African Swine Fever in Pigs: What It Is and the Prevention That Actually Works

There is no vaccine and no cure for African Swine Fever, and it can kill up to 100% of an infected herd. That makes prevention the entire game, and it’s worth being precise about what prevention actually means. According to the World Organisation for Animal Health (WOAH), biosecurity is the most important and effective measure available against ASF, not a water treatment, not a feed additive, and not any product marketed as a cure. Here’s what the disease actually does, how it spreads, and the measures with real evidence behind them.

What African Swine Fever is and why it’s so dangerous

ASF is a highly contagious viral disease affecting domestic and feral pigs of all ages, most commonly appearing as a hemorrhagic fever. It ranges from mild to severe, and in its worst form, mortality can reach 100%. The virus is exceptionally hardy: it can survive at least 11 days in feces and up to 15 weeks in decomposed serum, and remains viable for long periods in blood and tissue. The one piece of genuinely reassuring news: ASF is not zoonotic. It cannot infect humans, and it poses no food safety risk to people, even though it’s devastating for pig herds.

How it actually spreads

• Swill feeding. Feeding pigs food waste or table scraps that contain uncooked or undercooked pork products is one of the most significant drivers of ASF outbreaks, particularly on smallholder farms. This is a well-documented, major risk factor, and it’s worth naming directly since it’s often overlooked.
• Live pig and pork product movement. Transporting infected pigs, or pork and pork by-products like skins and offal, spreads the virus over long distances.
• Ticks. Ornithodoros ticks are a known biological vector for ASF in parts of Africa, where the virus can cycle between ticks and wild pig populations.
• Contaminated equipment and vehicles. Fomites, anything that touches an infected pig or its environment, and then touches your farm, are a real transmission route.
• Panic sales during outbreaks. When farmers sense an outbreak coming, some sell sick pigs quickly to avoid total loss. This is understandable, but it actively spreads the virus further into the value chain.

The measures that actually work

• Avoid swill feeding entirely if you can. If you must feed food waste, it needs proper heat treatment first. International guidance differs slightly here, WOAH recommends heating swill to at least 90°C for 60 minutes with continuous stirring, while FAO recommends 70°C for 30 minutes. The inconsistency reflects real scientific uncertainty, but the takeaway is the same either way: undercooked scraps are a genuine risk, and proper heat treatment matters.
• Move toward confined housing in high-risk areas. FAO guidance identifies upgrading from free-range to confined rearing as the safest option in ASF-endemic or high-risk regions, since it limits contact with wild pigs, ticks, and outside contamination sources.
• Control movement onto your farm. Restrict visitor access, disinfect vehicles and equipment before they enter, and quarantine any new pigs before introducing them to your existing herd.
• Isolate suspected cases immediately. If you see signs of illness, don’t wait or attempt to sell affected animals. Enclose suspected cases and report them, since prompt isolation is one of the few actions that can actually slow a farm-level outbreak.
• Use verified disinfectants on surfaces and equipment. Sodium hypochlorite, glutaraldehyde, caustic soda, and potassium peroxymonosulfate have all demonstrated strong effectiveness against ASF virus on contaminated surfaces in controlled studies, and are recommended by international animal health bodies for this purpose. Clean surfaces of organic matter first, since dirt and residue reduce how well any disinfectant works.

A word on unverified “cures” and water treatments

You may come across claims that adding a specific product to your pigs’ drinking water or feed, to lower its pH below a certain threshold, can prevent or kill ASF virus before it reaches your herd. Be cautious here. Research has actually found that ASF virus survives across a wide pH range, from 4 to 10, and reliable inactivation of the virus depends much more on heat than on acidity, 56°C for 70 minutes or 60°C for 20 minutes, according to laboratory studies. Acid-based products with real evidence behind them are tested and used as surface and equipment disinfectants, not as something added to a pig’s actual drinking water or feed as a preventive treatment. Don’t let a product claim replace the biosecurity basics above, that substitution is exactly how outbreaks catch farmers off guard.

For the full picture on getting your pig farm’s fundamentals right, see our beginner’s guide to pig farming.

Key takeaways

• There is no vaccine or cure for ASF; biosecurity is the only measure with real evidence of effectiveness, according to WOAH and FAO.
• Swill feeding, feeding pigs uncooked or undercooked pork scraps, is a major, well-documented driver of outbreaks and deserves direct attention.
• ASF is not zoonotic; it cannot infect humans and poses no food safety risk to people.
• Confined housing is the safer option in high-risk or ASF-endemic areas, compared to free-range systems.
• Be skeptical of any product claiming to make contaminated water or feed “safe” against ASF, the evidence supports heat treatment and standard disinfectants used on surfaces, not additives given directly to pigs.

FAQ

Is there a vaccine or cure for African Swine Fever?

No. There is currently no approved vaccine or treatment. Prevention through biosecurity is the only measure with proven effectiveness against the disease.

Can humans get African Swine Fever?

No. ASF is not zoonotic and cannot infect humans. It poses no food safety risk to people, though it can be devastating to pig herds.

What is swill feeding, and why is it risky?

Swill feeding means feeding pigs food waste or table scraps, which can contain uncooked or undercooked pork products carrying the ASF virus. It’s one of the most significant documented drivers of ASF outbreaks, particularly on smallholder farms, and should be avoided or properly heat-treated first.

Can adding a product to drinking water prevent African Swine Fever?

There’s no strong evidence for this. Research shows ASF virus survives across a wide pH range (4 to 10), and reliable inactivation depends on heat rather than acidity. Products with genuine evidence behind them are used as surface and equipment disinfectants, not as additives given directly to pigs as a preventive treatment.

What should I do if I suspect ASF in my herd?

Isolate the suspected animals immediately and report the case rather than attempting to sell or move them. Panic sales of sick pigs during outbreaks are a documented way the virus spreads further into the value chain.