By Dr. Becker
Feline chlamydophila, formerly known as feline chlamydia, is an infection caused by the Chlamydophila felis (formerly known as Chlamydophila psittaci) bacterium. Chlamydophila felis is an atypical bacteria because it lives and multiplies inside the cells of cats rather than outside the cells.
It appears most often in kitties as conjunctivitis, which is inflammation of the tissues of the eye (pink eye).
Sometimes feline chlamydophila is referred to as feline pneumonitis, indicating a problem with the lungs. However, most symptoms of a chlamydophila infection in cats involve inflammation of the tissues surrounding the eye and the upper respiratory tract only.
Feline chlamydophila is part of the feline upper respiratory disease complex, which is a group of viral and bacterial infections. Many cats with chlamydophila also have a viral upper respiratory infection such as calcivirus or herpesvirus.
Are Some Cats More Susceptible to a Chlamydophila Infection?
Feline chlamydophila is most often seen in multi-cat households, catteries, shelters, foster homes and rescues – any environment where several cats are in close contact and new cats are regularly introduced.
Infections are more common in purebred cats, kittens under the age of one, cats with compromised immune systems, and those who are stressed due to illness or changes in their environment. The infection is usually more severe in kittens.
Kitties acquire chlamydophila infections from direct contact with an infected animal’s sneeze or cough. Kittens can become infected during birth.
Indirect contact through the environment or handling isn’t as likely to transmit infection, since the bacteria doesn’t survive long outside a cat’s body.
What are the Symptoms?
If your kitty has been infected, symptoms will appear between 2 and 10 days after exposure.
The most common symptoms of chlamydophila affect the eyes. The problem can start in one eye but usually winds up in both. There will be swelling and redness of the conjunctiva, squinting, tearing and discharge from the eye which starts out clear but evolves to thick, yellow-green colored mucus.
There might also be a nasal infection which causes sneezing and a clear or colored discharge from the nose. Other signs can include fever and lack of appetite.
Symptoms of chlamydophila are often recurrent or chronic.
Diagnosis and Treatment
Many vets treat for chlamydophila based on symptoms only. I don’t recommend this approach.
A definitive diagnosis is made by taking scrapings of the cat’s conjunctiva and sending them to a lab for culture and identification. Since the chlamydophila bacteria lives inside the cells unlike most bacteria, it requires the right antibiotic.
It’s also important to rule out other problems that produce similar symptoms, including a foreign body in the eye, corneal ulcers, entropion (eyelids that roll inward toward the cornea), and distichia (abnormal hairs that irritate the cornea).
Cats with chlamydophila are often also tested for other infectious diseases like feline leukemia, FIV, calicivirus, herpesvirus, mycoplasma felis, bartonella henselae, and Bordetella Bronchiseptica.
Most cases of feline chlamydophila are treated with antibiotics, typically tetracycline, which may be given orally, as an eye ointment, or both. Only certain antibiotics can penetrate inside the cells where chlamydophila resides.
Applying warm water compresses to the cat’s eyes several times a day can help reduce discomfort and keep the area clean.
Sometimes hospitalization is necessary if there are other diseases present or the upper respiratory infection is severe. Some kitties may need additional support in the form of IV fluids and rest.
Unfortunately, feline chlamydophila can become chronic even after successful treatment with antibiotics. Keeping your kitty’s stress level low can help reduce flare ups.
Healthy cats should be kept separate from infected cats.
If you have a cat with a chlamydophila infection, keep him away not only from other cats, but also from young children and anyone with a compromised immune system. It’s also a good idea to wash your hands after handling your cat.
There are a few reported cases of chlamydophilal conjunctivitis in pet owners with an infected cat. Human infections are uncommon and easily treated. However, if you have an infected kitty and a family member develops sore or runny eyes, he or she should consult a doctor and mention the presence of feline chlamydophila in the household.
Also, if you happen to have a pet bird, you should know that on rare occasions, birds have passed the chlamydophila bacteria to cats. And if your bird is carrying the bacteria, she can also transmit it to you.
There is a vaccine available for feline chlamydophila, but I don’t recommend it. It doesn’t prevent infection, only reduces the severity of symptoms. Side effects include loss of appetite, depression, fever, lethargy and lameness. It’s another vaccine with risks that far outweigh the benefits, in my experience.
The American Association of Feline Practitioners also does not recommend routine use of the chlamydophila vaccine.