Felis ISSN 2398-2950

Hepatozoon felis

Synonym(s): H. felis, Hepatozoon canis, H. canis

Contributor(s): Stephen Barr, Susan Dawson, Grace Mulcahy




  • Phylum: Apicomplexa.
  • Class: Sporozoa.
  • Subclass: Coccidia.
  • Order: Euccidiidae.
  • Family: Haemogregarinidae.
  • Genus: Hepatozoon.
  • Species: felis.


  • Gr: heparo - liver; zoion - animal.

Clinical Effects



  • In the tick (Rhipicephalus sanguineus).


  • Cats ingest infected tick   →   sporozoites in tick released by digestive enzymes   →   sporozoites penetrate intestinal wall   →   schizogony in reticuloendothelial cells   →   macroschizonts   →   macromerozoites   →   reinfect reticuolendothelial cells of spleen, bone marrow, liver, lungs and muscles   →   microschizonts and micromerozoites   →   micromerozoites infect blood monocytes and neutrophils   →   form gametocytes   →   ingested by tick   →   oocysts in body cavity of tick   →   sporulate   →   infective sporozoites.


  • By ingestion of an infected tick.

Pathological effects

  • Schizonts, sporozoites and merozoites infect monocytes, neutrophils and cells of the reticuloendothelial system.
  • Micromerozoites stimulate granulomatous inflammation.
  • Few reports in cats.
  • Micromerozoites in liver may cause granulomatous cholangiohepatitis.
  • Clinical signs: recurrent fever, loss of condition and lumbar pain.

Other Host Effects

  • May cause subclinical infection in some hosts.
  • H. felis is probably the same organism as H. canis.


Control via animal

  • Control of ticks.

Control via chemotherapies

  • Combination of primaquine and oxytetracycline Oxytetracycline.
  • Palliative treatment with non-steroidal anti-inflammatory drugs.

Control via environment

  • Control of ticks.


  • None available.


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Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Lloret A, Addie D D, Boucraut-Baralon C et al (2015) Hepatozoonosis in cats: ABCD guidelines on prevention and management. J Feline Med Surg 17 (7), 642-644 PubMed.
  • Ewing G O (1977) Granulomatous cholangiohepatitis in a cat due to a protozoan parasite resembling Hepatozoon canis. Feline Practice 7 (6), 37-40 VetMedResource.
  • Klopfer U, Nobel T A, Neumann F (1973) Hepatozoon-like parasite (schizonts) in the myocardium of the domestic cat. Veterinary Pathology 10 (3), 185-190 PubMed.