Foot-and-mouth disease poses a very serious threat to pigs and can cause substantial economic losses for farms. Some livestock producers report that losses actually increase during efforts to prevent and control the disease. This may be because they have fallen into common pitfalls when preventing and controlling foot-and-mouth disease in pigs.

 

 

One: indiscriminate injections

 

The habit among pig-farming personnel of “giving an injection whenever an illness is seen” offers little benefit to pigs infected with foot-and-mouth disease. It can increase stress and accelerate the spread of the disease (for example, when multiple pigs share a needle or personnel act as carriers). If combination preparations containing central nervous system antipyretics such as Analgin, aminopyrine, or anti-allergy drugs such as dexamethasone are injected, they will undoubtedly cause a sharp decline in the animals’ cellular immune function. In addition, chasing pigs to give injections causes considerable stress, making myocarditis more likely and increasing deaths.

 

II. Indiscriminate Disinfection

 

Foot-and-mouth disease is a respiratory viral disease. The foot-and-mouth disease virus first damages the respiratory mucosal defense barrier; chemical disinfectants are used to disinfect pigs.

 

First, it can severely damage the pigs’ respiratory mucosa, leaving the mucosal barrier full of gaps and, instead, opening the door for viruses and bacteria to invade.

 

Second, it increases the humidity in the air, making the pigsty damper and wounds harder to heal.

 

Third, it increased stress. Sick pigs instinctively avoid being sprayed with disinfectant, which can cause their hooves to fall off and instead hinder recovery.

 

Three, Emergency Immunization

 

There are always some people with a bad habit: they do not take precautions against foot-and-mouth disease in their daily routine and keep relying on luck. But as soon as they hear that a pig at someone’s home nearby has contracted it, they immediately begin emergency immunization. One batch today, another tomorrow, and before all the pigs have been vaccinated, they contract foot-and-mouth disease.

 

After an outbreak of foot-and-mouth disease, they look back and say, “The foot-and-mouth disease vaccine doesn’t work. All the pigs that were vaccinated got sick, while those that weren’t vaccinated were fine.”     

 

Why does this happen? Is there any truth to what they say? In fact, that is exactly what happened. If the vaccine they received was appropriate for the strain, the problem was not that the vaccine they used was ineffective, but that they chose the wrong time to immunize—the pigs happened to be in the incubation period when they were vaccinated.    

 

As everyone knows, it takes 20 days after vaccination for a foot-and-mouth disease vaccine to produce an effective antibody titer. However, once the vaccine has been administered, the toxins in it gradually stimulate the pigs’ immune systems to produce some antibodies. But those antibodies are not enough to fight the actual foot-and-mouth disease virus; they only become effective after 20 days. If foot-and-mouth disease strikes at that point, the vaccine will of course be ineffective. The key is that when foot-and-mouth disease strikes, the pigs’ immune systems are focused entirely on responding to the toxins in the vaccine and have no capacity left to fight the actual foot-and-mouth disease virus. That is why vaccinated pigs are the first to be infected.

 

The foot-and-mouth disease virus itself harms pigs, and the toxins in the vaccine also harm them to some extent. When these two different sources of toxins converge, vaccinated pigs may actually suffer more severe harm from the actual foot-and-mouth disease virus. Their incidence rate is also higher, and they naturally take longer to recover. By comparison, pigs that have not been vaccinated may have a lower incidence rate, leading to the impression that “the foot-and-mouth disease vaccine doesn’t work; all the vaccinated pigs got sick, but the unvaccinated ones were fine.” So, once foot-and-mouth disease is at the door, emergency vaccination is not advisable.