Abstract
Coccidiosis is one of the most economically important protozoan diseases affecting young calves, primarily caused by host-specific Eimeria species that target the intestinal epithelium. This study investigated the prevalence, species identification, and epidemiological determinants of Eimeria infections in calves from Holy Kerbala, Iraq, using combined parasitological and molecular approaches. A total of 296 fecal samples were collected from calves of different age groups between May 2024 and January 2025 and examined using flotation techniques, followed by PCR amplification of the internal transcribed spacer 1 (ITS-1) region for the molecular detection of Eimeria bovis. The overall prevalence reached 70%, with significantly higher infection rates in calves ≤1 year of age. Seasonal variation was evident, with peak infections recorded during December and January. PCR successfully amplified the expected 238 bp product specific to E. bovis, confirming its predominance among the detected species. The findings underscore the epidemiological significance of coccidiosis in calves in Kerbala and highlight the superiority of molecular diagnostics over conventional microscopy for accurate species identification. Integrating PCR-based assays with improved management and hygiene practices is essential for effective control and prevention of coccidiosis in cattle herds.