The desexed male dog is less likely to develop dominance aggression problems (either towards other dogs or people). Sexually associated behaviours such as roaming, urine marking, and humping are reduced with less testosterone. However, it is important to note that many of these unwanted male dog behaviours can quickly become a learnt habit once they have already emerged. For this reason it is advisable that all male dogs not intended for stud use be desexed by six months of age.