Why on Earth would you NOT neuter him?!
Spaying and neutering are the most common procedures that vets perform. There is no reason to be fearful of this surgery for your pet. Of all the people on YT (most of whom have multiple dogs and pets), I have not come across a single one who has lost their pet during a routine spay or neuter. There is ALL kinds of info on the Internet about the advantages of neutering, most of which are for HEALTH reasons, including preventing testicular cancer, which is prevalent in un-neutered dogs. Here are some sites that discuss the advantages of neutering your dog:
http://www.peteducation.com/article....&articleid=911 http://www.cuhumane.org/topics/neuter.html http://www.bakersfieldcity.us/acsd/d...20neutering%22
If you are not going to breed your dog, there is absolutely no good reason not to get your dog neutered. The health benefits of neutering your dog far outweight any risk you take putting them under anesthesia to get them neutered. I have 2 yorkies and in my extended family are about a bazillion other dogs. All of them are fixed. All of them lived through it and are more delightful and healthier pets for it. If you don't get your male dog neutered, yes, he will mark and spray his territory, which will most likely be all over your house; he will roam; he will hump things; he will be at risk of testicular cancer; if he is ever around a female that is in heat, you will fight a losing battle to keep him off of her; I could go on and on.......
In my opinion, there is no better pet than a neutered male yorkie. They are so delightful and cuddly and loving, and not to mention easier to potty train. I got Hobbs neutered at 5.5 months. He still squats to pee, he has never marked his territory, he does not hump, he does not show his "lipstick," and he is just the most delightful pet I've ever encountered.
If I were you, I would get your male yorkie neutered between 4-6 months of age.