In this study, clinical coccidiosis diagnosed in a 3 years old Holstein cow brought to Firat University, Faculty of Veterinary, Veterinary Teaching Hospital on June 2012 with the complaints of bloody diarrhea, anorexia, and malaise was presented. The anamnesis indicated that the diarrhea had started in the animal 3 days ago, which resulted in the bloody diarrhea 1 day before the examination. In physical and laboratory examination, rectal temperature was 39.8oC, pulse frequency was 80/min, respiratory frequency was 28/min, rumen contraction was 2/5min and the hematocrit value was 40%. The feces obtained from the cow's rectum was watery, mucusy and bloody. An intense amount of Eimeria oocysts were determined during examination of the feces with flotation technique. A solution of 2.5% potassium dichromate (K2Cr2O7) was added to the Petri dishes containing feces with oocysts to allow them convert into the sporulation phase, then the identification of the coccidia species was performed. As a result of this examination, the cow was observed to have been infected with a total of 4 species including E. bovis, E. bukidnonensis E. ellipsoidalis and E. zurneii. According to anamnesis, physical and feces examination findings, the case was diagnosed as clinical coccidiosis and treated.

As a result, although coccidiosis is a well-known disease of the young animals up 3 to 6 weeks old, it should be considered in the older animals with bloody diarrhea.