Tapeworms infect the intestinal tracts of both animals and humans. These parasites belong to the biological class Cestoda. There are several types of tapeworm: beef, pork, fish, rodent, or dog. The length of the worm ranges from 2 centimeters to 25 meters. Tapeworm infections in humans are usually contracted by eating undercooked beef or pork that contains worm cysts. Appropriate hygiene and drug treatment is effective in eliminating this infection.