How small is too small?

How long is the 88gram one? My BP is about 19 inches long and has been 90grams or so for a month since he had a really bad shed and didn't eat for 2 weeks. I had to go down a size two weeks ago to get him to eat, and last Monday he had 2 fuzzies. I'm slowly working back up to the regular mouse he used to eat.

I havent been able to get my hand on a live one yet. tommorow i will go and get the soiled think and put the bedding in with the snake, but before that ill try and feed Live.
Ill get back to you on his reactions.

Edit: hes about that what you said. hes just not as full as the other one. i think its just because hes finicky because hes only eaten once for me and i think the petstore fed him 2 time or so. so i dont think its parasites. because he was gaining weight until he stopped eating for me i think it was the change of cage.