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Breeding pigs is the most profitable business in the livestock industry. Including breeding pigs in a private backyard. If the local veterinary station has nothing against it. Pigs have rapid puberty. Sows bring numerous offspring. Piglets grow rapidly and already at 6 months reach marketable weight. Everything would be fine if the successful and profitable business was not hindered by infectious diseases of pigs, often leading to mass loss of livestock.
One such disease is erysipelas in pigs. An infectious disease that can only be treated with antibiotics and is 100% fatal within 3 to 5 days if treatment is neglected.
Causative agent
The cause of erysipelas is the bacterium Erysipelothrix insidiosa, which belongs to the ubiquitous microorganisms. The bacterium has 3 types: A, B and N. The disease is caused by the first two. 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 swine erysipelas persists in corpses for several months. When out of direct sunlight withstands 1 month. Under 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 fully viable.
Sources of the disease
The disease belongs to the natural focal. Bacteria are widespread in both soil and water, so it will not be 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.
Carriers may not get sick themselves, since for them the bacterium is not the causative agent of the disease, but they carry the infection from sick pigs to healthy ones. Carriers of the disease are also bacterial carriers: clinically healthy animals that excrete the infection into the external environment with urine and droppings.
Since pigs are omnivores, they are often fed sausage waste. Poorly treated waste from a sick pig can be a source of infection for a healthy herd.
Pigs can get sick directly from other carriers only if they eat the carrier. But this rarely happens. Basically, the mechanism of infection of erysipelas is different. It can be transmitted through care products contaminated with bacteria and the environment:
- food and water in contact with the carrier of the infection (mice, pigeons, rats);
- inventory;
- bedding;
- 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 before that the insect drank the blood of a sick animal).
The main route, however, 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, type A accounts for the majority of infections. There are far 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 erysipelas pathogen may be present in a clinically healthy animal in a latent form, nesting in the intestinal follicles and tonsils. Under stress, with a drop in immunity, the pathogen can go into the active phase. Therefore, the disease often occurs in farms without a drift 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 proceeds. 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
This type of flow is rarely recorded in gilts at the age of 7-10 months. Death occurs within a few hours, so the owners do not always have time to notice the symptoms of lightning-type erysipelas in pigs:
- increase in body temperature up to 41-42°C;
- refusal to feed;
- oppression;
- sometimes there are signs of damage to the nervous system.
In some cases, red-violet spots characteristic of erysipelas may appear on the neck, in the intermaxillary space or on the inner side of the thighs. But usually these signs do not have time to develop.
Outwardly, the pigs do not show any signs of the disease. It all looks like the animal died for no reason at all. If you do not perform an autopsy and do not examine the tissues, you can accuse the neighbors of maliciously poisoning the piglets.
In the photo, the erysipelas of pigs in a lightning-fast form.
Acute or septic form
The first signs of a septic form of erysipelas in pigs:
- an increase in body temperature up to 42 ° C;
- fever;
- chills;
- weakness;
- food refusal.
With the further development of the disease, all these signs persist. A few days later, they are added:
- unwillingness to get up
- weakness in hind legs;
- unsteadiness of gait;
- possible development of conjunctivitis;
- sometimes there is an urge to vomit or vomiting;
- constipation and atony of the gastrointestinal tract develop.
24-48 hours after the appearance of the first signs of the disease, pale pink spots appear on the skin of the animal, which 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 the case, 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 fade. Bubbles may appear at the site of the spots, which, after opening, form crusts from dried serous fluid.
Due to pulmonary edema and weakening of the heart, the pig’s condition deteriorates rapidly. The pulse becomes frequent and weak: 90-100 beats / min. The skin on the sides, chest, thighs and in the submandibular space acquires a bluish color. Death occurs 2-5 days after the onset of clinical signs of erysipelas. The mortality 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: in subacute, dense swelling forms on the skin.
At the very beginning, the swelling is colorless, then they acquire a light pink color and continue to darken up to a red-blue hue.
The shape of the swelling is often rectangular or diamond-shaped. With the further development of the disease, the spots merge, and form extensive lesions.
The “plus” of this form of erysipelas is that bacteria only affect the skin, without penetrating inside. The appearance of urticaria means that the pig has begun to recover. The disease resolves 10-12 days after the onset of symptoms.
But with a subacute form, complications are possible. If the urticaria begins with diffuse inflammation of the skin, the animal usually dies. In place of the spots under the epidermis, serous fluid sometimes accumulates or the skin in the place of the spots becomes necrotic. The scab is rejected and it all depends on the area of the lesion. Sometimes a piglet is easier to kill.
Chronic form
The chronic form occurs either when the subacute phase of the disease passes into it, 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 the internal organs. After 1-1,5 months after recovery from the septic form, pigs die from heart failure.
Pathological changes in swine erysipelas
With a lightning-fast course, the signs of the disease do not have time to appear on the skin. Upon opening, they find:
- pulmonary edema;
- hyperemia of organs;
- with a “white” form of erysipelas, a small amount of hemorrhage is present on the serous integuments.
Due to the absence of external signs of the disease, with the sudden death of gilts, it is necessary to conduct research on the face in the laboratory.
In the acute form, “bruises” appear on the skin in the region of the neck, abdomen, chest and ears caused by subcutaneous hemorrhages. The spleen is slightly enlarged. Lymph nodes are juicy, with a red-blue tint, enlarged. The mucous membrane of the stomach is bright red, swollen, with petechial hemorrhages. It may be covered with poorly washed off viscous mucus. In the small intestine, the changes are similar.
Buds are cherry red, with well-defined foci of a darker color. The boundary 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, after rejection, leave scars behind. At autopsy, lesions of the bicuspid valves are found in the heart. The tricuspid, pulmonary, and aortic valves are less commonly affected. On the valves there is fibrin sprouted with a connective mass, looking like a head of cauliflower.
When diagnosing a chronic form, it is necessary to exclude:
- the plague;
- polyarthritis;
- mycoplasmosis polysezorite;
- corynebacterium infection;
- rickets;
- adenococcal infection;
- osteomalacia.
Swine fever can look very similar to erysipelas.
How to treat erysipelas in pigs
Treatment of swine erysipelas is prescribed by a veterinarian. Erysipelas bacteria are sensitive to tetracycline, gentamicin, erythromycin, penicillin. On all antibiotics for veterinary use, the dosage is indicated per kilogram of body weight. Diseases such as swine erysipelas are best treated if a course of antibiotics is combined with an anti-erysipelas serum. Serum is administered subcutaneously or intramuscularly.
Antibiotics reduce serum activity, as they have an immunosuppressive effect. Serum is produced by several manufacturers at once. Therefore, the dosage of serum against swine erysipelas should be viewed in the instructions for the drug.
Specialized antibacterial treatment is combined with symptomatic: purulent wounds are washed if the skin has begun to be shed. Provide piglets with warm food and drink. Sick pigs are isolated and returned to the general herd only 2 weeks after the disappearance of the last signs of the disease.
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 “home conditions” means the use of “folk remedies”, it is better to forget this idea right away. No folk remedies for a bacterium – the causative agent of erysipelas do not work.
Vaccine against swine erysipelas
In Romania, in the 30s of the last century, a strain of swine erysipelas WR-2 was isolated, which has a 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 trade networks, the vaccine, depending on the manufacturer, may have different names, which are patented trademarks. In Our Country, the vaccine is produced by the Stavropol Biofactory under the proprietary name Ruvak and the Armavir Biofactory, which uses the generic name.
Instructions for use of the Ruvak vaccine against swine erysipelas
The vaccine is produced in vials of 20 ml. Each vial contains 10 to 100 doses of dry vaccine. Before use, 10 ml of distilled water or saline is injected into the vial. It is easier to buy a sterile saline solution than water, so it is better to use the first one. 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 dose of the vaccine per animal is 1 ml. The vaccine is administered near the auricle or intramuscularly into the inner part of the thigh. Vaccination of pigs against erysipelas is carried out according to several schemes, depending on the age of the vaccinated individual. Piglets are vaccinated at 2 months of age so that by the time their passive immunity ends, the animals would be protected.
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 swine 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 erysipelas vaccine can trigger the bacteria to become active. This happens if the vaccinated animal already had erysipelas in a latent form or it still had an incubation period. In the second case, the pig would still get sick with erysipelas, but the vaccine in this case exacerbates the course of the disease.
With a latent form, pigs look healthy, but the additional introduction of a portion of live pathogens works as a catalyst for the process. Usually in this case, the pig becomes ill with a chronic form of erysipelas.
In the photo, the occurrence of erysipelas in a pig after vaccination.
Instructions for use of serum against swine erysipelas
Serum against swine erysipelas is made from the blood of cattle and pigs that have had erysipelas. In Our Country, 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 the use of serum from swine erysipelas provides for 2 options for using the drug: therapeutic and prophylactic.
The frequency of use and dosage of serum from swine erysipelas is different for each case. For prophylaxis, serum is used once and in the amount indicated on the vial. Usually there is indicated 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. In the treatment, the drug is used together with antibiotics. If necessary, repeat the serum after 8-12 days.
The drug is administered in the same places as the vaccine: behind the ear or in the inner side of the thigh. There are no contraindications for the use of 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 the pathogen from the outside. Since the bacterium is present everywhere, it is enough for an outbreak of the disease that the immune system weakens in pigs. Therefore, the provoking factors for the onset of the disease are poor conditions of detention:
- lack of ventilation;
- dampness;
- dirty bedding;
- overcrowding of pigs;
- dirty walls.
The main preventive measures are compliance with sanitary standards for keeping pigs.
In the event of a disease outbreak, obviously unhealthy pigs are isolated and treated. A healthy livestock is pierced with a vaccine and an anti-erysipelas serum. Healthy livestock are observed for 10 days. Quarantine is removed from the farm 2 weeks after the last case of death or recovery of the pig.
The mandatory conditions for lifting the quarantine are:
- livestock vaccination;
- thorough cleaning and disinfection of the territory of the entire pig farm and equipment.
Pigs are vaccinated in Our Country most often with the Ruvak vaccine. But it is almost impossible to carry out a major cleaning of a pigsty in a private courtyard.
Is it possible to eat meat in pigs with erysipelas
The solution to the dilemma of whether it is possible to eat meat if the pig is sick with erysipelas depends solely on disgust and awareness of the presence of the disease. The reference books on veterinary medicine indicate that swine erysipelas is not a disease in which the consumption of meat is prohibited.
But few who have seen how erysipelas appear in pigs will want to eat this meat. Selling it without warning the buyer is unethical. True, few people care. At meat processing plants, the meat of pigs with signs of illness goes into sausages. Heat treatment in this case kills the pathogen, and the sausage becomes safe to eat. And necrotic foci in the sausage are not visible.
Conclusion
It is best to observe the conditions for keeping pigs in order to prevent an outbreak of erysipelas. But if it was not possible to avoid the disease, 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 thorough boiling.