
I have no idea what breed your dogs are, but most breeds have some health problems that need to be tested for to minimise the chances of these being passed on and affecting the pups.
Certainly most breeds should be Hip Scored, and many eye tested. Some also should be elbow tested, heart tested etc.
If you haven't had these tests done, then I would suggest you get Dad done before the pups are due to go, and also get Mum done once pups are weaned and write this into your puppy agreement. It won't prevent action being taken against you if the pups do develop a hereditary problem, but will at least show that you tested, and hopefully that the parents were clear.
If it turns out that one or other of the parents are not clear, then at least this will be known, and the prospective buyers will need to be informed of the extra risks involved in purchasing a pup.
Good luck.