Red disease or swine erysipelas is a notifiable disease that can become very serious in pigs. The first image that comes to mind about this disease is the reddish skin lesions around the pig's skin. However, red evil can give rise to much more symptoms, from septicemic forms to arthritic or endocardial forms with sudden death.
The control of this disease must be through vaccination, since the bacterium is very resistant in the environment and highly contagious, so eradication is really difficult. Keep reading this article on our site to learn more about erythema in pigs, its symptoms and treatment
What is red sickness in pigs?
Swine erythema is an infectious and highly contagious disease that affects pigs causing acute cutaneous and septic conditions, as well as chronic with arthritis, dermatitis and endocarditis. Other animals that can be affected are wild boars, turkeys, sheep or fish. Sick people can also be affected, since the red sickness is a zoonosis, causing a skin lesion called Erypsela of Rosenbach.
This is a multifactorial disease, so environmental factors are involved in its development. These factors are:
- High temperatures.
- High humidity.
- Climate changes.
- Groups of pigs.
- Food changes.
- Transportation.
- Other infections (mycotoxins, PRRS, parasites…).
- Vaccinations.
- Consanguinity.
- Differences in temperature between day and night.
You may also be interested in this other article on the most common diseases of Vietnamese pigs.
What causes red sickness in pigs?
The disease is caused by Erysipelothrix rhusiupathiae, a bacteria in the form of a bacillus, aerobic or facultative anaerobic, sensitive to a pH below 7, 5.
Infected pigs shed swine erypsela in feces, oronasal exudates, urine, and semen; and are infected orally by consuming food or water contaminated with the bacteria or by contact with an infected animal or matings. Pigs are more susceptible between 10 weeks and 10 months of age
The bacteria is very resistant in the environment, remaining for months in the facilities, meat and flour. It is eliminated with quaternary disinfectants of ammonium, soda, formaldehyde and glutaraldehydes.
In addition, it presents two serovariants:
- Serovariant 1: very virulent, causes septicemia.
- Serovariant 2: less virulent. It causes the chronic and subacute forms.
Clinical forms of red disease in pigs and their symptoms
The incubation period is short, with a maximum of 7 days. This disease can give rise to septicemic (acute or subacute), urticariform, endocardial, arthritic and dermal forms.
Septicemic forms of swine erythema
After infection, the bacteria travel to the tonsils or Peyer's patches, which are lymphoid structures. Then will be located in the blood, damaging the endothelium of blood vessels thanks to neuraminidase, which also decreases the viability of blood cells. This releases fibrin and causes ischemic necrosis of perivascular tissues, hyaline thrombi, edema, accumulation of monocytes in the vascular wall, anemia, hemolysis, immunosuppression, coagulopathies, and thrombocytopenia.
The acute form is characterized by:
- Fever.
- Apathy.
- Anorexy.
- Painful arthritis.
- Enlarged spleen.
- Blepharoconjunctivitis.
- Decay.
- Lethargy.
- Skin erythemas, consisting of reddish-pink skin lesions, with diffuse and irregular edges and a flat surface on the ears, back and areas declines.
The subacute form occurs when the pig has some immunity. They hardly have symptoms, and fever, respiratory signs, growth retardation and abortions may appear.
Urticariform form of swine erythema
It is usually produced by serovar 2 in immunized animals. The bacterium in this case goes to the skin, where it causes damage to the dermal capillaries and is characterized by:
- Moderate fever.
- Bad general state.
- Restlessness.
- Anorexy.
- Deep red skin papules, polyhedral, with raised surface, hot and non-painful on the outer face of the hind limbs, area back-lumbar, ears and back. These lesions progress to vesicles, dark discolored lesions in the center and scabs that fall off.
Endocardial form of porcine erythrocyte disease
It is produced by evolution of a septicemic form. A Verrucous proliferative valvular endocarditis develops in the mitral valve, which may be accompanied by aortic stenosis. This produces:
- Endothelial degeneration.
- Thrombosis.
- Dyspnoea.
- Tachypnea.
- Cyanosis.
- Sudden death by collapse.
- Stunted growth.
Arthritic form of swine erythema
Also caused by the evolution of a septicemic form. A acute arthritis occurs initially in which bacteria-rich synovial fluid builds up, making the joint hot, painful, and swollen. The pig will present:
- Tip toe walking.
- Pain.
- Limp.
- Stunted growth.
- Ankylosis.
- Lordosis.
Dermal form of swine erythema
It is produced by the evolution of an urticariform form, it occurs only in places with very poor conditions. It occurs dermatitis with cold, dry and insensitive skin that peels off like paper or cardboard.
Diagnosis of red disease in pigs
Swine disease is suspected if symptoms appear in pigs between 10 weeks and 10 months of age, under favorable environmental and husbandry conditions, or if there has been any deficiency in the vaccination plan. The differential diagnosis of red disease in pigs includes the following swine diseases:
- Classical Swine Fever.
- African Swine Fever.
- Porcine salmonellosis.
- Pasteurella multocida serotype B.
- Clostridiosis.
After obtaining the samples (blood, spleen, heart, liver and lung), direct or indirect laboratory tests will be carried out. The direct laboratory diagnosis is indicated, in which the bacteria is searched for, by:
- Culture and isolation in blood agar media.
- PCR.
- Immunohistochemistry.
- Bacterioscopy (viewing the bacteria under the microscope).
The indirect laboratory diagnosis looks for antibodies to the red evil, by means of:
Indirect ELISA: Although not very useful, due to vaccination and carriers. It is used to check the level of antibodies against the disease.
Treatment of red disease in pigs
The eradication of the disease is not considered, due to the high permanence in the environment and the large number of carriers of the infection. In the event of an outbreak of red disease in a pig community, do the following:
- Isolation of suspects.
- Antibiotherapy with beta-lactam antibiotics such as penicillins or amoxicillin.
- Hyperimmune sera, although they are no longer in use.
- Separate the sick.
- Cleaning and disinfection.
Vaccine against swine disease
Prevention is carried out with vaccination. Inactivated or monovalent serotype 2 or polyvalent vaccines are used. The vaccination schedule is as follows:
- Piglets at 3 months the first dose, revaccinating at 3 weeks. In Iberian pigs revaccination every 3 months due to their long development.
- In first parity sows, two doses (of red evil + parvovirus) 2-3 weeks before mating.
- In breeding sows vaccinated with Mal Rojo + parvovirus 10 days after farrowing.
- Adult male pigs should be revaccinated every 6 months.
Although this is a situation that usually occurs especially on farms, we remind you that on our site we are against animal exploitation, so our recommendation is that if you have a pig as a farm animal company, keep a good veterinary control so that he can have a long and happy life.
