increase your pet's risk for an infection.
Conjunctivitis, also called pink eye, is a common type of eye infection in dogs, cats, and small animals. The contagious infection may be caused by a virus or bacteria. Conjunctivitis affects the tissue that lines the eyelids and makes up the white part of the eye.
In some cases, eye infections can be related to other health issues. For example, dental problems in rabbits can cause eye infections, according to Ferrets, Rabbits, and Rodents. Dirty bedding or a dusty environment may increase your small animal's risk for infection. Keeping your hamster, gerbil or guinea pig's cage clean is a simple way to prevent infections.
Has your cat received the herpesvirus vaccine? The vaccine protects against feline herpesvirus 1 (FHV-1), a viral infection that causes sneezing, coughing, runny nose, and fever. Infected ulcers can form on the cornea due to inflammation caused by FHV-1. The cornea is the clear tissue that covers your pet's iris and pupil. Your cat could suffer permanent vision damage if the infection causes scarring on the cornea.
Treatment Options for Pet Eye Infections
Your veterinarian may perform a few tests to help determine the cause of the eye infection. Taking a sample of eye discharge helps your pet's doctor determine if the infection is caused by bacteria, viruses, or fungi. Special eye drops that contain dye make it easier to spot scratches or ulcers on the cornea. Your veterinarian may also test your pet's tear production and measure pressure inside the eye.
Treatment depends on the cause of the eye infection, but may include:
Antibiotics. Your veterinarian will prescribe antibiotic drops or oral antibiotics for bacterial eye infections.
Anti-Fungal Medication. This medication kills the fungus that causes some eye infections.
Anti-Viral Medication. Anti-viral medication helps your pet's immune system fight the virus that caused an infection or illness.
Steroids and Antihistamines. Steroid and antihistamine drops reduce swelling, inflammation and redness, improving your pet's comfort.
Artificial Tears. Artificial tears also improve comfort by lubricating your pet's eyes.
Unfortunately, eye infections rarely get better on their own. Without treatment, your pet could develop scarring or other issues that permanently affect its vision.
Have you noticed a change in your pet's eyes? Prompt treatment is the key to preventing vision issues. Contact our office to schedule a visit with the veterinarian.
Sources:
American Kennel Club: Dog Eye Infections: Symptoms, Causes, and Treatment, 8/3/2023
https://www.akc.org/expert-advice/health/dog-eye-infections/
Purina: Cat Eye Infections: Symptoms and Treatments, 9/22/2023
https://www.purina.co.uk/articles/cats/health/symptoms/cat-eye-infections
Merck Manual: Eye Disorders Resulting from Generalized Diseases in Cats, 9/2024
PubMed: Ferrets, Rabbits, and Rodents: Ophthalmologic Diseases of Small Mammals, 5/29/2020