A dog is both a pleasure and a responsibility. A responsibility that would remain for the rest of the dog’s life. The pet would naturally be a wonderful companion that would love the master unconditionally, but the dog also depends on the master for food, water, companionship and medical care. Caring for the dog involves understanding its reproduction cycle. A puppy would be a priceless gift from the beloved pet. No doubt holding a puppy would be very fulfilling, but puppies would also be a big responsibility that would demand lots of time and of course money. Many unwanted puppies were put to sleep because dog owners have not taken into consideration the fact that the pet has matured sexually. Some responsible owners would take the spaying and neutering options, but it would still be advantageous to learn about canine reproduction.

A male dog reaches sexual maturity at 5 to 6 months. Younger male dogs would manifest a mounting behavior, but no sperm are as yet produced. Females or bitches sexually mature at about 6 to 12 months of age. Large breeds though can take up to two years or more to gain sexual maturity. The reproductive cycle varies from dog to dog but females usually have a 7 months reproductive cycle. The cycle involves four stages – the proestrus, estrus, deistrus and the anestrus. The eggs in the ovaries mature in the proestrus stage and the estrogen level starts to rise. This stage generally last for about 9 days. During this stage, the males will now be attracted to the non-receptive females. Small amount of vaginal discharge, swelling of the vulvar lips can be noticed. The bitch will be restless and will sometimes need to urinate more frequently. The next stage is the estrus. Mature eggs will be released from the ovaries and estrogen levels will increase. These two stages (proestrus and estrus) will generally last from 5 to 21 days. Females during these periods are commonly referred to as “in heat”. A bitch on the estrus stage is now ready for copulation. It is only during this stage that copulation will result to pregnancy.

Receptive female would hold the tail to the side (flagging) to allow the dog to mount. Unreceptive females would be uncooperative. The bitch may move away, snap or lie down. The male would mount the bitch from behind. This position is commonly known as doggy style. To get a good hold on the bitch the male moves around trying to penetrate the female’s vulva with the rather limp and slender penis that is only made rigid by the baculum, a small bone inside the penis. Canine copulation is different from human intercourse given that human penis has to be erect to penetrate the vagina while canine penis only swell and becomes erect after penetration is achieved. Human testicles constantly produce sperm. The sperm that has to be released or ejaculated at the end of the sexual intercourse is stored in the epididymus, a channel at the back of the testicles. As dogs do not have this storage space they have to pump and transfer the sperm from the testicles directly into the female. The bulbus glandis, a large spherical gland at the base of the penis will become engorged with blood and traps the penis inside the vagina. This is known as the “tie”. This will ensure that no sperm will leak and that the female especially one that is mounted for the first time will not be able to run away. The male dog usually swings a leg over the female dog’s back so that both dogs would stand end to end. The dogs will stay tied from 5 to 20 minutes or even longer. The bulbus glandis will disengorge with blood once ejaculation is finished to allow the dogs to separate. Virgin dogs may be distressed and would try to pull away. Supervision during copulation is necessary to calm and settle the dogs. However, NEVER attempt to separate the dog even if you know that your pet is extremely uncomfortable.

Deistrus stage follows after mating. This stage normally last from 56 to 58 days in pregnant dogs. Anestrum is the last stage in canine reproduction. This stage typically lasts from 4 to 5 months in which time the female dog will not show any interest in male dog in the same manner that male dog will not be attracted buy the female dog.