Well good Monday morning; we're going to get right into it this morning and discuss mounting. Mounting is vastly misunderstood, confusing and left to it's own far too often. Some dogs mount more than others in general, I have noticed though that alot of "puppymill" dogs mount alot. Mostly they have no idea why they are mounting and many slip into a habitual mount or humpering. I'm not sure why so many puppymill dogs are mad humpers but it is more than likely caused by a psychological issue; ripped away from their mother sometimes as young as 4 weeks old, this has alot of damaging effects.
There are three reasons that dogs hump, the first being dominance. This means that it is a male or female behavior; there is no difference between the sexes when it is caused by dominance. My little 15 lb female Jack Russell regularly mounts my other dogs, mostly my male because he crosses the line too often. When I brought a new puppy into our home last year, the first thing on Jessie's mind was to mount it. Mounting is a hierarchy behavior; and is seen in the smallest little teacup yorkies all the way up to our canine ancestors, the wolf.
Dominance mounting is why dogs mount children most of the time. They are attempting to weed out the week and gain a higher status within the pack. This should never be allowed and be quickly stopped and the behavior completely discouraged. Many children need adult assistance when interacting with a status seeking dominant dog. It is important the the child never crawl around on the floor, play dog type games like tug-o-war or run to be chased.
Another reason for mounting is of course the desire to mate; although sometimes a dog has the drive but no knowledge of the procedure. Many young dogs mount and hump and they are much to young to even know what they are doing. It is an instinctual behavior that many practice at young ages and this can get them into alot of trouble. Some learn early on when it is and is not appropriate.
And the last reason for mounting is excitement. It is closely linked with dominance and mating ritualistic mounting but intertwined with the lack of knowledge and experience. Seen mostly in very young dogs who are aroused by excitement. This is where I see the puppymill mounting; which seems to have a general lack of gray matter behind the activity. You will often see these dogs also mounting and hump inanimate objects which often leads to the obsessive humping dog.
Mounting and humping are only one piece of the puzzle, you must pay close attention to the environment, interactions and other body language that the dog is displaying to really read into what is going on. Often it is a simple explanation, sometimes it may seem to be easily explained by sex drive but may be clearly and only dominance. But in all cases it should be immediately stopped, unless of course you are breeding the particular dogs. ;)