Cryptosporidium parvum screening in young calves with diarrhoea in Sulaymaniyah Governorate, Iraq

The parasitic protozoan <i>Cryptosporidium parvum</i> causes cryptosporidiosis in young calves, leading to diarrhoea and financial losses in the farming industry. This study aimed to examine the occurrence of <i>C. parvum</i> in preweaning calves suffering from diarrhoea in Sulaymaniyah, Iraq, using both enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) methods. Faecal samples were obtained from 80 young calves categorised into various groups according to age, breed, sex, and geographic origin. Notably, a greater occurrence of <i>C. parvum</i> infection was observed in female calves, those in the 5-30 days age group, and those of the Friesian breed. Furthermore, the highest infection rate was reported in the Zarayan region. A strong correlation was observed between the ELISA and PCR findings. The molecular analysis detected both <i>C. parvum</i> and <i>C. ryanae</i>, with <i>C. ryanae</i> documented for the first time in Iraq. <i>C. parvum</i> infection considerably affects physiological indicators, particularly in younger calves, including body temperature, heart rate, and respiratory rate. PCR positivity in our study was substantially correlated with dehydration. Overall, this study highlights the need for prompt identification and intervention for the management of <i>C. parvum</i> infections in young calves.