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Classic swine fever can affect any animal, regardless of age. As a rule, if a farm is exposed to plague, almost 70% of the pigs die. After a mass death, large sums have to be spent on disinfecting premises, disposing of animals, and carrying out quarantine measures. In order to minimize costs, it is recommended to carry out preventive measures to prevent diseases and detect plague in the early stages. This type of disease is called classical swine fever. This was done so that it was possible to distinguish the disease from a more dangerous type - African swine fever.
General characteristics of the disease
As you know, the study of this disease began for the first time in the United States in 1830-1833. It was possible to prove the viral nature of swine fever in 1903. By this period of time, signs of swine fever began to appear overseas and in other European countries.Classical plague was first discovered in Russia in 1893.
At first, scientists assumed that this disease was caused by a pathogen - B. Suipestifer. But later, American scientists discovered that the presence of this microorganism, dangerous for animals, is caused by paratyphoid fever of pigs. The pathogen appears in the body of animals exposed to this disease.
Pathogen
Classical plague is known to be caused by an RNA virus secreted by many sick animals. It is important not only to first study the manifestations of classical swine fever in photographs, but also to take into account that this virus has a high level of resistance to environmental conditions. The plague virus can survive on pig farms for 12 months.
Viability is observed even in food products of slaughtered animals:
- 300 days in corned beef;
- from 2 years or more in frozen meat products.
The classical plague has several types of virus, among which the following are worth highlighting:
- type A – capable of causing an acute form of the disease;
- type B – pathology that can develop in an atypical and chronic form;
- type C - in this case, the disease occurs without visible symptoms; as a rule, this type is used to prepare a vaccine.
Infection can be carried out through the respiratory route, through defects in the skin. Once the virus has entered the animal’s body, it begins to penetrate the liver and bone marrow.
In the photo below you can see signs of swine fever.
How dangerous is the disease?
In addition to studying the signs of plague in pigs in the photo, you need to know how dangerous this disease is from the scientific literature.In this case, it is necessary to understand that swine fever does not pose a danger to humans. As a result of the fact that the causative agents of plague and its varieties have not been studied well enough to date, it is recommended to refrain from eating the meat of an infected animal. The virus that infects pigs can mutate and persist in meat products for 150 to 300 days.
As a result of the fact that classical plague is detected at a late stage and it is no longer possible to treat it in this state, veterinarians, when an epidemic is detected, eliminate infected individuals and all animals that were in close proximity to sick pigs. For farms, classical plague is a real disaster, as it kills almost all livestock.
Forms and symptoms of classical swine fever
It is important to have information not only about the general symptoms and treatment of swine fever, but also about the existing forms of this type of disease. As is known, classical plague can occur in pigs in the following forms:
- lightning;
- acute;
- subacid;
- chronic.
If you understand how these forms differ from each other and how to recognize them, then you can prevent mass infection of animals on a pig farm.
Fulminant form of plague
As a rule, this form appears only in suckling piglets. During infection, you can observe a fever, a depressed state of the animal, and vomiting. In some cases, piglets may fall into a coma or begin to convulse. As practice shows, death occurs 24-48 hours after the first signs of the disease appear.
Acute form of swine fever
This form is characterized by the following symptoms:
- hyperthermia with an increase in body temperature to 40.5-42°C;
- after 2-3 days, the animals gradually begin to lose their appetite;
- pigs experience a constant feeling of thirst;
- chills appear over time;
- vomiting appears;
- constipation is replaced by hemorrhagic diarrhea;
- conjunctivitis appears, the eyelids begin to swell and stick together due to the large discharge of pus;
- the back becomes hunched, the animals bury themselves in the litter;
- paresis of the hind limbs appears;
- urine becomes darker;
- on the skin you can see small bubbles, which are filled with a yellow liquid;
- In addition, you can observe hemorrhages on the surface of the skin, which merge. After some time, the skin turns purple. If you press, the stains will not disappear;
- nasal bleeding develops;
- heart damage occurs;
- the ears, tail, and snout turn blue;
- Before death occurs, hypothermia develops with a temperature of 35-36°C.
In young pigs, the acute form of classical plague lasts for 7-10 days, and abortions will be observed in sows.
Subacid form of swine fever
In this case, the disease can occur in several forms:
- intestinal;
- pulmonary
It is important to understand that the subacid form develops in those animals that have developed some resistance to the plague pathogen. The illness period can last from 2 to 3 weeks.
In the photo below, a weakened animal with signs of classical swine fever.
Intestinal form of plague
Enterocolitis occurs in animals, which in turn is characterized by the presence of fever and stool retention in pigs. Afterwards the condition is replaced by diarrhea and lack of appetite.
Pneumonic plague
With this form of the disease, pigs develop pneumonia, resulting in severe coughing and shortness of breath. Gilts, in order to reduce the level of pain experienced, adopt a sitting position, like dogs. If animals develop pneumonia, it can be fatal.
Chronic form of plague
As a rule, the chronic form of classical plague appears on those pig farms where pigs are vaccinated, but there are some violations in housing standards and diet. First of all, all weakened animals are exposed to the disease. The duration of the disease can vary from 60 days or more. The following signs of classical plague can be observed in infected animals:
- coughing;
- interruptions in appetite - at first it completely disappears, after a while it appears again;
- eczema appears;
- the animals look exhausted.
As a rule, the chronic form of classical plague completely weakens the animal, as a result of which pigs become maximally susceptible to paratyphoid and pasteurellosis.
Signs of swine fever at autopsy
After the infected animal has died and no signs of disease have been identified, an autopsy is usually performed. In this case, classical swine fever can be identified by the following signs:
- there are a large number of hemorrhages on the skin, which differ in configuration and size;
- the lymph nodes are hypertrophied, have a dark bloody tint, and when cut, you can see marbling;
- there are spots on the lungs;
- When opening the heart, hemorrhages can be detected;
- if you look at the signs of swine fever in the photo after autopsy, you can see that there are small, light-colored hemorrhages on the kidneys;
- if death occurs in the subacute form, then you can see buboes characteristic of plague on the intestinal mucosa.
Thanks to the autopsy, it is possible to identify classical swine fever, while excluding the African form (the most dangerous), dysentery and erysipelas.
Is it possible to cure swine fever?
It is important to understand that classical pig plague has a low survival rate, which makes the disease much more dangerous. If necessary, only one way is guaranteed to destroy the plague virus - increasing the temperature. The virus dies immediately during the boiling process, and at a temperature of +75-80°C only within a few hours.
In order to get rid of the virus, it is recommended to use a 2% formaldehyde solution and a bleach solution. It is possible to cure pigs only in the early stages; in the future, the mortality rate can vary from 60% to 100%.
Control measures
In the case where signs of distemper in pigs were identified in the early stages, it is necessary to immediately carry out treatment, using in this case hyperimmune serum. As practice shows, the effectiveness of the drug used largely depends on the stage of the disease.
Today, every farmer has the opportunity to purchase a developed pharmacological complex of drugs, using which the largest number of livestock can be saved.The most important thing is to understand and identify classical plague in time, and then immediately take appropriate measures for further treatment of infected animals.
Prevention measures
In order to prevent such a disease on the farm, it is recommended to resort to preventive measures:
- protect the farm from attacks by wild animals;
- promptly disinfect the premises in which pigs stay;
- new animals must first be quarantined;
- subject the feed to heat treatment, disinfect the water.
The main method by which it is possible to prevent a number of infectious diseases, including classical swine fever, is a vaccine. Complex vaccines are considered the most effective, which have shown their best performance in the course of ongoing research.
It is recommended to vaccinate adults every 10-12 months; piglets should be injected on the 50th and 75th days of life, using 2 ml of the drug. It is recommended to start vaccinating sows 20 days before the expected mating.
Conclusion
Classic swine fever is harmless to humans, but poses a particular danger to farms. This is due to the fact that the mortality rate can even vary from 60 to 100%, as a result of which significant damage will be caused to the pig farm. To prevent the onset of the disease, it is recommended to carry out disease prevention in a timely manner.
