When training our dogs, we talk about food-motivated dogs, for example. Food-motivated dogs are relatively easy to train by positive reinforcement, because, as long as the trainer is doling out treats, she pretty much has the dog's undivided attention. Some dogs are toy motivated: if there is a tennis-ball within visual range, these dogs can be oblivious to anything and everything else in the environment. Some dogs can become so focused on a tennis-ball that they will chase a tennis-ball into a busy street, even if they are otherwise "street smart" when there are no toys around.

Dogs that are dog-motivated think that other dogs are the best. Period. I saw a dog get hit by a car and killed because it was trying to get to another dog on the other side of the street during the evening rush hour. Even though the dog was on leash, the dog saw the other dog before the person holding the leash did, and the person was not able to hold onto the leash when the dog unexpectedly bolted. The sad irony is that this happened right outside the gates of a park in which five or six other dogs were playing. The dog's owner had decided not to bring her dog into the park to play with the other dogs, because she was afraid that her dog would become too excited and that she would not be able to control her dog. Very, very sad.

An excessively dog-motivated dog becomes intensely excited around other dogs. If the dog "knows" obedience commands ("sit," "stay," "come," etc.) he will not respond to these commands when other dogs are present. If the dog is on leash, he will pull obstinately trying to get to other dogs. Donaldson observes that

the dog's intense excitement, sudden non-responsiveness to the owner and pulling on leash make the owner feel out of control. The concerned owner starts avoiding other dogs, choking up on the leash, jerking the leash or otherwise trying to discipline the dog, all selectively in the presence of other dogs.

There is a spiral or snowball effect involving both the dog and the owner. Other dogs come to mean not only an excited dog but also an angry owner. Both the dog and the owner grow increasingly tense and unhappy around other dogs.

Sadly, many dogs that are excessively dog-motivated are often deprived of all access to other dogs. These are the dogs that bark at you from behind the window when you walk past with your dog.

When a dog-motivated dog that is deprived of intra-species (dog-dog) socialization does meet other dogs, fights can result. His extreme excitement can cause him "to commit social gaffes—he is too much in the other dog's face and fails to read the other dog's body language." His social skills—meeting, greeting and reading novel dogs—are "coarse." Donaldson calls these poorly socialized, highly dog-motivated dogs "Tarzans:"

Think of a human who has been raised without being around other people until age 18. Imagine him as a guest at a cocktail party. Not only might he walk on the table and put his fingers into he dip. he might go right up to someone, stand too close, slap then on the back (or worse grab their privates) and fail to read subtle cues from the host or guests that he is out of line. He is eventually wrestled to the ground and handcuffed. The dog equivalent has terrific interest in other dogs but also lacks social grace.

If your dog does happen to meet a "Tarzan-type dog," you would do well to monitor their interaction closely and remove your own dog if the situation seems likely to deteriorate. Donaldson cautions that "a severe Tarzan can dish out some pretty awful stuff:" "body-slamming, growling, mounting, and failing to turn any of this off when [the other dog] delivers 'back off' body language." Subjecting your dog to this kind of sociopathy puts your dog at risk of developing a fearful response not only to Tarzan but "to all dogs that remind her of him, to most large dogs except those in her circle already or, in the worst case, to all dogs."