Have you ever been out on a walk with your dog only to have him dart from your side, fling himself on his back, and wriggle around quite happily on the decomposing carcass of some animal?
Have you ever just finished bathing your dog and before you've even revelled in the clean, fresh smell of the scented dog shampoo, turned around to see your dog covered in wet dirt and bits and pieces of grass, having immediately headed for the garden when you've released him?
Have you ever groaned in disgust when you've witnessed your dog rolling around in his own poop, the poop of other dogs, or even the scat left behind from wild animals? If you have, then you must have wondered why on earth he would do such things–surely it's not just to upset and frustrate you.
It is important for us to remember that when it comes to dogs, "the nose knows it all."
Smell is the dominant sense that a dog possesses, and everything about the dog's nose is designed to maximise the capture and analysis of odours.
While humans may prefer the scented shampoos that contain ingredients such as lavender, peppermint and aloe vera, dogs generally want to have nothing to do with such scents.
Unfortunately for us, their choice of cologne often ranges from dead frog to iguana poop and all other such repulsive–to humans at least–aromas. Your doggie best friend may therefore be rolling in the garbage simply because he likes how it smells and wants to douse himself in it. Directly after a bath, he probably resorts to getting the smell of the shampoo off by covering it up with a different–and smellier–scent. This being said, when you bathe your dog always use dog shampoo which is formulated for the health of canine skin and hair.
Do not use things like laundry detergent, blue soap, dishwashing liquid, human shampoo or soap, all of which may irritate and damage the dog's coat resulting in hair loss and skin infections.
Scent is so important to dogs that they often mark territory with their own body smells by pooping, urinating or scratching in strategic locations. It is possible that rolling around in certain places they leave their scent behind and it's a way of marking that area with their own body scent.
We must also not forget the common ancestor of all breeds of dogs–the wolf–who is a predator and therefore hunts for food.
A successful predator is one who is able to sneak up on unsuspecting prey and pounce at the last moment. Part of this skill involves being able to mask your own body scent which, if identified by the prey, would have the prey bounding out of range to safety. An effective strategy evolved which involved covering the scent of the predator with the scent of a carcass or even the scent of poop or scat by rolling around in it. This masquerade of smelling like the surroundings fooled the prey into not immediately recognising the presence of a predator and hunting was therefore easier. Although our dogs do not necessarily hunt for food anymore, they have retained this instinctive behaviour from their ancestors.
Wolves–and dogs by extension–are pack animals and one of the responsibilities that comes with living in a family is that of sharing food with the other members.
Another theory for rolling around in dead animals is because the wolf or dog is communicating to other members of the familial pack that he has found a source of food. Although wolves generally hunt for food, they are opportunistic animals and will scavenge if there is "free" food lying around in the form of a carcass. Our dogs may have retained this instinctive behaviour of telling others where to find food.
Whatever the reason for this malodorous behaviour, it is clear that the dog is not doing it to get on your nerves and you should never punish him for it although you may be furious. Better supervision and having the dog on leash during walks will help to reduce his opportunity to roll around in stinky environments. Towel-drying the dog or waiting until he is dry before you release him after a bath and picking up poop in your garden before he has access to it will help to ensure that you can breathe easier.