litter box issues

hi there,

I have two cats.  For the past few days, i've noticed that one of them (not sure which one) can't quite seem to make it to the litter box. Neither cat is urinating outside of the litter box, but one of them is pooping outside of the litter box.  I've been finding little piles of cat poop in close proximity to the litter box.  the poop seems to be a little runny. The good news is, is that the poop always seems to be in same spot and we haven't found poop elsewhere in the house.  does it sound like one of the cats may have diarreah (diarrhea) and is trying to make it to the litter box, but can't quite make it?  Otherwise, both cats seem like themselves...no lack of appetite, energy (no more than usual).  Is this something that I should consult their veterinarian about?  Or is it a "wait and see approach?"  thanks!

[Aleda M Cheng, D.V.M., C.V.A]

Are either of your cats overweight or arthritic?  Some times overweight or arthritic cats can't get into the right position to defecate.  Parasites, or enteritis could also be a problem.  Yes, if your cat has diarrhea can cause a cat not to make it to the litter box.  If it is a simple viral enteritis it may resolve on it's own, but it could pass from one cat to the other.  

I would bring some of the loose stool to your veterinarian to perform a fecal exam for parasites and a giardia test.  You can also bring the cats in for an exam just in case.