I have a GSD mix. I also have 2 other dogs that are younger than her. At first, she didn't like the idea of other dogs in the house, but after a while she was in love with them. She needed her own time, as any animal, or person does. My relatives have cats, and since she didn't get a early start with cats, she is very scared of them. It's best to get a young dog, or an older dog that has been raised with cats and other animals. They are very protective dogs. One day, a man was trying to break into our house, and my GS mix scared him away. If my friends are behind me and my dog thinks they are going to attack me, she will attack them first. I know that sounds like a mean dog, but it is for my protection. She doesn't like anything bad happening to her family. She is 8 years old, and has never tried to jump the fence, or dig. She is a very obediant dog. Whatever you tell her to do, she will do, and no, she didn't have classes. She was also potty-trained within the first week we had her. Mostly all dogs dig, but that's a natural instinct. I hope that has helped you some.