There are so many opinions on this that you will just have to find your place in it. Early neutering can result in "legginess" or just a weird look. There also seems to be some connection (still studying about this) between early neutering (before one year) and osteosarcoma in giant breeds particularly, which is far worse than your dog marking his territory. This may not apply to Yorkies at all but I don't think there is one right answer. I'm not really into the neutering thing anyway. I still don't know exactly where I stand on the issue.
