Symptoms of African Swine Fever in Domestic Pigs at Each Stage and Effective Prevention and Control Methods
Since the first case of African swine fever was discovered in Northeast China in August last year, the disease has crossed more than half of China and spread to the central provinces. For early detection and early prevention and control, here is an introduction to the relevant basic knowledge of this disease, especially the symptoms of African swine fever in domestic pigs at each stage.
Since the first case of African swine fever was discovered in Northeast China in August last year, the disease has crossed more than half of China and spread to the central provinces. For early detection and early prevention and control, here is an introduction to the relevant basic knowledge of this disease, especially the symptoms of African swine fever in domestic pigs at each stage.
I. Relevant Basic Knowledge
1. It does not infect humans
Pork is one of the most common foods on Chinese dining tables. When it comes to swine fever, what most people care about most may be its harm to the human body. There is no need to worry about this, because the only host of African swine fever is pigs (including domestic pigs and wild boars), and humans will not be infected even if they eat sick pigs. As long as it is pork purchased through normal channels that has passed quarantine inspection, it can be safely eaten after being processed by normal high-temperature cooking methods.
2. Fast spread and high mortality rate
Second, African swine fever is an epidemic disease with a very high transmissibility and a mortality rate close to 100%. In a pig farm, as long as one sick pig is found, the entire pig farm will suffer, and it will be a catastrophic disaster. Therefore, in places where the epidemic appears, large-scale culling is usually carried out, leading to a rise in pork prices.
II. Symptoms of African Swine Fever at Each Stage
In fact, the incubation period and onset period of African swine fever are very short. Once infected with this disease, pigs usually do not live more than 10 days, so there is no division into stages. According to the degree of clinical symptoms, it can be divided into four types: chronic, acute, subacute and peracute.
1. Chronic: difficulty breathing, emaciation or stunted growth, and weakness. Joint swelling, local skin ulcers, and necrosis. It can usually survive for several months, but recovery is very difficult.
2. Acute: body temperature rises to 42°C, listlessness, loss of appetite, and even diarrhea, with symptoms such as blood in the feces. The skin turns purple and has bleeding spots. Pregnant sows will suddenly miscarry.
3. Subacute: body temperature fluctuates greatly, remaining above 40.5°C for a long time. Respiratory distress, with obvious symptoms such as coughing, joint pain, and swelling.
4. Peracute: sudden death without symptoms, approximately between 8-10 days after infection.
III. How to Prevent and Control It
The world's first case of African swine fever appeared in 1921. Nearly 100 years later, no related vaccine has yet been developed. Therefore, this disease currently cannot be prevented or treated, and the spread can only be intervened in artificially to achieve the purpose of isolation. Specifically, there are the following methods.
1. Activity spaces must be disinfected in a timely manner
Not only do the spaces of pig farms need to be kept clean and disinfected every day, but other spaces where live pigs move must also be disinfected in a timely manner, such as live pig transport vehicles and feed delivery vehicles, to ensure that no African swine fever pathogens are present. Personnel entering and leaving the pig farm must also pay attention to proper isolation, so as to prevent pathogens carried by the keepers from infecting the pigs on the farm.
2. Food sources must be legitimate
Ordinary cooking methods cannot eliminate the African swine fever virus in pork. Therefore, if healthy pigs accidentally eat the body tissues of sick pigs, the probability of infection is especially high. In the daily feeding process, pay attention to ensuring that the feed and swill sources of the pig farm are legitimate, and do not feed restaurant swill of unknown origin or uninspected pig feed.
3. Prevent further spread after an outbreak
When it is found that piglets on a pig farm show symptoms of African swine fever, first of all, the pigs must not be transported elsewhere. Second, before leaving the pig farm, be sure to change clothes and put them in well-sealed bags, so as to avoid expanding the scope of virus transmission and infection and causing greater losses. Finally, promptly notify local animal husbandry departments, epidemic prevention stations and other institutions, and start large-scale inspection and handling measures as early as possible to prevent the spread.
African swine fever has brought huge losses to farmers and has also caused the pork market to fall into a periodic downturn. Therefore, whether it is individual farming or large-scale farming, it is necessary to understand the symptoms of African swine fever at each stage, handle sick pigs and dead pigs promptly and reasonably, and do a good job in epidemic prevention and control.