Babies kittens are now ten weeks old, one little girl hissy, still has very little interest in food, Mom has stopped nurse her. I have to feed her separately, it takes a lot to get her interested in food, she eats very little, I have tried many flavours. The vet said she appears healthy. He suggested adding Nutri-cal supplement to her food, and just keep trying. Has anyone used Nutri-cal ? Is there anything else I should be doing?