Among the diseases that can cause significant damage to the livestock of a pig farm, pig pasteurellosis is an infectious disease caused by Pasteurella multividia. Infection is transmitted by airborne droplets, affecting the blood vessels of the host. The pathogen in a short period of time is able to infect all the inhabitants of the pigsty, and without timely treatment, mortality among piglets and young animals reaches 75-100%.
The main danger of this disease for pigs lies in the wide spread of bacteria and its rapid adaptation to environmental conditions and carriers. At present, there are known strains capable of living in the organisms of almost all species of mammals, including humans and birds. Insects can also become carriers of infection, especially ticks.
Ways of infection also varied. In many cases, the bacterium enters the body of an animal using the airborne droplet, although there are known cases of infection of pigs when eating infected food or water, as well as after the bites of blood-sicking insects.
Weaned piglets and young feeding animals, which do not have a strong immunity to this pathogen, are most susceptible to the disease. Pasteurella penetrates into the blood vessels, where it begins to thrive and multiply, poisoning the host organism with toxic waste of its vital activity. The animal produces antibodies that kill the bacteria, resulting in the accumulation of a large amount of mucus that is expelled when sneezing.
In pigs, blood clots may occur, which ceases to fully flow to the organs. There is lethargy, and without treatment, after 3–8 days, most piglets die. Animals with stronger immunity are able to fight infection for several months, but they almost never reach the standard bottomhole weight.
Afraid of the sun and heat
The causative agent of pasteurellosis in pigs has a low resistance to disinfectants and can be quite easily destroyed in the case of regular sanitary and hygienic measures on the farm.
Without disinfection, the bacterium can live in water for 27 days at a temperature of 5 to 8 degrees. In the humus, it retains its viability for a month, and in slurry up to 72 days.
In corpses of animals, pasteurella continues to develop and is dangerous from 90 to 120 days, and in frozen meat of slaughtered pigs, life-resistant bacteria can be detected even after a year.
Despite the ability to quickly adapt to environmental conditions, pasteurella perishes during processing:
- 5% solution of phenol and 0.5% creolin - for one minute;
- 1% solution of blue vitriol - for 3 minutes;
- 5% milk of lime kills the pathogen in 4-5 minutes;
- treatment with bleach removes bacteria from 20 minutes;
- direct sunlight destroys Pasteurella multividia within 5-10 minutes.
The causative agent of pasteurellosis in pigs does not tolerate temperatures from 70 degrees Celsius and above (Pasteur barrier), dying for 5-10 minutes.
Disease of weak pigs
In most cases, the disease is transmitted by airborne droplets through the saliva and mucus secreted by sick animals when sneezing. For the introduction of pasteurellosis into the host organism, it is necessary that the pigs have small wounds in the mouth and mucous membranes. Through them, the bacterium enters the lymphatic fluid and the blood is carried throughout the body.
She prefers to localize in the oxygen-rich alveoli of the lungs. If the body of a pig or young pig is not immune from pasteurellosis, then the parasite will multiply rapidly in the affected organ, which will poison the host with toxic substances.
The pig's immune system produces a large amount of antibodies that die with the bacteria. They form accumulations of mucus that clogs the respiratory passages, and provoke sneezing reflexes that cause the spread of bacteria.
The toxic substances produced by pasteurella negatively affect the walls of the lymphatic and blood vessels, significantly increasing their permeability. As a result, an animal that is sick with pasteurellosis develops edema in the chest area, reduces blood clotting and increases bleeding.
Bruises appear on the body of the pig, and when it is pressed against the chest, it feels pain. In milk pigs infected with pasteurellosis from sows, diathesis is possible.
Pulmonary disease with high mortality
The causative agent of pasteurellosis at penetration into the body of the carrier does not manifest itself immediately. Depending on the resistance of the pig to infection, the incubation period can be from 1 to 14 days. There is a septic course of the disease and a secondary form that affects animals that have undergone other diseases.
The septic form of the disease is called hemorrhagic septicemia. It can be acute, over-acute and chronic.
With an over-acute course of the disease, the body temperature in pigs rises to +41 or more degrees, and fever begins. The animal feels depressed, it loses its appetite and shortness of breath. Cyanosis develops in the chest, stomach, thighs and ears. To save such a pig is impossible and he will die within 1-2 days.
Disguised as other pathologies.
In the acute course of the disease, pigs often begin to cough and feel severe pain when pressing on the chest. Red and bluish spots appear on the skin, mucus is released from the nose, and suffocation occurs. The death of a sick animal occurs in 3-8 days, although some individuals are able to fight with pasteurellosis for up to 14 days, and in some cases the disease can become chronic.
Individuals with a chronic course of the disease constantly cough, their joints become swollen and scabby eczema appears. Pigs can live for several more months and even get meaty condition, but they surely die, remaining the center of the spread of a dangerous infection.
Due to the fact that the first signs of the disease are difficult to distinguish from the plague, erysipelas, salmonellosis, and viral pneumonia. If you identify a sick animal, you must immediately isolate it from the rest of the pigs and show the vet.
Only employees of the veterinary service are able in laboratory conditions to identify the pathogen and prescribe a treatment for pasteurellosis.
Isolation and surgical treatment of pigs is required.
If the disease is detected at the initial stage of development, then treatment of animals can be prescribed. As a rule, Ekmonovotsillin, Dibiomycin, and Novarsenol solution are used to destroy the pasteurellosis pathogen and to eliminate intoxication. Good results are demonstrated by antipasterelae serum, administered to piglets along with penicillin and tetracycline antibiotics.
A special vaccine against pigs pasteurellosis is made on the basis of cattle blood. It contains the deactivated cells of this bacterium, which are conserved by 0.5% phenol solution. Whey is a yellowish-red slurry, which may be white precipitate.
It is necessary to store the serum at a temperature of + 2 + 15 degrees Celsius in a dark place, and before the introduction into the body of an animal to warm up to +26 degrees.
In severe cases, sows and manufacturers are prescribed blood transfusions, oxygen inhalation, and medications of the ATP group (adenosine triphosphate acid).
A prerequisite for treatment is enhanced nutrition with foods rich in B vitamins, as well as abundant drinking. Indoors, with the help of ventilation, it is necessary to reduce the level of humidity as much as possible, but drafts are not allowed. In some cases, it is prescribed in the summer to remove animals from a pig farm in order to expose their bodies to ultraviolet solar radiation.
Vaccinations and prophylaxis will protect against infection
Today, vaccination is considered the most effective way to protect pigs from pasteurellosis. Pigs born from unvaccinated sows are vaccinated at the age of 12-15 days. Babies receive immunity for a period of a month from females vaccinated against pasteurellosis; after 30 days of life, they should be vaccinated. And after 35-40 days the injection with serum is repeated. Only after double vveniya effect is possible.
Immunity to the disease in animals after vaccination persists for six months, after which the introduction of serum is required to be repeated.
However, vaccination is not able to 100% guarantee that a pig with weak immunity will remain healthy. Without constant prophylaxis it is impossible to maintain the health of the livestock and get a serious income when slaughtering animals.
A prerequisite for the preservation of healthy livestock is the creation of optimal conditions for the growth of animals with enhanced immunity to various infectious diseases. In the pigsty it is necessary to keep the optimum level of humidity and cleanliness, regularly removing the waste of pigs. Systematic disinfection of premises will also reduce the risk of infection with pasteurellosis.
When identifying problem animals, they should be immediately isolated from the rest. If treatment is impractical, then the sick pig must be rejected and its body burned.
Eating meat from pigs infected with pasteurellosis is strictly prohibited.
Such pigs can not be sold to other farms, donated to slaughterhouses or meat processing plants. Vaccination should be carried out only among healthy individuals.
In the event that a pasteurellosis center appears on your farm, all premises should be subjected to a two-week quarantine, during which you need to disinfect several times. In some cases, it is recommended to repair the interior of the pigsty and remove building materials contaminated with bacteria.
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