My second yorkie (now gone) was not neutered and I had reached the end of my rope with his marking his territory wherever he wanted. He was 18 mos. old at the time. So my vet at the time recommended that he be neutered, as he said "All his problems are in his testicles". We had him neutered and the difference was night and day. He still lifted his leg to pee, but did not do 'little squirts' to mark his territory. From then on he was housebroken. Hope this helps.
