My daughter has a dachshund that is not neutered. He is about 1.5 years old. when he was a pup, his shots almost killed him from a reaction, so he can't have shots anymore, which means that she can not take him to a kennel when she goes out of town. He is marking and pee'd all over my house including on my couch, so I suggested that she have him neutered but she is afraid he will get fat. She believes when she payed her other dog, that made her fat. Is there any truth to that idea, that fixing a dog will make it fat? Anyone have an experience with a dog having a bad reaction to vacinations? thanks!