Feline Chlamydia
The Cause, Symptoms and Treatment

Feline Chlamydia is also known as Chlamydiosis, Chlamydia Psittaci, Feline Chlamydophila or Feline Pneumonitis.

It is an eye infection which causes the conjunctiva (the inner 'lining' or membrane of the eyelids) and the white of the eye (sclera) to become red and inflamed.

Feline conjunctivitis can be caused by a number of things like allergies to pollen, dust; irritants; viruses and bacteria.

In the case of chlamydiosis, the offending organism is a bacterium called chlamydia psittaci.

About a third of all reported cases of feline conjunctivitis are caused by this bacterium.

In the early stages of this feline eye disease, it may bear a resemblance to cat flu (calicivirus) and herpes virus due to the chronic discharge from the eyes and nose.

Initially the discharge is watery, but as the feline eye infection progresses, it may become muco-purulent i.e. characterized by the presence of mucus and pus.

Feline eye problems like chlamydia, can be found in cats of any age, but kittens appear to be more susceptible to this infection and often, the entire litter of kittens will be infected.

Kittens between the ages of 6 weeks to 8 months are more likely to contract this infection.

how is feline chlamydia transmitted?

The mode of transmission is believed to be via direct contact with the eye and nasal discharge of cats infected with c. psittaci.

Direct contact would occur during self-grooming or by droplet transmission during sneezing.

As this bacteria is relatively unstable and short-lived outside the body, it is unlikely, but not impossible, that cats may be infected when sharing food bowls and bedding.

For obvious reasons, this feline eye disease is far more prevalent in breeding catteries, multi-cat households and rescue shelters.

NOTE: There have been isolated cases of zoonotic infection (humans been infected by feline chlamydia).

It is suggested that good hygiene procedures are followed when treating feline eye infections.

Washing your hands after handling a cat with feline conjunctivitis will prevent you and any other cats in the house from being infected.

signs and symptoms of feline chlamydia

The incubation period (i.e. the time is takes from exposure to the disease to the appearance of the first signs) is about 14-days.

  • The first sign will be a watery discharge from one or both eyes
  • Eyes become red and swollen
  • In some cases, the third eyelid, which are normally not visible, will become red and swollen making it difficult for the cat to open its eyes
  • As the infection progresses, the discharge becomes thick and muco-purulent (contains mucus and pus)
  • The cat may also have a nasal discharge and sneezing is not uncommon
  • The cat or kitten may have a slightly raised temperature and whilst the cat may be 'off color', there is no loss of appetite.
  • Some experts believe that the bacteria may infect the digestive and reproductive tracts.
  • Whilst these signs generally go unnoticed, it can cause reproductive failure (spontaneous abortion) in pregnant queens.

Untreated, this feline eye infection will persist for 3 - 4 weeks before clearing up.

Sadly, the kitten or cat will continue to experience less severe symptoms for months to come and it may be contagious for up to a year or more.

veterinary diagnosis of feline chlamydia

The veterinarian will obtain a full medical history from the cat owner.

A scraping will be taken from the conjunctiva for microscopic examination at a veterinary laboratory.

There are a number of tests that can be performed in the lab and the results of these tests will either confirm all exclude c.psittaci.

treatment of feline chlamydia

Once the diagnosis of this feline eyes infection has been confirmed by the veterinary practitioner, he or she will decide on the appropriate course of treatment.

Treatment will generally involve the administration of topical and systemic antibiotics.

Topical eye ointments or drops contain tetracycline which needs to be applied 3 to 4 times a day.

Oral antibiotics (tablets or syrups) must be administered for a couple of months or for at least a couple of weeks after the last symptoms are noted.

The veterinarian will monitor the cat's progress and make the necessary adjustment to treatment.

In order to relieve any discomfort, the vet may also prescribe a saline eye wash to clean the kitten or cat's eyes prior to the administration of the ointment or drops.

In multi-cat households, it is highly recommended that all cats be treated simultaneously to avoid infection or re-infection.


Provided treatment starts early and all cats in the household are treated, there is a low incidence of recurrence.

Whilst the infection can be incapacitating it is treatable and every cat deserves to be healthy, comfortable and disease free.

feline chlamydia vaccination

There is a vaccine available which may assist in reducing the severity of this feline eye infection.

It is not believed to be 100 % effective in preventing the disease.

There are many cat vaccines available, some are considered core, this vaccine is not considered core in single-cat households but is highly recommended in multi-cat households.

Related Pages:


Feline Herpes Virus

Feline Calicivirus

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