In June 2004, nursery pigs and growing-finishing pigs in a large-scale pig farm suffered from sudden death, pale skin, subcutaneous (neck and abdomen) edema, weakness in the hind limbs, and diseases characterized by individual neurological symptoms. This epidemic caused 77 deaths of nursery piglets and 46 deaths of growing pigs. Epidemiological investigations, clinical symptoms, necropsy pathological changes, and laboratory tests confirmed that the deficiency was caused by selenium deficiency. The diagnosis is reported as follows: 1 Incidence At the beginning of June 2004, the weaned pigs in this field exhibited some symptoms of depression, decreased appetite, and normal body temperature. The nursery pigs suddenly died and the piglets that developed well had more deaths. Some growers and pigs couldn't afford to lie down in their backs, then slumbered, some limbs were scratched and the body temperature was normal. During this period, the mortality rate of nursery pigs was 6.8%, and that of growing-finishing pigs was 4.93%. 2 clinical symptoms 2.1 Piglets that grew faster after weaning died suddenly without any warning. The surviving performance was difficult to breathe, and they could die when lying or driving. 2.2 Growing fattening pigs had more than 60 kg before onset. They showed weakness in standing, paralyzed forelimbs, muscle twitching and hoarseness screaming when they forced to walk, and they could not afford to lie down when they fell seriously. They were paralyzed and died of exhaustion. 2.3 Nursery and Growing Pigs The pigs were both depressed in spirit and edema in the subcutaneous tissue, especially in the neck and chest and abdomen, and some of the joints were also swollen. Individual pigs have ataxia and unstable neurological symptoms. 3 pathological changes 3.1 Sudden death of the nursery pigs chest, pericardial effusion and light yellow jelly-like material, myocardial surface sheet hemorrhage, was mulberry heart-like, liver dark black necrosis, touch easily broken. 3.2 Growing fattening pig liver light yellow, was like bean curd residue, lung blood stasis edema, bladder swelling, gastrointestinal congestion. The back and buttocks muscles have coagulative necrosis, and pale white, such as boiled, with severe white muscle markings. 3.3 Partial nursery and growing pigs showed subcutaneous yellow jelly-like edema, diffuse hemorrhage, colonic edema, and catarrhal inflammation. 4 Diagnosis 4.1 Clinical diagnosis: From the clinical symptoms and anatomical changes can be initially diagnosed as the piglet selenium deficiency. 4.2 Epidemiological diagnosis: The area is severely deficient in selenium, and the pig population mainly relies on artificial selenium supplements. Since January 2004, the pigs and sows in the delivery room have no selenium supplements. 4.3 Laboratory Diagnosis: Aseptically collected dead pig liver, spleen, etc. Inoculated on Martin broth and chocolate agar for 48 hours, no bacterial growth was observed. Myocardium and liver were sent to the field to detect selenium content of 0.050 mg/kg. 0.065 mg/kg, severely deficient in selenium. 4.4 Treatment Diagnosis: The whole group of nursery pigs were injected with 0.1% sodium selenite-vitamin E 3 ml/head. The condition was quickly controlled, the health condition was significantly improved, the fur gradually became bright, the mental state improved significantly, and the appetite increased. 5 Prevention 5.1 Sow Selenium-Vitamin E powder 12.5g/head was added to the diet for the first 3 weeks before the sow was given, once a week for 3 weeks. 5.2 The piglets were injected intramuscularly with 0.1% sodium selenite-Vitamin E formulation 1.5 ml/head 7 days post-partum, and the sow was given intramuscular injection of 0.1% sodium selenite-vitamin E formulation 10 ml/head. 5.3 After the weaned pigs were transferred to the nursery, 200 mg/kg of sodium selenite-vitamin E powder was added and fed once for 15 days. 6 Discussion 6.1 Selenium is one of the indispensable trace elements in the growth of pigs. It participates in a series of metabolic processes in the body. At the same time, it is also a component of many enzymes and antioxidants. Its deficiency can lead to metabolic disorders and a series of Lesions occur. 6.2 This area is where selenium is scarce. At the same time, wheat, which contains less selenium-containing raw materials and contains more selenium, has a small amount of wheat bran, which may also be a cause of the disease. 6.3 Since the disease did not occur for a long time, some production management personnel did not pay attention to the disease and neglected the prevention of drug addition and injection prevention in feed. In the diet, only pay attention to vitamin E supplementation without giving selenium or just giving selenium without supplementing vitamin E Even if feeding according to the standard, it is difficult to prevent the occurrence of hepatic necrosis or mulberry heart. Diabetes Insipidus Treatment, Urnary System Drug, Urinary System Use Drug,Urinary Drug Taizhou Volsen Chemical Co., Ltd. , https://www.volsenchem.com