Determining whether an individual dog is of a pit bull breed can be necessary for health or legal reasons. Pit bull breeds and their mixes can be prone to certain health issues and proactive care can prevent or mitigate certain issues. Pit bull breeds, pit bull type dogs, and their mixes are legally regulated or banned in many countries. The burden of proof can lie with the dog owner or with the authorities. In Denmark, the police can request that a dog owner provides proof that the dog is not prohibited under the Danish Dog Act. Danish authorities recommend that dog owners make sure they have documentation of their dog's origin and breed, especially if their dog has characteristics similar to those prohibited: "Possessors of a dog, which in appearance have some features in common with one or more of the prohibited breeds, are recommended to ensure that they possess documentation of their dog's breed." In the United Kingdom it is also a dog owner's responsibility to prove that the dog is not one of the prohibited types (dog types bred for fighting) under the Dangerous Dogs Act 1991 or that the dog has a Certificate of Exemption (grandfather clause). The UK uses Dog Legislation Officers (DLO) which have special training and experience in dog identification. Those officers also provide expert evidence for authorities.
Methods There are various ways to identify a pit bull's specific breed. It can be proven through
registration papers (
pedigree) and through testing a dog's DNA to validate parentage or it can be determined through testing DNA-based ancestry, through examining a dog's traits or the use of artificial intelligence. Which method is suitable depends on the purpose of the identification. While some methods might be good enough to satisfy a dog owner's curiosity, not all methods are accepted for legal reasons. For example, France banned pit bull type dogs (category 1) in 1999, but purebred registered American Staffordshire Terriers (category 2) are only restricted, not banned. Therefore, only American Staffordshire Terriers registered with Central Canine Society (
fr.
Société centrale canine) are legally allowed to be in or to re-enter the country. Parental DNA testing of a not-registered purebred dog would not be sufficient under French law to legally transfer such a dog into or through France.
Pure breed identification Two pit bull breeds, the
American Staffordshire Terrier and the
Staffordshire Bull Terrier, can be registered at internationally recognized Kennel Clubs, such as the American Kennel Club (
AKC), through their respective breed clubs to receive registration papers. Both breeds are also recognized by the Fédération Cynalogique Internationale (
FCI), which maintains and publicizes their breed standards. In contrast, the
American Pit Bull Terrier and the
American Bully are not recognized by international Kennel Clubs, though they can be registered at other Kennel Clubs, such as the United Kennel Club (
UKC). File:Bullterrier and staffordshirebullterrier.jpg|A Staffordshire Bull Terrier (right) is easy to tell apart from a
Bull Terrier. File:Two dogs and a fireplace.jpg|An AKC registered American Staffordshire Terrier (left) and a
UKC registered American Pit Bull Terrier (right). File:Staffordshire Bull Terrier 600.jpg|alt=A Staffordshire Bull Terrier is of of small to medium size.|Staffordshire Bull Terriers are small to medium sized. File:Bully.jpg|The
American Bully shares phenotypic traits with other pit bull breeds. Through selective breeding, pit bull breeds have developed characteristics that distinguish them from one another, as well as from other dog types in terms of form and function: "[...] the name
Pit Bull is actually a generic term that applies to the various breeds that share the same ancestry or have a similar appearance. This includes the APBT, the American Staffordshire Terrier, Staffordshire Bull Terrier, and the American Bully. Sometimes people even refer to the Bull Terrier or the Miniature Bull Terrier as Pit Bulls. Although enthusiasts of these different breeds can easily tell them apart, to those who are unfamiliar with them many of the breeds appear quite similar." An example of distinct
traits that a Labrador Retriever and an American Pit Bull Terrier have. This list considers characteristics of a dog's form as well as function and typical behavior:
Dog type identification Breed assessors look at a suspected pit bull's physical characteristics like the shape of the head, ears, flews, jowls, teeth, eyes, chest, legs and tail, as well as the characteristics of the dog's coat (color, hair length, growth and texture), skin, weight, height and body length to determine if a dog categorizes as a pit bull type dog or not. "Pit bull-type dogs are defined as any dog displaying a majority of physical traits of any one or more of the specific breeds mentioned above [American Pit Bull Terrier, American Staffordshire Terrier, or Staffordshire Bull Terrier], or any dog exhibiting those distinguishing (physical) characteristics that substantially conform to the standards established by American Kennel Club or United Kennel Club". Whether the dog type pit bull can be sufficiently defined has been the subject of legal disputes. For example, the claim that the legal phrase "commonly known as a pit bull dog" is unconstitutionally vague has been dismissed by judicial decisions: "...the ownership of a dog 'commonly known as a pit bull dog' is
prima facie evidence of the ownership of a vicious dog, is not unconstitutionally void for vagueness since dogs commonly known as pit bulls possess unique and readily identifiable physical and behavioral traits which are capable of recognition both by dog owners of ordinary intelligence and by enforcement personnel." The court also found that specific behavioral features distinguish pit bulls from other dogs and therefore can be taken into account when identifying a pit bull: "Furthermore, the dog owner of ordinary intelligence, when determining whether he or she owns a pit bull dog, need not rely solely on the dog's physical traits. Rather, the pit bull possesses certain distinctive behavioral features which differentiate it from other dog breeds."
Challenges of mixed or cross breed identification Mixed or cross breed identification can be more challenging than pure breed identification and can be supported by testing for genetic markers. Studies have found that when people involved in dog rescue, adoption, and regulation identify the breed of a dog of mixed parentage, this identification did not always correlate with the DNA analysis of that dog. Mixed-breed dogs are often labeled as pit bulls if they have certain physical characteristics, such as a square-shaped head or bulky body type.
Deliberate mislabeling of pit bulls In Australia some dog owners give false information regarding the breed of their dog to local authorities, despite this being an offence under the Crimes Act. Inquests after fatal or serious dog attacks showed that pit bull owners registered their dogs under a wide range of other breeds, like the
Australian Terrier, to evade their local laws and regulations. In France, investigations following the dog attack death of
Elisa Pilarski led to the discovery that her partner and dog's owner had deliberately passed off a purebred American Pit Bull Terrier as a mix of a
Whippet and a
Patterdale Terrier and imported it into the country illegally. American Pit Bull Terriers are not recognized as a breed in France and are considered a pit bull type, which has been banned in the country since 1999. == Dog attack and death risk ==