Content
Pig breeding is the most profitable business in the livestock industry. Including breeding pigs on a private farmstead. If the local veterinary station has nothing against it. Pigs go through puberty quickly. Sows give birth to numerous offspring. Piglets grow quickly and reach marketable weight by 6 months. Everything would be fine if infectious diseases did not interfere with successful and profitable business pig diseases, often leading to mass mortality of livestock.
One of these diseases is erysipelas in pigs. An infectious disease that can only be treated with antibiotics and is 100% fatal within 3-5 days if treatment is neglected.
The causative agent of the disease
The cause of erysipelas is the bacterium Erysipelothrix insidiosa, which is one of the ubiquitous microorganisms. The bacterium has 3 types: A, B and N. The first two cause the disease.Moreover, type B has high immunogenic properties and is used for the production of vaccines.
The bacterium is highly resistant in the external environment. The causative agent of pig erysipelas persists in corpses for several months. When out of direct sunlight, withstands 1 month. In direct sunlight it dies within a few hours. Sensitive to heat treatment: at +70°C it dies in 2-5 minutes, at +100°C – in a few seconds.
The bacterium is sensitive to broad-spectrum antibiotics and disinfectants. When smoking and salting pork products, the causative agent of erysipelas in pigs remains completely viable.
Sources of the disease
The disease is classified as natural focal. Bacteria are widespread in both soil and water, so it is not possible to completely get rid of them. Piglets aged 3-12 months are most susceptible to the disease. Like many diseases, erysipelas in pigs is transmitted through carriers of the disease:
- rats and mice;
- birds;
- livestock;
- blood-sucking insects.
The carriers themselves may not get sick, since for them the bacterium is not the causative agent of the disease, but they transmit the infection from sick pigs to healthy ones. Bacteria carriers are also carriers of the disease: clinically healthy animals that release the infection into the external environment through urine and droppings.
Since pigs are omnivores, they are often fed waste from sausage production. Poorly handled waste from a sick pig can become a source of contamination for a healthy herd.
Directly from other carriers, pigs can only get sick if they eat the carrier. But this rarely happens.Basically, the mechanism of infection with erysipelas is different. It can be transmitted through bacteria-contaminated care items and the environment:
- food and water that have been in contact with the carrier of the infection (mice, pigeons, rats);
- inventory;
- litter;
- floor and walls of the pigsty;
- soil in which the corpses of dead animals are buried (up to 1 year);
- slurry (several months);
- blood-sucking parasites (if the insect previously drank the blood of a sick animal).
The main route, after all, is the soil, and erysipelas is subject to seasonality. The peak of diseases occurs in autumn and spring. In winter it is too cold for bacteria, in summer it is too hot. But if the summer is cold, pigs can get sick in the summer.
Forms of the disease and their symptoms
Of the 3 antigenic types A, B and N, the majority of cases of infection occur with type A. There are much fewer cases of infection with type B, and N very rarely provokes the development of the disease. It is usually isolated from clinically healthy animals.
The causative agent of erysipelas may be present in a clinically healthy animal in a latent form, nestling in the intestinal follicles and tonsils. Under stress, when immunity declines, the pathogen can enter the active phase. Therefore, the disease often occurs on farms without being introduced from outside.
There is no exact picture of what erysipelas looks like in pigs, since it all depends on the form in which the disease occurs. The only common feature is the incubation period, which lasts 2-8 days.
The course of erysipelas can be:
- lightning fast;
- sharp;
- subacute;
- chronic.
There can also be 3 forms: septic, cutaneous and latent. With a latent, that is, hidden, course, the animal looks healthy, but infects the livestock.
Lightning fast
This type of course is rarely recorded in gilts aged 7-10 months. Death occurs within a few hours, so owners do not always have time to notice the symptoms of fulminant erysipelas in pigs:
- increase in body temperature to 41-42°C;
- refusal of food;
- oppression;
- Sometimes signs of damage to the nervous system appear.
In some cases, red-violet spots characteristic of erysipelas may appear on the neck, in the intermaxillary space or on the inside of the thighs. But usually these signs do not have time to develop.
Externally, pigs do not show any signs of disease. It looks like the animal died for no reason at all. If an autopsy is not performed and tissues are not examined, neighbors can be accused of maliciously poisoning the piglets.
In the photo, pigs have lightning-fast erysipelas.
Acute or septic form
The first signs of septic erysipelas in pigs:
- increase in body temperature up to 42°C;
- fever;
- chills;
- weakness;
- refusal of food.
With further development of the disease, all these signs persist. A few days later the following are added to them:
- reluctance to get up;
- weakness in hind legs;
- unsteadiness of gait;
- possible development of conjunctivitis;
- sometimes gagging or vomiting occurs;
- constipation and gastrointestinal atony develop.
24-48 hours after the first signs of the disease appear, pale pink spots appear on the animal’s skin that protrude above the surface of the body.
The photo shows what the septic form of erysipelas looks like in pigs in the initial stage.
Shortly before death, these areas become dark purple due to the formation of blood clots in the blood vessels. The spots merge and acquire clear boundaries. When pressed, the marks turn pale. At the site of the spots, bubbles may appear, which, after opening, form crusts of dried serous fluid.
Due to pulmonary edema and weakened cardiac activity, the pig's condition quickly deteriorates. The pulse becomes frequent and weak: 90-100 beats/min. The skin on the sides, chest, thighs and submandibular space becomes bluish in color. Death occurs 2-5 days after the appearance of clinical signs of erysipelas. The mortality rate of pigs reaches 55-80%.
Subacute form
At the initial stage of erysipelas in pigs, the signs of acute and subacute forms are identical. After 1-2 days, differences can already be observed in the two forms of the disease: with subacute, dense swellings form on the skin.
At the very beginning, the swellings are colorless, then they acquire a light pink color and continue to darken to a red-blue hue.
The shape of the swelling is often rectangular or diamond-shaped. With further development of the disease, the spots merge and form large areas of damage.
The “advantage” of this form of erysipelas is that the bacteria only affect the skin without penetrating inside. The appearance of hives means that the pig has begun to recover. The disease disappears 10-12 days after the onset of symptoms.
But with the subacute form, complications are also possible. If urticaria begins with diffuse inflammation of the skin, the animal usually dies. At the site of the spots, serous fluid sometimes accumulates under the epidermis or the skin at the site of the spots becomes necrotic. The scab is rejected and it all depends on the area of the lesion. Sometimes it's easier to kill a pig.
Chronic form
The chronic form occurs either during the transition to the subacute phase of the disease, or as a result of an exacerbation of the latent form of erysipelas. Symptoms of chronic erysipelas in pigs:
- skin necrosis;
- arthritis;
- endocarditis.
In the chronic course, animals die not directly from erysipelas, but from the consequences of the disease. The bacterium affects not only the skin, but also internal organs. 1-1.5 months after recovery from the septic form, the pigs die from heart failure.
Pathological changes in swine erysipelas
With lightning-fast progression, signs of the disease do not have time to appear on the skin. Upon opening they find:
- pulmonary edema;
- organ hyperemia;
- with the “white” form of erysipelas, a small amount of hemorrhage is present on the serous integument.
Due to the absence of external signs of the disease, in case of sudden death of gilts, it is necessary to conduct tests for erysipelas in the laboratory.
In the acute form, “bruises” caused by subcutaneous hemorrhages appear on the skin in the neck, abdomen, chest and ears. The spleen is slightly enlarged. Lymph nodes are juicy, with a red-blue tint, enlarged. The gastric mucosa is bright red, swollen, with pinpoint hemorrhages. May be covered with difficult to wash off sticky mucus. The changes in the small intestine are similar.
The buds are cherry red, with clearly defined foci of a darker color. The border between the medulla and the cortical layer is erased.
The acute form of erysipelas is differentiated from anthrax, plague, pasteurellosis, listeriosis, salmonellosis, heat and sunstroke.
In the chronic form, black scabs form on the skin, which, when rejected, leave behind scars.At autopsy, lesions of the bicuspid valves are found in the heart. Less commonly affected are the tricuspid, pulmonary and aortic valves. On the valves there is fibrin overgrown with a connective mass, looking like a head of cauliflower.
When diagnosing the chronic form, it is necessary to exclude:
- plague;
- polyarthritis;
- mycoplasmosis polysesoritis;
- corynebacterial infection;
- rickets;
- adenococcal infection;
- osteomalacia.
Swine fever can look very similar to erysipelas.
How to treat erysipelas in pigs
Treatment for pig erysipelas is prescribed by a veterinarian. Erysipelas bacteria are sensitive to tetracycline, gentamicin, erythromycin, and penicillin. All veterinary antibiotics indicate the dosage per kilogram of weight. Treatment of diseases such as swine erysipelas occurs better if a course of antibiotics is combined with anti-erysipelas serum. The serum is administered subcutaneously or intramuscularly.
Antibiotics reduce serum activity because they have an immunosuppressive effect. The serum is produced by several manufacturers. Therefore, the dosage of serum against pig erysipelas should be found in the instructions for the drug.
Specialized antibacterial treatment is combined with symptomatic treatment: purulent wounds are washed if the skin begins to tear off. Provide piglets with warm food and drink. Sick pigs are isolated and returned to the general herd only 2 weeks after the last signs of the disease disappear.
Treatment of erysipelas in pigs at home is carried out under the supervision of a veterinarian and according to the usual treatment regimen for this disease. In fact, no one takes pigs to special clinics.But if by “home conditions” we mean the use of “folk remedies”, it is better to immediately forget this idea. No folk remedies work against the bacterium that causes erysipelas.
Vaccine against swine erysipelas
In Romania, in the 30s of the last century, a strain of pig erysipelas, WR-2, was isolated, which has high immunogenicity. Today, it is on the basis of this strain that all vaccines against swine erysipelas are made.
The phrase “generic name” means that this is the international designation of the drug. In retail chains, the vaccine may have different names, which are proprietary trademarks, depending on the manufacturer. In Russia, the vaccine is produced by the Stavropol biofactory under the patented name “Ruvak” and the Armavir biofactory, which uses a non-proprietary name.
Instructions for use of the Ruvak vaccine against swine erysipelas
The vaccine is produced in 20 ml bottles. Each vial contains from 10 to 100 doses of dry vaccine. Before use, add 10 ml of distilled water or saline solution into the bottle. Sterile saline solution is easier to buy than water, so it’s better to use the former. It can be bought at the same veterinary pharmacy as the vaccine.
After adding the saline solution, shake the vial vigorously until a suspension is obtained. The vaccine dose per animal is 1 ml. The vaccine is administered near the ear or intramuscularly into the inner thigh. Vaccination of pigs against erysipelas is carried out according to several schemes, depending on the age of the vaccinated individual.Piglets begin to be vaccinated at 2 months, so that by the time their passive immunity ends, the animals would have protection.
Young animals are vaccinated three times:
- At the age of 2 months.
- 25-30 days after the first vaccination.
- 5 months after the second revaccination.
If the age of the first vaccination was missed and the piglets have grown to 4 months, they are vaccinated 2 times: the first time at the age of 4 months, the second time at 9 months. Sows are vaccinated once a year 10-15 days before insemination.
After vaccination against pig erysipelas, animals may experience a reaction to the virus:
- temperature rise to 40.5°C in the first 2 days;
- loss of appetite;
- depressed state.
These side effects usually go away on their own and do not require intervention.
Complications after vaccination
Instead of protecting against the disease, the vaccine against swine erysipelas can provoke the activation of bacteria. This happens if the vaccinated animal already had latent erysipelas or its incubation period was still long. In the second case, the pig would still get erysipelas, but the vaccine in this case worsens the course of the disease.
In the latent form, pigs appear healthy, but additional injection of live pathogens acts as a catalyst for the process. Usually in this case the pig becomes ill with a chronic form of erysipelas.
The photo shows the occurrence of erysipelas in a pig after vaccination.
Instructions for use of serum against erysipelas of pigs
Serum against swine erysipelas is made from the blood of cattle and pigs that have had erysipelas. In Russia it is produced by the Armavir biofactory.The drug is intended for the treatment and prevention of erysipelas in pigs. Provides passive immunity for 2 weeks.
Instructions for using serum against pig erysipelas provide 2 options for using the drug: therapeutic and prophylactic.
The frequency of use and dosage of pig erysipelas serum is different for each case. For prevention, the serum is used once and in the amount indicated on the bottle. Usually it indicates the number of milliliters per kilogram of live weight. The indicated dose is multiplied by the weight of the animal.
For medicinal purposes, the dose of serum is doubled. During treatment, the drug is used together with antibiotics. If necessary, the serum is reintroduced after 8-12 days.
The drug is injected into the same places as the vaccine: behind the ear or into the inner thigh. There are no contraindications for using the serum. There are no restrictions on the use of meat after the introduction of whey.
Prevention of erysipelas in pigs
Erysipelas in pigs can occur even without the introduction of a pathogen from outside. Since the bacterium is present everywhere, all it takes for a disease outbreak to occur is for pigs to have a weakened immune system. Therefore, poor conditions of detention serve as provoking factors for the occurrence of the disease:
- lack of ventilation;
- dampness;
- dirty bedding;
- crowding of pigs;
- dirty walls.
The main preventive measures are compliance with sanitary standards for keeping pig stock.
When an outbreak occurs, pigs that are clearly unwell are isolated and treated. Healthy livestock are injected with vaccine and anti-erysipelas serum. Healthy livestock are monitored for 10 days.Quarantine is removed from the farm 2 weeks after the last case of death or recovery of a pig.
The mandatory conditions for lifting quarantine are:
- livestock vaccination;
- Thorough cleaning and disinfection of the entire pig farm and equipment.
Pigs in Russia are most often vaccinated with the Ruvak vaccine. But a thorough cleaning of a pigsty on a private farmstead is almost impossible.
Is it possible to eat meat from pigs with erysipelas?
The solution to the dilemma of whether it is possible to eat meat if a pig has erysipelas depends solely on disgust and awareness of the presence of the disease. Veterinary reference books indicate that swine erysipelas is not a disease that prohibits the consumption of meat.
But few who have seen how erysipelas manifests itself in pigs will want to eat this meat. Selling it without warning the buyer is unethical. True, few people care about this. At meat processing plants, meat from pigs with signs of illness is used for sausage. In this case, heat treatment kills the pathogen, and the sausage becomes safe for consumption. But necrotic foci are not visible in the sausage.
Conclusion
It is best to observe the conditions in which pigs are kept to prevent an outbreak of erysipelas. But if the disease cannot be avoided, treatment and quarantine of the livestock is carried out under the supervision of a veterinarian. It is better not to eat the meat of sick pigs without thoroughly boiling them.
