Although your pampered pooch curled up on the couch doesn't look much like a wolf, he still has many of his ancestor's hunting instincts. If you see your dog pick up a toy in his mouth, clamp his teeth shut then shake the toy violently, this is an instinctive behavior used to kill or maim a prey animal.
The simplest function of shaking a small prey animal is killing the prey. Dogs are hunters by genetics and history -- in the wild, a dog's survival may depend on his ability to hunt and kill small animals for food. Wild dogs commonly kill and eat small rodents, from mice or rats to squirrels or rabbits. Shaking one of these small animals quickly kills the prey, usually by breaking the neck or spine. Your domestic dog may still have a strong instinct to kill similar small prey animals.
By shaking a toy, a dog is practicing the hunting skills that his instincts tell him are necessary to survive. An adult dog may use a toy to teach puppies this skill. In the home, dog toys provide a safe and appropriate outlet for your dog's killer instincts. They can also be a great way for your dog to burn off his excess energy, and keep him out of your way while you are cooking or working. Additionally, "killing" a toy builds your dog's upper-body muscles, works his fine motor skills and coordination, and strengthens his jaw and teeth.
Shaking a toy may look like a lot of fun for your dog, and watching her in action can be entertaining. However, the joke is over the moment your dog transfers this shaking behavior to anything other than a dog toy. Shaking behaviors can become a serious problem if a dog starts picking up and shaking other pets -- or even young children -- in the home. Cats, babies and other pets could be in serious danger if your dog's shaking behavior becomes problematic.
Teach your dog from the outset that she can only pick up her own dog toys in her mouth. If she picks up and plays with anything else -- for example, your old sneakers or a child's soft toy -- do not allow her to continue this behavior. Tell your dog "no" and quickly retrieve the item, providing her with an appropriate substitute such as a dog toy or chew. You can make this process easier by teaching your dog the command "drop" or "leave it" -- when she follows this command quickly, give her plenty of praise. If your dog refuses to drop the item, don't get into a tug of war with her, as you risk getting bitten. A small water pistol can be helpful in teaching a dog what she may or may not pick up in her mouth -- a cold squirt of water is a good deterrent if your dog goes to pick up and shake your shoe.
- russian toy-terrie image by Andrey Armyagov from Fotolia.com