In response to the comment by @keshlam and the recent question I am wondering if maybe we should have one or a couple of generic questions along the line of "My pet is behaving abnormally, what should I do?" With an answer along the lines of "Go to the vet ASAP, the behaviors A, B & C are indicative of possible serious issue. Your pet needs to see a trained Vet to rule out possible serious issues before seeking answers online."
We could vote to mark questions as dupe of the the "behaving abnormally" Q&A, if/when the pet has seen the vet, the OP edits the question on why it is not a vet issue and we provided answers.
Maybe the question is written by an expert on that type of pet, so we can get a good foundation of all the behaviors that specific to that species (cats, dogs, rabbits, etc)