Hi all,
Thanks for your valuable advise. I have done some think thru and did some research on the web and talk to the vet, I decided not to get his sister to avoid any complication, altho I liked her a lot, I really do. I really feel connected with her but I don't intent to neutered my little Tezel yet coz I would really like to keep one of his puppy. I guess I will just have to bring him to choose his mate once the breeder has some new female available to offer.
Thanks again SW for your lenthy advise. Really appreciate that.