Feline Chlamydia in Cats
What is Feline Chlamydia?
Feline chlamydia in cats is a bacterial infection caused by Chlamydophila felis (formerly Chlamydia psittaci sp felis). This Gram-negative intracellular bacterium mainly affects young cats aged 5 weeks to 9 months, although all age groups are susceptible. Male Birman cats appear more frequently affected.
Cats living in multi-cat environments, such as shelters or catteries, have increased risk. Transmission occurs through direct contact, aerosols, or contaminated objects (e.g., clothing, accessories). Fortunately, the bacterium survives less than 48 hours in the environment and remains sensitive to common disinfectants.
Some cats become chronic or asymptomatic carriers, representing about 5-10% of cases. The incubation period typically ranges from 5 to 10 days.
Symptoms of Feline Chlamydia
Symptoms depend on the infection’s severity and mainly affect the eyes, though respiratory or systemic signs can also occur.
Common ocular symptoms:
- Conjunctivitis
- Eye discharge (initially unilateral, becoming bilateral and mucopurulent)
- Chemosis (conjunctival swelling)
- Blepharospasm and blepharitis
- Prolapse of the third eyelid and hyperemia
Respiratory symptoms:
- Sneezing
- Mild rhinitis
- Nasal discharge
Possible systemic symptoms: In severe infections, symptoms include:
- Lameness
- Abortions
- Infertility
- Neonatal death
- Lymphadenopathy
- Fever
- Depression
- Loss of appetite
- Weight loss
Feline chlamydia often co-occurs with infections like herpesvirus, calicivirus, Bordetella bronchiseptica, or Mycoplasma felis. Acquired immunity after infection is weak and temporary, increasing recurrence risk.
Diagnosis of Feline Chlamydia
Accurate diagnosis requires specific tests, as symptoms resemble other diseases:
- Feline rhinotracheitis: 4-5 day incubation, marked respiratory symptoms, bilateral conjunctivitis.
- Calicivirus: 3-5 day incubation, often accompanied by ulcerative stomatitis.
Diagnostic methods:
- PCR (most reliable, from conjunctival swabs)
- Bacterial culture (less common)
- Serology (less common)
Treatment of Feline Chlamydia
Effective treatment involves antibiotic therapy. It’s crucial to treat all cats simultaneously to prevent reinfection. Topical ocular treatments or artificial tears can alleviate symptoms but are insufficient for systemic infections.
An optional vaccine is available to reduce symptom severity upon infection.
Prognosis and Prevention
The prognosis is favorable; however, C. felis can be zoonotic, particularly affecting immunocompromised individuals.
Recommended preventive measures:
- Limit contact between infected and healthy cats.
- Regularly disinfect objects and surfaces.
- Consider vaccination for high-risk cats.
