Hello! We have a 17 week old GSD/ Golden Retriever mix named Cosmo. My husband and I both grew up with dogs, but this is our first puppy. We are having quite a difficult time with the biting, it seems really aggressive and intentional(if that makes any sense. I am just coated in bruises, he is biting really hard. We have 3 kids and at this point, we don't have the kids in the same room as Cosmo except to just walk by him and give him a treat. We keep Cosmo on a leash in the house at all times and are crate training. We have been going to puppy classes and he is doing well with pretty much everything else, you can tell he is smart, he just hasn't made much progress in the biting department. We are trying to keep everything as positive as possible and have tried time outs when he is crazy biting, ignoring it, saying ouch, treating him if we are able to get him to stop, using very appealing treats......etc., etc., Our trainer has suggested a gentle leader for him, does anyone have experience with this with a puppy our age? Our trainer also told us not to run him, just walk, and that the calmer we could keep things the sooner he would get the message. So we walk him in the morning and in the evening, but honestly it is getting really tough. He snarls, really lunges and tries to get his teeth in whenever he can. Anyone have any other suggestions, coping ideas?