I think about the closest you could get to that would be with a dog. We have helped out a few critters and made their lives better. The feeling you get from seeing them get heathy is all the appreciation I could want.
No doubt!! :)
animals don;t think that way.
Mine certainly did. He was so glad to be away from where he had been, and so happy we got him groomed...he would come up, give us a single lick and just lay by us so he was touching us. It was like " thank you!".
I did and I think it felt safe with me as it kept returning for a while, but I think appreciated might be too complex a feeling for an animal. I have no idea though... some are much smarter we have thought in the past... dolphins in the wild often amaze me with their empathy and intelligence whenever I encounter them. If anything could feel appreciated, they would.
We rescued a cat. I have yet to see any sign of gratitude.
I often ask one of my rescue cats, "Do you think we crossed paths for a reason?" I hope I have enriched his life, because I know he has enriched mine.