Cats are fastidious and it is easy to train your cat to use the litter box. Thus if she suddenly stops using the litter box, there is something awry. The most common reason your cat may avoid the litter box is that it is dirty. A smelly or wet litter box will push your cat to find a more pleasant but inappropriate place to go. Your cat may feel stressed because there are new family members including new pets, houseguests or the noise of construction in or around your home. Even something as simple as moving the sofa can stress your cat. Be prepared to set up another litter box near where she hangs out as she adjusts to these changes in your household. Your cat may also avoid the litter box because she doesn’t feel well. Make an appointment with your Fort Bragg, NC vet for evaluation and treatment as needed.