We have a 4 month old lab/pit mix that has shown ferocious aggressive behavior. We worked with him and thought he was better. We trained him to sit before he ate and also to allow us to take food away. Yesterday my nine yr. old son tried to get him from eating something outside. He growled and my son took him by the loose skin on the back of the neck to gently correct him . He bit my son and left a nice puncture wound. Later in the evening my 13 yr old tried to take a toy away and he bit her. Today he growled at my husband when he tried to stop him from eating something dropped on the floor. Our vet recommended we not keep him. He has not been neutered yet. The vet said he does not attribute this behavior to testosterone, due to his young age. The vet said some dogs are just unpredictable in biting and should not be around children ( we have 4 kids and lots of neighborhood kids visit).. I visited a behavior specialist today, but they charge $175.00 to evaluate. Please advise if you think his behavior can be corrected.