I have a 5 month yellow (Fox Red) male, I chose a different colour following the loss of my beautiful chocolate - Mr Pickles. From the day I bought this fella home he has been biting like crazy, far worse than I think my other pups did. He even attacks from behind, if I turn away to escape he justs bites my back, legs, head or whatever. His moods are a bit schizophrenic, happy and wanting cuddles but in the blink of an eye frenzied biting, my arms are covered in bruises, bites and scratches where he lashes out with his paws. My elderly mother (90yrs) shares my homes and she is terrified of him, this is a Lady who has spent most of her life living with dogs. I think he sees biting as a game but no one will come to my house as they just get attacked, if I put him in the crate, garden or another room he just barks/screams the house down. The vet has now prescribed Fluoxetine and he is being seen by a behaviourist who described him as the most anxious dog she has ever seen, I have no idea why he is so anxious. He will just go into a biting frenzy attacking anyone and everyone, I have resorted to very early or late walks as he cannot be trusted and I don't want to use a muzzle. I have to train this fella but am stumped. He will bark or whine non stop which having a newborn baby next door is not going down well. Weight gain is slow despite increasing his food - Wellness Core puppy food, vet has checked him over and done blood tests at my request, poop normally. Paws to top of head 25 inches and weight 19kg, most adult teeth through. He was taught to sit before I bought him home and since then come, down, wait, drop, touch and a few more (not 100% yet), I now no longer give a treat until all 4 paws on ground, he eats as expected and I can put my hand in his bowl and feed him by hand no problem. Yet, he will not let me put his harness on without a fight. My son having been attacked quite badly believes that the dog just doesn't like people as he is great with other dogs. I have had a number of dogs and all I have ever done is basic training at home and then obedience or Good Citizenship classes. I feel really out of my depth and scared he might harm someone seriously if I don't sort this out. Any suggestions welcomed please.