Males can start to mark as they become sexually mature, which many owners consider an undesirable trait. It begins with mild swelling of the vulva and a bloody discharge. Male dogs can breed as young as 6-7 months though it is recommended that you wait until they are mature in mind and body which at a minimum I would say is 18-24 months old. First and foremost, it is important to get your dog checked out by the vet to find out if there is an underlying cause behind excessively sexual behaviour or aggressive sexual behaviour in your dog. A great many conditions and issues can interfere with your dog’s hormone levels and moods, causing them to act out in unusual ways. Between 12 to … Or at least, male dogs are sexually capable at an earlier age than females, which is different than being sexually performant. It is worth being aware that often once false pregnancy in dogs starts, she will continue to have them each heat. They do not become sexually mature until about 6-8 months of age, but dogs hump as a sign of dominance. Bitches usually have their first heat at six months to a year. Dog - Dog - Reproductive cycle: The heat cycle of the female lasts from 18 to 21 days. During this phase the bitch may attract males, but she is not ready to be bred and will reject all advances. He's trying to show your son that he's the boss. Males are sexually active all year-round, but they are most fertile after 12 to 15 months of age, i.e., once they are fully physically mature. To understand whether a male dog can be in heat, we need to define our terminology. They are sexually active year-round, but they are most fertile after 12-to-15 months of age, once they are fully physically mature. They can impregnate a female dog from the point of puberty on. The first stage is called proestrus. By: Erika Raines El Segundo, CA Replied on 04/19/2011. There is some variation and every dog is different. Male dogs do not go into heat like females. Generally speaking, puppies will start to mature sexually between 7 and 10 months of age. Male dog puberty symptoms. Female Dogs go into heat at any time between 6-12 months usually. The onset of sexual maturity (puberty) is triggered by hormonal changes that lead to physical and behavioral changes. Male dogs can start marking as they become sexually mature. Sex of the Dog. Males do not have a season like bitches, and once sexually mature they can breed all the time, although are at their most fertile between around 12-18 months old. In general, male dogs become sexually mature at an earlier age than bitches. Again, you want to wait until they are mature before having to raise pups of their own. A male dog usually reaches sexual maturity when they are over a year old, however they usually begin puberty when they are six months to eight months old. The Adolescent Female Pup If you want to use your dog for breeding when it is at its maximum fertility, wait until it is at least a year and a half old. An eager learner who will work and play hard, the Lab makes a good family companion or hunting dog. Funny. Dogs may be able to sire at five months. This lasts for about 9 days, although it may vary by 2 or 3 days. Sexually active. Female dogs reach sexual maturity between the ages of 6 to 12 months, although some larger breeds may take up to 2 years.The length of time it takes to reach puberty depends on different factors, including breed, health and the individual. They also can develop a tendency to mount and roam free. You may think it'll be six months or a year before your pal outgrows his puppy ways, but Labs don't show signs of complete maturity until they're about 3 years old. We had an 8 week old puppy that was already neutered when we got him from the humane society and he humped everything in site. Unfortunately all there is to do is separate them or have him neutered or her spayed.