Dipylidium

Adult tapeworms live in the intestine of cats and dogs. Gravid proglottids containing egg capsules are shed. The capsules, each of which contains many eggs, are eaten by flea larvae. The eggs hatch and the enclosed oncosphere penetrates the gut of the flea and enters the hemocoele. The parasite develops into a cysticercoid larva which survives metamorphosis of the larva into an adult flea. When the infected flea is eaten by a grooming dog or cat, the cysticercoid is released and develops into an adult tapeworm.