Analysis of the main causes of sudden death in pigs

In the process of pig production, many problems often occur. Some problems are short-lived, some problems occur from time to time, and some problems emerge one after another. As the managers and technicians of @ # @ 227 workshop, we should learn to give up those who are short-lived, care about those who happen from time to time, and focus on solving those who emerge one after another. The problem of sudden death of pigs belongs to "those who occur from time to time", which often puzzles farmers and requires the attention and concern of managers and technicians.

There are many cases of sudden death in pigs, and the causes are also different. At the time of occurrence, the weight of the pig and the course of the disease were different sooner or later. The main causes of sudden death of pigs are white muscle disease of piglets, foot-and-mouth disease of suckling piglets, acute Aspergillus flavus poisoning, edema disease of piglets, early onset of porcine dysentery, acute yellow dysentery, acute porcine erysipelas, intestinal bleeding syndrome and stress syndrome.

1. Sudden death mainly occurs in piglets

(1) Porcine dysentery

Piglets from 49 to 84 days old, occurred in four seasons, first acute outbreak, then chronic, not easy to clear. In the early stage of the epidemic, he died suddenly without showing symptoms. Most diarrhea in varying degrees, first pull soft stool, gradually yellow thin feces, mixed with mucus or blood. It is mainly swelling of mucous membrane of colon and cecum, hyperemia and bleeding, intestinal cavity is full of mucus, there is bran skin-like pseudomembrane. Microscopic examination showed that there were a large number of spirochetes in the intestinal mucosal smears. Dysentery Jing oral and injection is very effective.

(2) Acute yellow dysentery of piglets

1Mel at the age of 3 days was the most common, and the most acute piglets died suddenly without symptoms a few hours after birth. Diseased piglets discharge yellow thin feces, which contain small curd slices and flow down the anus, leaving no fecal traces around them, which are easy to be ignored. When diarrhea is severe, the tip of vulva and hind limbs of sows are contaminated by feces, sick pigs eat less or no milk, poor spirit, anal relaxation, defecation incontinence, dehydration and weight loss, and finally fall to the ground in a coma and die.

(3) leukomyopathy (muscular dystrophy)

White muscle disease mostly occurs in 20-day-old piglets, sick piglets are physically strong and suddenly onset. Normal body temperature, loss of appetite, lethargy, shortness of breath, like to lie down, often die suddenly. The cause of leukomyopathy is selenium deficiency.

(4) foot-and-mouth disease of suckling piglets

Sudden death is usually caused by acute gastroenteritis and myocarditis.

(5) edema disease of piglets

Most of them occur before and after weaning and can occur all the year round, mostly in well-nourished and strong piglets with sudden onset and death. Some mild diarrhea followed by constipation, some eyelids and other edema, or neurological symptoms such as ataxia. The main anatomical manifestations were edema, gelatinous edema of gastric mucosa and muscle layer of cardia, mesentery and subcutaneous edema.

Other major sudden death diseases of medium and large pigs

(1) Aspergillus flavus poisoning

Pigs developed symptoms 5-15 days after eating moldy feed. Acute cases can die during exercise or within two days after onset. Sick pigs show mental malaise. Loss of appetite or lack of food, weak hindquarters, wobbly walking. The mucous membrane is yellow-stained, the body temperature is normal and the stool is dry. Die within a few days after onset, or die suddenly without symptoms.

(2) Acute porcine erysipelas

It showed symptoms of septicemia, and at the beginning of the epidemic, some strong pigs did not show any symptoms and died suddenly. Most of the diseased pigs showed diet loss, vomiting and chills, and their body temperature suddenly rose to more than 42 ℃. They often lay down and refused to move around, and their stools were dry. Some have diarrhea in the later stage; erythema of different shapes and sizes appear on the skin and fade during finger pressure. If piglets get erysipelas, they often have convulsive neurological symptoms.

(3) intestinal bleeding syndrome

Sudden death syndrome caused by massive intestinal bleeding in pigs. The disease is most common in SPF-free pigs and lean breeder pigs, which can occur in pigs of all ages after weaning, but the incidence is higher in young reserve sows, 6-9-month-old boars and 4-8-week-old pigs after weaning. It is fulminant and sporadic, and the course of the disease is generally very short. Stress factors are the inducement of the disease, especially the sudden stress death of individual sporadic boars and fat pigs at the age of 6-9 months, and small intestinal bleeding found during autopsy. The main clinical manifestations of sudden death, dead pigs and sick pigs in the same group mostly show pale skin, excretion of loose feces with blood or fibrin tube feces, other aspects are normal. During the growth period, many dysplasia, periodic excretion of bloody feces. Autopsy showed that there was a large amount of blood in the small intestine, and the bleeding usually extended from the ileum to the entire small intestine and large intestine, and no obvious bleeding point was found. In some cases, there are changes of intestinal wall thickening in different parts of the posterior part of the small intestine, that is, proliferative hemorrhagic bowel disease. Chronic cases, due to secondary bacterial infection, can develop into necrotizing enteritis. Prevention and control methods (1) 200 mg / kg furazolidone was added to the feed. (2) for infections with proliferative bowel disease and campylobacter mucosae, 200 mg / kg of tylosin or 100 mg / kg of penicillin should be added to the feed. (3) the combination of antihistamines, corticosteroids and vitamins was successfully used in acute cases.

(4) sudden death stress syndrome

It is mainly due to sudden death without any clinical symptoms when stimulated by a strong stressor. If the boar is overexcited and dies suddenly during mating, the pig is too frightened during chase, or overcrowded during transportation, it may be due to nervous tension and excessive activity of the "sympathetic-adrenal" system when it is strongly stimulated, causing shock or circulatory collapse, resulting in sudden death. Prevention and treatment methods: specific prevention and treatment measures should be selected according to the nature of stressors and stress syndrome: (1) remove stressors and improve feeding management such as good ventilation in pig houses to prevent hot and humid crowding, sudden cold and heat, noise and annoyance. Do not feed or reduce feeding within 12-24 hours before leaving the fence, drink oral rehydration saline; pay attention to vehicle transportation or land expulsion to avoid excessive stimulation; or pigs that are sensitive to stress before transportation, use anti-stress hormones, anti-stress additives or tranquilizers such as chlorpromazine to prevent stress. For heat stress pigs with heatstroke, head with cold water and cold water enema. (2) pay attention to breeding and breeding. Pigs with nervous nerves, difficult to manage, easy to panic, skin prone to erythema, elevated body temperature and plump appearance are mostly stress-sensitive and had better not be selected for breeding. If necessary, modern technology should be used to detect whole blood or serum CPK (creatine phosphokinase), as well as halothane screening test, so as to eliminate such pigs from the breeding herd.