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.

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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.


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Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Di Francesco A, Carelle M S & Baldelli R (2003) Feline chlamydiosis in Italian stray cat homes. Vet Rec 153 (8), 244-245 PubMed.
  • Sturgess C P, Gruffydd-Jones T J, Harbour D A et al (2001) Controlled study of the efficacy of clavulanic acid-potentiated amoxycillin in the treatment of Chlamydia psittacci in cats. Vet Rec 149 (3), 73-76 PubMed.
  • Ramsey D T (2000) Feline chlamydia and calicivirus infections. Vet Clin North Am Small Anim Pract 30 (5), 1015-1028 PubMed.
  • Dawson S & Willoughby K (1999) Feline infectious upper respiratory tract disease - an update. In Practice 21 (5), 232-237 VetMedResource.
  • Sparkes A H, Caney S M, Sturgess C P et al (1999) The clinical efficacy of topical and systemic therapy for the treatment of feline ocular chlamydiosis. J Feline Med Surg (1), 31-35 PubMed.
  • Sykes J E, Studdert V P & Browning G F (1999) Comparison of polymerase chain reaction and culture for the detection of Chlamydia psittaci in untreated and doxycycline-treated experimentally infected cats. J Vet Int Med 13 (3), 146-152 PubMed.
  • McDonald M, Willett B J, Jarrett O 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 PubMed.
  • TerWee J, Sabara M, Kokjohn K 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 PubMed.
  • Gunn-Moore D A, Werrett G, Harbour D A et al (1995) Prevalence of Chlamydia psittaci antibodies in healthy pet cats in Britain. Vet Rec 136 (14), 366-367 PubMed.
  • Sturgess C P, Gruffydd-Jones T J, Harbour D A et al (1995) Studies of the safety of Chlamydia psittaci vaccination in cats. Vet Rec 137 (26), 668-669 PubMed.
  • O'Dair H A, Hopper C D, Gruffydd-Jones T J et al (1994) Clinical aspects of Chlamydia psittaci infection in cats infected with feline immunodeficiency virus. Vet Rec 134 (15), 365-368 PubMed.