My Frenchton is midway through a course of steroids for a nasty skin rash.
The vet said she would pee a lot and be hungry all the time, but didn't suggest any other side effects.
She seems EXTRA GRUMPY to me in addition to hungry and full of pee.
Some dogs can get more "amped up" when on prednisone, which is a steroid. If your dog is having behavioral changes while on prednisone (or any medication for that matter), you should contact your veterinarian immediately to discuss possible other treatments or weaning your dog off the current dose more quickly. You should not stop giving prednisone cold turkey, since there can be other side effects. Best bet is to contact the veterinarian who prescribed it for advice.
When my dog was on Prednisone, he was drinking excessively and therefore, peeing more. He didn't get grumpy though.
Long term steroid use has been found to be a contributing factor in Cushings Disease.