Poodles are petite usually but don't go by actual weight, go by body condition scoring. You should be able to feel ribs with slight pressure but not see them or have to use a lot of pressure to feel them. When looking at him standing, from the side view he should have a nice tummy tuck & an hourglass shape when looking at him from above. This would be a body condition scoring (BCS) of 3 which is ideal. If you can see bones without touching him, it's not good. If you feel his hips & spine, not good.
Talk to your Vet about possible conditions that may be causing his poor weight, get some blood work done to make sure he doesn't have any kind of internal infection or a thyroid issue.
Hope I helped.
"Multi BIS (local) GreatGrowkenn Agnes CGC" is ranked #5 (all-breed) in Best Malaysian Bred Dog Of The Year 2010"
(This post was edited by GoldenAddict on Sep 2, 2010, 8:52 PM)