B-ultrasound diagnosis of small animals such as dogs and cats is still in its infancy in my country, and there is still a certain gap between China and developed countries. However, judging from the current development of small animals, this new diagnostic method has broad application and development prospects. B-ultrasound diagnosis is an advanced diagnostic method that is fast, accurate, non-destructive, and intuitive. It has fully demonstrated its superiority in the diagnosis of many obstetric and internal medicine diseases, and provides an intuitive and reliable basis for surgical operations. However, B-ultrasound diagnosis also has its limitations and shortcomings. For example, B-ultrasound cannot examine gas-containing organs (such as lungs), and is not as practical and reliable as X-rays in diagnosing fractures and dislocations. The diagnostic range of B-ultrasound is also limited by the resolution of the probe. For example, the spleen, pancreas, adrenal glands and other organs of dogs and cats are relatively small in size, so it is difficult to observe their abnormal changes with a low-frequency probe. Increasing the resolution (probe frequency) will reduce the penetration ability [2]. At present, many issues of B-ultrasound diagnosis of small animal diseases are still under discussion. It is believed that with the improvement of instruments and equipment and the further development of relevant clinical and scientific research work, B-ultrasound diagnosis of dogs and cats will reach a new level.

Application of animal B-ultrasound in obstetric surgery

There are two situations of dystocia. One is dystocia caused by the delivery process, that is, the animal delivers part of the fetuses one after another, and after 12 hours or 24 hours, the delivery posture appears again. The B-ultrasound examination results show that there are still fetuses in the uterus, but the mother itself is unable to expel the fetus, causing dystocia. The second is that the expected delivery date has been reached or exceeded, and the animal only discharges a small amount of amniotic fluid from the vulva, but cannot deliver the fetus. B-ultrasound examination, according to the presence or absence of fetal heartbeat, can show that some fetuses have died and some fetuses are still alive. This type of dystocia is more common in incomplete opening of the cervix and/or vulva, excessive or deformed fetuses, etc. After diagnosis by B-ultrasound, such cases should be immediately caesarean section to remove the fetus.

Application of animal B-ultrasound in gastrointestinal surgery

Foreign bodies in the gastrointestinal tract are one of the most common diseases of the digestive system. Foreign bodies can be divided into four types: high-density materials, such as bones, stones, glass balls, etc., which are easier to diagnose; medium-density materials, such as rubber bottle stoppers, foam plastics, etc.; low-density materials, such as cotton thread, balls of thread, sponges, plastic bags, etc., which are difficult to diagnose when the amount of foreign bodies is small; thin objects, such as suture needles, thin metal wires, etc., are also difficult to diagnose. In general, the gastrointestinal tract is a gas-containing organ, and gas-containing organs are not suitable for B-ultrasound examination. Because ultrasound will be completely reflected when encountering gas and cannot penetrate, it is impossible to make a diagnosis. However, under certain conditions, if used properly, B-ultrasound examination is also an effective means of diagnosing gastrointestinal diseases. Letting dogs and cats drink water before the examination can improve the penetration of ultrasound, enhance the contrast of the image, and help make a diagnosis. Sometimes, although it is difficult to distinguish between tissues and foreign bodies in terms of density, foreign bodies cause intestinal obstruction, leading to gastric emptying disorders, and reverse reasoning can also help make a diagnosis. The nature and location of foreign bodies can be determined by B-ultrasound machines, so that effective surgical plans can be formulated, which can greatly improve the success rate of surgery.