My dog has been on Previcox for over a year, and just within the last couple days he's starting having pretty bad diarrhea. I know that is listed as a side effect of the medication, but it seems odd it would just start now after he's already been taking it so long. I can't think of anything else that would be causing it. Of course I can't call my vet until Tuesday. Has anyone else had any similar experience? Or do you think it's unrelated to the Previcox?