Many cats have chronic problems with upper respiratory congestion (runny or stuffy nose, nasal discharge) and/or conjunctivitis (inflammation of the eye membranes; the eyes may be red, swollen, watery, crusty, or goopy). Nasal or eye symptoms may be both be present, or you may see one without the other. Often, the problem comes and goes.
Causes include viral or bacterial infection, congenital defects (small or absent tear ducts), facial conformation (Persian features), scarring from previous infections; and (rarely) allergies. But by far the most common cause of these symptoms in cats is infection with a Herpes virus. In cats, Herpes is an upper respiratory virus; it’s also called “rhinotracheitis” and is one of the components of the combination upper respiratory/panleukopenia (feline distemper) vaccine that most kittens receive. The vaccine does not actually prevent Herpes infection; its main function is to reduce the severity of the disease.
Nearly all cats are exposed to Herpesvirus as kittens. For most cats, no further problems occur. However, Herpes is a sneaky virus, and likes to lie dormant until it gets a chance to overwhelm the immune system. Because stress suppresses the immune system, cats under stress are particularly susceptible to recurrent Herpes flare-ups.
Herpes conjunctivitis is painful, and usually causes quite a bit of redness and a watery discharge. It often attacks only one eye, producing a lopsided squint. Cats tend to be photophobic; that is, they squint against bright light, or try to avoid it altogether.
There are several treatment options for Herpes. One of the simplest is l-lysine, an amino acid that is inexpensive and readily available at the health food store. It comes in capsules or tablets, usually 500 mg. Capsules are much easier to work with, if you can get them. The dose is 500 mg twice a day for 5 days (total 1,000 mg/day). Lysine has a slightly salty taste, and is easily disguised by mixing with canned cat food or baby food. If that seems like a huge dose for a cat, it is–but that’s what it takes to work. Once the acute episode is under control, a maintenance dose of 250 mg per day can be given indefinitely.
To relieve irritation and wash viral particles from the eye, you can make a homemade saline solution. Use 1/4 teaspoon of table salt to 1 cup of lukewarm water (slightly above room temperature). Three or four times a day, use a cotton ball to drizzle a small amount saline into the cat’s eyes. Make the saline fresh each and every time, because bacteria could grow in the solution between treatments. Or, try an herbal eye wash. Eyebright is an excellent for many eye problems; Halo Herbal Eye Wash is a two part rinse that includes eyebright, as well as infection-fighting goldenseal.
If symptoms worsen, or persist more than a few days, a check by your veterinarian is warranted. Herpes can cause serious corneal ulcers that may result in loss of vision if untreated.