After fleas appear on the dog, the dog should be dewormed internally and externally. During this period, the dog should wear an Elizabethan collar to prevent the dog from licking the medicine and causing discomfort. In addition, fleas on dogs can be transmitted to humans, and will usually cause symptoms of itching, redness and swelling. You should pay attention to the cleanliness of your home environment and do not let your dog play in places with woods or grass to avoid being infected with parasites.