We've spent thousands in end of life care over the years for our kitties.
But, the deciding factors about doing that, and continuing any treatment or palliative care, have been... How is kitty doing? Is this for kitty, or me? Is kitty able to do the simple things he has liked to do? Is kitty in discomfort? All the same factors we'd look at for ourselves.
Our Miss Teia is 19. She has thyroid trouble and weak kidneys. We are treating her for both. She eats and excretes just fine. She sleeps well. Is social, gets around the house okay, keeps the 3 year old boy cats in line. We watch her carefully and have had her at the vet about 5 times thus far this year. Right now she is in my lap, jumped up there with only a little help. When she is unable to be herself...then we will make that hardest, loving decision.
We lost 2 girl cats to intestinal lymphoma, Kestrel in June 2012 and her younger sister Hildikatt in June 2014. Kessie made it about 5 months before she let us know it was time. Hildie, we had been treating her for diabetes, which was masking the cancer. Once we found out Hildie had it, too, it was less than 2 weeks.
There are palliative treatments than can help kitty, even some effective chemo treatments.
The main thing is to watch kitty and see what his ability to do the simple things that cats like to do. Follow your head on this. As I wrote above, it is a hard, loving decision.
I would ask the same question.....how much? I have had 6 dogs, and 6 times my heart has been broken with grief when it was time to let them go, in their elder years, for various reasons. 6 times I would nurse them and accommodate their needs in order to delay their departure from ME. But 'decision day' always came, regardless. And as any animal lover here will attest, those are some of the worst days of your life. I always hoped that God would make the decision to take them so that I wouldn't have to.
I always chose to not prolong their existence with surgeries or extensive testing at their ages. After all, what quality of life is that for the animal? I believe that most, if not all, of this is done for US, not for the pet, so that we can delay that awful day.
I would nurse mine at home through nutrition and supplements, and make sure they were comfortable. More than once I made slings and harnesses to help them up and to basically hold them up while they walked or ate, as their legs were getting weak, or cook oatmeal and eggs when it became difficult to chew.......they were family.
At my age I have decided that I will not have anymore dogs as I do not want a dog to outlive me. And I have seen and read how devastating the loss of a master can be to a pet.
All I have left is my 22 year old Tabby who was here before any of the dogs, and is still here after they have all passed. He is losing weight, but he is eating and drinking. He has not been to the Vet in 11 years, and that may well be why he is still with us. I am a veteran homeopath of 30 years, and am currently researching his weight loss. I will be administering some 'natural' options based on what I learn. Right now I am mixing some papaya with his food as it is possible that he needs assistance in breaking down the protein.
As for your cat, yes, unfortunately for most of us, money is also a factor, but even more so, 'how much do you put THEM through' for OUR sake? Personally I would never put them through anything medical at that age. And as heartbreaking as it is, it may soon be time to let him go. Until then, nurse him as best you can, and love on him, and know that he was fortunate to have you.
One bit of advice that I would give though, to any cat owner, is to give them only distilled water. I have done so with mine for the last 11 years. I believe the higher acid content is beneficial to cats. And NEVER give any animal (or human) tap water from a municipal water source that has not gone through a good quality charcoal filter.
My heart aches for you in this situation.