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Horses in Research

Did you know that pregnant horses are used to produce hormone replacement therapies for post-menopausal women? Urine is collected from pregnant mares because it is rich in estrogen, and is used by pharmaceutical giant Pfizer, Inc. to produce drugs such as Premarin (whose name is derived from the words PREgnant MARe urINe) and Duavee.

This practice has long raised concerns among animal welfare advocates, because in order to collect the urine, mares are confined to narrow stalls and fitted with urine collection harnesses for about six months during their pregnancies. While “best practices” regarding the care and handling of horses in pregnant mare urine (PMU) operations indicate that the equipment and harnesses used to collect urine should be placed in such a way as to not injure the mares, the urine collection devices can cause chafing and other sores to develop on the mares. Also, this confinement prevents the horses from normal mobility, such as simply walking around. In addition to being cruel and inhumane, this can lead to serious health problems in the future.

There are also concerns about what happens to the mares’ offspring, who are byproducts of this industry, as well as to the mares who are no longer “productive.” These horses are often sent to auction, where they can be bought for recreational riding, for use as working ranch horses, or by individuals who send them to feedlots where they are fattened up for slaughter.

Demand for Premarin decreased over a decade ago, in part because of concerns raised in a report which disclosed that the drug increased the risk of blood clots, stroke, heart disease, and breast cancer. As a result, the U.S. no longer has PMU farms. However, PMU farms can still be found in Canada and China. Pfizer Canada recently announced that it actually plans to expand its operations to increase the amount of PMU collected from ranches in Manitoba and Saskatchewan due to an increase in demand for Premarin.

Fortunately, women in need of hormone replacement therapies have other options, including synthetic and non-PMU based organic (and FDA-approved) alternatives to “conjugated equine estrogen” which do not involve the inhumane treatment of horses.

Please consider making a donation to NAVS’ Sanctuary Fund which supports sanctuaries and rescue organizations who have saved horses from PMU farms and the slaughter industry.