I am not up to date on current rabies vaccines for dogs, but I know that in the past there was more than one formulation, as my next door neighbour's dog had an anaphylactic reaction when vaccinated and the vet made a note to use a different formulation for the next annual shot. In future the dog had no difficulties. There are known side effects to most vaccines. Aggression is not one I am familiar with, however, with rabies vaccination in countries that require it there isn't much choice. It would not be my first thought with an 18 month old dog showing aggression. Especially a Basenji objecting to being moved from a comfortable place.