Breed or type bans—
Concerns about “dangerous dogs”
Dogs have caused many local governments to consider
supplementing existing animal control laws with ordinances
directed toward control of specific breeds or types of dogs.

Members of the AVMA Task Force believe such ordinances are inappropriate and ineffective.
Statistics on fatalities and injuries caused by dogs cannot be responsibly used to document the “dangerousness” of a particular breed, relative to other breeds,
for several reasons.
First, a dog’s tendency to bite depends on at least 5 interacting factors: heredity, early experience, later socialization and training, health (medical and behavioral), and victim behavior.
Second, there is no reliable way to identify the number of dogs of a particular breed in the canine population at any given time (eg, 10 attacks by Doberman Pinschers relative to a total population of 10 dogs implies a different risk than 10 attacks by Labrador Retrievers relative to a population of 1,000 dogs).
Third, statistics may be skewed, because often they do not consider multiple incidents caused by a single animal.
Fourth, breed is often identified by individuals who are not familiar with breed characteristics and who commonly identify dogs of mixed ancestry as if they were purebreds.
Fifth, the popularity of breeds changes over time, making comparison of breed-specific bite rates unreliable. Breed-specific ordinances imply that there is an
objective method of determining the breed of a particular dog, when in fact, there is not at this time.

Owners of mixed-breed dogs or dogs that have not been registered with a national kennel club have no way of knowing whether their dog is one of the types identified and whether they are required to comply with a breed-specific ordinance.
In addition, law enforcement personnel typically have no scientific means for determining a dog’s breed that can withstand the rigors of legal challenge, nor do they have a foolproof method for deciding whether owners are in compliance or in violation of laws.
Such laws assume that all dogs of a certain breed are likely to bite, instead of acknowledging that most dogs are not a problem. These laws often fail to take normal dog behavior into account and may not assign appropriate responsibilities to owners.
Some municipalities have attempted to address notice and enforcement problems created by unregistered and mixed-breed dogs by including in the ordinance a description of the breed at which the ordinance is directed.

Unfortunately, such descriptions are usually vague, rely on subjective visual observation, and result in many more dogs than those of the intended breed being subject to the restrictions of the ordinance.
Animal control legislation has traditionally been considered a constitutionally legitimate exercise of local government power to protect public safety and welfare. Breed-specific ordinances, however, raise constitutional questions concerning dog owners’ fourteenth amendment rights of due process and equal protection.
When a specific breed of dog is selected for control, 2 constitutional questions are raised: first, because all types of dogs may inflict injury to people and property, ordinances addressing only 1 breed of dog appear to be under inclusive and, therefore, violate owners’ equal protection rights; and second, because identification of a dog’s breed with the certainty necessary to impose sanctions on the dog’s owner is impossible, such ordinances have been considered unconstitutionally vague and, therefore, to violate due process…..

Source….. American Veterinary Medical Association
Task Force on Canine Aggression and Human-Canine Interactions
More to come…..