The effect of familiarity on behavior of kenneled dogs during interactions with conspecifics.

Kenneled environments often prevent direct physical contact between dogs, potentially causing stress, and so it has been recommended that such contact should be provided. This study examined the effect of familiarity on the behavior of dogs during off-lead interaction. Kenneled dogs (3 breeds) were given 15-min off-lead interactions with a familiar dog and an unfamiliar dog; the behavior of the focal dog and the distance between the dogs were recorded. More time in contact and interaction behaviors were recorded at 0 to 3 min with unfamiliar dogs than with familiar dogs. At 9 to 12 min, familiar pairs spent more time within 5 body lengths and more time being followed than unfamiliar pairs, who spent more time at more than 5 body lengths apart. This suggests that the initial interaction is more important when dogs are unfamiliar, but once this "greeting" has occurred, unfamiliar pairs are more likely to investigate their surroundings independently rather than together. Breed differences were observed only at 0 to 3 min. The study suggests that familiarity should be taken into account when assessing the effectiveness of conspecific contact as a potential enrichment for kennel-housed dogs.

Habituation and dishabituation during object play in kennel-housed dogs.

Domestic dogs are reported to show intense but transient neophilia towards novel objects. Here, we examine habituation and dishabituation to manipulable objects by kennel-housed dogs. Labrador retrievers (N = 16) were repeatedly presented with one toy for successive 30-s periods until interaction ceased. At this point (habituation), a different toy was presented that contrasted with the first in both colour and odour (since the dog's saliva would have accumulated on the first), colour alone, or odour alone. No effect of the type of contrast was detected in the number of presentations to habituation, the difference in duration of interaction between the first presentation of the first toy and the presentation of the second toy (recovery), or the duration of interaction with the second toy (dishabituation). Varying the time interval between successive presentations of the first toy up to habituation between 10 s and 10 min had no effect on the number of presentations to habituation, nor did it alter the extent of dishabituation. Varying the delay from habituation to presentation of the second toy, between 10 s and 15 min, affected neither the recovery nor the dishabituation. Overall, the study indicates that loss of interest in the object during object-orientated play in this species is due to habituation to the overall stimulus properties of the toy rather than to any single sensory modality and is also atypical in its insensitivity to the interval between presentations.