Why does the penis lock the vagina when dogs mate?

The penis of a male dog has penis bone, which can be inserted into the vagina of a female dog without erection during mating. After the penis is stimulated by vagina, the bulbous sponge of glans penis located at the front end of penis bone immediately fills with blood and expands rapidly, and its circumference is about 1 times larger than the original, so it will be caught and locked by the vagina of the bitch, and the penis of the male dog cannot come out and be connected.

When the male dog ejaculates and the corpus cavernosum contracts, the penis can come out and separate them.

Extended data:

If it is not a breeding dog, sterilization is recommended. The benefits of castrating dogs are as follows:

Avoid unnecessary duplication. If cats and dogs are not sterilized, the number of offspring will increase geometrically: if a pair of unsterilized cats and dogs are allowed to mate and reproduce, if two babies are born every year, the fifth year will theoretically increase to 12680. In many countries or regions, groups of wild cats or stray dogs are the result of castrated pets constantly multiplying outside. A large number of unwanted small animals were born into this world, and their fate must be very tragic.

Castrated pets are more docile and easier to raise; At the same time, it also avoids the pain of longing for love for pets and the possibility of getting lost from home because of looking for a partner. Uncastrated bitches are in estrus twice a year, and female cats are in estrus once every three months.

In estrus, animals always try to go out and find a mate. Even if you keep it at home, you will be agitated, urinate and defecate everywhere to attract the opposite sex, and even damage furniture and articles, which will bring a lot of trouble. Male dogs don't fight and hurt each other because of jealousy.

Castration is beneficial to the health of pets, and reproductive diseases, such as breast cancer and uterine infection in women, testicular cancer and prostate disease in men, will no longer occur.

Is it cruel to castrate pets? Obviously not. Castration is a minor operation, especially for men. Veterinarians are carried out under anesthesia, and animals will not suffer and recover quickly.

References:

Baidu encyclopedia-dog