Evaluating the prevalence and effectiveness of breed-specific legislation

Felicia E Trembath, Purdue University


Dog bites pose a persistent public health problem, which some jurisdictions pass breed-specific legislation (BSL) to address. However, very little non-anecdotal evidence regarding the efficacy of BSL has been presented. Currently, BSL research is hampered by the absence of standard terminology, an established prevalence, or a scientific consensus on its effectiveness. The purpose of this study is to propose standardized terminology for BSL, establish the prevalence of each type of BSL in the USA, and conduct a systematic review of the effectiveness of BSL. After review of terminology currently in use, as well as review of the regulatory actions of 100 breed-specific ordinances, the standardized terminology proposed to discuss BSL is: declaration, restriction, ban, and grandfather clause. Municipal ordinances with breed-specific language were located through compilation of existing lists and mining of ordinance websites. Ordinances were reviewed and classified according to the proposed terminology. Six representative bibliography databases were queried using search string (dog* or canine) AND (law or legislation) AND (breed). The summary of findings and quality of the body of the evidence were generated using the GRADE approach. Of 1144 ordinances evaluated, 5 were erroneously reported, 11 could not be classified, 44 were not municipalities, and 139 were repealed. Of the remaining 945 ordinances, many fit into more than one category: 505 declared a breed dangerous a priori, 741 placed ownership restrictions, and 513 banned at least one breed. Exemptions for existing animals were included in 338 of the bans. Five studies met the inclusion criteria; three of these showed some effect, and two reported no effect. The majority of studies had methodological flaws, consequently the overall evidential quality was graded very low. Despite being a goal, a meta-analysis proved impossible, and the low quality of evidence precluded substantive conclusions about the global effectiveness of BSL. However, studies show evidence that BSL may reduce dog bite injury hospitalizations and that the effect may differ for various age groups. Efforts should be made to standardize data collection and warehousing procedures to make dog bite injury data accessible to researchers. Additionally, future studies on BSL should consider temporal trends, requisite lead time prior to legislation passing, the severity of injuries, differing effects in subgroups, the type of BSL, and the length of time required for an effect to become demonstrable.




Beck, Purdue University.

Subject Area

Law|Public health|Epidemiology|Veterinary services

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