Site and hosts - The site of the adult parasites in the sheep is given and other possible sites mentioned. Alternative hosts are listed. Life cycles - Many of these parasites live part of their life in the sheep and part on the ground. In a direct life cycle infection is passed from sheep to sheep via the pasture. Other parasites with indirect life cycles require an intermediate host for their development.
Protozoan parasites can multiply within the host.
For worm parasites multiplication is by production of numerous eggs. The morphology of parasites refers to their physical features. Only those used to identify them are illustrated here. In addition to broad classification of shapes and sizes, specific features such as the heads and tails of nematodes are helpful in identification. Features of the mouth are often used too.