B-ultrasound for cattle can diagnose abnormal reproductive organ conditions in dairy cows, mainly including: ovarian cysts, ovarian cysts after treatment and uterine abnormalities.

Observing ovarian cysts in dairy cows with B-ultrasound: Ovarian cysts are an important cause of infertility, which can be divided into follicular cysts and corpus luteum cysts. It is necessary to distinguish between the two to determine the treatment method. Ultrasound imaging is a good means of distinction. B-Ultrasound imaging for cattle shows that follicular cysts are a uniform non-reflective structure with a diameter of >25mm and a membrane thickness of <3mm. The non-reflective structure of the corpus luteum cyst has a diameter of >25mm, with gray spots in the corpus luteum cavity or along the inner membrane, and a membrane thickness of >3mm. At the same time, it is also necessary to distinguish between corpus luteum cysts and corpus luteum with cavity, because the latter is non-pathological. The two can be distinguished according to size, cavity shape, membrane thickness and internal area reflection characteristics. Usually, the corpus luteum with cavity is <3mm, the membrane thickness is about 5--lomm, the shape is oval, the cavity shape is round or oval, and the cavity filled with fluid is uniform and almost non-reflective. The reflection is often seen in corpus luteum cysts.

Ultrasound observation of ovarian cysts after treatment in cattle: ultrasound in cattle can be used to quickly and effectively check the treatment effect of ovarian cysts. In the cystic follicles of cattle treated with GnRH, the ultrasound image changes, the cystic homogeneity and non-reflective structure become blurred, the cystic wall becomes luteinized, the cyst becomes smaller, 1 to 4 corpora lutea appear in the cystic ovary or the contralateral ovary, and superovulation occurs occasionally.

Treatment of ovarian cysts with progesterone vaginal sponge or GnRH does not take effect immediately, but will cause estrus and ovulation. Corpora lutea will also appear. Treatment of corpus luteum cysts with PG will significantly reduce the size of the cysts within 2 to 4 days, and new corpora lutea will appear within 1 week.

Ultrasound observation of uterine abnormalities in cattle: Uterine abnormalities that can be diagnosed with ultrasound in cattle include endometritis, uterine suppuration, embryo loss and fetal mummification. For the ultrasound image of endometritis, the cavity is expanded, and the cavity contains scattered small fragments of semi-reflective structures to varying degrees. The degree of reflex depends on the composition of the intrauterine fluid. When the uterine contents are thick and filled with white blood cells and fibrous debris, the reflex properties resemble those of the uterine wall. In fetal loss, the uterine wall thickens and the fetal skeleton is stretched out in the non-reflective amniotic fluid, which can produce reflexes. In fetal mummification, the fetus is a mass, completely lacking in amniotic fluid.