What are the typical symptoms and anatomical features of swine fever?

Swine fever can be divided into 4 types according to the course of the disease, of which the most acute and chronic types.

The most acute type: the onset of the disease is rapid, rapid death, mainly showing acute septicemia. Autopsy reveals a few hemorrhages in certain plasma membranes, mucous membranes and viscera.

Acute type: persistent high fever up to about 41℃, depressed, lethargy, fear of cold, conjunctiva flushing, with a lot of viscous or purulent secretion, and even sticking the two eyes closed. There are bleeding spots or hemorrhagic spots on the skin, and the common parts are the tip of the ear, under the neck, limbs, under the abdomen and perineum and other parts with little hair. The feces are dry and globular, and later pass liquid stools, or constipation alternates with diarrhea, often with mucus or blood. Sometimes vomiting occurs. Urine accumulates in the prepuce of boars and flows out when squeezed by hand, emitting a foul odor. Anatomy reveals hemorrhagic changes in the mucous membranes, plasma membranes, and viscera in varying amounts and degrees, usually in the form of spots. Lymph node changes are more specific, most noticeable in the intra-abdominal lymph nodes, which are enlarged, dark purple, hemorrhagic at the margins of the section and in the parenchyma, and with anemic changes, thus marbled. There were hemorrhagic infarcts around the spleen.

Chronic type: the main manifestations of emaciation, anemia, general weakness, walking wobbly and weak, constipation and diarrhea alternately, with diarrhea more common. Some sick pigs have blue-purple or necrotic ear tips, tail ends or lower limbs, and the disease lasts more than 1 month. Anatomy is mainly necrotizing enteritis, in the end of the ileum, the mucosa of the cecum and colon, concentric whorls of laminar button ulcers can be seen, protruding from the mucosal surface, with a low central depression. This change can be regarded as a characteristic of chronic swine fever.

Mild type: this type of sick pigs in recent years, the occurrence of more, clinical symptoms are mild, atypical, moderate condition, pathological changes are not typical, the disease is not long, but the lethality is still high. There are more cases in weaned piglets and piglets. It is common in pig herds that are not timely vaccinated against swine fever.