Haemoproteus columbae in domestic pigeons in Sebele, Gaborone, Botswana.

Mature and immature stages of Haemoproteus columbae gametocytes, an avian haemosporidian protozoan parasite were found in 75% of blood smears prepared from 30 healthy domestic pigeons in Sebele location, Gaborone, Botswana. Parenteral administration of an immuno-suppressive dose of dexamethasone, lowered the level of parasitaemia, the packed cell volume and the heterophil:lymphocyte ratio in the test pigeons. However, both the dexamethasone-treated and the control pigeons remained clinically normal.