Ocular herpes in cats is a contagious infection caused by the feline ocular herpes virus, FHV-1. The disease is quite common, and is one of the primary reasons cat owners seek emergency veterinary treatment. Untreated feline ocular herpes can cause permanent damage to the eye, including impaired vision and blindness. In severe cases, feline ocular herpes necessitates removal of the eye.
Symptoms of Feline Ocular Herpes
The herpes infection caused by the FHV-1 virus leads to swelling of the eye, conjunctivitis and discharge from the eye. Your cat may suffer clouding of the cornea in the infected eye. He may squint excessively and display signs of impaired vision. He may become lethargic and lose his appetite.
Diagnosis and Treatment of Feline Ocular Herpes
Your vet will want to run a range of tests in order to rule out the possiblity of other eye diseases before he can confirm infection with feline ocular herpesvirus. In fact, feline ocular herpes is usually diagnosed by exclusion, simply because tests designed for its diagnosis aren't terribly accurate. Your vet will check for infection by bacteria and other viruses, and he'll look for injuries and birth defects. If he doesn't find any of these, he'll diagnose feline ocular herpes.
Feline ocular herpes can't be cured. Your cat will suffer an initial outbreak, after which the virus will go dormant and may not recur for years. In some cases, no other outbreaks occur after the initial one. Your cat will carry the feline ocular herpesvirus for the rest of his life and will remain capable of infecting other cats for the rest of his life.
Your vet will treat outbreaks of feline ocular herpes with a combination of oral and topical medicines. These medications will increase your cat's eye lubrication, stave off secondary infection by bacteria and relieve your cat's pain. If your cat's outbreak is severe but your vet deems him otherwise healthy, antivirals may be precribed to lessen the severity of the outbreak. If an outbreak of feline ocular herpes goes beyond the reach of other treatment methods, your cat will need surgery to remove the infected eye.
Complications and Transmissibility of the FHV-1 Virus
Your cat will experience no symptoms of feline ocular herpes while the virus is in its dormant stage. Outbreaks can lead to corneal scarring and damage to the cornea, which could impair your cat's vision. There is no way to cure or prevent an outbreak. Feline ocular herpes can be fatal; kittens die from this disease more frequently than adult cats, and almost all deaths from feline ocular herpes occur when the cat didn't receive appropriate treatment from a vet.
The FHV-1 virus is not contagious to humans, but it is very contagious to other cats. Vets believe that as many as 90% of cats are infected with this virus. Cats in multi-cat households who become infected with feline ocular herpesvirus will almost certainly pass on the virus to the other cats in the home. FHV-1 can be passed from cat to cat, even when symptoms aren't apparent.