Sheep Abortions: What Causes Them & What Can We Do About It? Dr. Jocelyn Jansen, Disease Prevention Veterinarian—Small Ruminants, OMAF The presentation will cover the reasons for abortions in sheep but will focus on the 3 most common infectious causes in Ontario. Prevalence of disease in Ontario, diagnosis, management of the aborting flock and prevention will also be discussed.

1. Abor tions in Sheep
What causes them and
what can we do about it?
Dr. Jocelyn Jansen
Disease Prevention Veterinarian – Small Ruminants
Veterinary Science & Policy, OMAF
Grey Bruce Farmer’s Week – Sheep Day, January 11, 2014

2. Sheep Abortions
• The Issue:
– industry expansion has led to
poor biosecurity implementation
• buying animals from multiple sources
• both new & veteran producers
– increased incidence of
flock abortions and/or
abortion storms

3. Buyer Beware
• Sources of replacement animals
– salesbarn
• animals mixed together from multiple farms
– leads to multiple problems
• good chance that animals are someone else's culls
• if the price is too good to be true, don’t buy
– private sales
• animals from 1 source  minimizes disease risk
• discuss flock history & look at management
– management should be the same or better than yours
– home grown replacements
• maintain a closed flock

4. Working with a Veterinarian
• Benefits of a vet-client-patient relationship
– help you develop a flock specific health program
 focus is on prevention !!
• establish goals for the flock
• keep good records that can be reviewed
– know when to call the vet versus
waiting and seeing
• perform post-mortems and diagnostics
• source of vaccines and antibiotics and
the knowledge of how best to use them

5. How Many Abortions Are Too
Much?
• In most flocks the visible abortion rate is
<2%
• The accepted rate of abortion is <5%
– concern if >5%
– concern if clustering of abortions in time/group
– chronic abortion rates of 2 – 5% yearly suggest
an endemic problem
INVESTIGATE

6. Record Keeping
Abortion Rate
=
number of ewes aborting
number of ewes pregnant or exposed to ram
Lamb Mortality Rate (1st 7 days)
= number of lambs born alive but dying in 1st 7 days
number of lambs born alive

7. Causes of Abortion
• Infectious Causes
–
–
–
–
–
–
–
–
–
Coxiella burnetii (Q Fever)
Warning:
Chlamydia abortus
all 4 are
Campylobacter
ZOOnOTiC
Toxoplasma
!!
Listeriosis
Salmonella
Border disease
Leptospirosis
Cache Valley
• Non-infectious Causes
–
–
–
–
Iodine deficiency
Stress & trauma
Selenium deficiency
Starvation
• energy/protein deficiency
– Overnourishment
• ewe lambs
– Toxic plants

8. CCCT – Zoonotic Risks
• Coxiella (Q fever)
– flu-like symptoms, repeated fevers, pneumonia, heart &
liver problems (inhalation, raw milk, indirect contact)
• very few bacteria are required to cause infection in a
human
• Chlamydia
– miscarriages / stillbirth in pregnant women (ingestion)
• Campylobacter
– vomiting, diarrhea, fever with C. jejuni (ingestion)
• Toxoplasma
– birth defects in human fetuses, inflammation of the brain
in immunocompromised adults (undercooked meat,
cleaning litter box, raw milk)

9. What do we See in
Ontario?
AHL Project (Hazlett et
Final Diagnosis
al, 2013)
Sheep (cases,%)
n=163
Goats (cases,%)
n=96
Toxoplasma gondii
31 (19%)
16 (17%)
Coxiella burnetii
12 (7%)
15 (16%)
Chlamydia abortus
19 (12%)
36 (37%)
Campylobacter spp
21 (13%)
0
Salmonella spp
3 (2%)
0
Listeria monocytogenes
1 (1%)
1 (1%)
Other infectious bacteria
7 (4%)
5 (5%)
73 (45%)
30 (31%)
Unknown cause

10. AHL Project
• Coxiella was detected in 69% (113/163)
of sheep abortions and 75% (72/96) of
goat abortions
M
M
N
O
– cause of abortion in 7% (s) and 16% (g)
O
C
• Chlamydia was detected in 26%
(42/163) of sheep abortions and 56%
(54/96) of goat abortions
– cause of abortion in 12% (s) and 37% (g)

11. Q Fever in Ontario
• “Prevalence of Q fever (Coxiella burnetii) in
Ontario sheep flocks and goat herds and
their farm workers”
– collaborative effort – OVC, OMAFRA,
MOHLTC, PHO
• 148 farms randomly selected (meat/dairy)
– 35 animals per farm randomly selected
– at least one lambing/kidding
– blood test (antibodies)
• farm management survey

12. Q Fever in Ontario -- Results
• Meat sheep
– farm-level: 42% positive flocks (21/50)
• flock with at least one animal testing positive
– animal-level: 10% positive sheep (166/1619)
• Dairy sheep
– farm-level: 64% positive flocks (14/22)
– animal-level: 24% positive sheep (181/744)
• Within-herd prevalence ranged from
0% - 74% for sheep farms

13. Q Fever in Ontario – Human
Results
• Farm workers tested if they wanted
– 1-3 people/farm, >14 years of age
– blood test (antibodies)
– results for sheep and goat farm
workers not separated
– 79% of farms (59/75) had at least 1
person with antibodies to Coxiella
– 67% of farm workers (116/172) had
evidence of past infection/exposure

14. What You Might See in Your
Animals
• Return open
– losses in early to mid gestation are often
undetected
• animals are rebred
• Mummified fetuses
– not common
Ewes rarely
become ill
• Abortion
– most commonly seen during last 2 months
• Stillbirths
• Weak lambs
– often don’t survive past first week

15. Diagnosing the Cause
of Abortions
• Testing
– very important to submit both the fetus AND
placenta to a diagnostic lab
• submit more than one fetus/placenta if possible
• as clean as possible & not frozen (keep chilled)
• cause of abortion can vary from year to year
– blood samples taken from ewes not as useful
• exposed versus cause of abortion
• spend your money on placenta/fetal samples

16. Diagnosing the Cause of
Abortions

17. Management of the
Aborting Flock – Things
•to Considerstill to lamb from those
Separate females
that have aborted
– move to a clean area
• keep aborted ewes in the contaminated pen or
pasture
– deal with females still to lamb first
• prior to aborted females and new moms
• Remove bedding & fetal materials (bury,
compost)  decrease environmental load
– wear masks to prevent inhalation of organisms
– don’t spread manure when windy

18. Management of the
Aborting Flock – Things
to Consider
• Remember the ZOONOTIC risks
– wear gloves for all lambings
• wash hands frequently
– wear coveralls and boots
• change and clean frequently during lambing
• don’t wear the same ones to manage the rest of the
flock
– pregnant women should not assist at lambing
• in addition to aborted, newly lambed
– children & elderly also at risk
– drinking raw milk is a risk factor

19. Coxiella burnetii (Q fever)
• Common cause of abortion in sheep & goats
– organism can survive in dust for years
• Sources of the organism
– aborted fetus, placenta, uterine fluids
• cattle, cats, rodents, birds & insects can also be a source of
the organism
– vaginal discharge, milk, manure, urine
– venereal spread by males
– “carrier females”
• immunity is not complete  large proportion of flock may be
shedding with few abortions
• shed organism but deliver normal lambs

20. Coxiella burnetii
• Infected by inhaling contaminated air/dust or
mucous membrane contact with aborted
materials or birthing fluids
– localizes in placenta
• abortions, stillbirths and/or
weak lambs
• Treatment
Menzies
– antibiotics?
•
•
•
•
may or may not stop further abortions
carrier females will still shed the organism
effectiveness of feed vs injections
TALK TO
drug residues in dairy animals
YOUR

21. Coxiella burnetii
• Prevention
– separate pregnant ewes from aborting flock
• management of environment & contaminated materials
• don’t spread manure when windy
– good management  avoid overcrowding, good
nutrition
– biosecurity  “buyer beware”
– Coxevac® vaccine
TALK TO
• veterinary application to CFIA
YOUR
• decreases number of abortions
VET
• decreases shedding into the environment
• vaccinate unexposed replacements twice before breeding,
booster yearly

22. Chlamydia abortus
• Common cause of abortion in sheep & goats
• Sources of the organism
– aborted fetus, placenta, uterine fluids
• after aborting, immunity lasts about 3 years
• birds and insects may play a role in spreading disease
– “carrier females”
• vaginal secretions at time of heat
– rams can be temporarily infected
• venereal spread
– infected through mucous membranes or eating
contaminated materials or feeds

23. Chlamydia abortus
• Incubation period = 50 to 90 days
• Individual Scenario
– infected in early to mid gestation
• abortion
• stillbirths and/or weak lambs
– infected in late gestation or when not pregnant
• abort during next pregnancy
• Naive Flock Scenario
– 1st year  replacements abort
– 2nd year  abortion storm
– 3rd year  ewe lambs abort

24. • Treatment
– antibiotics?
• during an outbreak
– multiple injections
– effectiveness of feed vs injections
– often poor results due to long incubation period
& damage done to placenta
– drug residues in dairy animals
TALK TO
YOUR
VET
Foster, AHL
Chlamydia abortus

25. Chlamydia abortus
• Prevention
– separate pregnant ewes from
aborting flock
TALK TO
YOUR VET
• manage ewe lambs separately
• management of environment & contaminated materials
– vaccinate (Chlamydia psittaci Bacterin)
• twice before breeding & booster yearly
• vaccine does not prevent shedding but will decrease
abortions
• NOTE  cat vaccine does not work (different strain)
– good management  avoid overcrowding
– biosecurity  “buyer beware”

26. Campylobacter
• Common cause of abortion in sheep
• Campylobacter jejuni
– sporadic abortions
• more so in Ontario
• Campylobacter fetus subspecies fetus
– large abortion storms
• more so in western flocks
• Incubation period = 7 to 60 days

27. Campylobacter
• Sources of the organism
– “carrier sheep” have the organism in their
intestines
• environmental contamination via manure
– aborted fetus, placenta, uterine fluids from
aborted females
– birds (crows) can spread organism between
flocks
– others infected by eating contaminated
materials or feeds

28. Campylobacter
• Most abortions occur during the 3 rd
trimester
– lesions seen on placenta & in fetus
– ewes are not ill
• some become immune (at least 3 years)
• while others become carriers
– if infected 2 weeks before
lambing may see stillbirths and
weak lambs

29. Campylobacter
• Treatment & Prevention
– antibiotics
TALK TO
YOUR VET
• stop the outbreak
• effectiveness of feed vs injections
– separate pregnant ewes from aborting flock
• management of environment & contaminated materials
– vaccinate (Campylobacter fetus-jejuni Bacterin-Ovine)
• twice before breeding & booster yearly
• effectiveness questioned due to strain differences?
– good management  avoid overcrowding
– biosecurity  “buyer beware”

30. Toxoplasma
• Common cause of abortion in
sheep & goats
– parasite infection
• cat  rodent lifecycle
• Source of the organism
– nonimmune kittens are infected by eating rodents
• shed large numbers of toxo eggs in their manure
• kittens defecate & bury manure in hay & feeds
– adult cats are immune, don’t shed eggs
– sheep infected by eating contaminated feed
and/or water

31. Toxoplasma
• Individual Scenario
– if ewe not pregnant but exposed to eggs
• become immune and do not abort
– if infected before 40 days post breeding
• return open
– if infected between 40 and 120 days
• mummified fetuses, abortion
– if infected after 120 days
• stillbirths, weak and/or normal immune lambs
• normal & affected can be delivered at one time

32. Toxoplasma
• Immunity
– life-long for sheep
• No treatment for current abortions
• Prevention
– keep cat feces out of feed & water
• provide litter box, don’t feed top bales, feed bins
• stray cat & pasture control difficult
– neuter kittens and control rodents
• exposing youngstock to kittens works poorly
– coccidiostat fed throughout gestation
• no evidence that it treats existing infections

33. Conclusions
•
•
•
•
Abortions are costly to your bottom line
Visible abortion rate <5%
Investigate  submit placenta (and fetus)
CCCT most common causes
– ZOONOTIC!!
• Separate pregnant females from aborting
flock
• Use of vaccines and antibiotics
• Biosecurity  “Buyer Beware”, clean
coveralls, gloves, hand washing, masks, etc

34. Questions ?