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.
A Tie Mating. When the dog and bitch lock together, this is called a tie mating. This is peculiar to the canine race. Around twenty minutes is fairly normal for the dog and bitch to remain in this position, but it can vary from around ten minutes up to an hour.