Try a Tuna based cat food with something else in the mix - Tuna with Shrimp or something like that. I feed my cats a variety of canned food each day. Chicken and this or just Chicken; Tuna and that or just Tuna etc... They eat dry kibble the rest of the day and both are old. Smokey is going on 21 (getting too that point though) and Missy (my mother's cat) is about 17.
I gave him a chicken flavored food last night and he ate some of it--seemed to go over well. Found a "sensitive stomach" dry cat food at the grocery store last night--he ate a significant portion of that, so I'm pleased. Not his usual amount but more than he's had in this past week. Junior was a little more like himself this morning--even returned to being my alarm clock, which he hasn't done in days. I hope this good streak continues.
That is a good sign. You had us all worried. How old is Junior now? Might be time to switch him to a senior's diet. We feed our cats Purina Beyond dry food. We get three or four different flavors and mix them together. We try to keep some in the bowl at all times. That way, they only eat a little every now and again throughout the day. If it goes empty, they tend to gorge when we fill it.
He is going to be 12 in December. I used to just fill his bowl at meal times, and then leave a little dry food in the automatic feeder, so his 5am demand for food wouldn't wake me up. But he would inhale his food every time. Now, with him not feeling so great, he is only eating a little bit at a time--but seems to be nibbling a little more consistently. It's been a rollercoaster this week--he has bad days and good days, but I'm hopeful. He seems to be acting more like his old self. I just wish he would eat a little more. A cat his size needs more than what he is currently eating.
Heard my cat chewing but he hadn't been fed anything, so I look over and ask if he's eating his barf. Then he starts to make that sound. You know the sound. So I grab him, pull him off the carpet and hold him over the floor until he does the deed.
^^^ Looks like a mushroom cloud in the background, and the look on the cat's face says, "Yeah, I did that. Want to make something of it?"