Food refusal becoming serious

[Allthingswithscales]

I've had my pacman frog Button since November of 2014 and I'm not sure how old he was when I got him but he couldn't have been particularly old. His species is a chacoan/cranwell's horned frog or ceratophrys cranwelli and he's roughly the size of a baseball if that helps. I'm not exactly worried yet but my concern is growing. I know pacmans can go a very long time without eating, especially when they sometimes start brumating when it gets cooler which I originally thought was the problem because he was at room temperature at 73 degrees and I got him a better heating pad not too long ago but he has barely eaten all summer and is still refusing food which is starting to get alarming real quick. He's pretty much outgrown crickets but will still take them sometimes. Otherwise he eats nightcrawlers, roaches, sometimes canned grasshoppers and occasionally thawed mice. He usually reacts to movement pretty well and sometimes he'll cooperate with forceps and even when he doesn't you might be able to force him to open his mouth but even that isn't working. With the heating pad and space heater now the tank is usually about 80-85 degrees and 73 degrees+ at night yet he still refuses food even though he seems to be getting more active. In our house we keep the air conditioning on when it's warm and I have the space heater in winter, usually with the house heat on so to him summer is probably more like winter and winter more like summer. He's still looking pretty good and hasn't lost too much weight but I still wish I could find out what's wrong. I wish someone would just take a look at him but it seems like most veterinarians won't do their job and see anything other than dogs and cats. I've seen terrarium animals refuse food until they starved despite everything before and I don't want to watch that happen again. I don't know though, maybe it's just his time, pacmans can live up to 15 years but sometimes as little as 5 and I still don't know exactly how old he was when I got him. Despite still being pretty round, two meals in 5 months is unacceptable even for an animal that can slow it's metabolism down considerably for very long periods. Here's a picture of him I just took a couple minutes ago.