quote:
I usually try to stay out of these types of discussions but I have to correct this.
There are absolutely no olfactory cells in the lining of the lips (flews) of a dog. A hound's large lips (along with their floppy ears) do help in collecting/trapping smells and then re-directing them either to the cilia (hair-like projections) of the olfactory cells lining the nasal cavity or to the vomeronasal organ (a little gland on the roof of the mouth just behind the upper front teeth). You are correct about dogs not being able to track as well when the mouth is dry, but mainly because saliva helps to carry scents towards the vomeronasal organ. The vomeronasal organ is responsible for detecting pheromones and body smells. They can still pick up certain scents with their noses pretty well, even with a dry mouth (maybe just not the week old body scents). Have you ever seen dogs/cats/horses lift their heads and "lick" the air? They are using the tongue to push scent containing saliva towards the vomeronasal gland. This is also how snakes "smell".
The majority of the dogs sense of smell happens in nasal passages and the olfactory bulb, (which helps the brain to processes the information).
It is estimated that about 20-30% of the dog's brain is devoted to smell alone.
PS: when a dog is underwater, it finds things by eyesight, not scent.

In addition to a simple anonymous upvote, I wanted to personally thank you for pointing out why Germandawg is full of shite. We already knew he was full of shite, he has a long history of being full of shite, but you validated it, on this particular topic. You took some time to educate everyone here in the process of calling him out, which is the best type of validation we can receive. On behalf of the entire board, thank you.