Ovine Abortion Quick Guide

Ovine Abortion

Specimens to submit:  Entire fetus and placenta are the preferred specimens.  Fetal tissues should include:

Brain

1/2 of organ, formalin-fixed

Ewe serum

Optional, see notes on abortion serology.  3 - 5 ml ewe's serum

Heart

1/2 cm slice, formalin-fixed

Kidney

1 entire kidney, fresh/chilled

Liver

1/8 - 1/4 of organ, fresh/chilled

1/2 cm slice, formalin-fixed

Lung

1/8 - 1/4 of organ, fresh/chilled

1/2 cm slice, formalin-fixed

Placenta

3 cotyledons, fresh/chilled

2 cotyledons, formalin-fixed

Spleen

1/2 of organ, fresh/chilled

Stomach contents

1 - 3 ml syringe or tube, fresh/chilled

Thoracic fluid

Clear, uncontaminated, fresh/chilled

Thymus

Fresh/chilled;  1/2 cm slice formalin-fixed

Vaginal swabs

Optional, select recently aborted ewes

sampling techniques

1.   Do NOT freeze tissues.

2.   Submit placenta whenever possible.

3.   Submit ewe's sera, retain 1/2 of sample frozen.

agents detected by routine examination

Bacteria

Arcanobacterium pyogenes, Bacillus, Campylobacter, Chlamydia, Listeria monocytogenes

Parasites

Toxoplasma gondii (see comments), neospora

Viruses

Border disease virus

comments

Diagnosis of toxoplasmal abortion can be accomplished through detection of characteristic lesions in placenta and brain and detection of antibody in fetal thoracic fluid.  Detection of antibody in ewe serum is not evidence for abortion, only infection at some time; antibody titers persist for months.  Absence of antibody in the ewe would rule out toxoplasmosis.

Diagnosis of Chlamydial abortion is most readily accomplished through an ELISA test conducted on fresh placenta.  The ELISA can also be conducted on swabs of fetal fluids or liver or vaginal swabs from affected ewes (within 5 days after abortion).

Cache Valley virus infection can only be identified by serological studies conducted at a reference laboratory.  Fetal fluids or precolostral serum from live-born affected lambs can be examined.  Analysis of serological results from paired ewes (affected/unaffected) also may be helpful.

Chlamydia and Toxoplasma gondii are 2 of the 3 most common infectious causes of ovine abortion.  Without placenta, brain, and/or fetal thoracic fluid, we cannot properly address the primary differentials.