I was just reminded by a very knowledgable breeder and owner of our goofy newfies...slow slow slow growth! My boy is 82 pounds, 24 inches at 7 months, also from a fairly large line. I got worried that he hadn't grown much...only 5 pounds and a half an inch in almost two months, but was reminded that his diet has him on a very slow growth schedule/rate. He was seriously low in the pasterns, so we put him on a turkey neck diet to correct him and that diet has him growing niiiice aaannnndddd ssslllloooowww. As long as you can feel ribs, but not too much spine, pup is at the right weight. Height comes as it will, with most height gain between 6 and 10 months...if I remember correctly.