Are cats more equal than dogs?

Abstract The impact of cats and dogs on biodiversity has been the focus of intense debate. Here, we review the scientific literature on the impacts themselves and discuss societal perception of cats and dogs from a cultural point of view. This includes varying feelings of fear and appreciation, related to differences in risks posed to people, animal size, difficulty in handling, and behavior. We then analyze existing international rules on the management of cats and dogs, particularly international treaties and European Union legislation. The documented adverse biodiversity impacts of cats appear to be significantly greater than those of dogs, but in many countries dogs are prevented from roaming free, whereas cats are often allowed to roam freely on a massive scale. This appears to run counter to many legal obligations. A mismatch thus appears to exist between science on the one hand and law on the other hand, which may partly be explained by differing social perceptions. The results of our analysis justify a more homogeneous legal treatment for dogs and cats with regard to their freedom of movement, through a tightening of the rules that affect cats.