What Are the Early Symptoms of African Swine Fever in Finishing Pigs

African swine fever is an infectious disease caused by the African swine fever virus, extremely harmful to domestic pigs and wild boars. So what are the early symptoms of African swine fever in finishing pigs?

1. What is African swine fever?

African swine fever is an acute, hemorrhagic, highly virulent infectious disease caused by the African swine fever virus. It is characterized by a short course of disease, with mortality reaching up to 100% in the most acute and acute infections. Clinical signs include fever (reaching 40-42°C), rapid heartbeat, difficulty breathing, some coughing, serous or mucopurulent discharge from the eyes and nose, cyanosis of the skin, and obvious hemorrhage in the lymph nodes, kidneys, and gastrointestinal mucosa. The clinical symptoms of African swine fever are similar to those of classical swine fever, and diagnosis can only be confirmed through laboratory testing.

This disease was first reported in Kenya in 1921 and has persisted in sub-Saharan African countries. In 1957 it spread to Western Europe and Latin American countries, where most outbreaks were promptly eradicated, but it remains endemic in Portugal, southwestern Spain, and Sardinia, Italy.

China also discovered domestic cases of African swine fever in 2018.

2. Early Symptoms of African Swine Fever in Finishing Pigs

The pig's body temperature will rise and remain elevated for about 4 days, reaching a maximum of around 41°C, and then gradually decrease in the 48 hours before death. When finishing pigs contract African swine fever, their appetite also decreases, and they may even stop moving and lie in a corner. Purple spots will also appear on the pig's abdomen, armpits, ears, nose, and other areas.

3. Vectors of African Swine Fever Transmission

Several species of soft ticks in Africa and the Iberian Peninsula are reservoir hosts and vectors of ASFV. Many other tick species widely distributed in the Americas and elsewhere can also transmit ASFV. It is generally believed that the introduction of ASFV into disease-free areas is related to feeding pigs with uncooked infected pig products or swill from international airports and ports, or to contact with contaminated materials from infected domestic pigs, fetuses, feces, and tissues of diseased pigs, along with feeding contaminated feed.

Generally, there are four main routes by which African swine fever is introduced across borders: first, international trade and smuggling of live pigs and their products; second, pork and pork products carried by international travelers; third, kitchen waste and catering leftovers on international transport vehicles; fourth, migration of wild boars.