While there are variables, such as wind direction, strength and sustained flow, there is solid, established, evidence that some creatures, notably carrion feeders such as vultures, are able to detect very small particles of a scent (decaying flesh as an example), down into a very few parts per million. Vultures are not primarily sight feeders, but can detect and react to a scent, under favorable conditions from miles away.
The average dog has more than 200 million scent receptors
A female dog will never lose her distinct scent. The particular scent of her being in heat, however, ended immediately with the surgery.
The police dog tracks a criminal by scent.
you give the dog the scent and they can know the scent of the animal the master is ordering him to find
Keep in mind that what you think is stinky, is very different to your dog. Usually, a dog who rolls in some other scent is trying to either wipe out that scent by putting his own on it, or is trying to pick up that scent for reasons only known to dogs.
Female dogs give out a scent when they are in heed. Heed is when a female is in a position were that is the only time they can mate. So they have a scent that the Male dogs can smell that scent. Also it is in their Urine.
Yes, dogs have such a good sense of smell, they can even tell what gender, what age, what breed, if it is healthy, and if it is happy.
you evaluate them by how well they sniff
air freshener
Bloodhound
Katts and Dog - 1988 Scent of Evil 2-19 is rated/received certificates of: Canada:PG USA:PG
Dogs are attracted to the scent of their owners, and socks carry a strong scent due to sweat and skin cells. This can make them appealing to your dog, leading to an obsession with them.