Feline Upper Respiratory Infections

Hey Doctor….I Have a Question!

In this column, I will attempt to answer some of the most commonly asked questions we get in the exam room about a particular disease or illness. This issue’s topic: Feline Upper Respiratory Infection

Q: I just adopted a kitten and I think he has an upper respiratory infection. How did he get it and what signs am I looking for?

A: The major causes of upper respiratory disease in cats are two highly contagious viruses: feline herpesvirus and feline calicivirus. Young kittens, unvaccinated cats and cats housed in shelters or catteries have the greatest risk of infection. They can be infected by direct contact with sick cats or by fomites (contaminated cages, food and water dishes, human hands and clothing). Sneezing alone can propel virus up to 4 feet in the air, so it’s easy to see how the virus spreads rapidly in close quarters. Typical signs of upper respiratory infection are sneezing, coughing, discharge from nose and eyes, lethargy, decreased appetite and fever.

Q: Dr. C., do I need to bring my cat in for an exam for this condition or can I watch her for awhile?

A: If your cat is older (not a kitten) and is showing mild signs such as occasional sneezing and clear discharge from eyes or nose but is still eating and active, most likely you can watch her. The condition will usually start to resolve in 5-7 days. However, if she isn’t eating, is depressed or has thick, yellow discharge, she should be seen. The above is true for kittens also, but they need to be watched even more closely. Kittens can dehydrate quickly if they aren’t eating and drinking in as little as 1 day. In this case, they made need fluid therapy (IV or subcutaneously) to feel better. Don’t hesitate to call the clinic if you have a question or are wondering if you need to make an appointment.

Q: How do you diagnose this infection?

A: Usually we can diagnose upper respiratory infection based on your kitten’s clinical signs and history of being exposed to other sick cats. We usually don’t test for the virus directly unless the case is severe. We will encourage you to test your kitten for feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) at the time also, because these two viruses suppress the immune system causing the infection to persist longer than we would expect. Besides, knowing the FeLV/FIV status of your cat is always a good thing due to the deadly nature of these viruses! More on this topic in another newsletter.

Q: How do you treat upper respiratory infection?

A: As you probably know from your own doctor, viral infections are not treated with antibiotics, but bacterial infections are. Thus, if we believe your kitten has a secondary bacterial infection (thick, yellow or green eye or nose discharge for example) we will prescribe an oral antibiotic. Your kitten may also need topical eye medication if conjunctivitis/eye discharge is present. We may also prescribe an appetite stimulant if needed. Other medications we sometimes use are interferon (inhibits replication of some viruses) and l-lysine (interferes with reproduction of the herpes virus). Any of these medications will work to shorten the course of the infection, but won’t provide a quick cure. Remember, the virus itself will have to run its course and that takes time.

Q: I want to help my sick kitten get over this as soon as possible. What can I do in addition to giving the medicines?

A: Glad you asked! Supportive care at home is very important. Here are some treatments we recommend you do:

  • Clean discharge from eyes and nose frequently.
  • Stuffy noses mean lack of smell which makes cats less likely to eat. Offer a variety of canned foods and broths to encourage eating. Increase aromas of food by microwaving until just warm. Hand-feed if you have time.
  • Provide rest and warmth.
  • Use a humidifier or vaporizer to reduce congestion. Steam works well also.

Q: My cat had an upper respiratory infection when she was a kitten, but now she seems to get “sick” with the same signs of the illness occasionally. Why is this happening?

A: Unfortunately, if the infection was severe, some cats will have symptoms of the illness throughout the rest of their lives. Some will have mild signs such as sneezing and watery discharge every few months and get over it themselves without treatment. Others never seem to get over it with nasal congestion, raspy breathing and sneezing. Most likely these “chronic snufflers” are the result of herpesvirus infection. Herpesvirus can be quiet or dormant in the body for some time and then reappear causing a flare-up, especially during times of stress. It can also permanently damage the nasal architecture making it easy for secondary bacterial infections to occur. For most of these cases, there is no effective treatment. We usually control flare-ups with long-term antibiotics, l-lysine and appetite stimulants. We may also use decongestant nasal drops, but these need to be used with caution in cats. This is a very frustrating condition and we hope there will be more effective antiviral treatments in the future. Research is actively being done in this area.

It is very important to vaccinate your cat/kitten for these viruses. In the case of an exposure, the vaccine may not totally protect against the virus, but it will shorten the course and reduce the severity of the infection.

Dr. Christy Collignon