Erysipelas is a long recognised bacterial disease of pigs and represents one of the most common clinical problems encountered in pigs kept in small populations such as smallholdings, hobby farms and specialist pedigree small herds.
It is also seen occasionally in individual pigs kept as pets and can prove fatal. The reasons for its prevalence in these types of pig keeping enterprises are:
It is however also seen regularly in commercial pig farms particularly in open pen straw yard systems typically found in the UK. In commercial farms it is most commonly seen on adults and in grower finisher pigs but can affect all ages. The causative organism of Erysipelas in pigs is the ubiquitous bacterium Erysipelothrix rhusiopathiae, formally known as Erysipelas insidiosa of which there are many serotypes which may account in part for the variations in presentation of disease. Serotypes 1 & 2 are most commonly found - especially in systemic disease - and are typically incorporated in commercial vaccines.The bacterium can survive in soil or dung for 6 months or more but probably more significantly is carried by a wide range of wild birds, as well as rodents, especially mice. Pigs are particularly susceptible to disease with this organism and the classical manifestations are the acute, septicaemic form producing sudden deaths or in milder cases "diamonds". These forms of the disease can be controlled by a combination of hygiene, medication and vaccination.
Additionally, chronic (long term) changes can occur in pigs challenged with Erysipelas and present in 3 forms:
In adult breeding animals, all of these forms of the disease can be seen although the arthritic form is rare in sows other than those at the beginning of their breeding life. Additionally, infertility can occur in affected sows (particularly those showing other clinical signs around serving time) and in established pregnant animals, abortion can occur without any other clinical signs presented. Rarely piglets may be born infected and affected if the sow has been challenged in late pregnancy.
The range of manifestations of Erysipelas seen mean that clinical presentation can vary.
Erysipelas is particularly evident in systems that allow or promote:
1. Contact with bird faeces
2. Mouse contamination
3. Access to solid muck
In practice, this means that the disease is most prevalent in straw based systems, particularly in open barns (i.e. the supposed welfare friendly pig keeping systems) and tends to peak in the summer months, although can occur at any time.
In small populations kept in back yards, orchards or paddocks there is plenty of opportunity for access by birds and rodents and the persistence of the organism in soil favours persistence of disease.
The acute disease (diamonds, abortion) is relatively easily and effectively treated with narrow spectrum penicillin-based antibiotics, either given by injection, in water or in feed depending on the extent and duration of the outbreak. A full course of treatment must be given - whilst a single short acting dose of penicillin by injection will often rapidly lead to apparent recovery (i.e. reduced temperature, return of appetite) failure to provide 3 - 5 days treatment can lead to chronic signs or re-emergence.
In outbreaks of peracute, acute and endocarditic forms of the disease it is appropriate to treat the entire population metaphyllacticly using penicillin based antibiotics in feed or water.
Treatment of chronically lame pigs is often disappointing - antibiotics are rarely effective against Erysipelas lameness but use of NSAID or even cortisone can give relief from pain.
Safe and effective vaccines are available and are very cheap. Considering the high risk of Erysipelas to pigs, particularly in straw based, and back yard outdoor systems, it is an essential component of any health programme to vaccinate all breeding stock (gilts, sows and boars) to prevent the disease. A primary 2 dose course, with appropriate interval, should be followed by boosters for sows every parity and every 6 months for boars. Sow boosters are often given at weaning although protection of the offspring up to 8 - 10 weeks of age can better be achieved by vaccinating 2 - 3 weeks before farrowing. For sows, vaccines are available in combination with other pathogens.
In rare cases the strain involved may not be covered by a commercial vaccine in which case if the problem persists in a herd an autogenous vaccine may be required produced under special licence using the specific farm isolate.
In high-risk situations, vaccination of young stock from 6 weeks of age (either with a single dose or, if necessary, a 2 dose course) can be applied.
The key to preventing Erysipelas arthritis rests in limiting exposure to the organism, which can come from several sources (i.e. birds, mice and other pigs).
Bird scarers, bird netting, proximity of birds of prey and coverage of feed hoppers etc will all reduce the chances that feed will become contaminated with bird faeces. Likewise, a vigorous rodent control programme is essential. (This also has benefits for Salmonella control and other biosecurity issues).
Hygiene is also vitally important and where disease has occurred and ground becomes contaminated, a rest period of more than six months may be appropriate. Washing and disinfecting of pens, sty's or compounds, where feasible is also advisable.
Avoid bird and rodent contamination of feed storage area.
Erysipelas is a common infectious disease affecting all ages of pigs and is a particular problem in small populations that are not protected by vaccination. Whilst serious and potentially fatal, the acute form of the disease responds well to appropriate antibiotic treatment and the disease can be easily and cheaply prevented by applying a routine vaccination regime.
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