The intermediate hosts for the tapeworm Dipylidium caninum are fleas or lice.

• A. True
• B. False
• C. Not sure
• D. Depends on species

Answer: (A)

Dipylidium caninum relies on an intermediate host to complete its life cycle. The adult tapeworm lives in a dog’s or cat’s intestine and releases segments that contain eggs. Those eggs are taken up by flea larvae (usually the flea Ctenocephalides species) and a cysticercoid develops inside the flea. When a pet grooms and swallows an infected flea, the parasite matures into an adult in the intestine. Lice can also serve as intermediate hosts in some situations, though fleas are the more common route. Because both fleas and lice can harbor the larval stage, the statement that intermediate hosts are fleas or lice is true. Reducing flea (and lice) exposure through effective control helps prevent this infection in pets and people.