I have a 3 week old Pomeranian that I started bottle feeding when he was a 1 week old due to the momma dog not having enough milk to for the puppy. Now that he is 3 weeks old, sometimes he sleeps over his feeding time. I'm not sure if I could wake him because he isn't crying. A lot of times I'll know when he's hungry or cold because he does whine. So, should I wake him up when it's feeding time or let him sleep?