My 18 year old female cat has a swollen front paw. Within the last year she has become anti social, cries very loudly at night at nothing, sleeps all the time except to eat and use the litter box, stopped grooming herself and within the past two days she has started smelling horribly. I’ve taken her to the vet twice within this time frame and both times tests were ran but nothing was amiss and it was just chalked up to old age. She seems miserable and looks like she is uncomfortable except when she’s sleeping. Should I have her put down? I don’t want her to suffer but I don’t know what else to do….