This is serious. I would get a second opinion from a feline vet.

If they still cannot find anything, may want to ask for kitty to be prescribed an appetite stimulant medication.

http://www.catvets.com/cat-owners/find-vets-and-practices

Did you get a copy of the test results and take a close look yourself? I'd be looking into kidney or thyroid especially. The problem with kidney results too is that until they get really bad they often come back as normal since the kidneys can compensate for quite a long time until their function is very low. At his age these would both be on my radar. My cat came back with very good kidney test results, within a year her kidneys were so bad she suddenly developed non regenerative anaemia and we had her put down only weeks later. unfortunately with kidneys it's hard to catch it early. perhaps discuss this with your vet and look at a low protein diet, antacids etc to see he improves and starts feeling better.

I'd trust the Vet a heck of a lot more than shopping for an opinion you want to hear. It's 15 years old...kind of depends on how much do you want to put it through. It's the horrible downside of pet ownership, but the decision falls to you. Sorry. Look on the bright side and all the years you both had, and what you'd be saving your pet from having to go thru. At least that's what I try to do.

You should ALWAYS acquire and keep copies of ALL test and lab reports from your vet. There are many resources online to help you understand lab reports, and if you post the results here, we can tell you if there's anything that we think merits further discussion with your vet or even a second veterinary opinion. I can't tell you how many times vets have told me that blood test results were all "normal", only to find that it wasn't at all the case when I saw the lab report myself.

Many animal caretakers make the mistake of expecting their vets to know all things about all diseases and all injuries in all animal species. They also expect vets to be expert hematologists and radiologists. This is, of course, a thoroughly unrealistic expectation. In order to provide your cat with the best possible veterinary care, you have to accept the fact that vets are fallible. They all have gaps in their knowledge, and they all make mistakes. They are, after all, human.

It's up to us caretakers to be proactive and well-informed partners in the health care of our animals. That means asking questions of our vets, doing online research, maintaining our own set of health records on our animals, and being willing to seek second veterinary opinions when necessary.

So, get the most recent lab report and post it here. At the very least, it'll let you know exactly which tests were and were not run, and which tests might still be advisable to run. You might also do a Google search to find a veterinary dentist in your area and take your cat in for a dental checkup and x-rays. Dental x-rays are really the only way of identifying problems under the gum line.

Laurie

As Laurie said, find a veterinary dentist to check her teeth. They'll be able to advise you better and will also know the safest way to check your cat's teeth.
Also, try different brands of wet food that has fish or tuna. When my cat will eat nothing else she rarely turns down a fresh can of Bumble Bee tuna. It won't hurt to feed her this in order to get her appetite back.

http://vetspecialistsofrochester.com/pdf/Internal-Medicine/Anorexic%20cat.pdf

"Regardless whether an underlying cause is found, aggressive therapy is warranted as cats
can develop severe liver changes (hepatic lipidosis or “fatty liver”) from their anorexia
(decreased appetite) within a very short amount of time. Hepatic lipidosis is a condition
that is unique to cats when they stop eating. During hepatic lipidosis, fat is deposited in
the liver. When too much fat accumulates within the liver, liver stops working
appropriately and the cat can progress into liver failure. Hepatic lipidosis can be
devastating and fatal if not addressed quickly. For this reason, any cat that stops eating
for any reason is considered an emergency situation."

thanks for all your comments. I'm aware that kidney function doesn't show up until it's very bad. However, he's not drinking inordinate amounts of water, as did my cat that had kidney issues. I can't get him to eat wet cat food of any kind, any flavor. He even turned down smoked turkey which he usually will eat. I tried several different types of dry over the weekend, and he would eat one small helping and then refuse it the next time. He acts like he would want to eat but nothing appeals. He did eat a bit more yesterday than he did on Saturday. Doc Allred said that if he didn't rebound or so interest in other food the next step was a dental exam to see if there were under the gum issues. He had one bad tooth a year back. Of course Anybody had a cat to have bad teeth that showed no visible evidence of plaque or cavities? He also said that chronic colitis can gradually get worse. Of course, with Ike not eating much, it's hard to tell if his bowel habits are indicative of increased colitis. Calling vet today when they open, also want to see if I can get some of that high calorie Nutri cal or something to tide him over until we can figure out what--if anything--we can do.

I didn't know cats could take antacids.

certain antacids help with painful stomach acids in cats with crf, which often stops them from wanting to eat. I think an oral xray might be the next step to see if there are dental problems going on. I have found that the larger emergency vet hospitals can be much better at diagnosing my animals in the past even where the ordinary vet wasnt much help, but unfortunately they generally cost a lot more and tests etc can run the bill up pretty quickly.

there also aren't any here within easy driving distance. My local clinic has several drs, so they do have access to '2nd' opinions if they aren't sure of diagnosis. I called earlier and have him set up for a dental checkup tomorrow to see if that will find anything, and also asked that they do an xray to see if there are any masses in tum or elsewhere. I will ask about the possibility of antacids, esp'ly since he's always had a sensitive tum. Fort'ly my boy is incredibly easy to pill. Not so easy with liquids.

Wanting to eat & not being able to sounds like maybe a blockage?

I've had good luck with canned pumpkin mixed with warm water & a little Karo syrup.

I wish you & your beloved cat the very best.

He pooped Sat a.m. It was messy, but that might have been from trying the new food Frid night.

Got my boy back from his dental yesterday. Poor old guy had a bad canine! Doc said it was so bad that even under the anesthesia Ike twitched when they messed with it. He's still off his feed, but I'm hoping that's from the anesthesia, the anitbiotics and left over soreness. He did eat a bit this a.m. I got a tube of the NutriCal from the vet (naturally Ike hates it) and am trying to give him some but am not very competent at it. Anybody got any suggestions on how to get this in a reluctant cat? It would be easier if I knew it didn't hurt his mouth when I get a hold of him.

On another note, I'm thinking he's going to have regular dentals every year from now on, even if his teeth show no signs of plaque accumulation. (which they didn't--he had his last cleaning 2 years ago Sept, when he had the first bad tooth). Either that, or the next time he looks like he's losing weight, we will go for the cleaning first!

Im so glad you found a likely reason for his lack of apetite bizabet! Hopefully now he gets back to his old self. Did they give you any pain meds for him?

yes, meta cam, 3 days worth. But I imagine even with pain meds, that it's probably still quite sore to the touch. I actually rinsed out the first one and used it to suck up some nutrical so I could squirt it in his mouth, but it's such a tiny little syringe, I probably only got an 1/8 t. Still every little bit helps.

try putting some on his paw, so he can lick it off - sometimes works

I could--but I remember trying that with one cat and cat lax. She looked at her feet and raced to the litterbox to dig frantically. I think she thought it was poo.

I'm so glad to hear he's all right!

You might try mixing some nutrical with a little warm water & feeding him with a syringe.

@bizabet - LOL, have done a lot of feline rescue/shelter volunteer work and we often try that to administer hairball treatment; never saw a kitty run to the litter box. Too funny! 8-)

bad news. Ike relapsed. Friday he ate hardly anything, and this a.m. wouldn't eat at all. Back to vet. 3 shots. one to boost appetite, one to suppress vomiting, since he vomits up anytime he tries something new, and another long antibiotic shot, since we were pretty sure he might have horked up the pills. He wasn't running a temp, and the tooth extraction area looked good. This evening he was quite happy to eat some fresh catnip. I just dont' know what else I can do to trigger his urge to eat! I must have 8 different types of catfood and/or flavors and he's just not interested. At least he hadn't lost any more--still holding at 9 lbs, and he's drinking so he must be getting a bit of food in him somewhere.

Again, I recommend a second opinion from a feline vet.

A fresh set of eyes & hands often sees/feels something previously missed.

Did you ever get copies of his lab results? If so, it would be very helpful if you'd post them here so that we can take a look. It's very difficult to speculate on what may be occurring with your boy without that information.