The lil' guy's probably weak due to the anemia from all the fleas. Bouncing back from that takes quite a while, but just make sure he gets plenty of water, and as much wet food as he'll take. The Nutrical is vitamin packed, and should hopefully build him up soon. Any type of kitten formula is good if you can't find KMR. There are other brands available, they just may be different in Canada. Maybe Just Born is carried up there? Don't worry, he'll start feeling better soon once his red blood cells start coming back well. Fleas can do quite a number on these babies. (((HUGS)))