Pneumonitis is an infectious upper respiratory disease of cats. It is caused by the organism Chlamydia psittaci and is spread by contact with discharges from the eye, nose, or mouth. Cats usually develop signs of infection 5 to 10 days after exposure.
The organism also causes inflammation of the conjunctiva (conjunctivitis), characterized by squinting, red, painful eyelids, and excessive tearing. The eye discharge may become yellow or green, and such respiratory signs as sneezing, coughing, or discharge from the nose may appear. Occasionally, the disease reappears in recovered cats after stress or other illness.
Vaccination is the best means of preventing pneumonitis.
Public Health Significance
Because the same organism that infects cats also causes eye infections in people, strict hygiene should be practiced when handling infected cats.