Cat update
Woody finally supplied a sample and the vet couldn't find a trace of infection, only an elevated ph level which could possibly cause some discomfort. He sent me home with a case of special canned food to feed him for three weeks. On the way home I figured out the plan: I would give Woody his canned food in the bathroom and feed the other two their regular kibble in their regular eating area. Woody's a big eater, so he would demolish the canned food, so I'd leave him in there for a while until the other two finished and then let him out-no problem. That was the plan.
I opened the can to a captivated audience (cat's are genetically programmed to respond to the can opener), put the food in his bowl, and put Woody and the food in the bathroom and closed the door. I fed the other two, they were a bit disappointed with the lack of canned food, but quickly recovered. 3 minutes later, Woody's crying at the door. Turns out, he doesn't want the canned food and he doesn't want to be locked in the bathroom. I tried to get him to taste it, which he did, but he still wasn't interested. I left him in there for a bit longer. The other two cats went to investigate the cause of the crying and scratching on the other side of the bathroom door. Solution? I took the two cats and put them in the diningroom with what was left of their food and let the whiner out and put his food back in its normal place. After two hours, he still hadn't touched the food, so I let the other two out of the diningroom (they were napping) and they wolfed down his food in no time flat. At least I know that it doesn't taste bad. We went through the whole thing again this morning. He's hungry, but he refuses the yummy soft food. Let's hope that tonight he'll be hungry enough to eat it.