Erysipelas is a systemic bacterial disease characterized by diamond shaped skin lesions and arthritis in its chronic forms.
It is a frequent disease caused by a bacteria called Erysipelothrix rhusiopathiae found in most farms. It is estimated that up to 20% of healthy animals carry the organism in the tonsils, and it is eliminated through feces or saliva, thus, this is the way the disease maintains a low infection level in the environment. It also can be found in many other species, including birds and sheep, and can survive outside the pig for a few weeks, mainly in flooring where sand is used as bedding. Infected feces are probably the main source of infection, mainly in growers and finishers.
The disease is not very common in pigs 8 to 12 weeks old or less due to the protection provided by maternal antibodies in colostrum. The more susceptible animals are growing pigs, gilts and not vaccinated sows.
This bacteria can cause infection on its own, but recurrent viral infections such as PRRS or influenza can trigger erysipelas outbreaks. The bacteria invades the blood stream through different ways including skin lesions or through the digestive tract’s wall, producing septicemia. The incubation period is 24 to 48 hours.
Sporadic cases are frequent, but if a sow gets infected, the exposure of the rest of the animals to its urine and feces is high, thus it is advisable to inject penicillin to all the animals in contact with the sow.
- High temperatures; sperm can be affected during all the development period, which lasts 5 to 6 weeks. Infertility is seen as returns, empty sows and small litters.
Hyper-acute and acute disease
- Death, general infection.
- High temperature.
- Might look normal.
- Might cause abortion.
- Mummified piglets.
- Characteristic skin lesions that look like skin eruptions of 10 to 50 mm, and diamond shaped all over the body that can change from red to black.
- Pigs do not want to wake up and are rigid, indicating joints infection.
- Sudden death is frequent due to acute septicemia or heart failure.
- Loss of appetite.
- Characteristic skin lesions.
- Temperature variations.
- The disease can be so mild, it goes undetected.
- Some piglets die in the uterus after a sub-acute infection and are mummified.
- May or may not be present after the acute or sub-acute disease.
- Affects joints producing lameness or chronic arthritis and swollen that can be responsible for condemnation at the slaughterhouse.
- Heart valves can be affected, which lead to an increase of the heart’s size, and ultimately heart failure.
- Not common in piglets
Weaners and growers
- Sudden death.
- High fever.
- Characteristic skin lesions diamond shaped all over the body that can change from red to black.
Sub-acute and mild disease:
- It is the most frequent form of the disease.
- Might present skin lesions, but the pig does not look ill despite having fever.
- Might affect joints producing chronic arthritis and swelling.
Causes / Contributing Factors
- Pigs movements that imply mix of animals and stress.
- Hot summer weather with high humidity.
- Humid and dirty pens.
- Liquid feeding, mainly if milk- derived products are used, which can be an important source of infection because the microorganism reproduces in them.
- Barns continually used that do not follow the all-in/all-out system and are not disinfected.
- Water supply systems that may get contaminated.
- Viral infections, particularly PRRS and influenza.
- Common in systems that use stray bedding.
Based in clinical signs and isolation of the organism, which easily grows in the laboratory. Serology tests only indicate exposition to the organism but not necessarily the presence of the disease.
- The organism is very sensitive to penicillin.
- Normally one injection of a long acting penicillin is enough, but in severe cases it may be necessary to repeat 2 or 3 days after the first dose.
- If a high number of animals is affected, medicate the water with amoxicillin or penicillin.
- In prolonged outbreaks, medicate the feed with penicillin.
- In individual outbreaks of finishing pigs, the pens must be cleaned and disinfected between lots.
- In case of continuous outbreaks in the growing area, it might be necessary to vaccinate the pigs at 8 weeks of age, and possibly revaccinate at 10 to 12 weeks of age. Usually, pigs do not get vaccinated before 8 weeks of age because colostrum antibodies reduce the response to the vaccine.
- Vaccinate replacing gilts.
- Vaccinate the breeding herd every year.