Dog heartworm is primarily transmitted by which type of pest?

Dog heartworm is primarily transmitted by mosquitoes, making this the correct choice. Mosquitoes are vectors that carry the larvae of heartworm (Dirofilaria immitis) from infected dogs to other dogs. When a mosquito bites an infected dog, it takes in the microfilariae in the dog's blood. The larvae then develop within the mosquito before being transmitted to another dog during subsequent bites.

This transmission cycle is crucial to understand for pest management and prevention strategies. While other pests like fleas, ticks, and flies can be problematic for dogs and carry different pathogens or diseases, they do not play a role in the transmission of heartworm. This highlights the importance of targeted mosquito control in preventing heartworm disease in canine populations. Understanding the specific role of mosquitoes in this disease transmission can help in developing effective prevention and control measures.