Sheep Medicine Q&A 11

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A two-crop ewe from a group of 155 pastured sheep due to start lambing in 3 weeks has aborted two fresh fetuses. Three other abortions have occurred over the previous 5 days. The ewe is bright and alert but there is a red–brown vulval discharge over the wool of the tail and perineum. The rectal temperature is 40.0°C (104.0°F). The udder is reasonably well developed and there is some accumulated colostrum.

Question	Answer		Article
What samples would you collect?	A vaginal swab, fetuses, and placentae should be submitted for laboratory examination. Blood samples are collected from all aborted ewes for toxoplasma and EAE serology.		Link to Article
List the common causes of abortion.	Common abortifacient agents include: Chlamydophila psittaci (EAE) salmonellosis including Salmonella montevideo, S. typhimurium, and other serotypes Campylobacter fetus fetus Toxoplasma gondii Listeria monocytogenes Pasteurella spp. tick-borne fever. C. psittaci was demonstrated in direct smears from the placentae and a strong positive titre obtained in three of four blood samples; a very high titre for toxoplasma was recorded for the other ewe. Any further aborted material must be submitted to monitor the situation. The zoonotic risk of chlamydial abortion, especially to pregnant women, should be stressed.		Link to Article
What treatments would you consider?	The ewe was treated with intravenous oxytetracycline and made a rapid recovery. The ewe accepted a small male triplet foster lamb. All ewes in the group were injected with 20 mg/kg long-acting oxytetracycline intramuscularly that same day to reduce further abortions.		Link to Article
What control measures could be adopted?	Aborted ewes must be isolated for at least 6 weeks and all aborted material buried or burned. With EAE now present in the flock the farmer should be strongly advised to vaccinate all replacement females even if purchasing EAE-accredited stock. In this case it was recommended that all ewes which had possibly encountered infection this spring should also be vaccinated, and treated with long- acting oxytetracycline next year 6 weeks and 3 weeks before lambing. Vaccination against toxoplasmosis would depend upon titres in aborted versus control ewes.		Link to Article