Polymorphisms in the canine monoamine oxidase a (MAOA) gene: identification and variation among five broad dog breed groups.

Dogs exhibit significant variation in certain intronic regions of the MAOA gene, while the coding and promoter regions are well-conserved. Distinct genetic differences were observed between breed groups. Further studies are now required to establish whether such polymorphisms are associated in any way with MAOA level and canine behaviour including aggression.