Dogs communicate using a complex language of body signals. Snapping may convey different messages based on context. A dog who snaps must be taken seriously, as left untreated, this prebite behavior may progress to an actual bite. If your dog is snapping, it's important to intervene in a timely manner to nip this behavior in the bud. The methods used for disciplining a snapping dog may vary, but should never include any harsh, physical corrections.
Rule Out Medical Problems
It would be unfair to discipline a dog for snapping when he's suffering from some medical condition. If your dog has started snapping out of the blue, consider the possibility of an underlying medical condition. For instance, a painful ear infection may cause an otherwise sweet-tempered dog to snap upon being petted. Other painful conditions such as arthritis, a pinched nerve or abdominal pain also may lower your dog's threshold for aggression, causing him to snap unexpectedly. Low thyroid levels are sometimes associated with behavior changes including aggression. See your vet to rule out medical conditions.
Learn How Behavior Works
Consequences are what fuel your dog's behavior and prompt him to act in certain ways. All behavior has a function. If your puppy or dog is snapping, consider that he may be doing so to make something pleasant begin or make something unpleasant stop. Keep in mind that what's considered pleasant or unpleasant is from your dog's perspective, not yours. To better understand why your dog is snapping, you will have to put yourself in your dog's shoes and determine what's triggering his behavior and what the function of the behavior is.
Apply Negative Punishment
Dogs who are snapping to make something pleasant begin are often doing so to engage the owners in play or to gain attention. You often see this behavior in puppies or bored, understimulated dogs, paired with dog owners who have been inadvertently reinforcing the behavior with attention for some time. Disciplining through negative punishment, which entails removing something desirable that fuels the inappropriate behavior, may be helpful in such cases.
For instance, in the case of a puppy snapping to engage you in play, you would totally ignore him -- no talking, touching or eye contact. If you stick to your guns, after the occasional extinction burst, your pup will learn that his snapping behavior removes the opportunity to play or get attention from you and therefore the snapping behavior should reduce. You can up your chances for success by rewarding your dog with treats in the form of attention or play contingent on polite behaviors.
Snapping often involves dogs who don’t get enough exercise or mental stimulation. A good exercise program, structured play and interactive toys may help keep these dogs busy.
Keep in mind that from a bored, understimulated dog's perspective, even negative attention is better than no attention. By reprimanding your snapping dog or telling him to stop, you may be inadvertently reinforcing the snapping behavior.
Change the Emotions
Some dogs snap when they anticipate something unpleasant is about to happen, such as getting their nails clipped, being picked up or having a favorite toy taken away. In their own language they are telling you to back off and make the unpleasantness stop. Once you understand the trigger that leads to your dog's snapping, you can change your dog's emotions through a desensitization and counterconditioning program implemented by an experienced trainer or behavior consultant. The goal is to gradually desensitize and create positive associations. For instance, if your dog snaps when you pick him up, you would split the action of being picked up in several components and work to make them pleasant by associating them with yummy treats.
Prior to snapping, most dogs will exhibit subtle early-warning cues of stress such as stiffening, lip licking, yawning or turning the head. It's when these warning signals go unheeded that dogs may decide to escalate to a snap. By familiarizing yourself with canine body language, you can avoid pushing your dog to the point of snapping.
Avoid Harsh Methods
Harsh methods such as grabbing the dog's muzzle, shaking the dog by his scruff or and other forms of force or intimidation can put you at risk of being bitten or attacked. Additionally, harsh methods won't change the underlying cause of the behavior -- instead, they risk suppressing a dog's aggressive display, which may lead to increased stress and a dog who bites without warning. If your dog is snapping, enlist the aid of a qualified behavior professional who's familiar with learning theory and gentle to both you and your dog .