CS: abortion in sheep Flashcards
Can you differentiate Toxoplasma gondii and Chlamydophila abortus based on tucked up abdomens and red/brown vaginal discharge?
No - neither are pathognomic
What does Heptavac protect against?
pasteurella and clostridial diseases in sheep
What are short term treatment options in cases of EAE? Effect?
OTC for in-contact ewes (mayyy reduce number of abortions but can’t reverse placental damage; best use is to keep ewes carrying lambs to closer to term so that the ewes can be used as foster ewes for lambs. Use 6ml/ewe
Advice to farmer in a EAE outbreak
Reduce/prevent movement
Isolate affected ewes and lambs
Destroy aborted material and infected bedding
How long can C.abortus persist in environment?
up to 6 weeks
What are longer-term options for EAE?
Vaccinate - 2 available in UK - Enzovax and CEVAC Chlamydophila (£2-3/sheep). Both inactivated vaccines - initially need 2 shots, then re-vaccinate (lasts a maximum of 3 years but probably best to do every 2 years). Can vaccinate one-month before tupping with a live vaccine (Enzovac or Cevac Chlamydophila)
Can T.gondii cause baronness and abortion?
Yes:
Infected early in pregnancy –> kills foetus and ewe may present as being barren
Infection in later pregnancy –> may cause abortion, stillbirth or weak but alive lambs, mummification possible.
Why do most ewes that abort due to T.gondii belong to younger age groups?
Lack of established immunity against this parasite.
Describe the appearance of foetuses affected by T.gondii.
Mummified or autolysed.
What drugs can you give in the face of a T.gondii abortion storm?
No effective drug to prevent further losses as the foetuses/lambs are likely already to be dead.
How can T.gondii affect humans?
If immunocompromised, it can cause meningo-encephalitis.
Pregnancy (tachyzoites can cross the placenta and cause birth defects and abortion)
Outline the vaccine protocol for Toxoplasma gondii in sheep
Toxovac - single IM dose up to 4 months and at least 1 month prior to tupping, from the age of 5 months, NOT to be given to pregnant ewes, live vaccine containing tachyzoites of avirulent S48 strain. No need to booster because it is a live vaccine. Vaccinate ewe lambs only when there is an outbreak as other ewes likely to have already developed immunity. Vaccinate ewe lambs once in most instances, twice if high risk. Then they will have lifelong immunity.
How should cats be controlled in T.gondii infected farms?
Limit numbers (excrete parasite in urine/faeces)
keep older neutered male to ward of additional felines (most cats seroconvert at a young age)
Shed during pregnancy and if ill/immunocompromised so vaccinate farm cats, feed them well and keep them healthy
How much does it cost to send off a lamb/placenta for investigation into cause of abortion?
about £90 total. You should send a minimum of 3 to be able to confirm your diagnostic suspicions.
How early should a farmer bring his sheep into lambing sheds?
Fine balance between nutritional supply of grass and disease risk. 6 weeks prior to lambing can be acceptable. It is very important at this stage of the pregnancy to feed according to the number of lambs the ewe is carrying so this is why sheep are often brought in prior to lambing.
