I spayed at 5-6 months old. The latest YT debate is growth places and hormone.....blah blah blah. But you also have to take into consideration the size of the dog. Smaller animals bones close earlier than larger animals. I have no issues with Pebbles and she was spayed at 5 months old and is now 7 yrs old. Because of the fact that she was spayed prior to her first heat her risk is 0.5%, those spayed after one estrous cycle have 8.0% of the risk, and dogs spayed after two estrous cycles have 26.0% of the risk of developing mammary neoplasia later in life. Overall, unspayed female dogs have a seven times greater risk of developing mammary neoplasia than do those that are spayed.
Personally, I feel very comfortable having spayed young. Also there is the retained puppy teeth issue that many Yorkies have that need to be removed. This is usually done during a spay/neuter since they will be under anesthesia anyway. Of course, be sure to do preop blood works.
