When my dog Goodboy was a puppy he was very aggressive toward me. He would bite my feet right through my shoes. He did not listen when told not to do this and I got to the point of thinking I would have to put him down. A trip to the vet to ask what could be done with our dog's bad habit, proved to be the best thing we could have done. The vet suggested using medication of female hormones for 1 month. He said some dogs have an extra gland in their body that produces testosterone, even after they have been neutered and the medication would calm our dog down. Within a months time Goodboy, had settled down and we were able to stop the medication and safe an otherwise good dog from needing to be put down.