Well... the scoping was somewhat inconclusive. The vet DID see some mild ulcers, but she said that's usually not enough to cause an attitude change. She said that they're bad enough that she would believe it if they were the cause... she's just not sure that they are. So I'm going to treat those with GastroGard for the next 10 days and go from there. If she doesn't seem better by then, we're going to do this thing: Surgi-Care Center for Horses | 813-643-7177
... and see if there's some pain somewhere else (somewhere hard to detect) that's making her grumpy.
Meanwhile, I'm making a couple changes to stop the ulcers from coming back. I've switched her from grain (she was only getting about 2 handfuls) to straight oats to lower her starch intake. She's on a great multi-vitamin, so I'll just up that if she seems to need more V&M from the missing grain.
She's on knee-deep pasture around 14 hours a day (overnight), and the 10 hours she spends in the stall is broken up between me riding her/messing with her (about 4 hours) and her eating (about an hour). So that leaves about 5 hours of her standing in her stall with no hay. I have this toy (Amazing Grace) which I specifically got to put her hay cubes in so they would last throughout the day, but I wasn't using it that often. I'm going to use it every morning now, and hopefully that'll make her cubes last a little longer. I'm also going to give her her evening cubes in the morning (since she goes outside as soon as she finishes her evening cubes anyway).