Mounting, thrusting (humping) and masturbation are normal behaviors exhibited by most dogs. Dogs masturbate in various ways. They mount and thrust against other animals, people and objects, such as wadded-up blankets, dog beds and toys. Sometimes, dogs just rub against people or objects (without mounting them), or they lick themselves.

Puppies often mount and hump their littermates, other playmates, people and toys. Some experts believe that this behavior functions as practice for future sexual encounters. As puppies reach sexual maturity, they start to mount other dogs in sexual contexts. After they're neutered or spayed, many male and female dogs continue to mount and even masturbate because they have learned that the behavior feels good.