Friday, September 14, 2012

Column: Lake tails

Virus could be cause of cat's allergic-like symptoms

Sneezing, wheezing and runny eyes: Many people suffer from these allergy symptoms as summer plants die off and fall foliage blooms. While allergies are a main cause of symptoms in humans, viral infections are the No. 1 cause of upper-respiratory symptoms in felines.

If your cat is ill, there are a few different causes of upper-airway symptoms that need to be ruled out by your veterinarian. While viral infections predominate, secondary bacterial and fungal infections can cause serious complications.

Allergies also occur in cats and can cause signs identical to an infection. Dental disease, especially in older cats, is an extremely common source of chronic irritation of the nasal tissue, which can result in sneezing and nasal discharge.

Foreign materials, such as grasses and plant awns, also can cause symptoms, as can tumors, which could require anesthesia, radiographs and surgery by your veterinarian to diagnose and treat effectively.

About 90 percent of all upper-airway infections are caused by two common viruses: feline herpesvirus-1 and feline calcivirus. While feline herpesvirus (FHV) is related to the virus that causes cold sores in humans, there's no reason to panic. They are distinct viruses, and people can not get sick from the feline virus.

The viruses are spread from cat to cat primarily by the inhalation of aerosolized droplets produced by sneezing. These droplets can come from an outside stray cat, travel a distance by wind and eventually pass through an open window and infect an indoor-only cat. And like what can happen with the common cold, a healthy cat can become infected by coming into contact with an object, such as a food bowl, that has been used by an affected cat.

Our hands also can play a role in spreading the viruses, so if you have touched a sick cat, wash your hands before touching another cat.

The most common signs of FHV or calicivrus are sneezing and watery or mucous discharge from the eyes or nose. A sick cat also may have a cough or a hoarse voice with a change in its "meows." Similar to any viral infection, a cat may have a fever, which can lead to lethargy, loss of appetite and general malaise.

Severely affected cats can develop painful ulcers in the mouth, which may cause marked halitosis (bad breath), anorexia and weight loss. Infrequently, these viral infections can lead to muscle cramps and limping, especially of the rear legs.

Chronic eye inflammation and discharge from scarring of the tear ducts are a common sequela of an FHV infection in a kitten. Throughout some cats' lives, relapses of signs of a latent herpes virus infection can occur, especially during periods of stress from, for example, boarding, introducing new pets or moving to a new home. (Think of those pesky cold sore outbreaks.)

Unless a cat has suffered from repeated outbreaks, veterinarians rarely test for the viruses and typically treat the symptoms. There are very few drugs that can effectively control viral infections, so treatment usually consists of supportive care as the virus "runs its course."

Keeping your cat warm, comfortable and eating and drinking properly are the mainstays of at-home care. Many sick cats lose their appetite because nasal congestion affects their sense of smell.

These cats may benefit from having their canned food warmed up and being offered baby food (without any garlic or onions as these are toxic to cats) or delicious treats. Gently wiping the eyes and nose to clear any discharge should be done as often as your cat will allow.

If your cat or kitten's illness lasts an unusally long time or is accompanied by unusual pain, facial deformity, significant weight loss or loss of appetite lasting more than two days, you should consult your veterinarian.

Your vet may prescribe broad-spectrum antibiotics for a secondary bacterial infection, eye medications for corneal ulcers and conjunctivitis, and administer pain medications or perform fluid therapy to treat dehydration if present.

There are also some medications such as Lysine, an amino acid which reduces replication of the virus, and Interferon, an immunostimulant, to help treat and prevent symptoms for cats that suffer relapses.

Like most veterinary medicine, prevention is the key. Vaccination against FHV and calicivirus is a core vaccine, which means it is recommended for all cats, both indoor-only and outside cats. The vaccines may not be100 percent effective in preventing a disease, but they do limit how sick your cat becomes if it is infected.

All kittens should have a series of vaccines from about 8 to 16 weeks of age. The number of vaccinations depends on the kitten's age when the first shot is given. Adult booster vaccinations also are recommended and should be discussed with your veterinarian.

While it is impossible to eradicate herpesvirus and calicivirus from all our cats, routine vaccination and prompt treatment is important to limit the complications that can affect your beloved pet during its life.