From the Founder: What We Can Learn from Recent Foot-and-Mouth Disease (FMD) Outbreaks

Recently, the World Organisation for Animal Health (WOAH) shared reports on Foot-and-Mouth Disease (FMD) outbreaks in China and Hungary (WOAH LinkedIn Post) in early 2025. While the incidents have very different characteristics, both provide some important lessons on how we approach strategy with these diseases. 

About the Virus

First off, let’s break down FMD a bit more. The virus that causes Foot-and-Mouth Disease is appropriately called the Foot-and-Mouth Disease Virus (FMDV). It’s in the Picornaviridae family, which are single-stranded RNA viruses that typically enter through the upper respiratory tract. They are able to infect a wide range of humans, animals including rodents, and birds (Zhang et al., 2025) and have a lot of genetic variability - meaning they can change up their genetic makeup and behavior pretty quickly.

Rhinovirus, which causes the common cold and is behind the common complaint, “We can’t vaccinate against the common cold,” is in this virus family. Knowing that high probability of genetic recombination and transmission through the respiratory route, and knowing that FMDV is already highly contagious in livestock, there’s a valid concern for potential crossover to humans, not to mention the impact of the health and suffering of the animals who become ill with FMD and the resulting economic costs to agriculture and communities.

Transmission and Location

FMDV will usually start causing signs of illness around 3 to 8 days after an animal has been infected, this is the incubation period. However, it can range from 2 to 14 days (WOAH, n.d.), which is a pretty wide window and similar to the incubation period for the SARS-CoV-2 virus that causes COVID-19. 

Remember, for the animal to be infected, it had to come into contact with (or be exposed to) enough of the virus to overwhelm the body’s first defenses. This is that exposure window that we talk about in epidemiology.

As of early 2025, we know that FMD has been endemic in several areas of the globe including: 

• Eastern, Southern, and West Africa,

• South, Southeast, and Middle Eastern areas of Asia,

• Southern and Eastern Europe,

• and Argentina, Brazil, and Uruguay in South America.

Clinical Signs and Symptoms

FMD can cause illness in animals with cloven hoofs like cattle, pigs, sheep, goats, and wildlife such as deer, giraffes, bison, and llamas and alpacas (Jamal & Belsham, 2013; Kitching, Harper, & Turner, 2006). Interestingly enough, buffalo are potential carriers and reservoirs of FMDV (CDC, 2005). 

Animals that are sick with FMD usually don’t want to eat or drink, especially due to the characteristic blisters that can pop up in the animal's mouth and on their feet and mammary glands (USDA, 2024). They may have a high fever that lasts 2-3 days, not be as active and may have a lot of nasal discharge or saliva (Agriculture Victoria, 2022). This is actually pretty similar to the way that Hand-Foot-and-Mouth Disease (HFMD) in humans presents. However, in cattle the disease can also reduce milk production in lactating mothers (Agriculture Victoria, 2022; USDA, 2024), heart inflammation and sudden death in calves, myocardial necrosis (“tiger-heart” lesions) and sudden death in neonate pigs (Merck Veterinary Manual, n.d.), and abortion in cattle and pigs (Iowa State University, n.d.), making it especially dangerous for pregnant or lactating animals and young animals. As with small humans that get the HFMD variety, we’re concerned about dehydration, especially with the very young that are still nursing.

How Does the Virus Spread?

Contact with the saliva, milk, semen, or excrement from an infected animal spreads the virus, along with contact with the fluid from the blisters. Animals can pick up viruses from these fluids in contaminated pens, trailers used to transport animals, or from animal products like raw meat foods, raw milk, nursing, etc (USDA, n.d.; WOAH, n.d.).

Aerosol spray from sneezing and other respiratory secretions can transmit the virus, with a transmission range of up to 40 miles (~65 km) in pigs (USDA, n.d.; WOAH, n.d.), who are amplifiers of the virus - holy cow! Aerosolized particles are part of why viruses that are spread through respiratory infections are so hard to control. Can you imagine the spread from infected pigs to other cloven animals on a ranch or to surrounding wildlife, or how much the virus would spread while being transported?

Additionally, the virus can be spread on fomites, or inanimate objects, making biosecurity and personal protective equipment especially important in transmission prevention since it can survive on clothing, shoes, equipment, trailers, bins and buckets, etc. for weeks (USDA, n.d.). Notably, the virus does well in cool temperatures and survives being frozen in meat or hay for months, so frozen meat and food stores are still at risk of transmitting the virus and causing disease. It can also survive in the soil, especially in cooler weather before the sunlight and heat have a chance to inactivate it (Commonwealth of Pennsylvania, n.d.). This is part of why we see more FMD, HFMD, and common colds in the colder seasons.

Photo by Oren Yomtov

Right, So What Can We Do About It?

Data Monitoring and Surveillance: Setting Up Your Systems for Success

For any communicable disease that can be spread from animal to animal, animal to person, person to person, or person to animal, and so on, I recommend keeping tabs on the health of your animal populations and the people in close contact with them. Depending on the disease, that system will look very different.

In this case, we know animal-to-animal spread is an issue, so we want to keep records of any livestock that become ill including the date they started showing symptoms, any illness testing that was done, pregnancy, age, and where they’ve been located during the last 14 days. This information is important in outbreak analysis because it helps us the probability of the disease actually being FMD, vaccination status for FMD, the illness severity risk for the animal, where the virus might have come from, and who all was exposed. There’s a ton more that we could collect but this information, at minimum, can help inform good, evidence-based interventions during an outbreak.

Additional information that is helpful to monitor is the species of wildlife surrounding the area to identify possible wildlife exposures, as well as any other livestock on the property. I’d want to know if pigs were within 40 miles, personally. 

Prevention

If and when vaccines are available for FMD, if an outbreak has occurred in the area or FMDV has been identified in local wildlife, vaccinate your livestock. The FMD vaccine is reliable but, for the same reasons that we have a hard time developing a vaccine for the common cold, it may not always be as effective as we’d like. The inactivated vaccine variety can provide protection for animals for up to 12 months, so an annual vaccine is needed in areas where it is endemic (USDA, n.d.), or regularly occurring. It also doesn’t work very well in pigs or llamas so there are special considerations for those species (Arzt, 2019; Parida, 2009). The other challenge is that there are 7 different types of FMDV and even subtypes by region (Kivéte, 2024), so the vaccine strategy requires identifying and matching serotypes in the vaccine. Then there’s the usual vaccine strategy challenges of the cost of mass vaccinating many, many animals or people to achieve herd immunity and nudge the virus out of circulation, and the logistic complications of vaccines that require constant cold storage before they are administered.

We’re getting better and better at creating vaccines through innovative technologies and research, so I’m hopeful that new strategies to enhance cross-protection for virus types and facilitate low-cost mass vaccination in areas with limited funding or cold storage will be on the veterinary health market.

The next major prevention step is biosecurity and personal protective equipment. If FMD is in the area: 

• disinfect any vehicles or trailers used to transport animals before and after use; 

• have any personnel wash their hands and equipment before and after entering the farm; 

• implement farm-only shoes, and either use shoe covers between pens or have a disinfection area between different animals enclosures if there have been FMD outbreaks in the past.

  
  

Also, stay in the know about what’s in the area. Network with your local agricultural and wildlife folks and have an understanding that you’ll contact and update each other if FMD or other diseases occur in the area. Knowledge is power, and knowing that FMD is a present risk will help everyone stay on their toes about their biosecurity measures.

Intervention

Like all things public health, the interventions once an outbreak has begun really depend on the situation. Two things stay constant though, infection control and monitoring.

The short advice is:

• isolate and test animals that look or act sick (drooly, sluggish, droopy eyes, you know your animals),

• setup disinfection stations outside of sick animals’ quarters,

• quarantine animals that have been in contact with the sick animal separately from any animals who weren’t in contact with it for 14 days,

• closely monitor all animals for a period of 28 days since the last new illness to make sure the outbreak has ended,

• and for the love of Pete, don’t transport Wilbur the pig if he looks sick, lest he spew FMDV in a 40-mile radius down the highway! 

  
  

I’m not a fan of culling because I feel that it is an animal ethics and immunity development issue. We don’t kill off people when they become exposed to an illness, and I don’t think it’s right to do the same thing to animals, although I do understand the reasons. I think there’s also an argument for giving animals an opportunity to recover and build immunity to certain infections, and prioritize those animals with exceptional immunity for breeding programs. Culling is cited as an effective intervention to FMD, however, and it certainly will end a localized outbreak.

The Human Piece

I mentioned that there is a risk for future spillover of FMDV to humans, especially with frequent contact with cloven livestock that the virus can infect. As with all pathogens with this risk, and especially viruses, the more contact the virus has with humans, the more likely it is that the virus will find an ingenious way to sneak past human cell defenses and cause illness. 

We already have Hand-Foot-and-Mouth Disease in humans (different virus, milder illness), and we certainly don’t want a more severe blister-type illness such as FMD to crossover. When people are dealing with animals that look or act sick, animals that suddenly died, or in an area where there are current FMD outbreaks in other livestock or nearby wildlife, they should act like the virus could get them sick and take the precautions that they would for something like COVID-19. That decreases the amount of exposure that they’ll get to the virus, and decreases the likelihood of FMDV getting too “chummy” with us.

We’re Here to Help

I hope you enjoyed learning more about Foot-and-Mouth Disease and how to keep Wilbur safe and germ-free with me. I am an Epidemiologist and part of what we do at One Life Epi Solutions is provide support with human and animal disease surveillance or outbreak response. We use an approach that integrates the principles of One Health for more comprehensive, coordinated response and better long-term outcomes. Reach out to us for strategy and support: https://tfft.io/14IVwOP

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The Founder

Dr. Ginger Dixon, DrPH, MS is an Epidemiologist, public health professional, and mother of four. She is the Owner and Founder of One Life Epi Solutions, and has extensive experience in research, program evaluation, and data analysis. Her expertise encompasses One Health epidemiology, surveillance of infectious diseases, opioids, and suicide, as well as population health assessment. Her contributions include developing surveillance systems, conducting outbreak investigations, and crafting policy recommendations informed by rigorous data analysis. Dr. Dixon has also served in leadership roles within public health agencies, including the Arizona Department of Health Services and Cochise County Health & Social Services, where she spearheaded initiatives to improve the quality and efficiency of epidemiological services. Her academic credentials include a Doctor of Public Health (DrPH) in Population Health Analytics and Decision Making from Samford University and an MS in Epidemiology from the University of Arizona. She has a substantial record of research presentations and publications, reflecting her commitment to disseminating public health knowledge.

References and Further Reading:

Arzt, J., et al. (2019). The pathogenesis of foot-and-mouth disease in pigs. Frontiers in Veterinary Science, 6. https://doi.org/10.3389/fvets.2019.00041

Centers for Disease Control and Prevention. (2005, December). Pandemic strain of foot-and-mouth disease virus serotype O. Emerging Infectious Diseases, 11(12). https://wwwnc.cdc.gov/eid/article/11/12/05-0908_article

Commonwealth of Pennsylvania. (n.d.). Foot and mouth disease. Commonwealth of Pennsylvania. https://www.pa.gov/agencies-pda-animals-diseases-foot-and-mouth-disease

Iowa State University. (n.d.). Foot-and-mouth disease (FMD). Iowa State University, College of Veterinary Medicine. https://vetmed.iastate.edu/vdpam/about/focus-areas/swine/swine-disease-manual/index-diseases/foot-mouth-disease

Jamal, S. M., & Belsham, G. J. (2013). Foot-and-mouth disease: Past, present and future. Veterinary Research, 44(1). https://pmc.ncbi.nlm.nih.gov/articles/PMC4028749/

Kitching, R. P., Harper, G. J., & Turner, G. E. (2006). Foot-and-mouth disease. Veterinary Research, 37(4). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC387408/

Kivéte, J., et al. (2024). Foot and mouth disease vaccine efficacy in Africa. Frontiers in Veterinary Science, 11. https://doi.org/10.3389/fvets.2024.1360256

Parida, S. (2009). Vaccination against foot-and-mouth disease virus: Strategies and effectiveness. Expert Review of Vaccines, 8(3), 347–365. https://doi.org/10.1586/14760584.8.3.347

Shariman, A., et al. (2022). Airborne transmission of foot-and-mouth disease virus. Viruses, 14(9). https://doi.org/10.3390/v14091424

United States Department of Agriculture. (n.d.). Foot-and-mouth disease response ready reference guide. https://www.aphis.usda.gov/sites/default/files/fmd_plan_rrg_ee_6.pdf

United States Department of Agriculture. (n.d.). Foot-and-mouth disease vaccination policy. https://www.aphis.usda.gov/sites/default/files/fmd-vac-policy.pdf

United States Department of Agriculture’s Animal and Plant Health Inspection Service. (2021, February). Foot-and-mouth disease. https://www.aphis.usda.gov/sites/default/files/2023-11/fs-fmd-general.pdf

World Organisation for Animal Health. (n.d.). Foot and mouth disease. https://www.woah.org/en/disease/foot-and-mouth-disease/

Zhang, N., Hu, B., Zhang, L., Gan, M., Ding, Q., Pan, K., Wei, J., Xu, W., Chen, D., Zheng, S., Cai, K., & Zheng, Z. (2025). Virome landscape of wild rodents and shrews in Central China. Microbiome, 13(1), 63. https://doi.org/10.1186/s40168-025-02059-0