Desensitization is the repeated, controlled exposure to the stimulus that usually causes a fearful or anxious response in such a way that the cat does not respond with the undesirable response. (cattime.com)
Desensitizing entails presenting the handling at very low levels so as not to trigger the usual anxious response. (vetcentercity.com)
Dogs like this typically suffer from chemical imbalances and may require a medication to assist with lowering anxious responses sufficiently for you to be able to begin behavior modification training to counteract the impulse to destroy things. (petfriendlyhouse.com)