Upper Respiratory Infection

There are many causes of respiratory infections in the cat, both viral and bacterial. Respiratory infections are usually viral and are often HIGHLY CONTAGIOUS to other cats. They may cause serious disease that can sometimes result in the death of the cat.

Some feline respiratory infections are thought to be spread primarily by carrier animals, which may show NO outward signs of disease. These are often cats that have recently had the disease and recovered.

Direct contact with sick or carrier cats or indirect contact, such as hands, clothing or food bowls may spread these diseases. Many upper respiratory viruses are airborne or can be carried in to an indoor pet on shoes or clothing. Both indoor and outdoor pets can become ill if not vaccinated, especially in hot, humid weather.

Clinical signs are usually seen 3-7 days after exposure to a virus. The most common signs include fever, sneezing, watery or reddened eyes, nasal or eye discharge, drooling, mouth ulcers, and loss of appetite, which is the result of the loss of smell due to nasal secretions and congestion. (Coughing is uncommon in feline respiratory infections. A cough in cats usually signifies a more serious problem, such as pneumonia, bronchitis, asthma or heartworm disease, and should be investigated immediately.) If respiratory infections go untreated, severe eye damage or pneumonia may result. Chronic sinusitis and permanent damage to the sinus cavities may also be a problem. Death is uncommon in otherwise healthy adult cats, but seen frequently in young kittens or weak, debilitated or elderly cats. Death, if it occurs, is usually due to airway obstruction, dehydration, a secondary bacterial infection or malnutrition.

Treatment usually involves antibiotics, which don’t cure the original viral infection but do help control secondary bacterial infections. Antihistamines for congestion, eye ointment, medications for fever and fluids may be needed. Running a vaporizer helps loosen nasal secretions and make the cat feel better.

After recovery, the cat may continue to shed the virus for several months, possibly infecting other cats. Rhinotracheitis, caused by a herpesvirus, is the most common feline viral infection. Over 85% of cats have had this disease, usually as kittens. Many harbor the virus in their system for years, flaring up with disease symptoms or shedding the virus in their nasal secretions or tears when they are stressed. (This is similar to the behavior of Herpes viruses in people, including cold sores and chicken pox, which can show up years later as shingles.) At these stressful times they are contagious to other cats. Vaccination for Rhinotracheitis diminishes the symptoms and severity of disease but has not eradicated it from the cat population.

Cats that have recovered from upper respiratory infections may soon be susceptible to re-infection unless appropriately vaccinated. Both indoor and outdoor cats are highly at risk from these diseases. Therefore ALL cats should be vaccinated for them. A primary vaccination series is done when kittens are 6 - 16 weeks old, and then boosters are given regularly with a combination vaccine covering many of the feline respiratory viruses.