The RSPCA recommends that you do not purchase a dog from markets or places where large numbers of dogs are kept for sale. Dogs sold from these establishments are very rarely examined by a veterinarian, and therefore may not be entirely healthy. Never purchase a puppy that looks unwell and if you are concerned about the welfare of the animal, contact the RSPCA Inspectorate.
Puppy Roundworms can infect humans. To prevent this infection, puppies should be wormed regularly throughout their first year of life, and owners should be thorough with their own personal hygiene after having interacted with the dog. Tapeworms, Hookworms, and Whipworms can also infect dogs, and your veterinary surgeon can advise when to worm the dog.