Why does one male dog hump another male dog?

Answer 1

There could be several reasons. Intact (not yet neutered) dogs, especially males, will try to mount female dogs in heat. Some neutered dogs may still do this. Another reason is that the dog has become over excited (usually from play) and has forgotten its manners. Mounting and humping are very natural behaviours for a dog, and are effective stress-relievers, but can be trained out if the behaviour is undesirable. A dog mounting another dog doesn't always mean it is a sexual-based action.

Answer 2

Your bigger dog does this to assert his dominance. It's all about power, not sex. If your smaller dog has accepted his role as the "non-alpha" dog, then he probably submits, otherwise, they probably fight about it. Both male and female dogs will engage in this activity, to assert dominance over other members of their "pack", including people.

Answer 3

This is probably just playfull behavior. Some dogs have a bad habit of humping everything so it may also be that.

2nd Answer:

Whether a male dog humps your leg or another male dog, the purpose is to establish dominance. My dog made the mistake of trying that on a male pit bull one time.

Answer 4

There are a number of reasons but the most likely is that it's dominance.