Feline chlamydia is usually seen in cats as conjunctivitis (inflammation of the tissues around the eye) and is caused by a bacteria. Cats that are infected with this bacterium often have upper respiratory viral infections at the same time.
Common name: Conjunctivitis, Pink Eye
Scientific name: Feline Chlamydia
All cats are susceptible to chlamydia, however it is most commonly seen in young kittens, old cats with poor immune systems, or cats that are stressed due to illness or change in their environment. Environments with many cats, such as catteries, shelters, or rescue households are also at increased risk due to the number of cats in close proximity and the constant introduction of new cats.
Feline chlamydia is one of the main bacterial causes of conjunctivitis in cats, although viral diseases are more commonly the cause of conjunctivitis. One report estimated that in the United States, it is responsible for less than 5% of upper respiratory disease in cat. Another study showed that it may range between 14.3%-59% of upper respiratory tract infections in cats.
There is no known geographic distribution for chlamydia in the United States. It is a disease that is reported to be much more prevalent in the United Kingdom.
Clinical signs (primary, most to least frequent, scientific term, synonyms)
Swelling of the conjunctiva (tissue around the eye), redness of the conjunctiva (pink eye), tearing, squinting, discharge from the eye.
Clinical signs (secondary, most to least frequent, scientific term, synonyms)
Mild rhinitis (nasal infection), i.e. sneezing, nasal discharge, cause (scientific, common term), Chlamydophila felis.
Organ systems affected (most to least affected)
Eyes, respiratory (nose).
Cytology-examination of the conjunctival cells under a microscope, Fluorescent Antibody test-may have false results, culture-may not be successful in chronic cases.
Calicivirus, herpesvirus, mycoplasma felis, bartonella henselae, Bordetella Bronchiseptica, ocular foreign body, ulceration of the cornea, entropion (eyelids rolled toward corneas), distichia (abnormal hairs irritating cornea).
Feline chlamydia is a bacterial disease that can cause infectious conjunctivitis or‚ pink eye‚ in cats. It is often present along with contagious upper respiratory viruses, such as calcivirus and herpesvirus. Chlamydia may start in just one eye, but usually affects both eyes within a few days to a few weeks. Discharge from the eye generally starts out mild and clear, but becomes a thicker yellow-green mucus. The cat is usually squinting and the tissue around the eye looks swollen and red. In rare cases, cats may also get a mild upper respiratory infection that manifests as sneezing and nasal discharge. This disease is very contagious to other cats, particularly those that are young, immune compromised, or ill for another reason. Households and other environments with large numbers of cats have a higher incidence of chlamydia infection. There are a few reports that suggest that chlamydia may be transmissible from cats to humans and may have been found in humans with respiratory disease. Transmission from cats to humans has not been proven at this time, however it is recommended that people in contact with cats suspected to have this disease wash their hands after handling.
New cats being introduced to a household that already has cats should be quarantined and seen by a veterinarian. Cleaning of the cat's bedding, litter box, and food and water bowls should be performed on a regular basis.
Although a diagnosis can be made by looking at scrapings of the cat's conjunctiva under a microscope, most veterinarians will treat based on suspicious clinical signs. Cats should be tested at that time for other infectious diseases, such as feline leukemia virus and feline immunodeficiency virus. Most cases of feline chlamydia can be treated from home, however if there are other diseases present and the upper respiratory infection is severe, the cat may need to be hospitalized. There is a vaccine available for feline chlamydia. It is not 100% effective and many cats that have been vaccinated will still get the disease if exposed, however they may have less severe clinical signs. Vaccination is not routinely recommended for all cats at this time.
Once feline chlamydiosis is suspected, veterinarians will devise treatment plans that may include topical and/or oral antibiotics, such as doxycycline, azithromycin, or tetracycline. Anti-viral medications, such as L-Lysine, may be beneficial if other infections are present, such as calicivirus or Herpesvirus. Application of warm water compresses to the eyes multiple times per day can help reduce discomfort and clean the eyes.
With appropriate treatment, clinical signs usually resolve, although some cases may recur or become chronic.
Greene, CE. and Sykes, JA. Chlamydial Infections. In: Greene, CE, ec. Infectious Diseases of the Dog and Cat, 3rd edition. St. Louis: Elsevier, 2006: 245-252.
Cara Lane, MA, VMD
Sharon Gwaltney-Brant DVM, PhD