It is really hard when you have a senior cat that is losing weight and the vet can not figure out why. I have been there too. Some things that helped me to get my cat to eat more were giving him some goat's milk or raw chicken when he would not eat his canned food. He was also fed canned fancy feast. I ended up switching my cat to pate style wellness wet which is a grain free wet food when I noticed the fancy feast was not agreeing with him. Eventually Tegato had a stroke and put him to sleep to end his suffering. I hope you find something that will help you. One of my friends who has experience socializing ferals has had success using human meat flavored baby food to get her cats to eat. She was then able to transition them to wet food. All I can say is keep trying different wet foods until you find one your baby will eat consistently. My friend got a lot of free cat food from when I was going through this and he would not eat. Hugs to you and your baby during this difficult time.