Eimeria species are frequently found in water buffalo (Bubalus bubalis) in Brazil. Here, we report those Eimeria spp. that infect buffalos during their first year of life. Fresh fecal samples were examined from 2 groups (1 group/yr for 2 yr, 2000-2002), each with 18 water buffalo calves (both sexes), from birth through 12 mo of age, in Selvíria, MS, Brazil. Five oocyst morphotypes were observed...