A horrible experience for any dog owner is the dog who engages in self mutilation. Why do dogs self harm?Here's our quick tip sheet on canine self mutilation and how you can prevent a dog from chewing itself. A dog that licks or chews on itself is manifesting stress or frustration about something. The problem may start because of some frustration relating to environment, but soon develops into a self-reinforcing habit, as the licking or chewing causes inflammation. Further licking or chewing can provide at least temporary relief, but this ultimately perpetuates the problem. <–More–> A complete veterinary evaluation should precede the behaviour program for rehabilitation. Flea or tick infestation must be ruled out as a cause. Possible allergies also should be considered, as the problem in many self-mutilators stems from food or other environmental allergies. Many practitioners recommend hypo-allergenic diets, even in the absence of clinical symptoms, as a matter of "insurance." Corrective measures must consider the environmental factors that bear on the problem. However, a general plan involving nonphysical, off-leash training and stabilization of the owner-pet relationship provides satisfactory results. Owner leadership is established by withholding petting and praise, except when the pet responds to some directive from the owner.