“Feline Upper Respiratory Infection Complex” is the term used to describe a condition affecting the mouth, nasal passages, sinuses, and upper airway in cats and kittens. There are multiple causes, both bacterial and viral, of feline upper infection complex. The majority of cases are caused by feline herpesvirus (also known as feline rhinotracheitis virus) or calicivirus. Other, less common, agents of infection are bordetella, mycoplasma, and feline chlamydia virus. These infections may occur alone or as multiple agents of infection together at once. Feline upper respiratory infection is not transmissible to people.
How is feline upper respiratory infection spread?
Upper respiratory viruses are spread through contact with discharge from the eyes and nose of an infected cat. This may occur from direct cat-to-cat contact or may occur indirectly from contact with surfaces contaminated with infected discharge.
What are the symptoms of feline upper respiratory infection?
Cats susceptible to upper respiratory infections generally develop signs about two to five days after exposure. The specific signs present rely, to some extent, on the particular disease agent causing infection. The most common signs are:
- Sneezing
- Nasal discharge
- Runny, red, or squinty eyes
- Cough
- Oral or nasal ulcers
- Sniffles
- Fever
- Hoarse voice
- Or any combination thereof
More serious complications may also occur, including lack of appetite (due to either oral ulcers or nasal congestion), pneumonia, or eye ulcers. Very young kittens have a higher incidence of pneumonia, and some do not survive the infection.
While most upper respiratory infections typically resolve in 10 to 14 days, some infections are more persistent. For instance with calicivirus, even after apparent recovery, an infected cat continues to spread virus and be contagious to other cats. This may continue for a few weeks to as long as a few years after apparent recovery. These cats are known as “carrier” cats. In feline herpes, much like herpes virus in people, the virus itself does not go away. Instead, it retreats into the patient’s nerves where it remains (latent), trapped by the patient’s immune system. In times of stress (e.g. during boarding, travel, big household changes, or illness) the immune system is taxed, and the virus is able to escape, leading to return of symptoms. In some cats who have experienced severe cases of upper respiratory infection as kittens, there may be chronic persistent signs of infection, such as nasal congestion or runny eyes.
Which cats are at risk for feline upper respiratory infection?
While any cat or kitten, especially one who is not properly vaccinated, is at risk for an upper respiratory infection, certain conditions lead to increased risk. Risk of infection is greatest in cats from areas that are overcrowded or have poor sanitation. This includes cats from catteries, rescue shelters, or outdoor feral cat populations. The disease is commonly diagnosed in the spring and summer months when many kittens are born.
How is feline upper respiratory infection diagnosed?
Diagnosing feline upper respiratory infection is generally based on physical exam findings and typical symptoms of fever, congestion, sneezing, watery eyes, nasal discharge, and occasionally drooling. Finding the exact viral or bacterial cause of the infection, however, is more difficult, requiring special laboratory testing. While most cases of upper respiratory infection can be treated without specific testing for the exact cause, testing may be advised for cases which are chronic or severe. Patients with severe signs, such as pneumonia, may require further testing, such as blood work or chest x-rays.
How is feline upper respiratory infection treated?
Since most upper respiratory infections are viral, there are no specific drugs available to kill these agents. Treatment is instead aimed at supportive care and maintaining your cat's overall health to bolster the immune system and help speed recovery.
Basic treatment often includes antibiotics, which are used to treat secondary bacterial infections as well as the less common bacterial causes of respiratory infection. Treatment may also include frequent cleaning of eyes and nose, nasal humidifiers or nasal drops, or eye medications. Also important are proper diet and sufficient fluids. If your cat does not respond to treatment at home, hospitalization may be necessary.
How can I prevent upper respiratory infections in my cat?
The best way to prevent upper respiratory infections is to follow the vaccination procedures provided by your veterinarian. Also, keep your cat away from other potentially contagious cats, and take precautions when introducing a new cat to the household, or after handling a cat that may be harboring infectious diseases.