My friend Jim has a dog, Casper. Casper (pictured above) is a six year old American Eskimo Dog who still has the energy of a puppy. This is not entirely an accident. Jim is a researcher at a local company, and he has made research into a way of life. His research when selecting dog breeds led him to the discovery that a dog’s lifespan and general health is closely related to how much the dog looks like a wolf.
If this seems surprising to you, consider this: each breed of dog is a descendant of wolves. The breeds were then created through, well, breeding. Humans selected features they wanted, and the very wolf-like first dogs led to dogs optimized to be small (toy breeds), or have comically short legs (Corgies), or short snouts (pugs). In this optimization for human-selected qualities, they have been optimized away from survivability, that is, health. This can also happen with plants, leading to unfortunate situations such as illustrated in the comic below.
There are some things that have not been bred out of dogs, though. For instance, the predilection to roll in the leavings of other animals. Some study has been devoted to this behavior. Theories of why it might be beneficial for a wolf to roll in poop or a rotting carcass include camouflage and group identity.
The camouflage theory does not apply to fooling prey so much. A study of wolves given various scents to roll in found some interesting results.
Surprisingly, the wolves were least interested in rubbing themselves in the faeces of herbivores like sheep or horse: the scientists did not see them rub at all on these odours. Food was similarly unappealing. Instead, their favoured scents were artificial odours like perfume or motor oil.
A powerful, strange smell like perfume is likely to make hunting more rather than less difficult. A savvy prey will run from any strange smell approaching. A predator, however, is more discerning. It may be less inclined to pick off a delicious straggler from a pack of wolves if its nose tells it that in fact what it smells passing by is merely a pack of poops or an ambulatory puddle of motor oil.
Group identity is even more fun. All the wolves in a group might roll in the same dung, identifying themselves together as “team bear poop.” Team bear poop then can more effectively work together and compete against “team deer carcass” and “team industrial sludge.”
I wonder if a dog who finds a scent it likes may just want to keep it around a little longer. What better way than to make it a personal perfume? So, the next time your dog chooses to express its membership in “team ruptured septic tank,” consider giving it human perfume after you wash it for a more sanitary Eau de Toilette.