I am in trouble,I took Lily to the vet for her itchy skin and the vet yelled at me

. Lily is now 6 Lb. When I got her 10 months ago she was 1.3LB and the vet said I would be lucky if she ever hit the 4Lb mark, now she is bitting my head off because she is 6Lb

. She gave us 2 months to go from 6Lb to 4.5-5Lb but ideally she wants her between 4 and 4.5 so my poor Lily is now on a diet. I posted this somewhere else with not help, it has been a week since the vet and she has gained .2 So my question is for those of you who feed dry food how much do you feed a day?