veterinary B-ultrasound to check the proestrus of female dogs

Proestrus is the first stage of the female dog's reproductive cycle, which lasts about 9 days. From the appearance, red blood-like liquid flows out of the female dog's vagina and begins to attract the attention of the male dog. Since the female dog has not reached the breeding stage, the functions of various parts of the body are not yet ready for mating, so the female dog refuses to approach the male dog at this time. Under normal circumstances, the specific start time of the proestrus of female dogs is difficult to determine. In the past, it was mainly judged by observing the swelling of the female dog's vulva. However, if observed by veterinary B-ultrasound, the changes in the female dog's ovaries can be clearly seen on the veterinary B-ultrasound image.

According to bleeding and vulva swelling, it is not always possible to accurately judge the estrus of the female dog. This is because the growth activity of the female dog's follicles is sometimes not fully manifested, so the follicles on its ovaries are checked by veterinary B-ultrasound. The blood-like substances flowing out of the vulva come from the uterus, mainly due to the increase in estrogen secretion in the follicles, which leads to the rupture of capillaries in the uterus and the exudation of blood cells. Since the secretion of estrogen is absolutely dominant at this stage, the vaginal mucosa becomes thicker, and a large number of epithelial cells keratinize and fall off and flow out of the vulva with the secreted blood-like mucus. If the vaginal smear method is used at this time, a large number of irregular exfoliated epithelial cells can be seen under the microscope. This is also an important diagnostic method for predicting the estrus period, ovulation time, mating time and artificial insemination time of female dogs. However, this method is more troublesome than the veterinary B-ultrasound method.

The reproduction method of domestic dogs is significantly different from that of other domestic animals. Understanding the reproduction laws and characteristics of dogs is of great significance for daily production and feeding practices. Veterinary B-ultrasound is of great help in the reproduction process of domestic dogs. Understanding the reproductive characteristics of domestic dogs is helpful to predict their estrus cycle, pregnancy and delivery time, and better follow the reproduction laws of domestic dogs to guide production practices. People have been able to use the measurement of changes in reproductive hormones of female dogs to predict the reproductive physiological cycle of dogs.

Veterinary B-ultrasound to check the late estrus of female dogs

In late estrus, at the end of the estrus period, the female dog begins to reject the male dog. Based on this, it is believed that the female dog has entered late estrus. Veterinary B-ultrasound can be seen that the follicles on the female dog's ovaries have basically disappeared. The length of this period has not yet been determined. If there is no pregnancy, this period generally lasts for 2-3 months. At this time, the concentration of progesterone in the plasma of pregnant female dogs continues to rise, but it drops to the basal concentration at the time of delivery.

Anestrus, this period is the transition stage from one reproductive cycle to another. The duration varies from 1 to 9 months. This stage is generally manifested by the ovaries being in a relatively static state on veterinary B-ultrasound. When the dog does not show reproductive behavior, it can be considered to be in anestrus. If the dog is pregnant and gives birth normally, the interval between the two estrus cycles of the female dog is about 2 months. Veterinary B-ultrasound examination can be used frequently at this stage.

The length of dog pregnancy is generally defined as the period from the first natural mating or artificial insemination to the successful delivery, with an average of 62-64 days. The range of gestation time is about 56-72 days, and it is related to many factors, such as the breed, age, parity, litter size, season and body size of the dog. The average litter size of most dog breeds is about 3-7, and the litter size of the smallest and largest breeds varies greatly, ranging from 1 to more than 15. During pregnancy, it is important to use veterinary B-ultrasound to check the litter size of the female dog for good management. Although the estrus time of different dog breeds is not exactly the same, the entire estrus period shows certain seasonal changes. Due to the high cost of hormone detection methods, most of the domestic methods are still using vaginal exfoliated cell microscopy and saliva examination methods, as well as more accurate veterinary B-ultrasound diagnosis methods.