cats are super adaptable, you can amputate on leg without any problem for recovery. i had to make a choice a couple of years ago between cutting my kitties front leg or letting her die of cancer, and now she is super lively and jumpy. i had to give up my pocket money for the year before to convince my parents to let her live (the ghouls) but that was possibly the best use i made of my money in my life yet.
You're assuming animals exhibit pain and pleasure the same way humans do, which reveals a speciesist solipsism on your part. What humans see as a prosthetic may be a torture device to a Galapagos tortoise. The safest option is the sweet comfort of oblivion. I say PUT THEM DOWN!
:joker-dancing: