A BOLUS FOR THE ADMINISTRATION TO CATTLE OF METACERCARIAE OF THE LIVER FLUKE FASCIOLA-HEPATICA

A gelatin-agar bolus, designed and developed for the administration of metacercariae of the liver fluke Fasciola hepatica, was evaluated in adult Holstein Friesian cattle. The metacercariae, enclosed within a g elatin capsule, were placed inside the bolus and delivered to each ani mal using an oesophageal balling gun. At slaughter, 13 weeks after cha llenge, an average of 25% of the challenge dose was recovered from eac h liver. This percentage recovery is similar to that obtained with oth er known methods. The new bolus, however, offers improved handling qua lities. In addition, the bolus also has potential for improving a numb er of other techniques including those for the administration of other parasites, compounds or chemotherapeutic agents.