weightloss & odd behavior, licking his lips

we took our 13 year old, Mouse, to the vet today. he's lost about 1 to 2 pounds in the last month and starting to loose his appetite in the last couple days.
he had a bout with jaundice 3 years ago and had a feeding tubefor 2 month but he's over all that.
my husband feeds them all wet food every morning at 5am when he gets up to go to work. Mouse sleeps between us all night and i usually know when he gets up, eats, uses litterbox and then comes back to bed and goes back to sleep right next to me. for the last couple mornings he hasn't gotten up for that. when it happenend again this morning i got up after my husband left, openend up another can and took it to him on the bed and set it right in front of him and he ate a little bit, then stopped and started to lick his lips and didn't eat anymore. i made a vet appt. for this afternoon. the vet said he's a little congested in the chest and his teeth needed cleaning. it's been 4 years since his last dental. another thing too is his breath never smelled bad at all but in the last 3 weeks it changed and doesn't smell good at all. i thought maybe an abcessed tooth or something like that but the vet didn't see anything like that. he gave him a shot of cortizone and B vitamins. he's got an appt for 4/12 for a dental and the vet also put him on 1cc 2xdaily of Pecmycin and 1 1/2cc 2x daily of Albon.
Mouse's behavior otherwise is as usual and he doesn't have any diarreah nor is he vomiting.
but just now as i tried to get him to eat something he sniffed the food and then turned away and started licking his lips again. i have never seen or heard of a cat doing that and it's got me worried.
any help would be greatly appreciated. thanks, Connie

Cats' sense of smell is much more developed than their sense of taste. If he's congested he may not be able to smell the food. As long as he hasn't stopped eating entirely I would give him another day or two for the medication to start working. I'm not familiar with the last two that you named. Did the vet tell what they are for specifically?

My recently diagnosed CRF cat is sometimes licking his lips, smacking, after drinking water. Also, his face and breath started smelling badly. He was a little backed up but has since pooped, and I noticed the smell has gone away. Did the vet check for constipation? Is he using the bathroom (pee AND poop) normally? If you think he may not have been pooping normally or hasn't gone in a day or two I would definitely mention that to the vet. I would definitely do blood panel too. Good luck with your sweetie.

Licking their lips can be a sign of nausea, so it could be he doesn't want to eat because he's nauseated. I'm going thru that with one of my guys right now since he just finished a round of antibiotics. Yesterday I could not get him to eat anything, and was just about to call the Vet this morning when I got him to take a little interest in some food. But yesterday no matter what I did, even holding shredded chicken up to his mouth, he would just back his head away, then walk away as soon as he could to get away from me. Thank goodness his antibiotics are over so maybe he'll start acting like normal again, and put some weight back on.

Anyway, if his teeth are bothering him, I would think that could be another sign of licking his lips.......