There are different types of worms that attack on pets as internal as well as external parasites. These worms can be transmitted from one animal to another. They hardly transfer from animals to human beings. The only worm that can get transferred to man is roundworm. They can transmit due to dirty surroundings, soil, and eating infected fish. They live in intestine of a person and cause health problems. It depends if your dog is carrying roundworm or some other worm. If your dog is showing problems like vomiting, diarrhea or lack of energy then you should be more than careful. It can be roundworm. Give it deworming medicines.