By Mike Metzger
Tapeworms are flat, ribbon-shaped worms that live inside the intestines of vertebrates, including humans. They are long, segmented worms that lack an intestinal tract, but are able to absorb nutrients through their skin. Adult tapeworms have hooks, spiny structures or suckers on their head, which allow them to attach to the wall of the intestine. The rest of the tapeworm is made up of a chain of flat segments. Mature tapeworms shed segments which are expelled with the feces. These segments are packed with eggs.
Tapeworms require an intermediate host to complete their life cycle. Different tapeworms require different intermediate hosts. All of the important species affecting sheep, goats and cattle require pasture mites. These mites live in the top layer of soil and in plant material in huge numbers. These mites ingest the eggs while feeding, and the larval stages of the worm develop inside the mites. Sheep and goats become infected when they ingest the mites containing tapeworm larvae. Once inside the animal, it takes six to seven weeks for the larvae to develop into adult tapeworms.
Reviews of research show that most of the time tapeworms do not cause any ill effects on sheep or goats, despite their rather troublesome appearance. If sheep, goats, lambs or kids are looking poorly and tape segments are seen in the manure, look for causes other than tapeworms. The animal is probably suffering from a nutritional deficiency or other worms such as Haemonchus contortus (barber pole worm). Michigan State University Extension recommends that you consult your veterinarian before treating sheep or goats for tapeworms. It is not necessary to treat animals every time you see segments in the manure. If there is a significant effect on sheep and goat health and production from tapeworms, the animal probably has a heavy infection. So just as with barber pole worm, the best strategy is to learn to live with the parasite and aim for control, not eradication. A treatment in spring when segments first appear in the manure will help reduce the level of infected mites for the grazing season.
Source: msu.edu