you evaluate them by how well they sniff
The average dog has more than 200 million scent receptors
I haven't heard of any working, but so long as it is just a scent and not applied directly to the dog it shouldn't hurt anything.
By licking the dog ballz
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
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.
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.
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.
Bloodhound
air freshener
Katts and Dog - 1988 Scent of Evil 2-19 is rated/received certificates of: Canada:PG USA:PG