Prevalence of blood parasites among cattle at the central area of Saudi Arabia.

The present study aimed to investigate the parasites infecting cattle blood at Al-Qassim region. Examination of 307 blood samples revealed that 235 (76.5%) and 3 (0.98%) of cattle were infected with Theileria annulata and Anaplasma marginale, respectively. T. annulata was the prevalent blood parasite among cattle while A. marginale was scarcely encountered. The monthly incidence of T. annulata ranged from 38.5% in March to 94.7% in October. Also, the infection rate reached a maximum (84.3%) in both autumn and summer seasons, while it decreased to reach (59.4%) in spring. It has been found that there was no difference between the infection rate of the laboratory and the abattoir collected samples. However, the intensity of infection was different between the two groups.