I have 3 new puppies, 3/4 pit 1/4 rottie mix. They are 7 weeks old today. My concern is their poop is very loose, not runny, but really mushy, and sometimes light colored. Actually one of them, the female, is starting to firm up. Is this normal for their age, or is it something they are eating, or just nerves? They have been here at our house for almost a week, been to visit a few times before that.