Infectious Causes of Anemia

Infectious Agent

Species Affected

Hemolytic

Marrow Affected

Bacteria

Clostridium haemolyticum

Cattle, sheep

Yes

No

Clostridium perfringens A

Cattle, sheep

Yes

No

Haemobartonella spp

Cattle, cats

Yes or no

No

Leptospira interrogans

Cattle, pigs, sheep

Yes

No

Mycoplasma spp

Cats

Yes or no

Rarely

Rickettsias:

  • Anaplasma spp

Cattle, goats, sheep

Yes

No

  • Ehrlichia spp

Dogs

Yes

Yes

  • Mycoplasma spp

Cattle, goats, llamas, pigs, sheepa

Yes (piglets only)

No

Viruses

Equine infectious anemia virus

Horses

Yes or no

Rarely

Feline immunodeficiency virus

Cats

No

Yes

Feline leukemia virus

Cats

Yes or no

Yes

Protozoa

Babesia spp

Cattle, cats, dogs, horses, sheep

Yes

No

Cytauxzoon spp

Cats

No

Yes

Sarcocystis cruzi

Cattle

Yes

No

Theileria sppb

Cattle, goats, sheep

Yes or no

No

Trypanosoma spp

Cattle, horses, pigs

Yes

No

a In adults, Anaplasma is clinically relevant only in splenectomized or critically ill animals.

b Pathogenic species of Theileria are found in Africa, the Mediterranean, the Middle East, Asia, and Europe. Species found in North America are nonpathogenic.