
If the parents have been tested as Nessa pointed out the results of these tests will be on the KC registration certificates of the individual puppies against the parents names.
If both parents were clear for the two DNA tests then against the puppies registered name it will show hereditary clear for that condition.
Unfortunately the Staffie is the most over-bred and casually bred breed out there, with most bred in the way this litter is, the owners do not have the necessary knowledge of the dogs behind the parents to make good breeding decisions.
Every good first time breeder should be relying not only on their own research but be backed by mentors within their breed who do know all about the good and bad points of the grandparents great grandparents etc.
To do this I would expect them to be involved with the breed club/s and in a non working breed being shown.
Anyone else is just slinging two dogs together to produce puppies, which may or may not have good health, temperaments and typical breed characteristics.
There are lot so less serious health issues that a good breeder will take into account in addition to official tests. the tendency to Demodectic mange, slipping patellas etc etc.