Firstly, welcome to the group. This is one of the best groups I have ever been a part of.... I do not believe that neutering a male Chihuahua will alter their personality for the worse. If anything, it will make him a better pet. It also cuts down or eliminates unwanted behavior such as marking, which is crucial. It is best to have your dog neutered between 5-6 months of age. This is what we tell all the clients at the Vet clinic. As far as feeding, it appears that the consensus here states that free feeding is best. I cannot do that because I have other dogs that will eat their food. However, for the smaller breeds, this is the best way to feed. Enjoy him!
~Camille
