Chlamydia Infections in Cats

Picture of a cat outside

Chlamydia infections are more common in cats than you might think, but the same rule applies to humans and any other mammals, for that matter. Cats can easily catch it from other animals they come in contact with, particularly outdoors.

In today’s article, we’re looking at everything you should know about this condition, from the symptoms it causes to how it is diagnosed and treated.

How Do Cats Get Infected With Chlamydia?

The most common way of catching the infection would, for this species, be through the nasal discharge that cats produce while experiencing the respiratory form of the disease.

That’s right – while in humans and other species, Chlamydia is a bacterium that can be transmitted through sexual contact, in cats, it is entirely different.

Cats in shelters, catteries or those that live in close contact with others or that tend to go outdoors on a regular basis are more exposed to the pathogen. For this reason, we advise you to consider keeping your feline friend only indoors as the chances of them being healthier, by comparison, are much higher.

Chlamydia tends to affect kittens aged 5 to 12 weeks in a more severe manner, so keeping young cats inside your home is even more important in this case.

Symptoms of Chlamydiosis in Cats

The most common clinical sign that pets can experience if they catch a Chlamydia infection is conjunctivitis, accompanied by eye discharge. The disease itself goes by the name of ‘Chlamydial conjunctivitis’ just to give you a clue as to how typical this symptom is.

Initially, most cats experience watery discharge from one or both of their eyes. As the days go on and they don’t receive any treatment whatsoever for their condition, the watery consistency changes into a thicker one. The color is modified, as well, turning into yellow or green.

That’s the moment when most pet owners will start feeling concerned about their cat’s health and will bring them to the vet clinic.

Other symptoms that can be seen in cats with chlamydiosis are the following:

  • Nasal discharge
  • Sneezing
  • Lethargy
  • A lack of appetite for either food or water
  • Coughing (in the later stage of the disease)

The worst thing about Chlamydiosis is that while it is a bacterial disease and there are antibiotics that can be utilized to treat it effectively if it affects young kittens, they might develop severe pneumonia and lose their life.

As you probably know, young cats don’t have fully developed immune systems, which is why they have a higher likelihood of experiencing more severe forms of any condition. The same rule applies to seniors.

Diagnosing and Treating Chlamydia Infections in Cats

Both the diagnosis and treatment of Chlamydia in cats are somewhat easy, especially when compared to the procedures involved in diagnosing and treating other conditions.

Your veterinarian can collect a sample from the cat’s eye and nasal discharge and send it to the lab, where a bacterial culture and an antibiogram will be performed. These two tests are very effective when it comes to diagnosing Chlamydiosis, and they can also lead to the right medication being recommended and administered by your vet.

In most cases, tetracyclines and doxycycline are the best antibiotics to use on the majority of cats. The first class of antibiotics proves its worth in case the cat has a mild infection, while the second, doxycycline, is commonly utilized for treating pneumonia.

Cats that have recurring Chlamydia infections might develop infertility over time.


There are ways of ensuring that your cat never catches this disease from other animals. First of all, a vaccine against it does exist, and since this is a bacterial condition, it is quite effective.

Unfortunately, it is not a part of the classic vaccination plan that most vets use, so while they might make a recommendation to the pet owners, they might not feel compelled to vaccinate their cats against Chlamydia.

However, if they have multiple cats and they also go outdoors, getting the vaccine is practically mandatory. The same rule applies to cats that live in catteries or shelters, so they have a much higher risk of getting the infection simply because they come in contact with so many other animals.

Keeping your cat’s living space and litter clean is a good idea, but it is not going to prevent a Chlamydia infection per se. The bacterium is quite sensitive to outdoor conditions, so dryness or high temperatures are capable of destroying it in a record amount of time.


Infertility in the Bitch and Queen, Gary C. W. England, 2019

Disorders of the Conjunctiva and Third Eyelid, Harriet J. Davidson, 2008



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