I totally agree, even I know about these genetic issues....and I am relatively new to Yorkies....Your breeder was very "ethical" and handled the issue appropriately.....
What concerns me is the Vet had never heard of these two genetic issues? Maybe a Vet that is versed in the small breed would be a better choice.......no offense......I just expect the Vet to know most everything....maybe I am putting them to high upon that pedestal......LOL