can be happy or distressed. I am sure you can tell the differance! I have older cats that don't much play but every now and then get frisky for a while and act totally goofy- and I know their happy yowls ( one is doing it right now because I let them out in the hall for a run- it's a catter-waul sp? of sorts...). Anyway, distressed cry is pretty obvious and a block in urinary tract would include several visits to the litter box to squat for long periods and dig for long periods. the males feel like they have to go all the time- It's probably so uncomfortable (and it can kill them pretty quickly I was told - males are "special" that way!).