Which parasite is transmitted to dogs by the bite of a mosquito?

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

Answer: (A)

Heartworm disease is transmitted to dogs by the bite of an infected mosquito. The process starts when a mosquito takes a blood meal from an infected dog and picks up microfilariae. Inside the mosquito, these microfilariae develop into infective L3 larvae, which are then passed to another dog during a subsequent bite. The larvae migrate, mature in the heart and pulmonary arteries, and cause significant cardiovascular and respiratory problems.

This pathway is specific to heartworms. Tapeworms are acquired by ingestion of intermediate hosts (like fleas or small animals), coccidia are spread through fecal-oral contamination, and fleas are a parasite themselves rather than the vector for heartworm. So the mosquito-borne parasite in dogs is heartworm.