The vet is baffled, maybe PTers will know

[jazzcat]

The vet checked her mouth pretty thoroughly and didn't see any problems. From what I could see her teeth and gums look great. Of course there could still be a hidden problem in her mouth so I will watch her closely. She did have an ulcer on her lip last year when I took her in and they gave her an injection which cleared it up immediately. I had changed her food right before that and the vet felt that was the cause. I changed her back at that point and every thing has been fine since.

[Freedom]

Sparkle is 13 and in a similar situation. Eats often, but little each time, and lost quite a bit of weight rather rapidly. Had her in for the full senior blood panel twice in 4 months. Nothing showed up either time, numbers hadn't changed, and she had still lost 4 pounds in 4 months. So I just started adding some canned /wet food for her alone every other day. She hasn't GAINED anything back, but seems to have stopped the dropping weight with every breath!

I was going to suggest teeth / gums, but some one already did and you answered that.

[smokey the elder]

Maybe she needs something like a/d or she just picks at her food. Bosun lost weight when she had bad teeth; once those were taken care of she put it back on. The excessive thirst makes me suspicious; maybe have her retested in a few weeks. (I have both a diabetic and a kidney cat.)