Taenia taeniaeformis is a parasitic tapeworm, with cats as the primary definitive hosts. Sometime dogs can also be the definitive host. The intermediate hosts of this tapeworm are primarily rodents and less frequently lagomorphs (rabbits) which the cat must kill and ingest their liver in order to acquire the tapeworm infection. The worm tends to be white, thick bodied, and around 15 to 60 cm in length. This species of tape worm is much less frequently encountered than Dipylidium caninum, which has fleas as its intermediate host rather than rodents but exhibits most of the same physical characteristics and is treated with the same medications.