Are Pit Bulls different? Behavioral evaluation within a rehabilitation program of ex-fighting dogs

Although pit bulls have been considered a potentially dangerous breed and thus are often a subject of legal restrictions, very few studies have been carried out to define their behavioral characteristics. The current project was aimed at comparing pit bulls’ behavioral responses to those of a control group on a series of tests carried out in 2 shelters. The first aim of the study was to outline a complete ethogram and sensitive evaluation scales, paying particular attention to aggressive behavior. These were then used to evaluate the behavioral responses of pit bulls (a subgroup consisting of ex-fighting dogs) compared to controls in a series of tests (Van der Borg et al., 1991). The tests focused on the dogs’ responses to 3 categories of social partners: an unfamiliar person, a doll, and an unfamiliar adult male dog. Behavioral categories considered were sociability, fear, aggressiveness, and frustration (the latter only in the unfamiliar dog test). In total, 72 dogs were tested, 36 pit bulls and 36 mixed-breed and purebred dogs (both groups: 19 females, 17 males, age range 2-9 years). A 3-way analysis of variance ANOVA was used to assess the effects of breed, sex, and shelter. In the unfamiliar person test, pit bulls did not differ significantly from controls in any of the variables measured. In the doll test, pit bulls, regardless of sex and shelter, showed significantly higher levels of aggressiveness compared to controls (P < 0.05). Forty-four percent of pit bulls manifesting aggressive behaviors obtained a score of 4 (on a 0 to 4 point scale), whereas none of the controls (0%) obtained the highest score. No differences between groups emerged in terms of sociability and fear toward the doll. In the unfamiliar dog test, male pit bulls were significantly less sociable (P < 0.01) than all other groups (female pit bulls, male and female controls), whereas the male controls were the most sociable toward the unfamiliar dog. Pit bulls as a breed were also significantly more aggressive than controls (P < 0.01), with mean scores of 2.89 compared to 1.25 for controls, and showed significantly (P < 0.01) higher levels of frustration. Male pit bulls in this sample were significantly less sociable and more aggressive compared to all other groups in 2 of the 3 tests considered. This is in partial contrast with the description of the breed as aggressive toward conspecifics, but sociable and nonaggressive toward people.