National Canine Research Council Summary and Analysis:
The paper by Sacks, Sattin, and Bonzo (1989) covers DBRFs in the United States from 1979–1988. The goal of this study was to estimate the number of DBRFs over the 10-year period and to identify the breeds of dogs most commonly involved. Two sources (the National Center for Health Statistics (NCHS) and the NEXIS search service) were used to identify the cases. Humane Society records and multiple-cause mortality tapes from the NCHS were used to verify information and gain additional details about the cases. As the first attempt to capture all DBRFs over a long enough period to collect a significant sample size, this report is widely cited. The incidence data, however, is limited to news accounts and NCHS death records, and is not verified beyond those sources. The lead author of this paper later co-authored the more comprehensive work by Patronek et al. (2013) which was not subject to the same pitfalls of visual breed identification and media reported data.
In 36% of the cases, no breed was reported. Another 14% were reported to be mixed breeds. Since this study predates the first attempt at rigorous breed identification (Patronek et al., 2013), the remaining cases where a breed was reported are subject to the unreliability issues of visual breed identification. Thus no reliable breed conclusions can be drawn from this data. Despite recognizing limitations in breed identification, unreliable population counts, and media biases, the authors still assert that “pit bulls” account for a disproportionate number of fatalities.
Sacks et al. (1989) go on to argue that DBRFs might be under-reported; they note that the humane society reports 45 deaths whereas their research uncovered 183. However, their count is in line with numbers found throughout the literature, including later large-scale studies, so their concern is unwarranted. The authors used multiple sources to identify the number of DBRFs, and this approach is common (Patronek et al., 2013; Sacks et al., 2000; Sacks et al., 1996). It may be true that any given source does not include all cases, but their colleagues in the field do not typically rely on one source for obtaining totals; media reports, the humane society, death records, internet searches, and surveys are all sources that have been used in this field.