Expected Vet Cost - Continuing vomitting

Hello everyone thanks for taking the time to read the cat.

Straight to the point, and more background information further down for those who are interested.

Persian cat, 17 years old, she was saved recently. She seemed fine but one day became super lethargic and started vomiting. I have taken her to the vet for blood tests, hydration, urine test, etc, and the bill has run up to $500 already.

Some friends have suggested that it will be time to euthanize her, while the vet says she is "fine" and looks very in shape for a cat her age. I have a feeling that this will continue to cost more (hydration, test on pancreas, etc), and I do not know if it is worth it for either me or the cat.

I just want some advice on if I should continue fighting with her, or let her rest for a long time. And if we were to keep on fighting, how much should I put aside to help her?

Thanks

Background:

This cat was rescued about 5-6 months ago. She lived at my GFs parents, where the cat has been locked up in a garage for pretty much all of her life, 23h/day 7 days/week. They were about to give her out to the SPCA as they were just fed up with the cat.

So we took the cat in, and she was doing wonderful. You could tell she was not a socialized cat, but she did not seem as if she was on the verge of dying, or suffering from any conditions. 

This was not the first time we had cats in our family, and we give them a very "wide" diet. Fish, milk, even certain vegetables. All in very small controlled portions, and this has never caused any issues. 

What I am worried about is that maybe this cat could not take it, and I have caused her great harm in feeding her various foods. She seemed fine eating anything for a long time, and never had any digestive issue (the litter was never a mess, and she never rejected anything she ate). I have reported what was fed to the vet, and she said it was ok, and just suggested to no longer stray away from regular "cat food" just to be sure.

Now my cat has stopped eating and drinking. I try to entice her with some treats, but most I could do was make her eat a nibblet or two, and that over a 4 day period. She had stopped grooming herself as well.

After taking her to the vet and giving the cat some anti-vomiting injections, as well as hydration, the cat seemed to do better, but still refused to eat or drink.

4 days later, and she has started to drink again, but that is all. No eating. And we tried various different foods and left her multiple options just in case she did not like a brand/flavour. 

I am supposed to get a call tomorrow from my vet, and will see what she has to say, but I am not sure what to do...

My cat just vomited again about 15m ago. The vomit does not contain any food. Only bile.

I collected some of the bile and will bring it to the vet tomorrow, maybe she can help her diagnose what is going on. 

"My" cat's name is Kitty

I have been through this so many times and it is never an easy decision especially when you don't know exactly what is wrong. I've done exactly what you are doing with trying all kinds of food to get them to eat and I have done it every single time with a Cat that I eventually had to euthanize. If she hasn't eaten in 4 days it's a sign for you. It's a shame that you just got her and were trying to give her a good life, but not eating in a cat this old is a sign. If she was 2 or 3 years old diffent story becuase cats that young are good at bouncing back.

The choices are tough, but there are only 2 really humane ways to go IMO. One is treat the cat and try and get her better, the other is euthanize, but allowing her to die slowly on her own is not a kind way to end her difficult life.  Talk to your vet, get the best medical opinions as you can, and spend what you can afford, but please don't let her waste away.

I always opt with trying to give the cat as much good quality of life as I can.  It's cost me a lot of money doing that, but I don't regret it.  However, I know there comes a time when money does become an issue and quality of life is more important than quantity.  My big problem is, I have no way of asking a cat if they are ready to give up on life or not.

I doubt this is because of anything you fed her. More likely it's because she's 17 and was abused for so long. Don't blame yourself for hurting her; be glad that you were able to give her a few months of love. I would not recommend leaving her to slowly starve. My advice would be give it a bit more time, pamper her, see if there's a chance for her to turn around. Maybe she will surprise you and bounce back. If not, there will come a time when you know in your gut she is dying. At that point I'd talk to the vet about final plans.

Good luck, my dear.

the blood tests showed a higher level of white blood cells. there was a little inflamation in the pancreas (we got her medication for that). there was a urine test taken and the vet found some sugar in the pee. however, when the vet took a diabetes test, the result was normal. all results have come back inconclusive. no signs of thyroid problems or anything else. still the cat has not eaten anything and drinks just a bit of water.

Maybe try some catnip too? This is hard for anyone. I've never be able to let go right away either. Since the blood tests did not seem too bad you may want to give her a couple more days. Have you tried just doing back and feeding her what she was eating? At this point the goal is to have her eat any food.

There are two things I would try. A course of steroids and if no improvement I would try a course of antibiotics. I have one cat who throws up and cannot keep food down without steroids. The vet thought it was related to asthma. I wonder if she has both asthma and inflammatory bowel.