Erysipelas in Pigs
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
- The pigs' particular sensitivity to the disease.
- The harbouring and prevalence of Erysipelas in other farm
species - particularly turkeys and sheep - to which "back yard"
pigs may have access.
- The ubiquitous nature of the organism in wild animal
populations that contaminate the pig keeping area and its survival
Fig 1: Sloughing of the skin of the scrotum
secondary to necrosis following Erysipelas
Fig 2: Sloughing of the skin of the neck secondary
to necrosis following Erysipelas infection
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:
- Endocarditis - the development of
'cauliflower' like lesions on heart valves that leads to death
(often sudden) due to heart failure. Surviving pigs are likely to
be condemned at slaughter. Other bacteria can cause such lesions
(eg Strep suis).
- Arthritis - a complicated form of the disease
which can be very difficult to control. The difficulties arise
because, in most cases, it is not the direct result of infection in
joints with the organism. Erysipelas arthritis is what is termed as
immune mediated or hypersensitivity reaction.
The most significant factor clinically is that because the
arthritis results from an immune medicated condition, it is not
necessarily the case that the acute form of the disease will be
seen prior to it. Moreover, it can occur in partially immune
animals (i.e. pigs that are already sensitised to the organism)
and, thus, can even occur following prior vaccination.
- Skin necrosis - developing in a similar way to
the arthritic form in which ischaemic damage to the skin occurs,
leading to death of the tissues and sloughing of the skin. It can
lead to loss of extremities, especially the ears but also scrotum
and any other areas (figs 1 & 2).
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.
- Peracute disease - sudden death due to acute
- 'Diamonds' - the classic acute form of the
disease. This is also a septicamaemic form, albeit milder, in which
raised red 'diamond' shaped lesions appear particularly over the
back (fig 3). The pig may have a very high temperature (42ºC+), be
depressed and inappetent. Pigs so affected or those in contact can
develop chronic signs such as skin sloughing (figs 1 & 2) or
may be found dead 4 - 10 days later (possibly having appeared to
recover) as a result of endocarditis (fig 4). Any pig sent form
slaughter with diamond lesions still evident in the skin is likely
to require skinning with resultant weight deduction and
- Arthritis -The animal will rarely have a
temperature and classical diamonds may not have been seen in the
individual or pen mates. The arthritis produces a very severe
lameness - particularly evident in the hind legs but rather than
producing a pig that is "off its legs", the legs stiffen and become
very upright. The joints in the spine may also be affected,
producing a hunched look where the back legs "bunny hop". Whilst
appropriate treatment in the early stages - as prescribed by the
veterinary surgeon - can arrest the damage, once they reach this
crippled state, recovery is unlikely. The animals may not be fit to
transport and require on farm destruction but mild cases, which can
be very common, may simply produce an awkward gait.
- Breeding problems. This can be presented
either as waves of return to service - possibly with preceding
clinical disease such as 'diamonds' - or as abortion at any stage
of pregnancy often without preceding signs in affected animals or
pen mates. Boars are also vulnerable to the disease and given that
very high fever can occur this may render the boar infertile for up
to 6 - 8 weeks, with implications for herd fertility.
Fig 3: Classic 'diamonds' in a growing
Fig 4: 'Cauliflower' growths on heart valves
Fig 5: Crippling, irreversible arthritis in a
growing pig (photo courtesy W J Smith)
Erysipelas is particularly evident in systems that allow or
1.Contact with bird faeces
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
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
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
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.