Pig Health - Leptospirosis in Pigs
Mark White BVSc LLB DPM MRCVS
Infertility in sows can result from a wide range ofcauses, both of an infectious and non-infectiousnature. The latter includes management factors,nutrition and environment. Disease can play a role,although in the UKmany of the specific reproductivediseases either have never occurred or have beeneradicated e.g. Brucella suis, Aujeszky's Disease. PRRS, Parvovirus (PPV) and the vaginitis/endometritis(discharge) syndrome - associated with vaginalcontamination at or around service - have probablybeen the most frequent infectious causes of infertility inthis country although changes in management systems- particularly the removal of stalls and tethers at the
Fig 1 The demise of stalls and tethers has seen a
end of the 20th century - have coincided with a marked
reduction in discharges associated with returns to
programmes have seen a marked reduction in PPV
and to some extent PRRS, whilst an increasing use of
Leptospiras are spiral bacteria, which are associated
artificial insemination in the pig herd has reduced the
with a wide range of diseases in many species. One of
spread of both specific and non-specific venereal
the best known is L.icterohaemorrhagiae, the cause of
Weils Disease in man, which is primarily carried by rats
However, failures of conception leading to regular and
and can be seen as a systemic disease in young pigs,
irregular returns and later problems in pregnancy
albeit sporadically. The dog Lepto - L canicola - can
relating to mummification, abortion and poor quality of
cause sporadic septicaemic disease in young piglets
pigs born remain major features on many breeding pig
L.pomona is a specific, severe cause of reproductive
units and whilst management is often the primary
loss in pigs (including abortion) but has never been
culprit, in many cases other infectious diseases may be
diagnosed in the UK. In this country, L.bratislava (part
implicated. Porcine Circovirus type II has become
of the Australis gp) may be the cause of a specific
enzootic throughout the UK pig population and has
disease pattern in sows but, unfortunately, tends to be
been linked with reproductive failure in gilts and sows
used as a bucket diagnosis for reproductive failure,
producing a SMEDI like syndrome similar to PPV.
frequently without any diagnostic backup.
However, there remains considerable uncertainty as toits actual significance in the field. Other primary
infectious agents that have implicated in reproductive
L.bratislava is not associated with illness in pigs, its
disease are Leptospira and Chlamydophila.
effects being restricted to reproductive damage.
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Fig 3 Late mummification can be a feature of
Confirmatory diagnosis is difficult to achieve. Demonstration of the organisms by fluorescent
Fig 2 Discharging prior to return to service may be a
feature of Leptospira infection
antibody test (FAT) in aborted material or in thereproductive organs of culled sows provides strong
The signs seen can include:-
evidence of its involvement. Serology is confusing.
1) An elevation in returns to service both at regular
Where a recent infection has occurred, the MA titres
3 week intervals and at abnormal times (e.g. 28-35
will rise dramatically (into the thousands) but will fall
days post service).
rapidly (within weeks).
2) Mucopurulent discharges may occur 2-3 days
It is common practice to blood sample a herd
before the sow demonstrates a return to oestrous.
suffering reproductive failure and find titres of 1:50,1:100 or even 1:200 in some animals. It is very
3) Abortions may occur, particularly in late
dangerous to assume any significance in such
results. Low level titres may be present in the
4) Increase in weak pigs born, stillbirths and
normal herd and there is some degree of cross
mummification are also typical features of a true
reaction with the many other serotypes present in
and around the pig farm, particularly in rodents and
5) Where confirmed cases do occur, they are
other wildlife (hedgehogs, foxes, badgers etc) to
frequently seen in established herds affecting gilts
which obviously the outdoor herd is frequently
only, suggesting that sows have some immunity. L.
bratislava may occasionally be implicated in herd
Caution should therefore be applied to interpreting
infertility outbreaks affecting all ages of sows that
last no more than a single herd cycle of five months.
- Sufficient samples should be taken. A minimum
6) Some veterinarians and producers believe that L.
of six samples, and up to fourteen, should be
bratislava can be the cause of long term cyclical
taken for a herd screen where fertility problems
infertility problems within herds but the definitive
evidence to support such a belief id frequently
- Sample sows when they abort or farrow with
abnormal litters - not two to three weeks later asis needed for PRRS investigation.
- For herd screens, paired sampling (two to three
weeks apart from suspicious animals) will revealchanging patterns.
- Widespread titres of 1:400 or more are
suggestive of actual circulation of the bacteria,though even that in itself is not diagnostic.
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Despite a commonly held view, there is no evidence
No vaccines are currently available in the UK to
appearing in the spring and autumn. This belief
control L.bratislava, although they are available in
seems to have arisen simply because such a
Europe and can be imported by a veterinary
pattern is seen in cattle affected with a totally
surgeon under a Special Import Certificate. (Farrow
different serotype - L.hardjo.
Sure B: Zoetis) Some UK based veterinary
surgeons are strong believers in using such
Where the disease is confirmed, herd treatment
with antibiotics is appropriate. This can take the
Leptospira species with Erysipelas and PPV.
(Leptospira pomona vaccination is widely used inAustralia and New Zealand where this disease is of
1) Blanket herd injection as a single or double
treatment with streptomycin.
Other species can act as a reservoir of infection for
pigs (e.g. rats and hedgehogs) but it must be
streptomycin or potentiated sulphonamides.
remembered that the rats are not the primary
3) In feed medication with tetracyclines, although
source - pigs are. Rodent control should be a
dose rate is important. A dose of at least 10mg/kg
priority in and around all pig farms. The inevitable
liveweight is needed and for large sows on low feed
contact between outdoor pigs and hedgehog
levels, this can require, for example, 10kg per tonne
environments does create a risk of infection.
of 10% chlortetracycline premix. Medication is
Attention to hygiene in service areas is vital,
needed from weaning until up to one-month post
requiring regular washing and disinfection. In
service, although in practice it is often only practical
outdoor units, care is needed with wallows that
to treat the whole herd for a full sow cycle (five
months). In the interests of responsible use ofantibiotics this regime should only be pursued
There is some circumstantial evidence that venereal
based on sufficient evidence of the disease; the old
spread is a major part of the development of the
idea of treating the sow herd routinely say every
disease and the exclusive use of AI is likely to be of
6mths for 1month is now regarded as inappropriate.
4) Regular treatment of boars (e.g. every 6 weeks)
with streptomycin injection. Use of preputial
It is virtually impossible to state a specific cost of
infusion using intramamary preparations off licence
Leptospira infection in a herd. In confirmed
into the boars has been widely used historically but
is of dubious value.
Over the years many herds have seen a positive
- Herd outbreak lasting four months causing a
response in sow fertility following the inclusion of
depression in farrowing rate of 7% and reduction
feed medication from weaning through to the post
weaned per litter (as a result of reduced
service period. Whilst this may be the result of
livebirths and increased neonatal mortality) led
control of Leptospira, in some cases it is not
to a 300 sow herd suffering a drop in annual
diagnostic. Such responses may occur as a more
production of 1.3 pigs per sow per year or 400
general effect of improved vaginal hygiene, by
pigs less weaned. At a marginal cost of £35 per
controlling other undistinguishable pathogens (e.g.
pig, this implied a cost of £14,000.
Chlamydophilia) or purely by coincidence.
- A persistent problem in gilts reduced farrowing
On an individual basis, chronically infertile sows (i.e.
rate in them by 11%, compensated by increased
"double repeats") are best culled both on economic
grounds and as potential disease carriers.
The use of feed medication in breeding rations has
All treatments must be done under the direction of a
often been applied to try and improve fertility but
veterinary surgeon with strict observations of
where used at the correct dose will add more than
dosage rates and withdrawal period.
£30 to the cost of the diet and used over a sow
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cycle will add costs of £15 per sow - a notinsignificant cost if no response occurs.
For this reason and to comply with the generalprinciples of responsible use of antibiotics inanimals, medication of breeding sows for "fertility"reasons should only be undertaken where there isgood evidence that sensitive infectious agents areimplicated.
Leptospirosis in pigs is clinically over-diagnosed inthe UK sows. Whilst it may be the cause of specificepisodes of reproductive failure and can beimplicated in long term herd infertility problems ingilts, it is wrong to assume that it is the cause of allepisodes of infertility with a knee jerk reaction toreach for medication.
information contained within this documentis accurate at the time of printing.
However, subject to the operation of lawNADIS accepts no liability for loss, damageor injury howsoever caused or suffereddirectly
information and opinions contained in oromitted from this document.
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Biomedical Science Letters 2014, 20(3): 173 179 Brief Communication eISSN : 2288-7415 Effect of Korean Red Ginseng on Artificial Sand Dust (ASD) Induced Allergic Lung Inflammation Jung-Ha Kim1, Tae-Jin Lee2, Im Jee-Aee3 and Duk-Chul Lee4,† 1Department of Family Medicine, Chung-Ang University Healthcare System, Seoul 156-756, Korea
AAHPM Special Article Five Things Physicians and Patients ShouldQuestion in Hospice and Palliative MedicineDaniel Fischberg, MD, PhD, Janet Bull, MD, David Casarett, MD, MA, MMM,Laura C. Hanson, MD, MPH, Scott M. Klein, MD, MHSA,Joseph Rotella, MD, MBA, Thomas Smith, MD, C. Porter Storey Jr., MD,Joan M. Teno, MD, MS, and Eric Widera, MD, for the AAHPM ChoosingWisely Task ForceDepartment of Geriatric Medicine (D.F.), John A. Burns School of Medicine, University of Hawaii,Honolulu, Hawaii; Four Seasons (J.B.), Flat Rock, North Carolina; University of PennsylvaniaHealth System (D.C.), Philadelphia, Pennsylvania; Division of Geriatric Medicine and University ofNorth Carolina Palliative Care Program (L.C.H.), University of North Carolina-Chapel Hill, ChapelHill, North Carolina; Hospice and Palliative Care (S.M.K.), Visiting Nurse Service of New York, NewYork, New York; Hosparus (J.R.), Louisville, Kentucky; Johns Hopkins Medical Institutions andSidney Kimmel Comprehensive Cancer Center (T.S.), Baltimore, Maryland; American Academy ofHospice and Palliative Medicine (C.P.S.), Glenview, Illinois; Warren Alpert School of Medicine(J.M.T.), Brown University, Providence, Rhode Island; and Division of Geriatrics (E.W.), University ofCalifornia-San Francisco, San Francisco, California, USA