Felis ISSN 2398-2950

Chlamydophila felis

Synonym(s): C. psittaci, chlamydia psittaci

Contributor(s): Martha Cannon, Melissa Kennedy




  • Order: Chlamydiales.
  • Family: Chlamydiaceae.
  • Genus: Chlamydophila.


  • Greek: chlamys - a cloak.

Active Forms

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Clinical Effects



  • Direct cat-to-cat transmission is most common route.
    • Inhalation or ingestion of infectious material, eg respiratory and ocular discharges.
    • Asymptomatic carriers may shed the organism.
  • Indirect transmission, via fomites, may also occur.

Pathological effects

  • Conjunctivitis Conjunctivitis.
    • Severe conjunctivitis in acute stage of infection.
      • Most common in young cats; 5 weeks to 9 months old.
    • Most cats remain systemically well.
    • Mild nasal discharge and sneezing may occur.
    • Clinical signs persist for weeks or months, but may eventually be self-limiting infection.
  • Possible link with feline infertility, abortion and neonatal death not proved.


Control via chemotherapies

  • Oral tetracycline Tetracycline.
    • Doxycycline Doxycycline, 10 mg/kg once daily PO for 4-6 weeks.
    • Amoxycillin Amoxicillin /clavulanic acid (12.5 mg/kg twice daily for 4 weeks) as alternative treatment for use in pregnant queens and kittens.
  • Treat all cats in the household.


  • Killed vaccines available for cats as part of multivalent vaccine.
  • Vaccination of breeding queens before mating optimizes maternally derived immunity in queens.


This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading


Refereed papers

  • Recent references from VetMed Resource and PubMed.
  • Di Francesco A, Carelle M S & Baldelli R (2003) Feline chlamydiosis in Italian stray cat homes. Vet Rec 153, 244-245.
  • Sturgess C P, Gruffydd-Jones T J, Harbour D A & Jones R L (2001) Controlled study of the efficacy of clavulanic acid-potentiated amoxycillin in the treatment of Chlamidia psitacci in cats. Vet Rec 149, 73-76.
  • Ramsey D T (2000) Feline chlamydia and calicivirus infectionsVet Clin North Am Small Anim Pract 30(5), 1015-1028.
  • Sykes J E, Studdert V P & Browning G F (1999) Comparison of PCR and culture for the detection of Chlamydia psittaci in untreated and doxycycline-treated experimentally infected cats. J Vet Int Med 13, 146-152.
  • Dawson S & Willoughby K (1999) Feline infectious upper respiratory tract disease - an update. In Practice 5, 232-252.
  • Sparkes A H, Caney S M A, Sturgess CP & Gruffydd-Jones T J (1999) The clinical efficacy of topical and systemic therapy for the treatment of feline ocular chlamydiosis. JESFM 1, 31-36.
  • McDonald M et al (1998) A comparison of DNA amplification, isolation and serology for the detection of Chlamydia psittaci infection in cats. Vet Rec 143(4), 97-101.
  • TerWee J et al (1998) Characterization of the systemic disease and ocular signs induced by experimental infection with Chlamydia psittaci in cats. Vet Microbiol 59(4), 259-281.
  • Sturgess C P et al (1995) Studies of the safety of Chlamydia psittaci vaccination in cats. Vet Rec 137(26), 668-669.
  • Gunn-Moore D A et al (1995) Prevalence of Chlamydia psittaci antibodies in healthy pet cats in Britain. Vet Rec 136(14), 366-367.
  • O'Dair H A et al (1994) Clinical aspects of Chlamydia psittaci infection in cats infected with feline immunodeficiency virus. Vet Rec 134(15), 365-368.