Your cat is pretty fastidious. Thus if your cat stops using the litter box, you can suspect something is wrong. The most likely explanation is that the box is dirty and smelly. If the litter box is disgusting, your cat will find someplace less appropriate to go. Your cat may avoid the litter box if she is stressed out. New household members including other pets can cause stress. Houseguests and even construction in or around your home can disturb your cat. Even simple changes such as moving the furniture around may cause a problem. Consider setting up a second litter box where your cat hides out while she works out her stress issues. Litter box avoidance may also occur because your cat doesn’t feel well. Thus if you can’t find an obvious reason for your cat’s behavior, make an appointment with your veterinarians Salem, VA for evaluation and possible treatment.