Provide plenty of fresh air and ventilation. Keep your cat away from other cats - especially kittens, to prevent transmission of the infection. Occasionally they involve the lower respiratory tract - the bronchi and lungs. All cats are susceptible to cat flu. The presenting signs do overlap between infections with the different organisms, but sneezing , a high body temperature and general dullness are common to all of them.
Some signs are more typical of specific infectious organisms than others.
Recurrent and persistent conjunctivitis - with inflammation of the eye and a purulent bilateral discharge is typical of Chlamydia infection, whereas calicivirus frequently causes sever ulceration in the mouth. Rhinotracheitis virus causes corneal ulcers and is most likely to affect the lower respiratory tract, which can lead to secondary pneumonia, as well as systemic effects such as abortion in infected queens. Some cats can become chronic carriers of infection, and immune-compromised cats may never fully recover developing chronic rhinitis. If untreated mild cases of cat flu can progress to pneumonia due to secondary infections. Unfortunately interpretation of the results can be misleading.