Final answer:
A flea and a dog have a parasitic relationship where the flea benefits and the dog is harmed.
Step-by-step explanation:
The type of symbiotic relationship between a flea and a dog is parasitism. In parasitism, one organism (the parasite) benefits at the expense of another organism (the host). The flea, being the parasite, feeds on the dog's blood, causing itching, bites, and possible infections.
Learn more about Parasitism between a flea and a dog