Studies on prevalence and histomorphology of Sarcocystis species infecting cattle in Andhra Pradesh, India.

The present study was carried out to determine the prevalence of bovine sarcocystosis and identify the different species of Sarcocystis cysts in cattle in different regions of Chittoor district, Andhra Pradesh. A total of 150 slaughtered cattle over a period of 1 year were examined both macroscopically and microscopically for the presence of Sarcocystis infection. Out of 150 slaughtered cattle examined, macroscopic sarcocysts were observed in nine cattle and were exclusively found in oesophagus. Examination of tissue samples collected from different predilection sites from each of 150 cattle by pepsin-HCl digestion method revealed presence of live banana shaped bradyzoites under light microscopy in 134 cattle. Six cattle that were positive by macroscopic examination were also positive by microscopic examination of tissues. The overall prevalence of Sarcocystis infection in cattle of Chittoor district was 91.33%. The prevalence of macroscopic and microscopic sarcocysts was 6.57 and 93.43% respectively. Statistically a significant relationship between the prevalence of infection among different age groups (P < 0.001) and no significant relationship (P > 0.001) between the prevalence of Sarcocystis infection in male (91.76%) and female (90.76%) cattle was observed. In both male and females the prevalence of Sarcocystis infection increased with age. Microscopically sections of tissues from cattle that were positive by tissue digestion technique revealed thin walled cysts (4.5 ± 0.5 µm) in 131 samples and thick walled cysts (0.5 ± 0.12 µm) in six cattle.