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Classical swine fever can infect 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 disinfection of premises, disposal of animals, and quarantine measures. In order to minimize costs, it is recommended to carry out preventive measures to prevent diseases and detect plague at an early stage. This type of disease received the following name – classical swine fever. This was done so that it was possible to distinguish the disease from a more dangerous species – African swine fever.
General characteristics of the disease
As you know, to study this disease began for the first time in the United States in 1830-1833. It was possible to prove the viral nature of plague in pigs in 1903. By this time, signs of plague in pigs began to appear across the ocean and in other European countries. Classical plague was first discovered in Our Country in 1893.
At first, scientists assumed that this disease was caused by a pathogen – B. Suipestifer. But later, American scientists found that the presence of this dangerous microorganism for animals was caused by swine paratyphoid. The causative agent appears in the body of animals that have undergone this disease.
Causative agent
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 the photo, 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 up to 12 months.
Vitality is observed even in the food of slaughtered animals:
- 300 days in corned beef;
- from 2 years and more in frozen meat products.
Classical plague has several types of virus, among which the following are worth highlighting:
- type A – can cause an acute form of the disease;
- type B – a 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 by the respiratory route, through defects on the skin. After 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 distemper 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 is not dangerous for humans. As a result of the fact that plague pathogens and its varieties have not been well studied 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 later date and it is no longer possible to treat it in this state, veterinary workers, when an epidemic is detected, eliminate infected individuals and all animals that were in close proximity to sick pigs. For farms, the classic plague is a real disaster, as it takes away 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 you know, classical plague can occur in pigs in the following forms:
- lightning fast;
- acute;
- subacidic;
- chronic.
If you understand how these forms differ from each other and how to recognize them, then you can prevent the mass infection of animals on a pig farm.
Lightning plague form
As a rule, this form appears only in suckling piglets. During infection, fever, depression of the animal, and vomiting can be observed. In some cases, piglets may go into a coma or have convulsions. As practice shows, death occurs 24-48 hours after the first signs of the disease appear.
Acute plague in swine
This form is characterized by the following symptoms:
- hyperthermia with an increase in body temperature up to 40,5-42°C;
- after 2-3 days, the animals begin to gradually lose their appetite;
- pigs experience a constant feeling of thirst;
- chills appear over time;
- vomiting occurs;
- constipation is replaced by hemorrhagic diarrhea;
- conjunctivitis appears, the eyelids begin to swell and stick together due to a large discharge of pus;
- the back becomes hunched, the animals burrow into the litter;
- paresis of the hind limbs appears;
- urine takes on a dark tint;
- on the skin you can see small bubbles that are filled with a yellow liquid;
- in addition, hemorrhages can be observed on the surface of the skin, which merge. After some time, the skin becomes purple. If you press, the spots will not disappear;
- nasal bleeding develops;
- heart failure occurs
- ears, tail, piglet become blue;
- before the onset of death, hypothermia develops with a temperature regime of 35-36 ° C.
In young pigs, the acute form of classical distemper lasts for 7-10 days, sows will have abortions.
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 period of illness can last from 2 to 3 weeks.
In the photo below, a weakened animal with signs of classical swine fever.
Intestinal form of plague
In animals, enterocolitis occurs, which in turn is characterized by the presence of fever in pigs, stool retention. After the condition is replaced by diarrhea, lack of appetite.
Pneumonic plague
With this form of the disease in pigs, the development of pneumonia is observed, resulting in a strong cough, shortness of breath. Gilts, in order to reduce the level of pain they experience, adopt a sitting position, like dogs. If the animals have pneumonia, it can be fatal.
Chronic plague
As a rule, the chronic form of classical plague appears on those pig farms where the pigs are vaccinated, but there are some violations in the standards of maintenance 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. In infected animals, the following signs of classical plague can be observed:
- coughing;
- interruptions in appetite – at first it completely disappears, after a while it reappears;
- eczema appears;
- the animals look emaciated.
As a rule, the chronic form of classical plague completely weakens the animal, as a result of which the pigs become maximally susceptible to paratyphoid and pasteurellosis.
Signs of swine fever at autopsy
After the infected animal has died and no signs of the disease have been identified, as a rule, an autopsy is performed. In this case, classical swine fever can be identified by the following features:
- on the skin there is a large number of hemorrhages, which differ in configuration and size;
- the lymph nodes are hypertrophied, have a dark bloody hue, marbling can be seen upon incision;
- there are spots on the lungs;
- at autopsy, hemorrhages can be detected on the heart;
- if you look at the signs of plague in pigs in the photo after opening, you can see that there are small hemorrhages on the kidneys of a light shade;
- if death occurs in the subacute form, then buboes characteristic of the plague can be seen 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.
Can swine fever be cured?
It is important to understand that with classical swine fever, there is a low survival rate, which makes this disease much more dangerous. If necessary, the only way to destroy the plague virus is guaranteed to help is to increase the temperature regime. The virus dies immediately during the boiling process, and at a temperature of + 75-80 ° C only for several 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 number of cases can vary from 60% to 100%.
Control measures
In the event that signs of distemper in pigs were detected in the early stages, treatment should be carried out immediately, using hyperimmune serum in this case. 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, you can save the largest number of livestock. The most important thing is to understand and identify classical plague in time, and then immediately take appropriate measures to further treat infected animals.
Preventive measures
In order to prevent such a disease on a farm, it is recommended to resort to preventive measures:
- protect the farm from attack by wild animals;
- timely disinfect the premises in which the pigs stay;
- send new animals to quarantine;
- 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. The most effective are complex vaccines, which in the process of ongoing research have shown their best side.
Adults are recommended to be vaccinated every 10-12 months, piglets should be injected on the 50th and 75th day of life, using 2 ml of the drug. It is recommended to start vaccinating sows 20 days before the expected mating.
Conclusion
Classical swine fever is harmless to humans, but it 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 the pig farm will be significantly damaged. To prevent the occurrence of the disease, it is recommended to carry out the prevention of the disease in a timely manner.
