Felis ISSN 2398-2950

Babesia felis

Synonym(s): B. felis

Contributor(s): Susan Dawson




  • Phylum:Apicomplexa.
  • Class:Sporozoa.
  • Subclass:Piroplasmia.
  • Order:Piroplasmida.
  • Family:Babesiidae.
  • Genus:Babesia  Babesia spp  .
  • Species:felis.


  • Victor Babes - Romanian bacteriologist.
  • L: felinus, feles - cat.

Active Forms

This article is available in full to registered subscribers

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

Clinical Effects



  • Infectious stages multiply asexually in ticks; passed between generations by transovarial and interstadial transmission.
  • Cats infected via tick saliva.
  • Infectious forms parasitize erythrocytes.
  • Trophozoites multiply asexually in erythrocytes.
  • Ingested by feeding tick.


  • Via tick bites.
  • Several genera of ticks probably involved.

Pathological effects

  • Premunition - cats remain immune due to continuous stimulation of immunity by persistent low-grade infection.
  • Carrier animals maintain low level erythrocyte parasitemia.
  • Level of parasitemia controlled by removal of infected erythrocytes by reticuloendothelial system.
  • Reduced immune defenses may lead to clinical illness:
    • Immunosuppressive drugs.
    • Splenectomy.
    • Stress.
    • Concurrent illness.
  • Infection of erythrocytes.
  • Parasite replicates in erythrocytes   →   parasitemia in 24-48 hours.
  • Anemia progresses over several weeks as infected cells destroyed by reticuloendothelial system   →   depression, weight loss, lethargy, anorexia, exercise intolerance.
  • Fever in less than 10% of cases.
  • Icterus rare, although increased fecal bile excretion.


Control via animal

  • Treat cats to prevent ticks.

Control via chemotherapies

  • Primaquine phosphate.
    Needs to be given at close to toxic dose.
  • Quinine and clindamycin   Clindamycin  .
    Not evaluated in cats.

Control via environment

  • Keep cats away from tick-infested areas.
  • Treat environment to prevent ticks.
  • Control of tick populations.


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 PubMed and VetMedResource.
  • Potgieter F T (1981) Chemotherapy of Babesia felis infection: efficacy of certain drugs. J S Afr Vet Assoc 52 (4), 289-293 PubMed.
  • Stewart C G, Hachett K J & Collett M G (1980) An unidentified Babesia of the domestic cat (Felis domesticus). J S Afr Vet Assoc 51 (4), 219-221 PubMed.