Runny, Red Eyes In Cats, Probably Herpes Virus

97% of Cats Exposed, 80% Persistently Infected with Herpes

When a cat has red, runny eyes, the odds are that it has Type 1 herpes virus. Worldwide, up to 97% of cats have been exposed to the herpes virus. Of these, 80% become persistently infected with the virus. Cats are persistently infected because the virus moves right into the cat’s cells becoming resident in the tonsils, nose, and the conjunctiva, which is the covering of the eyeball.

Stress and Steroids Awaken the Virus

Although the herpes virus can reside peacefully within the cat’s cells without causing illness for months or even years, the virus can also reappear suddenly, causing painful, inflamed eyes. Research shows that 50% of cats will develop an active herpes infection if they are stressed; and for cats, stress can mean anything— new litter, new babies, new housemates, new construction, jackhammers in the street, moving, or illness. In addition to developing ocular herpes infections when stressed, 70% of cats with latent infection will develop active herpes infections if put on steroid medications, such as prednisone or prednisolone.

Taken together, these numbers suggest that, while a cat can have red, runny, inflamed eyes because it has allergies, bacterial eye infections, fungal infections, foreign bodies, glaucoma, or cancer, the odds are that if a cat has red, runny inflamed eyes, it has herpes.

Holistic Therapy for Cats with Herpes

Holistic therapy for cats with inflammation of the lining of the eyeball (conjunctivitis) or of the cornea of the eye (keratitis) includes cool, dilute tea eyewash made fresh daily to prevent contamination, and the herb eyebright (Euphrasia officinalis). Eyebright can be given three ways: topically as an eyewash, orally as a homeopathic medication, or orally combined with other herbs, including lemon balm (Melissa officinalis) and calendula (Calendula officinalis).

Acupuncture (GB 41) and traditional Chinese herbal medications (TCM) containing peppermint (Mentha piperita) and Elder flowers (Sambucus nigra) can help. Eye wash or oral medication with chamomile (Matricaria), Eyebright, Fennel (Foeniculum vulgare) can help. Your holistic veterinarian will work with you to decide which is best, and will ensure you understand which meds can be used topically in the eyes and which meds should be given orally to your cat. If your cat has difficulty breathing through its nose because it is plugged with mucus, your vet can add pleurisy root (asclepias tuberosa) to the oral medication.

Autologous Serum Used In Inflamed Eyes

While acupuncture and TCM have hundreds and hundreds of years of research, trial and error behind them, there are newer approaches that are helpful, especially autologous serum. Your veterinarian can make autologous serum for your cat uring the office visit by using a centrifuge to separate the fluid or serum portion of your cat’s blood from the red cells in the blood. The fluid or serum portion contains infection fighting alpha 2 macroglobulins, which can be dripped into the eye four times a day without stinging.

Lysine for Herpes is Controversial

Although some studies found giving oral lysine helped cats with herpes conjunctivitis, there are also studies that indicate lysine is not helpful and may, in fact, worsen the inflammation, especially in cats housed in shelters.

Antiviral Meds: Cidofovir, Idoxuridine, Trifluridine, Famciclovir

There are three newer topical antiviral meds for use with feline herpes infections: Cidofovir, Idoxuridine, and Trifluridine. Cidofovir is compounded from the injectable medication to make a 0.5% solution that is used once or twice a day. Idoxuridine is also compounded specially. It is prepared as 0.1% solution of 0.5% ointment that is applied up to 6 times a day. Sometimes, Idoxuridine irritates the conjunctiva and cornea, rather than easing inflammation. Trifluridine is commercially available as a 1% ophthalmic solution and, unlike Cidofovir and Idoxuridine, doesn’t need special compounding. Unfortunately, Trifluridine also significantly irritates the eye.

The oral antiviral medication, which has recently become more affordable because it is available as a generic, is Famciclovir. Famciclovir is prescribed at 12.5 to 25 mg/kg up to three times a day. A 9 lb cat would receive between 50 and 100 mg up to three times a day.  

Helping Cats with Herpes

Unfortunately, herpes infection is ubiquitous, and it is an infection that the immune system cannot conquer because it lives inside the cat’s cells. We can help cats with ocular herpes by reducing stress, providing holistic or conventional meds, and easing the ocular inflammation with soothing eye washes and autologous serum.

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