Porcine epidemic encephalitis B

An acute zoonotic disease caused by a virus. Pigs suffering from this disease mainly cause abortion in sows and acute orchitis in breeding boars.

[pathogen]

Japanese encephalitis virus, which is very small and exists in the brain, spleen, blood and swollen testicles of diseased animals; in addition, blood-sucking Aedes albopictus and Culex pipiens mosquitoes are the storage hosts of the virus.

The virus is so weak that general disinfectants can kill it quickly.

[popular]

(l) it is often prevalent in late summer and early autumn and has obvious seasonality, which is related to the transmission of the disease by Aedes albopictus and Culex pipiens. The disease can also be transmitted by fetal infection and mating through the placenta.

(2) both boars and sows can be infected when they reach sexual maturity.

(3) the epidemic characteristics are: high infection rate, low morbidity (20%-30%), lower mortality, most of the causes of death are caused by complications, and most diseases do not relapse after recovery. The incidence of the first epidemic in a pig farm was high, and the disease was serious, then alleviated year by year, and finally became a disease-free pig with virus.

[symptoms]

(1) suddenly eat too little to eat, and the body temperature rises to about 41 ℃.

(2) depressed spirit, lethargy, lying on the ground soon after getting up, seems to be very tired; feces are dry and granular, attached with mucus, some with blood.

(3) some diseased pigs may have mild hindlimb paralysis, unstable walking, and some hindlimb joints are swollen and lame.

(4) sudden abortion and stillbirth of pregnant sows, retention of placenta and reddish-brown or grayish-brown mucus from vagina. Some diseases disappear before abortion occurs; others give birth to stillbirths and normal fetuses beyond the expected date, and there is a wide gap in the size of live fetuses. Within 2 days after birth, the live fetuses have spasms and fall to the ground and die.

(5) the testes of many boars were enlarged by 0.5 to 1 times, and the skin of the scrotum on the ipsilateral side was swollen and shiny, and most of them gradually decreased after 2 to 3 days, returned to normal or the testicles shrank and hardened, and lost the value of breeding.

[prevention]

(l) about 30 days before mating, 2 portions of attenuated Japanese encephalitis vaccine were subcutaneously injected into sows. Breeding boars were injected subcutaneously with 2 doses of the vaccine about 30 days before the first breeding, and then again at the beginning of summer every year.

(2) once the disease occurs, the injection 40ml of Radix Isatidis can be injected intramuscularly once a day, twice a day, and then halved, and then injected twice. To prevent complicated infection, penicillin and streptomycin can be injected intramuscularly. After abortion, 20 units of oxytocin can be injected intramuscularly to prevent placenta retention.