That's like 25% in one week, you can't really expect more than that. Since he started so small that is really quite a bit. That's pretty scary if I think about how much weight that would be for me if I gained 25% of my body weight in one week. I assume he is still quite healthy, so it will just be interesting to see where he ends up.
Clifford is still only about 100 lbs at 17 months old. I wanted a really big Newf, but so far he is on the small side. Of course I wouldn't trade him for anything. Except when he is a "bad, bad dog," he is the sweetest most wonderful dog I have ever known, so of course that is the most important thing.