I would definitely take it to have a vet examine him before buying. Find a good Bulldog vet,if possible. Do not take it to the owner's vet,but a different one. @mikeyjm26 I would also ask to see his shot records,and any other health records they have(though if they are not honest-they won't show them) Take a look at him-is his skin good-healthy hair,no goopy eyes,no limping. is he a registered dog-is he micro-chipped? Being registered is not necessary a requirement,unless you wanted to breed. Has the dog been spayed,or if male-castrated?