If she is suffering you need to let her go. Her quality of life sounds not too good at this time. She also has to stay in, other cats will pick up on it and try to and possibly succeed in killing her. Mama never acted sick, she has her intestine hanging out of her rear but as an outside feral cat she knew her life depended on not acting sick. An inside cat is not going to have that survival instinct to hide her illness and Mama was fine except for the prolapse. She was still able to do what she had to do.
When I was 24 I started having horrid stomach pain, barfing, retching and a lot and I mean a lot of nausea. I had to quit my job it was so bad. I cried when I turned in my badge but I was just too sick to do it.
I had doctors appointment and most everything turned out good except the CT scan that showed my stomach was pretty messed up. At the endoscopy they found out that besides being a little red it was fine and I did have stomach ulcer bacteria(actually I still do, couldn't handle the meds but no ulcers at all.) The hediscan showed that there could be something wrong with my gallbladder but who knew.
The surgeon gave me a 50/50 as to it would do anything to make me feel better. They got it out and found it was chronically inflamed and scarred. The scarring was so bad the doctor could see it with his naked eye. I took a 50/50 chance and with everything it came out to about the same amount it would cost for Ty's surgery. He has a better chance than me on it working. Mine also wasn't life or death.
Figure out if Ty has a quality of life and what doing anything further other than surgery will bring him back to. Abby

my Old English sheepdog was put down after her liver or spleen burst and she had massive internal bleeding. They could have tried to save her, but my parents had to decide what she would be coming back to. She was 11 1/2 years old(old for an OES), blind(even though she had been blind since 5 so that wasn't even a consideration in this decision, she and we had adapted to it, she was blind longer than she was sighted), what played into it was her severe arthritis. The arthritis meds likely caused her liver or spleen to burst and she had been on them for years(this was totally and completely unexpected, her last blood test had shown her in perfect health.) She had to have help to get up on a non-carpeted surface(and viscously growled about it, but it was all a bluff) and while she was healthy she could keep going as she wasn't ready to go and the vets saw no reason to put her down as she still had a quality of life, now that she was sick it would not be humane to force her through treatment and bring her back to what she lived just because we were going to be selfish and not let her go when she was ready. I have seen too many animals be forced my humans to survive because they are too selfish to let the animal go.
Does Ty have a quality of life? What are you bringing him back to when you have treatment done? If your husband refuses the surgery then you are going to have to decide when enough is enough. Is he suffering when you bring him back or does he still have a great quality of life? Is it fair and humane to continue to treat him? In this case the vet knew Abby had had enough and so did my parents and they knew it was time to let her know. I already knew before we carried her out to the car(she was so weak she couldn't even walk) that this was the end and she wouldn't be coming back home. I remember sitting on the kitchen floor with her when my parents went to get a stretcher to get her to the vet(it had been chewed so we had to use blankets, they didn't want to risk using a chewed up stretcher to support an 80 lbs dog) and told her it was ok to go, I gave her permission to die and her breathing got a lot worse. I told her she would be going to a better place, where she could see and run and play and chase squirrels. This was in Nov 2006 and I'm in tears writing this. I swear the day after she died I saw her walk by the screen door in the backyard. I think that was her saying we did the right thing and she was at peace.
It is hard to let go but you have to know when to say when. Paul had his dog put down in July, she was 17 years old, was having issues going in the house(and refused to use pee pads) her kidneys were going bad, she had bad teeth and she was losing weight yet her abdomen was swollen. She was there because of her teeth because it was obvious she was in pain. She wouldn't have even survived the anesthetic for them to attempt a dental so it was time to let her go. She was still lively as a puppy and had no arthritis issues, in fact she had no arthritis at all, the vet was amazed that at 17 she had zero arthritic changes, her joints were as healthy as they were when she was a puppy. It was just time, her mouth was hurting her and there was nothing that could be done to ease her suffering and with the kidneys, and the weight loss and her abdomen swelling it was her time. Paul couldn't stay in the room when they gave her the shot so I did, I just couldn't let her die alone. If you can stay in the room when they do it please do. I still feel guilty that Abby had to because my parents couldn't bear to stay in the room with her(I was at home taking care of my 4 year old so I couldn't go to her appointment.) I know most people can't but like I said I couldn't let her die alone and felt guilty that Abby did.
You have a choice to make when he has had enough. I and no one else here can tell you when it's time to let him go. Only you and your husband will have to decide when it's time and he has had enough. I just wish he could have the surgery, I would have given anything to have more time with Abby but it was just time to let her go. If there was a 50% chance of her getting better and having a quality of life no price would be too high.
Taryn