Cats : There is a high prevalence of contact with Chlamydofila felis in cats based on serological screening (45% of farm cats, and 30% of household cats showing conjunctivitis).
Dogs : Up to 50% of normal healthy dogs have antibodies to Chlamydia.
Cats : Chlamydofila felis is a common cause of conjunctivitis which often affects one eye a few days before the second one gets inflamed. Affected cats have inflammation of the conjunctiva, blepharospasm and an ocular discharge. Cats with feline immunodeficiency virus infection may develop prolonged signs. Chlamydia may be involved in genital infections of cats - but this is inconclusive.
Dogs : Chlamydia have been suggested to cause chronic keratitis in dogs, but they are also found in the eyes of normal dogs, so the significance is not proved. Only isolated cases of infection has been reported - possibly indicating transmission from other species e.g. budgerigars.
Generally swabs taken from superficial sites or aspirations from deeper tissues are examined directly for inclusions, or cultured on McCoy tissue cultures. Fluorescent antibody techniques are highly specific, and there are some ELISA tests available but interpretation is problematic.
Cats : Intracellular chlamydial inclusions can be seen in epithelial cells collected by swabbing the conjunctival membrane, or on positive fluorescent antibody testing of conjunctival scrapes. Chlamydia can be isolated from faeces and rectal swabs and may inhabit the genital tract.
Oral tetracycline is the treatment of choice (except for superficial infections) at a dose rate of 22 mg/kg three times daily for 3-4 weeks. Alternatively doxycycline at 5-10 mg/kg twice daily for 3-4 weeks.
Cats : Treat conjunctivitis due to Chlamydofila felis with topical tetracycline ointment administered four times daily for 2 weeks. Some authors recommend oral tetracycline or doxycycline as well. To eliminate the disease from a colony ALL cats have to be treated with doxycycline for 6 weeks, and kittening should occur in isolation.
NB Zoonosis Risk
Chlamydia have a lipid-containing cell wall that is susceptible to lipid solvents and detergents so quaternary ammonium compounds diluted 1:1000 are recommended for environmental cleaning.
Maternal antibodies provide protection in kittens until they are 7-9 weeks of age Live and killed vaccines are available for prevention . Sometimes a transient fever, anorexia and lameness are seen 1-3 weeks post-vaccination
Long term problems
Because Chlamydia are intracellular organisms complete elimination may not be possible from some individuals and they can become chronic carriers of the disease
Updated January 2016