The one behaviour we all love to hate. This is an EXCELLENT article to start with as it goes into the whys and what to dos too (and no, it isn't 'dominance' and evidence that the dastardly dog is trying to slowly take over the home :) ):
This should also help:
Humping: Is It All About Sex?
Why do dogs hump? Dogs humping humans may amuse other humans, but rarely the human who's being humped. Some dogs will hump a toy or sofa cushion incessantly. We accept dogs humping other dogs in the act of mating, but in other situations it can create problems. What does all this humping mean, and what can we do about it?
Puppyhood socialization to another dog of the opposite sex can help a dog orient sexual behavior for adulthood. Whether you're going to breed the dog or not, it helps for the dog to develop the concept that sexuality is toward other dogs, not humans or pillows.
Much of the humping you'll see among puppies as well as among adult dogs is play. Some of it expresses dominance, but that's not always the case.
If a dog persists in humping another dog in a social situation, distracting the dog who's doing the humping into another activity is a good idea. For one thing, it's best that a dog not get obsessed with humping. Besides the potential annoyance to others, it can even result in physical irritation. When you consistently interrupt the humping, you prevent it from becoming a strong habit in the dog.
Secondly, being humped can become oppressive to the dog who is the target, so that's another reason to interrupt. This is a common complaint in situations where dogs get together to play, such as dog parks. Just distract the humping dog, without punishment of any kind.
Irritation or itching in the genital area can cause both male and female dogs to hump in response to the physical sensation. Be alert to this possibility, and of course have your veterinarian prescribe treatment to correct any underlying condition.
When a female dog is in heat, she, other females, and of course the males around her may turn into humping fools. Of course, this would be sexual arousal. The excitement of the situation can lead to fighting, as well as the strong possibility of an accidental pregnancy. Female dogs in heat need to be kept under top security!
Effects of Neutering
Behaviors can start for physical reasons and then continue because they have become habits. Humping is a prime example. Perhaps initially the dog derived pleasure from it, or simply was allowed to do it for prolonged periods with another dog, a human or an object.
When a male dog is neutered, a female spayed, or a medical condition irritating the genital area corrected, an established humping behavior may continue because it was allowed to become a habit. For this reason, neutering a male dog is not a sure cure for humping people's legs any more than it's a foolproof method of stopping urine marking in the house after that has become a habit.
Neutering does reduce the physical pressure on the dog, and can make your task easier when changing habits through behavioral means. It's important to stress, though, that intact male dogs need not go around humping everything in sight, either. The same simple distraction into another activity that works for neutered males also works for those who are not neutered.
Correcting a dog in a harsh manner for humping is not necessary and can create problems worse than the humping. Work with the dog to develop several behaviors the dog will perform on cue, such as sit, down, come, fetch, go to a spot and settle calmly, go find a toy to chew, and any trick the dog enjoys doing for a reward.
The list of alternative behaviors can be endless. Vary which behavior you cue as a distraction from humping. This keeps your intervention interesting for the dog, and helps avoid encouraging new obsessions.
Note that such behaviour occurs in BOTH males and females and is rarely 'just' a sexual act except when two intact dogs are together, male and female; but more likely, a display to another dog, or stress, or insecurity. Or, it can just be an activity that feels good and becomes self rewarding and a habit. Whatever the case, it can be a problem in itself as most people don't want a dog doing this to other people's dogs (or pillows, children, toys or legs! :) ) as well as a bigger problem waiting to happen if the dog mounts a dog that fights back. So it is useful to work to train your dog to stop this.
Also from the same trainer:
Q: My dog is 8 months old and he is already fixed, but at the dog park all the male dogs hump him constantly. What could it be?
A: All sorts of things are going on with an adolescent dog! Some intact males get humped continually in free-for-all situations like a dog park, so it's not just the neutered ones. Testosterone is very high in adolescent dogs, and his could still be high even though he is neutered. Another smell such as from urinary tract or other infection could be stimulating the other dogs, too. But there's a good chance it's a behavior thing.
I'd suggest you call him to you for a treat whenever this starts. It would be nice if the owners of the humping dogs would do the same with their dogs, to interrupt the humping, but some won't. Another thing you can do to help your dog is teach him to sit on your cue, and give him that cue when the humping starts. Female dogs often learn to do this when a male tries to mount them.
You may also want to consider which dogs you're going to have him interact with. Some combinations of dogs wind up being bad for the temperaments of one or both of the dogs involved. It's not good for a dog to become too dominant, or to be forced into submission to the point that it suppresses his personality and makes him feel oppressed. Which dogs you put with him have a profound influence on how he will feel about himself and about the world.
Lots of dogs wind up at the end of this adolescent period really freaked out about other dogs due to the experiences they have had in dog parks. This can result in it being difficult or even impossible to so much as take your dog out for a walk on leash where there will be other dogs. Your dog can become terrified of other dogs, or determined to get them before they get him! Some serious behavior problems have resulted from experiences young dogs have in dog parks, so you are right to be looking at this now. As with human children, it's important to protect our dogs from running with the wrong crowd!
Neutered Dogs: Will They Still Hump?
Canine Behavior Questions & Answers
Q: This may sound funny but my husband and I actually have no idea and would like to know. We presently have a 10-month old female Westie and she was spayed when she was 6 months old. We bought another Westie, a male this time, and we'll be picking him up in about one month. We will definitely have him neutered as well. Our question is, since both our girl and our little boy will be neutered, will the male still try to hump her or not? I have read numerous articles about dogs' sex life and all but they never mention neutered animals. I know that a neutered male's urine smells much less "masculine" than if he were not neutered and that this will not be as "sexy" for the female but will she still want him or not. Is it up to us to try and stop him if he tries to hump her?
Sorry for our ignorance but we want to know what to expect.
A: Not a silly question! The smell of a neutered male seems to be not as provocative to other males who are intact as is the smell of an intact male, but they still know he's a male. The female dogs seem to adore neutered males. With both male and female spayed/neutered, they don't have the physical and emotional ups and downs of hormone cycles, and their relationship with each other tends to be pretty wonderful.
If she were intact and went into heat, you would need to separate them even if he were neutered, because a neutered male can sometimes still tie with an intact female in heat! Injuries can occur when unattended dogs tie, so you'd have to separate them whenever you were not closely supervising. Dogs generally do not go to this point unless a female is actually in heat, so with your girl spayed, that's not likely to be a worry. The female usually will not accept a male unless she is in heat (though there are exceptions), and a male is not nearly as intense about mating when those powerful scents are not present.
Some mounting is not sexual, and as with people, there's a wide margin of he/she interaction that is flirty but not leading toward sex. Likely you will see some mounting, and it could even at times be her mounting him. I have 3 dogs, a male and 2 females, and I interrupt this behavior within several seconds when it occurs, without making a big deal out of it. Dogs are generally quite tolerant about being mounted briefly, and in a way it's healthy, since it gives the dog a sexual orientation toward opposite-sex dogs rather than toward humans. You would not, of course, want to allow a dog to harass another dog with persistent mounting.
When we first brought home our youngest female, she had been recently spayed, and it was amazing how much she kept mounting our older, neutered male. I don't remember how long this behavior continued, but it wasn't long, and now that it's a couple of years later, I haven't seen her do this toward any animal or person in a very long time. The behavior just faded away.
Many people call mounting in dogs an act of dominance, but it certainly wasn't in that case, nor is it when my male mounts one of my spayed girls. He likes girl dogs, nothing wrong with that! People also report that a recently neutered male will sometimes show a temporary increase in mounting behavior. Though sometimes an increase in mounting behavior indicates an infection or other physical problem in one of the dogs, usually it's not a big deal. Just interrupt it calmly if it doesn't stop in a few seconds, and of course interrupt a dog who starts to do it to a person.
Females learn to tell the male "no," if the female has experience being bred. Some of this is instinctive. She may turn and snarl at him. She might just sit down. Notice if his front legs are locked in front of her hind legs. It's possible for her to be unable to get out of his grasp, and of course you would want to intervene. But remember, don't punish or make a big issue of it. Just calmly interrupt, and get them interested in a new game.