Focus on Chlamydophila felis

Chlamydophila felis (C. felis), formerly known as Chlamydia psittaci var. felis, is a specialised bacterium that primarily causes chronic conjunctivitis in cats.

Clinical signs develop within a week of infection and usually begin with a watery ocular discharge.  Cats often hold their eyelids partially closed due to discomfort and as the disease progresses, the conjunctiva redden and the discharge changes from watery to thick and yellow in colour.  Additional clinical signs include mild sneezing, nasal discharge and, occasionally, mild fever, lethargy and loss of appetite.

Known to be present in up to 30% of cases of feline conjunctivitis, the bacterium is more commonly seen where groups of cats are kept together, such as multicat households, catteries and shelters.  Although cats of all ages can be affected, disease is most commonly seen in kittens between 5 weeks and 9 months of age and cats often suffer persistent signs. 

Recent research also indicates that cats housed in catteries with feline upper respiratory tract disease (FURTD) present are more likely to be infected with C felis than those establishments with no reported signs of FURTD.

C. felis responds well to antibiotic treatment.  There are also vaccines available to help prevent the disease.