What medicine is she on pain wise? Depression and lethargy can be a side effect of the drugs. We didn't have any of that with Cadence. She did look pitiful sometimes but i think that had more to do with the cone she had to wear. Otherwise when we took it off of her she was frisky as ever. She kind of lost zest for her dog food (probably to do with the medications because she eagerly eats now on her regular schedule) but we supplemented one can mixed with her dry dog food right after surgery to help keep her strength/energy up. She is not used to wet food so we took her off of it after 4 days and then she ate her regular dog food without the addition of the wet.