African Swine Fever in Europe 2025: How Wild Boar Are Driving the Outbreak

African swine fever (ASF), a highly lethal viral disease affecting pigs and wild boar, surged across Europe in 2025 with devastating consequences. Poland reported 3,351 outbreaks — an increase of nearly 50% over 2024. Germany recorded 1,992, more than doubling its previous year total. And in late November, ASF appeared in Spain for the first time since 1994, with dead wild boar found in Bellaterra, near Barcelona.

Wild boar populations are at the center of this crisis, serving as both the primary reservoir for the virus in nature and the vector through which ASF spreads into new geographic regions.

The 2025 Outbreak by the Numbers

According to the European Food Safety Authority (EFSA), outbreaks in wild boar increased across most European countries in 2025.

Poland led with 3,351 confirmed cases, the highest count in Europe. The country’s large wild boar population and extensive forest habitat create ideal conditions for disease persistence.

Germany recorded a 113% increase over 2024, with outbreaks concentrated in eastern states near the Polish border but gradually moving westward.

Estonia experienced a dramatic reversal after years of decline, with cases jumping from 36 in 2024 to 259 in 2025 — a sevenfold increase that erased years of management progress.

Latvia, Bulgaria, Hungary, Lithuania, and Italy all reported significant wild boar outbreaks.

Spain represents the most alarming development. Two wild boar found dead on November 26 near Barcelona confirmed ASF’s arrival in the Iberian Peninsula. Since then, the number of confirmed cases has more than tripled, with additional dead boar found in the same area. Spain is Europe’s largest pig producer, and ASF’s arrival threatens an industry worth billions of euros annually.

For context on wild boar population dynamics that enable disease spread, see our guide to wild boar population dynamics.

Why Wild Boar Drive ASF Spread

ASF spreads through direct contact with infected animals, contaminated food or materials, and tick vectors. Wild boar are uniquely positioned to maintain and spread the virus for several reasons.

Population density — European wild boar populations have expanded dramatically over the past three decades, driven by milder winters, abundant agricultural food sources, and reduced hunting pressure. Higher density means more contact between animals and faster viral transmission. Our article on wild boar and climate change explains the environmental factors driving population growth.

Home range and movement — While individual wild boar typically maintain limited home ranges, young males dispersing to find new territories can travel dozens of kilometers, carrying the virus into previously unaffected areas.

Carcass persistence — ASF virus survives in wild boar carcasses for weeks or months, especially in cold weather. A single dead boar in a forest can infect other boar through environmental contamination long after the original animal dies. For more on tracking and identifying boar presence, see our guide to wild boar tracks and scat identification.

Human-mediated spread — Phylogenetic analysis published in Virus Evolution in 2025 confirmed that ASF’s dramatic geographic spread across Europe is driven largely by human activities. Contaminated meat products, hunting equipment, and vehicle transport enable the virus to “jump” hundreds of kilometers, far beyond the natural dispersal distance of wild boar.

Economic and Agricultural Impact

ASF is not dangerous to humans — you cannot catch it from infected pork or contact with infected animals. But its economic impact is catastrophic for the pig industry.

When ASF is confirmed in a region, immediate trade restrictions follow. Countries detecting ASF in domestic pigs face export bans from major markets, particularly China, Japan, and South Korea. For countries like Spain, Germany, and Poland, where pork exports represent billions of euros in annual revenue, these trade disruptions are economically devastating.

The disease itself has a near-100% mortality rate in domestic pigs, and there is currently no approved vaccine or treatment. Outbreaks in domestic herds result in the culling of entire farm populations — potentially thousands of animals per facility.

Wild boar outbreaks near pig-farming regions create constant biosecurity pressure. Even without direct contact between wild and domestic pigs, the virus can enter farms through contaminated feed, water, equipment, or the boots of workers who have walked through contaminated areas.

Management Responses

European countries are employing multiple strategies to contain ASF in wild boar populations.

Intensive carcass removal — Finding and removing dead wild boar from the landscape reduces environmental virus contamination. Systematic searches using trained dogs, drones, and organized ground teams are deployed in outbreak zones.

Hunting regulation — Some countries have increased hunting quotas for wild boar to reduce population density. Others have restricted hunting during outbreak periods to prevent scattering infected populations into new areas. The optimal balance between these approaches is actively debated. For background on the broader debate, see our article on wild boar management and population control methods.

Physical barriers — Denmark, Poland, and other countries have constructed fencing along national borders and around outbreak zones to limit wild boar movement. Our guide to wild boar-proof fencing evaluates different barrier designs.

Surveillance and monitoring — Expanded passive and active surveillance, including testing of hunter-harvested boar and systematic sampling of found carcasses, enables early detection in new areas. Camera trap monitoring and GPS tracking support population-level surveillance.

Looking Ahead

ASF in European wild boar is not a problem that will resolve quickly. The virus has been circulating in the region since 2007, and its geographic range continues to expand. No vaccine is currently approved for use in wild boar, though multiple candidates are in development.

The 2025 surge — particularly the emergence in Spain — signals that current containment strategies are insufficient to prevent geographic spread. The intersection of expanding wild boar populations, persistent environmental virus contamination, and human-mediated transport creates conditions for continued expansion unless coordinated European-level responses improve dramatically.

For wildlife observers and outdoor enthusiasts, the practical message is clear: report any dead wild boar found in the field to local veterinary authorities, avoid contact with carcasses, and clean boots and equipment after walking in areas where wild boar are present.

Sources

1. Epidemiological analysis of African swine fever in the EU during 2024 — EFSA Journal — accessed March 26, 2026
2. ASF in Europe in 2025 — pig333 — accessed March 26, 2026
3. African swine fever rips through Spain — FoodNavigator — accessed March 26, 2026
4. Phylogenetic analysis of ASF spread in Europe — Virus Evolution — accessed March 26, 2026