
I would ask about the paents hip scores, and if they have been tested for Von willebrands disease, also if they have checked for the eye condition PHPV, which is a congenital problem where fibres that should disappear before birth are still present. I wouldn't worry too much if this last hasn't been checked for, as it is uncommon, and inherited as a dominant trait, and therefore easily removed from a gene pool as it is present from birth and affected dogs aren't bred from.
Ask them for their Affix (which you can put i8nto a searchengine, and any show results etc should come up.
You will also find that they will be wanting to know lots about you. When you visit ask to see all the adult dogs, and find out the relationship iof these to the pup. this will help you gauge what sort of temperament the lines have.
I have a lot of friends in Dobes, and also I am sure Christine (Kerioak) will be able to advise privately if they are known and well thought of in breed circles!