The rapid decline in New Zealand’s terrestrial biodiversity from the impacts of exotic mammalian predators has prompted the nationwide application of anticoagulant rodenticides. However, this application has increased the occurrence of accidental poisonings in non-target species, particularly the domestic dog (Canis familiaris). Odour excretions from predators can induce long-term feeding avoidance in prey species, however, predator odours and their potential as a dog repellent have not been investigated. The aim of this study was to investigate the potential for biologically-derived olfactory repellents to deter dogs from consuming toxic baits, in particular, rat poison. To complete this aim two experiments were conducted where dogs and rats were presented repellent-treated kibble and rat chow via a series of two-choice preference tests. The first experiment examined the repellent effects of African lion (Panthera leo), tiger (Pantera tigris), baboon (Papio hamadryas), domestic dog (Canis familiaris) faeces, and a commercial repellent, on dogs’ feeding behaviour (N = 21). The second experiment examined if the repellents deterred rats (N = 10), the poison’s target species. The results revealed that (1) the dogs ate significantly less when presented with lion or dog faeces; (2) baboon faeces, tiger faeces, and the commercial repellent had virtually no repellent effect on the dogs; and (3) overall food consumption by the rats did not differ between repellent types. In summary, this study demonstrates the potential use of animal faeces as a repellent, deterring dogs, but not rats, from poison.