Tapeworms are flat worms that are segmented. They consist of a head, neck, and then a number of segments. The head usually has suckers or muscular grooves that enable the tapeworm to attach itself to the animal’s intestine.

Each tapeworm segment has its own reproductive organs. New segments are continually formed in the neck region of the worm while those at the end of the tapeworm are cast off as they mature. These mature segments contain large numbers of eggs, which are often grouped into packets. The segments may often be seen near the anus of the dog or cat. These segments may move if recently passed, or if dried, they look like grains of uncooked rice or cucumber seeds. Tapeworm infections are usually diagnosed by finding these segments on the animal.

Tapeworms of dogs and cats all have life cycles that include an intermediate host. These hosts include fleas, fish, and domestic animals such as sheep and pigs. All of the adult forms of these tapeworms live in the cat’s or dog’s digestive system. It is interesting that tapeworms have no digestive systems themselves, but absorb nutrients through their skin.

The most common tapeworms that infect dogs and cats are:

  • Dipylidium caninum
  • Taenia species
  • Echinococcus granulosus and E. multiocularis
  • Diphyllobothrium latum
  • Spirometra mansonoides