When autumn and winter arrive, pig farms need to stay on high alert. Among all seasonal risks, foot-and-mouth disease (commonly known as “Disease Number Five”) is one of the most serious. It is a Category I animal disease as designated by the state, spreads extremely quickly, and has a high morbidity rate. Most adult pigs can survive it, but piglets may die suddenly in entire litters. If it spreads through a farm, the losses will amount to far more than just a few pigs.
Inspect the pens every day, paying close attention to feed intake, standing, and gait; check any abnormalities early
I. First, know what foot-and-mouth disease looks like
The typical symptoms are “blisters in two places and lameness in one”:
· Body temperature rises to 40～41℃; the animal is lethargic and eats less;
· Mouth: blisters and sores develop on the snout, lips, tongue, and gums; the animal drools white foam and has difficulty eating;
· Hooves: the coronary band, interdigital cleft, and heel become red, hot, and painful, and blisters form. When they burst, they bleed and scab over. Affected pigs show obvious lameness, lie down and are reluctant to stand, and scream when forcibly driven. In severe cases, secondary infection can cause the hoof capsule to slough off;
· The udders and teats of lactating sows may also develop blisters and erosions.
The most important animals to watch are piglets: often, before blisters are obvious, the virus attacks the heart, causing acute myocarditis. They may suddenly squeal and die in groups, with a high mortality rate. The hearts of piglets that have died show gray-brown mottling on the surface, like a tiger’s coat, commonly known as “tiger-striped heart.”
If “high fever + blisters in the mouth or on the feet + lameness” occur together, especially in several pigs one after another, foot-and-mouth disease should be strongly suspected. Do not mistake it for ordinary laminitis or an injury.
Two. Why problems are most likely in autumn and winter
The foot-and-mouth disease virus is sensitive to heat but not to cold. It can survive for several days to several weeks in low-temperature, damp, dark environments, and even longer in contaminated bedding, soil, and manure; it is rapidly inactivated above 50°C, and can be completely inactivated by maintaining it at 70°C for a period of time. In autumn and winter, temperatures are low and sunlight is weak. In addition, windows are closed for warmth, the housing is damp, and ventilation is poorer, allowing the virus to survive longer and spread more quickly.
It also spreads through many routes: aerosols exhaled by infected pigs can travel long distances with the wind; contaminated vehicles, people’s clothing and footwear, equipment, feed, and drinking water can all carry the virus; infection can also result from eating contaminated swill that has not been heat-treated at high temperatures. In autumn and winter, animal movements become more frequent and the buying and selling of pigs increases, significantly raising the pressure to prevent external introduction.
Three. Solution one: Vaccinate where it matters (the fundamental measure)
Foot-and-mouth disease is subject to compulsory immunization. According to the National Guidelines on Compulsory Immunization Against Animal Diseases (2026–2030), the population immunization coverage rate must be maintained at above 90% year-round, the immunization rate among animals requiring vaccination must be 100%, and the qualified immunization antibody rate must be no lower than 70.
Be sure to check out the new developments in this year’s autumn prevention campaign
According to the Technical Guidelines for Compulsory Autumn Foot-and-Mouth Disease Immunization in 2026 and the Ministry of Agriculture and Rural Affairs’ requirements to strengthen prevention and control of South African 1 type (SAT1 type), pigs this autumn should be vaccinated against O type and SAT1 type. A bivalent vaccine containing the corresponding components is recommended, covering O-type CATHAY and Mya98 strains and SAT1 strains. SAT1 type has been reported this year in Xinjiang and Gansu. It spreads quickly and has a high mortality rate in young animals, so do not focus only on the older O-type vaccine. The specific strains and products should follow the local animal disease control authority’s plan for the current year and be determined by a practicing veterinarian.
Reference schedule:
· In large-scale farms, piglets receive the first vaccination at 28–60 days of age, a second vaccination 1 months later, and a booster every 4–6 months thereafter; an additional booster may be given 21–28 days before transport.
· For backyard farms, conduct mass vaccination in spring and autumn, with supplementary vaccination each month. Ensure that all animals requiring vaccination are vaccinated and that there are no gaps; collect blood samples for testing 28 days after vaccination. An individual is considered qualified only if the antibody test is positive.
Standardized immunization: restrain the animal, administer the injection intramuscularly in the neck, use one needle per pig, collect the vaccine from the cold chain, and take it out only when ready for use.
Four. Solution two: Keep the virus out (key).
Immunization is not a safe; biosecurity must also be properly implemented:
① Manage vehicles and people. Vehicles used to sell or transport pigs are the number-one risk source. Set up a vehicle disinfection pool and spray disinfection at the entrance. The wheels and vehicle body must be thoroughly disinfected before the vehicle can approach the production area. As a rule, outside visitors and vehicles must not enter the production area. If entry is essential, they must change clothes and shoes and disinfect; when moving between pig houses, avoid cross-contamination.
② Choose the right disinfectant. The virus has no envelope and is relatively resistant to povidone-iodine, quaternary ammonium compounds, phenols, and others. Reliable options include 2% sodium hydroxide (caustic soda), 4% sodium carbonate, chlorine-containing disinfectants, potassium peroxymonosulfate, chlorine dioxide, 0.2% citric acid, and 2% acetic acid. Prepare fresh solutions for immediate use. Thoroughly clean before disinfecting. Pile manure and contaminated bedding for fermentation or dispose of them using harmless treatment methods. Disinfectants can be rotated. Regularly replace the solution in the caustic soda footbath at the entrance and maintain an effective concentration.
③ Control animal introductions and feed. Practice all-in/all-out management. Source animals from negative-status farms through legitimate channels, check quarantine certificates, and isolate and observe animals upon arrival; test them and confirm they meet requirements before mixing them with the herd. Never feed pigs untreated swill or restaurant leftovers that have not been heat-treated at high temperatures. Disinfect the outer packaging of supplies before bringing them onto the premises.
④ Balance warmth and ventilation in autumn and winter. Do not seal up the housing for warmth and create an environment that is cold, damp, and stuffy. Keep it dry and provide moderate ventilation to reduce humidity and harmful gases. Healthy, fit pigs have stronger resistance.
The vehicle disinfection lane at the entrance to the farm premises is the first line of defense against pathogens entering from outside.
Solution Three: If You’re Facing This, Here’s How to Handle It Without Crossing the Red Line
Red Lines for Category One Diseases
Farmers must never treat sick pigs themselves, sell them privately, slaughter them privately, discard them, or move them. They must never conceal or fail to report cases. Secretly selling a few pigs with “mild” symptoms is often a direct cause of an outbreak spreading from one location to many, leading to far greater legal liability and losses.
The correct approach is to act “early, quickly, and strictly”:
1. If you discover suspected symptoms, immediately isolate the sick pigs and restrict their movement. Do not allow sick pigs, pork, bedding, tools, or vehicles to leave the premises, and do not inject them yourself to “suppress” the symptoms;
2. Immediately report the matter to the local agricultural and rural affairs authority or animal disease prevention and control agency. Official personnel will collect samples for diagnosis (fresh or unruptured vesicle skin and vesicle fluid are preferred for testing);
3. After confirmation, the government will designate the outbreak site, affected area, and threatened area in accordance with the law, and take measures such as imposing a lockdown, culling, carrying out harmless disposal, thorough disinfection, and emergency immunization. Compensation for culling and losses will be provided as stipulated by national regulations;
4. Cooperate throughout the epidemiological investigation, and truthfully report and track the handling of pigs and products sold within 14 days before the outbreak.
VI. A brief note about people
Foot-and-mouth disease mainly affects cloven-hoofed animals. Humans can occasionally become infected, but this is extremely rare and symptoms are usually mild, so there is no need to panic during normal contact. However, wear gloves and a mask and take precautions when handling sick pigs, performing necropsies, or disinfecting; take extra care if you have cuts on your hands. Do not slaughter or eat meat from pigs that have died of disease. If you feel unwell after contact, seek medical attention promptly and disclose your exposure history.
As autumn and winter approach, ensure vaccines are administered in line with this year's new requirements, keep both vehicle and personnel access points secure, and keep the pig housing dry and well ventilated. Also hold the line on “detect early, report promptly, and do not handle cases yourself”; this will help keep the major risk of foot-and-mouth disease firmly under control.