I didnt own my RR when he was a pup so i dont know exactly what they are like. But I did have my pit bull/bull mastiff mix since he was 7 weeks old. Since he is pure bully breeds they are known for mouthy behavior when they are young. It is playful, but they are also in a point of development where they should be around other dogs or puppies, so they can be put in their place if they bite to hard or nip when its not appropriate. Titan actually was extremely nippy, it seemed like for the first 3 months we were working on his problem. Titan was extremely submissive from the start so it wasnt dominance. I tried the holding his mouth shut, and all the others that you mentions as well. The one that worked best for me was saying owe, make it short and high pitched it will register as a yip in his mind. Its not an instant fix especially with the hard headed breed like RRs, but they start putting two and two together. They are extremely intelligent, you just have to make them want to figure it out. So say owe, and ignore them. They will want to know why you are ignoring them, so they will put their clever minds to work. Titan now is the most gentle dog ive ever seen, but he is young so when he gets a little to rough when were rough housing around. All i have to say is "owe" n he either starts licking me or he looks away and wont look at me until I start petting him telling him good boy. Also when you get done playing with them make sure you use a stern verbal signal to symbolize the end. Like "Im done" or "Enough" or anything like that. If they were still with the parents, they would get this signal in a growl or even a look to tell them they have had enough.
