Spray from a squirt gun is a good deterrent for most cats. When you leave the house, make sure the cat is not allowed access to the room with an object it likes to scratch, if possible. Most cats will learn to use a scratching post if you are persistent in attempts to alter the behavior. If your cat will not stop destructive scratching behavior, declawing is an option that may provide some peace in your household. In studies of this behavior, worries over behavioral changes or long term complications have been unsubstantiated.
Most owners feel that no behavioral change occurs after declawing.
While this should not be the first choice, it is an option. Declawing can be the difference between being able to have a good relationship with your cat or deciding to consider much less acceptable alternatives such as euthansia or abandoning your pet. When that level of frustration is reached everyone is better off with the decision to declaw. Alternatives are clipping the claws regularly so they are too dull to cause much damage and using Soft-Paws or beads glued to the claws to prevent damage from them. Inc. Opinions expressed are those of Dr. Michael Richards.