Davainea proglottina is a very small (0.5-2 mm) tapeworm which affects the duodenum and upper jejunum of chickens, other gallinaceous birds, and pigeons. The adult tapeworm has four to nine segments and the head (scolex) has four suckers surrounded by rings of hooks, with the mouth also ringed by hooks.
Davainea proglottina Life Cycle: D. proglottina has an indirect life cycle, using slugs and snails of the genera Cepoea, Limax, Agrilimax and Arion as intermediate hosts. Poultry become infected by eating slugs or snails carrying D. proglottina. Once inside the bird, D. proglottina begins to cause damage to their gastrointestinal tract, and gravid segments from the tapeworm's bodies, and their eggs (oncospheres) are released in the feces of that infected bird, contaminating the surrounding environment. Slugs or snails, or other birds, will then ingest those eggs or body parts from tapeworms from the environment, and the cycle continues.
Hosts: More than 1500 cysticercoids have been found inside the digestive tract of infected slugs and snails, which remain infective for more than 11 months and have a lifespan of 3 years.