Duhaime's Law Dictionary

Pit Bull Definition:

Dogs which exhibit appearance and physical characteristics of any of a pit bull terrier or Staffordshire, American or American Staffordshire bull terrier.

Related Terms: Dog Fighting

In 205, the Canadian province of Ontario enacted a regulation which required of individuals who own a restricted pit bull, they the dogs be muzzled, leashed and sterilized.

Pit bull was defined as:

"Pit bull includes, a pit bull terrier, a Staffordshire bull terrier, an American Staffordshire terrier, an American pit bull terrier, (or) a dog that has an appearance and physical characteristics that are substantially similar to (these) dogs...."

In Cochrane, Catherine Cochrane tried to overturn a pit bull ban suggesting that, inter alia, "the law fails to provide an intelligible definition of pit bulls, rendering the law unconstitutionally vague".

The case was ultimately heard by the Ontario Court of Appeal where Justice Sharpe rejected Cochrane's argument; in effect, accepting the statutory definition.

Similarly, in Ohio, the pit bull ordinance of the Village of South Point was challenged for alleged vagueness. That ordinance defined a pit bull as:

"... a vicious dog ... any Staffordshire Bull Terrier or American Staffordshire Terrier breed of dog, or any mixed breed of dog which contains, as an element of its breeding the breed of Staffordshire Bull Terrier or American Staffordshire Terrier as to be identifiable as partially of the breed of Staffordshire Bull Terrier or American Staffordshire Terrier by a qualified veterinarian duly licensed by the State of Ohio."

Justice Weber wrote:

"[T]he definitions of a Pit Bull Terrier in this Ordinance are not unconstitutionally vague. An ordinary person could easily refer to a dictionary, a dog buyer's guide or any dog book for guidance and instruction; also, the American Kennel Club and United Kennel Club have set forth standards for Staffordshire Bull Terriers and American Stafforshire Terriers to help determine whether a dog is described by any one of them. While it may be true that some definitions contain descriptions which lack mathematical certainty, such precision and definiteness is not essential to constitutionality....

"There is no statistically definable qualitative method to distinguish a Pit Bull by its biochemical makeup.

While identification of the breed of a dog may be difficult in some situations, ... there are certain confirming characteristics to what is described as a Pit Bull.... Pit Bull does describe an identifiable type of dog.

"Pit Bulls also possess the quality of gameness, which is not a totally clear concept, but which can be described as the propensity to catch and maul an attacked victim unrelentingly until death occurs, or as the continuing tenacity and tendency to attack repeatedly for the purpose of killing. It is clear that the unquantifiable, unpredictable aggressiveness and gameness of Pit Bulls make them uniquely dangerous.

"Pit Bulls have the following distinctive behavioral characteristics: grasping strength, climbing and hanging ability, weight pulling ability, a history of frenzy, which is the trait of unusual relentless ferocity or the extreme concentration on fighting and attacking, a history of catching, fighting, and killing instinct, the ability to be extremely destructive and aggressive, highly tolerant of pain, great biting strength, undying tenacity and courage and they are highly unpredictable.

"While these traits, tendencies or abilities are not unique to Pit Bulls exclusively, Pit Bulls will have these instincts and phenotypical characteristics; most significantly, such characteristics can be latent and may appear without warning or provocation.

"The breeding history of Pit Bulls makes it impossible to rule out a violent propensity for any one dog as gameness and aggressiveness can be hidden for years. Given the Pit Bull's genetical physical strengths and abilities, a Pit Bull always poses the possibility of danger; given the Pit Bull's breeding history as a fighting dog and the latency of its aggressiveness and gameness, the Pit Bull poses a danger distinct from other breeds of dogs which do not so uniformly share those traits.

"While Pit Bulls are not the only breed of dog which can be dangerous or vicious, it is reasonable to single out the breed to anticipate and avoid the dangerous aggressiveness which may be undetectable in a Pit Bull."




  • American Dog Owners Assn. v. Des Moines, 469 N.W.2d 416 (Iowa 1991)
  • American Dog Owners Asso. v. Yakima, 777 P.2d 1046 (1991)
  • Cochrane v. Ontario (Attorney General), 2008 ONCA 718
  • Colorado Dog Fanciers, Inc. v. City and County of Denver, 820 P.2d 644 (Colo. 1991)
  • Duhaime, Lloyd, Duhaime's Legal Dictionary
  • Duhaime, Lloyd, Duhaime's Legal Citations & Abbreviations
  • Greenwood v. North Salt Lake, 817 P.2d 816 (Utah 1991)
  • Hearn v. Overland Park, 244 Kan. 638, 772 P.2d 758 (1989)
  • Madronero v. Lachine (Ville), [1990] Q.J. No. 307
  • Manitoba Assn. of Dog Owners v. Winnipeg (City), [1993] M.J. No. 661
  • Pit Bull Controls, O. Reg. 157/05
  • State of Ohio v. Anderson, 566 N.E.2d 1224 (1991)

Categories & Topics:

Always looking up definitions? Save time with our search provider (modern browsers only)

If you find an error or omission in Duhaime's Law Dictionary, or if you have suggestion for a legal term, we'd love to hear from you!