Sheep Day - Sheep Abortions, Jocelyn Jansen


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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.

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  • -sometimes the problems show up shortly after bringing the animals home, other times it is within the first year or in 2-3 years
  • -it takes time to develop a relationship and time for the vet to get to know your flock/management style
    -in the past the relationship among sheep producers and veterinarians has not always been the best—wanting free advice over the phone is not the best way to engage a vet
    -if you put effort into the relationship so will they
    -a report out of the UK found that farmers lack of awareness of flock health & biosecurity definitely contributed to the spread of FMD in the 2001 outbreak
    -and one of the main reasons for this was because there was little veterinary involvement with sheep flocks
    -we have a membership of 77 veterinarians and another 25 students who have an interest in small ruminants, who eventually will go out into the work force
    -ask if they are a member of SRVO, if they are, they have available to them all sorts of useful information, if they aren’t maybe suggest they join
  • For lamb/kid mortality the numbers are more difficult to come by and they are often characterized as the first 10 days of life. But the numbers would suggest for the non-prolific breeds the mortality rate should be <5% and in the prolific breeds <10%. The key thing is to keep records to see what is normal in your flock/herd, are there changes over time, is your goal to lower the mortality rate. Can calculate rates from birth to weaning.
  • Be aware, know the risks, judge for yourself, taking into account those working with you, and decide how you want to proceed
  • From 2009 to 2011, sheep and goat abortions were received at the Animal Health Lab in Guelph. There was no cost for a full abortion work up as long as placenta was submitted, plus or minus fetuses. The AHL was evaluating 2 new tests, one for Chlamydia the other for Coxiella.
    Most common cause of abortion in sheep was Toxoplasma and in goats Chlamydia. Some abortions had more than 1 infectious agent detected (3% of sheep and 8% of goats).
  • Moral of the story—these organisms are out there and are common
  • Animal test is IDEXX ELISA.
  • Tested with IFA test (immuno flourescent assay). If Phase II>Phase I, then considered an acute infection.
  • Very common to see an injection site reaction with the vaccine (lasts for about 7 days). Vaccination may cause decrease in milk production in goats. Zero milk and meat withdrawal.
  • Deccox fed at 2mg/kg daily throughout gestation. Very expensive.
  • Abortions / abortion storms can significantly decrease a years lamb crop & profits
    losses of 15 – 70% have been reported
    feed for another season and/or culling of ewes
  • Sheep Day - Sheep Abortions, Jocelyn Jansen

    1. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 16. Diagnosing the Cause of Abortions
    17. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 34. Questions ?