Follow on from this thread Advice for chihuahua hand rearing

yesterday, he was gulping the welpi down but today and last night will not even suckle off the bitch and doesnt really want the welpi

Born at 110g
yesterday 96g (after feed)
now 86g (before feed)

Im so worried i could cry

Ive been back to the vets today and they said i should not be worried about weight gain!!!
They checked him over and said that he is fine, strong not dehydrated etc

Would you be worried about this drop in weight?

He was born a week to early and is now 5 days old