For decades, the answer from the veterinary world was frustratingly vague. Animals, we were told, "hide their pain." It was an accepted axiom of pet ownership. But modern veterinary science and animal behaviorists are now rewriting this narrative. Animals aren’t necessarily hiding their pain; rather, they are speaking a language of discomfort that humans are only just beginning to learn how to read.
In cats, urinating outside the litter box is frequently a sign of cystitis or kidney disease rather than "spite."