Wrigley (F1B Goldendoodle) is almost 6 mos old - when we first got him 3 mos ago, his coat was a fine, fleecy, wavy coat which did not shed - it is very wind-blown looking. However lately I've noticed he's started to really get a lot more fur, which seems to be more of an undercoat. It's definitely thicker than it was & he is much fluffier. When I brush him, the brush gets filled w/fur, whereas before there really wasn't much of anything in the brush when I was done. I haven't really seen any shedding though. Are there certain ages that puppies experience coat changes, like with growth spurts (other than when they blow their puppy coat) that I can expect?