
Infectious animal diseases are spreading to previously unaffected regions and species, with nearly half (47 per cent) capable of zoonotic transmission or spreading between animals, according to the inaugural State of the World’s Animal Health report released by the World Organisation for Animal Health (WOAH) on May 23, 2025.
Increasing distribution and intensity of diseases such as African Swine Fever (ASF), avian influenza, foot and mouth disease (FMD) and peste des petits ruminants (PPR) was highlighted by the report, warning that their proliferation was destabilising agrifood systems. These disruptions threatened global food security, public health and biodiversity.
Major outbreaks were recorded across several regions in 2024 and early 2025, driven by shifting climate patterns, expanding international trade and evolving pathogen dynamics.
“The spread, prevalence and impact of infectious animal diseases is changing, bringing new challenges for agriculture and food security, human health and development, and natural ecosystems,” said Emmanuelle Soubeyran, director general of WOAH.
Between 2005 and 2023, nearly half of the WOAH-notified diseases were zoonotic in nature — capable of infecting humans.
In October 2024, ASF — a highly contagious haemorrhagic disease of pigs with near-total fatality in some outbreaks — leapt over 1,800 kilometres to Sri Lanka from the nearest known outbreak zone, marking the most significant “disease jump” of the year. This incursion suggested that no region remained unaffected.
Montenegro and Albania also reported their first ASF outbreaks in early 2024. Overall, 16 countries and territories recorded 6,807 outbreaks during the year (1,532 in domestic pigs and 5,275 in wild populations), resulting in 195,191 reported cases and 222,174 animal losses among domestic pigs.
This continuing spread and the expansion of the disease across borders, has been a global concern for the pig industry and scores of farming families and communities.
Since its first incursion into Georgia in 2007, ASF had spread across Europe, the Asia-Pacific and the Americas, causing major economic disruptions and threatening global pork supplies. The disease impacts both domestic pigs and wild boars, which are difficult to monitor and control. Boars act as reservoirs of the virus, complicating eradication efforts, said the report, launched ahead of WOAH’s 92nd General Session in Paris scheduled from May 25-29, 2025.
Avian influenza, also known as bird flu or highly pathogenic avian influenza (HPAI), had devastated bird populations over the past two decades, causing the loss or culling of more than 630 million birds. In 2024 alone, the virus affected new regions and species, including mammals.
In a notable shift, more countries reported HPAI outbreaks in non-poultry species (55) than in poultry (42). A total of 2,570 non-poultry outbreaks and 943 poultry outbreaks were recorded. Particularly concerning was the doubling of outbreaks in mammals, to 1,022 in 2024 from 459 in 2023, raising alarms about cross-species transmission and potential adaptation to humans.
While the risk of human infection remained low, the report warned that infections in mammals such as cattle, cats and dogs could increase the likelihood of the virus evolving to spread between mammals and potentially to humans.
Vaccination was being considered as a complementary tool in disease management. In October 2023, France became the first European Union country to implement a nationwide vaccination campaign in ducks due to their key role in disease transmission. As a result of the vaccination campaign alongside other measures, the country suffered just 10 outbreaks as a result, despite modelling by the Toulouse Veterinary School estimating up to 700 outbreaks in 2023.
The assessment, which provided the first comprehensive review of animal disease trends, risks and challenges and the impacts on human health, food security and economies, cited climate change and increased trade among the factors influencing their spread and prevalence.
Bluetongue virus: A total of 3,626 bluetongue outbreaks were reported by 24 countries. It is a viral disease that affects ruminants like sheep, cattle and goats, spread by tiny biting midges.
FMD: 18 countries reported a total of 216 outbreaks, including 29 exceptional epidemiological events. Germany experienced its first FMD outbreak since 1988 and EU’s first since 2011. Meanwhile, a zone within South Africa recorded the first occurrence of serotype SAT 3, while Iraq and Kuwait have reported the first occurrence of serotype SAT 1 in the country or zone.
Lumpy skin disease: 319 outbreaks were reported from 11 countries, including 11 exceptional epidemiological events. The disease was detected for the first time in northern Africa, with outbreaks reported in Algeria, Libya, and Tunisia, as well as Japan. It also reoccurred in Eastern and Southern Asia.
New World screwworm: 8,363 outbreaks were reported by seven countries, involving 13 exceptional epidemiological events. The disease was detected for the first time in Mexico in December 2024, while it reoccurred in Nicaragua, which accounted for over 60 per cent of the reported outbreaks. Other affected countries included Belize, Costa Rica, El Salvador, Guatemala and Honduras.
Peste des petits ruminants: Once confined to the Global South, PPR recently re-emerged in Europe, with outbreaks in Greece, Romania, and Bulgaria in 2024 and in Hungary in January 2025. Despite years of progress in PPR control the disease spread to regions previously free of the disease, prompting serious concern and increased vigilance among veterinary authorities.
The authors, however, said that many of these diseases were preventable through a combination of vaccination, improved hygiene and biosecurity measures, but they also noted that access to animal vaccines remains uneven around the world and that challenges persisted in research, production, distribution, and uptake.
“To limit the spread of highly damaging diseases like avian influenza, FMD and PPR, the global community must strengthen international cooperation and ensure equitable access to safe, effective vaccines, alongside other control measures,” said Soubeyran.