Figure 2.

(a) Comparison of ‘aggressive towards owner’ scores of dogs between groups based on the results of the ‘take away bone’ test. After the behavioural test, dogs were sorted to ‘less aggressive’ (tractable) and ‘more aggressive’ (possessive) categories. Bars and whiskers represent mean ± s.e. GLM with Tukey's post hoc test, *p < 0.05. (b) Comparison of ‘aggressive towards owner’ scores of dogs between groups based on the neuter/spay status of dogs and the results of the ‘roll over’ test. After the behavioural test, dogs were sorted to ‘less aggressive’ (compliant) and ‘more aggressive’ (resistant) categories. Spay/neuter status and behavioural category are in significant interaction with each other. Bars and whiskers represent mean ± s.e. GLM with Tukey's post hoc test, *p < 0.05.