How does a dog know what direction to go with a track?

[Eric]

Experience. Watch a dog with 100 hogs under its belt vs one with 1500... its no comparison.

[Wmwendler]

This comes from a book I have Called "Meet Mr. Grizzly" by Montague Stevens (1943)

He used hounds to hunt grizzlys and owned a ranch out west where he often had his hired hands lay human scent trails for his hounds to learn from.  Which is why he says the trail of a man.

"While there is no yard-stick by which to measure the keenness of a hounds scent, there is, however, a way in which to get an approximate idea.  When a hound approaches the trail of a man at right angles, and scents the trail in the air, how does he know weather the man went to the right or two the left?  Usually he takes the correct end of the trail; that is, the way the man went, the other way being called his back trail.  But sometimes, due probably to the wind or some other atmospheric condition, the hound is not sure which way to go and he will run some 20 yards in each direction alternately several times, untill he has fully made up his mind which is the right end of the trail to take.  The question therefore arises: how much difference is there in the strength of the scent twenty yards one side or the other of a given point.  That difference is the measure of the keenness of a hound's scent"

This guy also beleived that often times a dog will run a trail by scenting the the air on one side or the other of the actual trail which is where the scent has disperced to, often due to the wind.  Ive seen dogs run a trail 10 or so yards off of where the hog actually ran by a min or so before.  Chances are the dog was on the down wind side of where the hog ran which is where the scent would be the strongest

Waylon

[Noah]

Man, great excerpt, that's pretty cool to see someone contemplate the same idea that long ago.

[Blake]

Noah some call this drifting the track when a dog picks its head up and runs the track on the wind not an expert but like previously stated most likely down wind very interesting to watch all this take place i know u hate my hounds but notice if a hog crosses where the dogs cross after never the same place 5 10 25 yards downwind when u get back call me i have a book that goes into detail

[raider54]

Ive been hunting and training hounds for thirty years and this question has been asked a thousand times in as many hunts. the truth of it is they hit the track the wrong way as often as they hit it the right way! contrary to a post earlier, the track deminishes (smell) as the track gets older, the theory behind what he was explaining is right only in that a drag runs out of smell but a animal doesnt as a matter of fact thier smell intensifies as they begin to get hot and sweat. there are several factors that contribute to the rate of the deterioration of a track, moisture, wind ,temperature, etc.

the hotter a track is the more likely a dog is to start it the wrong way, after being on the track for a bit the dog figures out that the further he takes the track that its either getting stronger or its getting weaker. He instinctively knows if its getting stronger he can run it faster and harder. If its deteriorates on him he will turn around and run it the other way.

I know you have seen a dog get excited and start running around rapidly in circles with his tail wagging vigerously and you have probably said he smells one! well you were right and the reason he is all over the place is because he is trying to figure out witch direction to run the track!

in a few mins he is gone and shortly after he is bayed! does this make since?