Pet Talk: What to know about African Swine Fever

Over the past couple of months, stories of African Swine Fever (ASF) spreading through Asia have frequented U.S. and international news.

While ASF is not currently present in the U.S., there are still precautions pig owners can take in case this disease does spread to America.

To offer clarification on this topic, Dr. Brandon Dominguez, a clinical associate professor at the Texas A&M College of Veterinary Medicine & Biomedical Sciences, has information that pig owners need to know about ASF and the similar Classical Swine Fever (CSF).

“CSF, also known as hog cholera, is caused by a virus that has been eradicated from the United States since 1978,” Dominguez said.

CSF can be contracted when pigs eat undercooked food or come into contact with infected pigs, contaminated objects, or flies and other vectors.

If pigs become infected with CSF, they usually exhibit high fevers and will huddle together and stop eating. Dominguez said constipation, diarrhea, and red eyes are common; young pigs may also show weakness and incoordination.

CSF is not always fatal, but it tends to cause more harm in populations of pigs that have not been exposed to the disease in the past.

By contrast, ASF, the current concern in Asia, has never been seen in the U.S. It can be spread in the same ways as CSF, but also by ticks serving as vectors for the virus.

ASF has many of the same symptoms but can cause a more serious illness and prognosis. If a pig with ASF does recover, it will be a carrier of the virus for several months and should be kept away from healthy pigs.

“Though both are viruses, ASF and CSF are from different viral families,” Dominguez said. “CSF is a pestivirus, an RNA virus related to Bovine Viral Diarrhea Virus, while ASF is an asfivirus, a DNA virus.”

The U.S. Department of Agriculture and state animal health authorities have strategies to reduce the occurrence of these diseases if they were to show up in the U.S., but other countries, including many in Asia, are struggling to keep the ASF virus from spreading.

“One of the biggest concerns with the spread of African Swine Fever in Asia is the amount of trade that occurs between the U.S. and Asian countries,” Dominguez said. “On one hand, the decrease in their swine population may drive more demand for U.S. pork; however, as the prevalence of ASF increases, the risk of it being transported to the U.S. through imported products increases.”

Luckily, there are many preventative steps pet pig owners and pig farmers can take to reduce the chance that ASF or CSF could harm their animals.

“Prevention of these diseases requires vigilance on the farm and national levels, to practice the highest levels of monitoring and security to keep these diseases out,” Dominguez said. “Restricting visitors from coming to a farm, especially if they have been near other pigs and pigs outside of the country, is one important step.”

Pig owners can also help keep viruses away from animals by getting feed and other supplies from reliable sources and practicing good farm biosecurity, including maintenance of fences and hygiene policies for personnel.

If traveling to other countries, especially those where these diseases are found, it is best to throw away any clothes that came into contact with animals and be wary about bringing regulated agricultural products back to the U.S.

Although we, in the U.S., currently have nothing to worry about in relation to ASF and CSF, owners of pet pigs and those who raise pigs to sell should always take precautions to keep animals safe from any swine disease, including ASF and CSF. Thankfully, strong agriculture laws in the U.S. are doing the most to help keep our animals healthy.

Pet Talk is a service of the College of Veterinary Medicine & Biomedical Sciences, Texas A&M University. Stories can be viewed on the web at Suggestions for future topics may be directed to

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