My dog just lunged at a puppy...first signs of aggression?
Today, I was at the park with my 16 month old mastiff/dogo mix. He has always been friendly with people and other dogs. Today he went after a 9 month old pup while his owner was taking him off the leash. My dog has played with this pup before (2 times) and has ALWAYS been gentle. I saw no signs that anything was different than normal until my dog lunged. Now I am concerned about my dog's behavior at the dog park even though I make sure he is well socialized with people and other dogs. We go to the dog park daily! Any ideas about what I need to do? I am weary about taking him back there. Luckily the pup was not injured.