Domestication is accompanied by marked changes in the phenotype of the domesticated form of a species relative to its wild ancestor. The domestic dog and its wild ancestor, the wolf, are a widely used model system to study the effects of domestication on cognition and behaviour. The aim of this study was therefore to compare the behavioural responses of wolves (Canis lupus) and domestic dogs (Canis lupus familiaris) to different odour stimuli. To this end, wooden logs were impregnated with one of four odours and repeatedly placed into the enclosure of a wolf or dog pack. The dogs (n=10) and wolves (n=9) both performed a significantly higher number of interactions with the wooden logs when these were impregnated with real blood compared to the blood odour component trans-4,5-epoxy-(E)-2-decenal, the fruity odour iso-pentyl acetate and the solvent diethyl phthalate. No significant difference in the frequency of interactions per animal was found between the wolves and dogs with any of the four odour stimuli. Sniffing was the most frequent behaviour in both wolves and dogs, followed by licking, biting, toying, and pawing. The only qualitative difference in behaviour was that the dogs, but not the wolves, displayed guarding behaviour when presented with the odorized wooden logs. The results of the present study suggest that domestication had little, if any, effect on olfactory behaviour in domesticated dogs. The results also indicate that odour-impregnated wooden logs are a suitable method of olfactory enrichment for captive wolves and domestic dogs.

A variety of prey species are able to detect predators by odours emanating from their urine, feces, fur and anal glands. However, it is unknown whether the odour of a predator’s blood also contains information signalling “predator” to a prey. The aim of the present study was therefore to assess if blood odour from a cat elicits avoidance or anxiety responses in CD-1 mice (Mus musculus). A two-compartment test arena was used to assess place preference, motor activity and fecal excretions when the mice were simultaneously presented with cat blood and a blank control. Additionally, the mice were tested with horse blood and N-pentyl acetate, a fruity odour. The mice did not show avoidance of any of the three odours. Nevertheless, the mice were significantly less active when exposed to cat blood in comparison to horse blood, but did not increase defecation when exposed to cat blood. This suggests that the information mice get by the odour of cat blood did not contain the signal “predator”.