
It would help if we knew what breed! ;)
As a rule your best bet, providing your bitch has passed all the breed-relevant health tests for hereditary conditions (I don't know what breed she is, but they could include hip-scoring, heart-testing, eye-testing, BAER, vWD, haemophilia etc) is to contact your bitch's breeder and ask which lines would be a good match and which should be avoided.