My parents 14 year old cat has recently had surgery to remove her thyroid, after being diognosed with hyperthyroidism. She lost a lot of weight due to her condition, but hasnt been making any progress since the operation (nearly 3 weeks ago). The way the vet described it she should "bouncing back" and continues to reassure to just give her more time. Is there i can give her diet wise in the mean time? Like any food that is good at building up weight on skinny cats? Thanks in advance!