Which parasite is transmitted to cats and dogs by fleas and is a tapeworm?

• A. Tapeworm
• B. Heartworm
• C. Coccidia
• D. Mosquito

Answer: (A)

The concept here is how a flea can serve as an intermediate host for a tapeworm. In cats and dogs, the classic flea-borne tapeworm is Dipylidium caninum. The life cycle starts with the adult tapeworm living in the animal’s intestine and releasing egg-containing segments that pass into the feces. Fleas ingest these eggs and harbor the cysticercoid larval stage inside. When a dog or cat grooms and swallows an infected flea, the cysticercoid develops into an adult tapeworm in the intestine, completing the cycle. That flea link plus the tapeworm nature makes this parasite the best fit for the question.

Heartworm, by contrast, is transmitted by mosquitoes and resides in the heart and vessels; coccidia are microscopic protozoa spread via environmental contamination with oocysts.