Raillietina is a genus of parasitic tapeworms that has chicken, turkey, geese and numerous other domestic and wild birds as final hosts. It is found worldwide. It is quite common in traditional and free-ranging poultry. Out of the 37 different species there are several species of veterinary importance with a different geographical distribution. The most relevant ones are:
Raillietina spp en el intestino de un ave. Imagen tomada de http://eimeria.chez-alice.fr Raillietina cesticillus, the broad-headed tapeworm, up to 13 cm long and 1-3 mm wide, in chicken, turkey and many wild birds; found worldwide
Raillietina echinobothrida, the nodular tapeworm, up to 25 cm long and 1 -4 mm wide, in chicken, pigeon, pheasants; found worldwide
Raillietina tetragona up to 25 cm long and 1-4 mm wide, in numerous domestic and wild birds; found worldwide
Raillietina bonini up to 7 cm long and 1.5 mm wide, mainly in pigeons; found in Europe, Near and Middle East