Pedigree or purebred dogs are more expensive to buy if purchased from a breeder and their nature and appearance is generally predictable (as they should conform to a breed standard). Crossbreeds (or 'designer dogs') are dogs of mixed ancestry. They are robust and often make great pets. Keep in mind though, that when you purchase a crossbred puppy it might be difficult to accurately predict how these puppies will develop. Both purebred and crossbred puppies and adult dogs are available at RSPCA Adoption Centres.
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.