Im kinda in the same boat as you
Stormchaser, only my 2 month old Ranger weighs 4 lbs. He went to the vet today for his 2nd set of shots and she said he's healthy and not over weight.
I've read that you can tell a dog is over weight when you can barely or no longer feel their ribcage in the belly area. Hope that helps some!!
Here's a website that's not specific to any breed:
http://www.placervillevet.com/canine...0condition.htm
~Danea