Do mosquitoes prefer dogs or humans?

Mosquitoes generally prefer humans over dogs, but they will bite both humans and dogs depending on species, availability, and attractants, as mosquitoes are opportunistic feeders that bite mammals, birds, and even reptiles to obtain blood needed for egg development. Some mosquito species like Aedes aegypti and Anopheles are highly anthropophilic, meaning they prefer humans and are attracted to human carbon dioxide, body odor, and heat, and they are primary vectors for diseases like malaria, dengue, and Zika that affect humans. Other species are more zoophilic and prefer animals like dogs, cattle, or birds. Mosquitoes are attracted to carbon dioxide from breath, body heat, and odors like lactic acid and sweat, and humans produce more carbon dioxide and have more exposed skin than dogs with fur, making humans easier targets, though dogs with less fur on belly and ears can be bitten. Dogs can be bitten by mosquitoes and can get heartworm disease transmitted by mosquitoes, so protecting dogs is important. In households with both humans and dogs, mosquitoes may bite humans more due to preference and exposed skin, but if human is using repellent and dog is not, mosquitoes may bite dog more. So mosquitoes generally prefer humans over dogs, especially human-preferring species, but they will bite dogs opportunistically, and both need protection from bites and mosquito-borne diseases.