Answers: 1.Circulatory system-pumping blood to and from the body and lungs with the heart 2.Digestive system-digestion and processing food with salivary glands, esophagus, stomach, liver, gallbladder, pancreas, intestines, rectum, and anus.
During the tie, the male turns around so the dogs are back to back and can defend themselves. The tie typically lasts 20 to 40 minutes. It may be just a few minutes, and dogs can mate successfully without becoming tied at all. The evolutionary reason for the tie is unknown, but it's assumed that if a male dog is tied to a female, it prevents other males mating with her. Unwanted Mating.
Breeding Dogs: The Tie. Male dogs can start to have sperm at seven months old, but ten months is more common. Young dogs do not have quality sperm. Almost all dogs will have sperm by one year. Stud dogs are at their prime between 18 months and 4 years old (or 5), after that, the quality of the sperm starts to lessen, and the ability to penetrate eggs, lessens. By 10 years old, most stud dogs do not produce sperm that will impregnate a bitch. A tie is a natural phenomenon of dog breeding in which the bulbus glandis of the male's penis swells inside the bitch's vagina.