Chlamydia felis

Species of bacterium

Chlamydia felis (formerly Chlamydophila felis and before that Chlamydia psittaci var. felis) is a Gram negative, obligate intracellular bacterial pathogen that infects cats. It is endemic among domestic cats worldwide, primarily causing inflammation of feline conjunctiva, rhinitis and respiratory problems. C. felis can be recovered from the stomach and reproductive tract. Zoonotic infection of humans with C. felis has been reported. Strains FP Pring and FP Cello have an extrachromosomal plasmid, whereas the FP Baker strain does not. FP Cello produces lethal disease in mice, whereas the FP Baker does not. An attenuated FP Baker strain, and an attenuated 905 strain, are used as live vaccines for cats.

The genus Chlamydia contains the species C. trachomatis, C. psittaci, C. abortus, C. felis, C. muridarum, C. suis, C. caviae, C. pecorum, and C. pneumoniae. However, there is some dispute that some of these species, including C. felis, should be classified in a separate genus, Chlamydophila, but this has not been widely accepted. The organism was not formally classified until 1999. microaerophilic bacterium, whose cell wall seems to lack peptidoglycan. Its morphology is that of a coccobacillus.

C. felis was originally discovered in the lungs of cats suffering from pneumonia. It has been reported to infect humans as well, giving it zoonotic potential, though it is rare. As typical of many members of its genus, C. felis is well adapted to live within its host and cannot survive for long outside of the host. Thus, direct contact is necessary for the pathogen to spread and is why C. felis infection is more common in multi cat environments. Clinical signs of infection are hyperaemia of the nictitating membrane (severity varies), blepharospasm, and discharge from the eye. The infection is not deadly, but if left untreated may cause blindness and pain for the cat. Infection is commonly spread among cats by ocular secretion. People generally prefer cats that appear happy, healthy, and playful. Doxycyline is an antibiotic that is commonly used to treat these infections at a dosage of 10 mg/kg of body weight daily for four weeks. This cost of treatment can be financially limiting considering that all cats within a facility, shelter, or home must be treated regardless of whether they are infected to ensure the disease is effectively eradicated.