[cowpony]

Even wet it's hard to tell if she's normal adolescent skinny or if she is truly underweight. I gauge it by checking the fat cover of the spine and hips. Brush your hand down her spine and over her hips. You should be able to feel the bumps of the vertebrae and the points of the pelvis, but they shouldn't feel sharp. (Imagine how it would feel if you put several acorns under four layers of a very thick luxuriant towel and ran your hand over them. ) There should be a moderate fat pad between the two pelvis points. The dog is a bit thin if you notice a depression between the two pelvis points. The dog is much too skinny if the fat pad is so thin you can feel the spine between the pelvis points. Your dog has developed a middle aged dad bod if you have trouble finding the spine and pelvis points at all.

 

[cowpony]

Based on your description and your vet's lack of concern I think you are fine. She's still an adolescent, so she's going to be a bit skinny even without the IBD issues. Plus, as Twyla mentioned, it's normal for poodles to be lean with a high tuck.

Poodles were originally a hunting breed. It might comfort you to look at pictures of some of their hunting cousins. Try searching for pictures of a Viszla, a Weimaraner, a German Shorthaired Pointer, or English Pointer. You'll see a similar long leg, deep chest, and high tuck as on a poodle.