Even though I'm one of the world's biggest advocates for s/n, in Fletcher's case I might be inclined to leave him as is. Unless, he had to be put under for teeth cleaning, then I might have him neutered. For females though, I would spay a female unless she was a very old yorkie. For senior yorkies I don't know if the benefit outweighs the risks.
Good luck, whatever your decision - I'm sure he will be fine.
__________________  ~Ruby, Reno, Razz, & Jack~ |