, My puppy, Eowyn, Had the procedure done at the age of 13 weeks. The older the dog is, they will not be able to have to procedure.... I was very scared about having it done, but I have to say, that I am extrememly happy that I did... She now has a 95% chance of NEVER developing any symptoms from the disease... Before the procedure, she was unable to run, manuever stairs, or jump. Now!!! OMG she is the most rambunctious creature around! She is absolutely PERFECT. I would recommend this surgery for any puppy that is diagnosed with HD. It will save you and your baby years of sorrow.