Distribution of the probability of having antibody levels of < 0.5 IU/ml for all main effects and interactions. A. Type of vaccine used. B. Interaction between breed size1 and number of vaccinations. C. Interaction between age2 at vaccination and time of antibody titre testing after the latest vaccination in the final multivariable logistic regressions analysis of variables associated with the success of rabies vaccinations in 6,071 Swedish dogs. 1vs-s = very small - small breed; s-m = small - medium breed; m-l = medium - large breed; l-vl = large to very large breed. 2Age in month (m) or year (y).