Animal Health Professionals Site

15 August 2015

Ewe blood tests reveal hidden diseases

MILTON KEYNES, UK, August 14 2015 – An underlying disease was a significant cause of barrenness or abortion in ewes last year according to an analysis of the latest diagnostic results released by MSD Animal Health (a division of Merck & Co., Inc., Kenilworth, NJ, USA.).

Blood samples from 500 UK sheep farms were tested during 2014 when the EXPERTISTM Barren EweCheck and FlockCheck diagnostic services (subsidised by MSD Animal Health) were made available to vets.

According to the data, more than 81 percent of the flocks tested showed evidence of exposure to the parasite Toxoplasma gondii, which causes toxoplasmosis. The data also show that 52 percent of flocks had been exposed to Chlamydophila abortus bacteria, the organism causing enzootic abortion (EAE); 43 percent of flocks had been exposed to both organisms.

“These latest diagnostic results highlight the continuing widespread prevalence of these financially damaging diseases in the national flock and we urge all sheep producers to discuss their individual farm situation with their vet, well in advance of the autumn tupping season,” says MSD Animal Health technical manager John Atkinson MRCVS.

Toxoplasmosis remains a key cause of barrenness as well as infectious abortion in UK sheep flocks. The disease is a real drain on profits.

“Toxoplasmosis can cause abortions, barrenness, reabsorptions, mummified foetuses, stillbirths and weakly lambs. Sheep pick up the infection from the environment and so normal biosecurity measures are not enough to control the disease. Infected cats shed toxoplasma eggs in their faeces and sheep become infected when they ingest these eggs from contaminated pasture, feed and water,” Mr Atkinson says.

Another underlying disease problem that often manifests itself as significant early lamb losses is enzootic abortion (EAE).

“EAE is caused by Chlamydophila abortus bacteria. The disease can cause devastating abortion storms affecting approximately 25 percent of ewes. Once a flock has the disease it is likely it will never disappear due to its persistence in carrier sheep. The disease usually arrives on farm through replacements and is passed on from ewe to ewe at lambing time. If an unvaccinated ewe is infected she will more than likely abort in the next pregnancy. Vaccination of already infected ewes reduces the risk of abortion and bacterial shedding thus reducing the chance of transmission to their lambs and the rest of the flock.”

Mr Atkinson urges any sheep producers who recorded a flock barren rate greater than

2 percent last season to talk to their vet for advice, even if diagnostic blood samples have not been taken. Ask for help too if any ewes aborted lambs during lambing, he says.

“If either toxoplasmosis or EAE has been diagnosed in a flock, vaccination is the most effective way to help protect against these diseases for future years. The TOXOVAX® vaccine is known to protect the ewe against toxoplasmosis for at least two lambing seasons and, conveniently, can be given up until three weeks before tupping.

“The ENZOVAX® vaccine helps protect the ewe for at least three years against EAE and can be given to ewe lambs intended for breeding from five months of age. Animals should be vaccinated at least four weeks prior to tupping,” Mr Atkinson advises.

About MSD Animal Health

Today's MSD is a global healthcare leader working to help the world be well. MSD Animal Health, a division of Merck & Co., Inc., Kenilworth, NJ, USA., is the global animal health business unit of MSD. Through its commitment to the Science of Healthier Animals™, MSD Animal Health offers veterinarians, farmers, pet owners and governments one of the widest range of veterinary pharmaceuticals, vaccines and health management solutions and services. MSD Animal Health is dedicated to preserving and improving the health, well-being and performance of animals. It invests extensively in dynamic and comprehensive R&D resources and a modern, global supply chain. MSD Animal Health is present in more than 50 countries, while its products are available in some 150 markets. For more information, visit or connect with us on LinkedIn.

MSD forward-Looking Statement

This presentation includes “forward-looking statements” within the meaning of the safe harbor provisions of the United States Private Securities Litigation Reform Act of 1995. These statements are based upon the current beliefs and expectations of MSD’s management and are subject to significant risks and uncertainties. There can be no guarantees with respect to pipeline products that the products will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, general industry conditions and competition; general economic factors, including interest rate and currency exchange rate fluctuations; the impact of pharmaceutical industry regulation and health care legislation in the United States and internationally; global trends toward health care cost containment; technological advances, new products and patents attained by competitors; challenges inherent in new product development, including obtaining regulatory approval; MSD’s ability to accurately predict future market conditions; manufacturing difficulties or delays; financial instability of international economies and sovereign risk; dependence on the effectiveness of MSD’s patents and other protections for innovative products; and the exposure to litigation, including patent litigation, and/or regulatory actions.

MSD undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise. Additional factors that could cause results to differ materially from those described in the forward-looking statements can be found in MSD’s 2014 Annual Report on Form 10-K and the company’s other filings with the Securities and Exchange Commission (SEC) available at the SEC’s Internet site (

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ENZOVAX® and TOXOVAX® are only available from animal health product prescribers or veterinary surgeons from whom advice should be sought. Enzovax contains Chlamydophila abortus strain 1B. Toxovax contains Toxoplasma gondii. Legal categories POM-V. Enzovax and Toxovax are the property of Intervet International B.V. or affiliated companies or licensors and are protected by copyrights, trademark and other intellectual property laws. Copyright © 2014 Intervet International B.V. All rights reserved.

Further information is available from: MSD Animal Health, Walton Manor, Walton, Milton Keynes MK7 7AJ. Tel: 01908 685685 