Researches in veterinary protozoology until the end of World War II were carried out entirely by Japanese workers such as Danagga, Yamada, Yuhoba and Isshiki. After the Korean war, investigations have been made by several Korean researchers such as Lee's, Son, Joen and Jang. The total species and genera of veterinary protozoa reported by authors up to date were 19 genera and 59 species except the commensal ciliates.

Incidence of the protozoa were carried out for 4 years(1972-l975) by examining fecal samples and vaginal swabs in order to know the parasitic status of the domestic animals and poultry. The results are shown as followings.

In dairy cattle: Entamoeba bovis 41.4% , Eimeria spp. 5.6-15.0%. In native cattle: Entamoeba bovis 47.6%, Tritrichomonas foetus 8.5%. In native horse: Eimeria sp. 10.0%. In goat: Eimeria spp. 100%. In swine: Entamoeba spp. 55.44%, Eimeria spp. 20%, Balantidium coli 66.58%. In dog: Isospora bigemina(Large type) 8.7%, Giardia canis 4.4%. In cat: Isospora spp. 12.8%. In hare: Entamoeba cuniculi 12.0%, Eimeria spp. 20.0%, Chilomastix cuniculi 12.0% , Giardia cuniculi 4.0%. In turkey: Eimeria spp. 33.3%, Hexamita meleagriais 8.3%. In chicken: Eimeria spp. 26.8%.

The main protozoan diseases of the domestic animals and poultry in Korea may be summarized from the data reported and surveyed as followings.

Coccidiosis; poultry, hare, goat, cattle, swine. Theileriasis; cattle. Babesiasis; cattle, dog. Anaplasmosis; cattle, goat. Eperythrozoonosis; cattle, swine. Leucocytozoonosis; chicken. Histomoniasis; chicken. Toxoplasmosis; swine, cat. Balantidiasis; swine. Besnoitiosis; native cattle. Amoebiasis; swine, cattle. Sarcosporidiosis; Cattle, swine.