If dogs have bugs like sesame seeds, they may be fleas, mites, ticks, or lice and other external parasites. The dog needs to be treated in time, otherwise it may be transmitted to humans, causing both humans and dogs to suffer. Skin redness, swelling and itching may occur. It is best to deworm the dog once a month and give the dog a bath every two weeks, which can effectively prevent the infection of external parasites; try not to take the dog to a dirty environment, especially in the grass.