To clarity this for all readers:
A male will not be more aggressive if he does not release sperm. A male, may however, become very restless if he senses a female but is not allowed to reach her.
Dogs do not mate for pleasure; it is simply a matter of canine instinct. While the act of procreating does bring pleasure for a dog (though some females do panic and a tie can panic them if it lasts too long), dogs do not mate for the goal of physical satisfaction. It is a pure and raw canine instinct to pair together.
Behaviors that Will Develop if a Male Does not Mate
Male dogs have viable sperm at an early age; by 4 months of age for most dogs. To follow proper breeding methods, one would want to wait until the male was at least 7 months old to breed him.
When a dog is not neutered, he will often exhibit certain behaviors:
The male will easily pick up on the scents of female dogs that are in heat. When a female in heat urinates, she leaves trace amount of blood with the urine. This is a signal that is carried to all males in the area. A dog will be able to pick up on this scent from as much as 3 miles away.
The instinct to track down the female will be so strong, that a dog will often try to escape to reach her. Even dogs with excellent training and those that normally do not try and leave the premises may run off. One of the leading causes of death for toy breed dogs is trauma; this includes being hit by a car. Therefore, if a an un-neutered male does run away, this puts him at risk:
- He may become lost and finding him may not be easy
- He is at risk for being hit by a car or otherwise injured
- He may father a litter of puppies and the owners of the dam may try to hold you responsible for her pregnancy care (if they trace your dog back to you)
- This may lead to a litter of puppies to be born that may not be wanted. While you may never know about them personally, this is a shame to allow puppies to be born when there are so many kill-shelters. If a dog did run off and tied with another, the chances of the owner of the female being an experienced breeder is just about nil.
An intact male dog may hump other animals, people and even inanimate objects. Most humping behavior is done by puppies. With older dogs, it may be done as a sign of dominance. However, either way, when a male is not neutered, he will hump much more than he would otherwise. This can be an embarrassing event. In households with small children, a male trying to hump the leg of a youngster can be troubling.
Marking is not necessarily done by a dog that is not allowed to mate; but is done by a dog that is marking his territory
… And this is done by intact males much more often than neutered ones. A male may spray urine in just one area of the house or in several different spots. Even some of the most well house trained dog will mark. In some cases, a neutered dog will do this as well; and at that point it will be a matter of the hierarchy of the house needing to be established.