What are the clinical signs of cysticercosis?

Cysticercosis is a type of tapeworm disease caused by the larvae of vesicular tapeworm ——— cysticerci parasitic on the liver serrosa, omentum and mesentery of sheep, goats, cattle and pigs. Cysticerci are mainly caused by stunted growth and development of domestic animals, especially lambs, piglets and calves, weight loss, and death due to severe liver damage when large numbers of infections occur. Its adult worms are parasitic in the small intestines of carnivores such as dogs, wolves, and foxes.

The disease occurs to varying degrees in all parts of the country, and sheep disease is mostly seen in the vast pastoral areas with close contact with dogs.

1.Cysticerci with a thin neck, commonly known as water bells, mostly hang over abdominal organs. The worm is vesicular in the shape of a vesicle containing a clear liquid.

The size of the sac varies, and the largest can be as large as a child's head. The outer layer of the capsule wall is thick and tough, and is an envelope formed by the connective tissue of the host animal; The walls of the cysts of the worm's body are thin and transparent. When viewed with the naked eye, it can be seen that there is an opaque milky white nodule on the wall of the sac, which is the neck and the inverted cephalic segment.

2.The body length of the vesicular tapeworm is 75 500 cm, and the chain body is composed of 250 300 proglottids. There are 4 suction cups on the cephalic segment, and the number of small hooks on the apical process is 30 40, arranged in two circles.

The anterior segment of the body is wide and short, the posterior segment gradually becomes longer, and the pregnant segment is longer than wide. The number of branches on each side of the uterus is 10 16, and each lateral branch has small branches. The uterus is filled with eggs, which are approximately round, 36 39 microns long and 31 35 microns wide, containing hexanchovy.

3.The clinical symptoms are usually not obvious in adult sheep and obvious in lambs. When the liver and peritoneum are inflamed under the action of hookworms, the body temperature may rise, depression may occur, ascites may increase, the abdominal wall may be tender, and even death may occur.

After these acute attacks, the disease becomes chronic, generally manifesting as emaciation, weakness, and jaundice.

4.In chronic cases of pathological changes, there are worm vesicles of different sizes on the liver capsule, mesentery, and omentum, and in severe cases, worm bodies can also be found in the lungs and thoracic cavity. In the acute course of the disease, acute hepatitis and peritonitis may be seen, the liver is enlarged, there are bleeding spots on the surface, there are worm passages where the worms migrate in the liver parenchyma, sometimes ascites mixed with exuded blood, and there are migratory and developing larvae in the lesions.

Cysticerci are extremely common in pigs, severe in sheep in pastoral areas, and less common in cattle. It is very harmful to piglets and lambs. When the number of larvae migrating in the liver is large, it can destroy the liver parenchyma and microvasculature, penetrate the adult tract, and cause hemorrhagic hepatitis.

At this time, the sick animal shows symptoms such as restlessness, salivation, failure to eat, diarrhea and abdominal pain, which may cause piglet death. Chronic diseases mostly occur after the larvae migrate out of the liver, and generally do not show clinical symptoms, and sometimes the affected animals have symptoms such as lack of energy, loss of appetite, emaciation, and stunted growth. Sometimes the larvae migrate to the abdominal or thoracic cavity and cause peritonitis and pleurisy, which manifest as symptoms such as an increase in body temperature.

Adult livestock are generally not obvious except for the clinical signs of a few infections that are particularly severe. Piglets and lambs often have obvious symptoms, due to inflammation of the liver and peritoneum, sick animals show increased body temperature, depression, and ascites, pressing the abdominal wall has pain, many cases due to abdominal hemorrhage, abdominal distention, and some piglets suddenly scream and die. Most sick animals are weak, emaciated and jaundice.

For example, there are parasites in the chest cavity and lungs, which can present with symptoms such as dyspnea and cough. Most of the disease is chronic, when the sick pig is parasitized by a small number of worms, there are no symptoms, and when a large number of worms are parasitized, the clinical manifestations are increased body temperature and loss of appetite, which can cause pig emaciation, system weakness, abdominal distension or peritonitis and jaundice hepatitis. <>

Porcine cysticercosis is caused by the parasitism of cysticerci on the surface of the liver, mesentery and omentum of pigs. A pig can parasitize one to dozens of cysticerci and weigh several kilograms. In addition to pigs, cysticerci can also parasitize cattle, sheep, goats and other domestic animals.

The insect body is vesicular and forms a water bell, so some people call it "water bell". The walls of the sac are milky white, and the colored vesicles are filled with clear liquid, and the volume is the size of a soybean to the size of an egg. There is a milky white nodule on the wall of the sac, which is the head of the worm's body.

When the nodule is turned out, an elongated head is visible, so it is called a cysticerci with a thin neck. The insect body is covered with a soft envelope, and some of the envelope is hard like cartilage, with a wall thickness of about 1 2 mm, similar to a ping pong ball.

Generally, sick pigs do not show clinical symptoms, only when the infection is particularly serious, the auspicious piglet suddenly screams and dies. The vast majority of sick pigs are emaciated, malnourished, and coarsely coated.

Cysticercosis is one of the parasitic diseases that seriously endanger the human body, commonly known as cysticercosis, generally speaking, people are caused by eating eggs or proglottids by mistake (adult worms parasitize the upper part of the human small intestine, and the pregnant joints often fall off from the chain body alone or 5 or 6 nodes in a connected way, and are discharged with feces, and the pregnant joints that are separated from the worm body still have a certain degree of activity), and the degree of harm varies according to the location and number of cysticerci parasitism.

Because cysticerci can invade the circulatory and lymphatic systems, they can parasitize almost any part of the body. As we all know, the brain is the headquarters of the human body, and almost all lesions here can lead to serious consequences. Similarly, in cysticercosis, cerebral cysticercosis (neurocysticercosis) is the most severe, and lesions in other parts may go undetected for a long time because the symptoms are mild.

Department of Infectious Diseases.