He stressed the importance of ruling out medical issues for any unusual or unwanted behaviors first, before jumping to possibly inaccurate conclusions. (kristenlevine.com)
If you haven't already done so, I'd rule out any medical issues with the cat who is not using it all the time before moving on to exploring behavioral issues. (consciouscat.net)
If this is a new behavior, take your cat to the vet to rule out any medical issues just to be safe. (consciouscat.net)