What are the detection methods of classical swine fever?

Characteristics of the disease: naturally, only pigs and wild boars are infected, and pigs of any age, breed and sex can get sick; This disease can occur at any season. In areas where vaccination is not carried out on schedule, once the disease occurs, it can cause a large-scale epidemic in a short time. The morbidity and mortality are high. It can be sporadic in frequent areas or areas with low injection density. Sick pigs are the main source of infection. The main route of infection is the digestive tract, but it can also pass through respiratory tract, conjunctiva and skin wounds. Improper sale, transportation and corpse disposal of live pigs, lax hygiene inspection of internal products and ineffective implementation of veterinary hygiene measures can all become indirect media, which can promote the occurrence and prevalence of the disease. Making piglets sick through placental infection has become a very difficult problem in prevention and control. Clinical symptoms: Classical swine fever is very similar to swine erysipelas, swine pneumonia and piglet paratyphoid complicated with septicemia, and should be differentiated accurately. The clinical characteristics of classical swine fever are as follows: the body temperature rises to 40.5 ~ 42℃, and the fever is missed; Purulent conjunctivitis; Constipation at the beginning of illness and diarrhea after illness; Red spots or erythema of different sizes appear behind the ears, abdomen and inner limbs of sick pigs, and the finger pressure does not subside; Boar foreskin has inflammation, and when squeezed by hand, it will spit out foul and turbid liquid. In acute cases, most of them died around 1 week. The mortality rate can reach 60% ~ 80%; Piglets have neurological symptoms; Chronic pig disease, high and low body temperature, good and bad appetite, constipation and diarrhea appear alternately. The sick pig is obviously emaciated, hairy and muddy, and walks unsteadily. The general course of disease can reach more than 20 days, and most of them die. Pathological autopsy changes: acute classical swine fever is mainly characterized by septic changes, and the changes with diagnostic value are: bleeding spots on the skin or subcutaneous; Maxillary recess, neck, moustache and visceral lymph nodes are swollen, dark red and bleeding around the cut surface; The kidney is pale, not swollen, and there is some small bleeding; Splenic marginal infarction; Laryngeal mucosa, epiglottic cartilage, bladder mucosa, epicardium, lung and intestinal serosa, mucosal bleeding. Pigs with chronic diseases are characterized by button-shaped ulcers on the mucosa of cecum, colon and ileum.

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