Occurrence and Morphometric Characterization of Cysticercus tenuicollis in Sheep From Minas Gerais, Brazil.

In livestock production, the health of slaughtered animals is crucial to ensuring food safety. In this context, animal cysticercosis poses serious problems within production systems. Cysticercosis caused by Cysticercus tenuicollis (larval stage of Taenia hydatigena) is common in pasture-raised ruminants. Although this helminthiasis is of low pathogenicity for production animals, it is difficult to diagnose during inspection procedures. Animals become infected by ingesting eggs present in water and/or feed contaminated with feces from domestic or wild canids. In this study, viscera from Dorper/Santa Inês crossbred sheep raised under a semiextensive system were evaluated in situ during four slaughter events in a slaughterhouse in the metropolitan region of Minas Gerais. Among 700 sheep slaughtered, 113 cysticerci were recovered and stored at 4°C for 3 h. They were then subjected to evagination using 1% hydrochloric acid/pepsin at 37°C for 10 min. Stereomicroscopy revealed cysticerci measuring 0.6 cm in length and 0.2 cm in width when invaginated and ranging from 2 to 7 cm in length and 1.5 to 8 cm in width when viable and evaginated forms. A total of 25.7% of parasites were found in the liver and 74.3% in the omentum, mesentery, and associated tissues. Microscopy also allowed the observation of rostellar hook morphology regarding number, width, and total length of large and small hooks. This study reports the first occurrence of ovine cysticercosis by C. tenuicollis in Minas Gerais, Brazil.