Serious unprovoked dog attacks are often the result of multiple factors:
indiscriminate, negligent breeding resulting in aggression;
a pet store or kennel selling the wrong breed to an unsuspecting owner or selling multiple dogs of a given breed which the owner has no realistic prospect of safely managing and controlling; and
a pet store or kennel selling a dog and giving no advice or faulty advice on socialization and training.
Therefore, a dog owner is not the only responsible party for a victim's injuries sustained in a dog attack.
Breeders May Be Liable
In-breeding and over-breeding has adverse effects on a dog’s temperament. In-breeding and over-breeding can result in a given breed’s characteristic traits being transformed from a relatively benign temperament trait into a dangerous behavioral aberration. For example, normal behavioral traits of herding, protecting and guarding are found in such breeds as Mastiffs, Dobermans and Rottweilers. These traits can become exaggerated and highly dangerous if the breeder does not properly assess the temperament of both the male and female dog being bred. Failure to do so can lead to genetic abnormalities that cause dangerous behavior in their offspring. Also, female dogs that are not healthy and genetically sound can interact with their puppies in such a way as to cause unwanted behavioral traits in those dogs.
When a given breed of dog becomes very popular, some breeders will breed indiscriminately to produce a sufficient number of puppies to meet the demand. There is a long, well-established history of behavioral problems developing in certain breeds of dogs after those breeds become popular. Hollywood movies, television shows, etc. can cause an explosion in a given breed’s popularity. Behavioral problems are sure to follow. This holds true with small, medium and large dogs.
There are some very simple, universal rules that responsible breeders follow. First, they determine the temperament of a dog before breeding that dog. If the dog has unwanted aggressive traits, the dog is simply not bred. Dogs with a history of unprovoked attacks are not bred. The genetic history of the dog is reviewed to ensure that excessive in-breeding has not taken place. These steps are simple and they are followed by responsible breeders. If they are ignored, they can and do lead to negative behavioral traits, including aggression.