The survey, conducted by Zogby International, also reveals that most women would prefer to take an alternative to Premarin once they know that tens of thousands of pregnant mares suffer every year to produce this drug. The number of women who object to Premarin increases even more once they know  that the majority of baby foals born to these mares are discarded for slaughter as an annual "byproduct" of Premarin production.

"This survey shows just how critical our education effort is on the Premarin issue," said Jeane Westin, president of United Animal Nations (UAN), a nationwide animal advocacy and rescue group based in Sacramento, California, which commissioned the survey. "More and more prescriptions are being written for Premarin and no one is telling women where this drug comes from." Manufactured by Wyeth-Ayerst, Premarin is taken by an estimated 9 million American women and those numbers are predicted to escalate as millions of baby boomers reach menopause during the next decade.

"Evidence clearly indicates that Premarin users face increased risk of breast cancer," says Neal D. Barnard, M.D., president of the Physician Committee for Responsible Medicine. "In fact, there's no reason to take Premarin. Diet and other lifestyle choices are much healthier and more powerful over the long run. However, women looking for a hormon replacement  therapy product will find many effective alternatives to Premarin."

The survey, which was conducted via telephone by Zogby International, asked women ages 40 and over if they were aware that Premarin and other like-sounding hormone replacement therapies such as PremPro and Premphase (which are used to treat menopausal symptoms) are derived from the urine of pregnant horses. About half of the respondents (231 women of the 487 respondents or 47 percent) said they were not aware of the source of Premarin while only 31 percent (less than a third of the respondents) said they were very aware of where Premarin comes from.

When asked if their doctor or other medical professional had told them that  there were various alternatives available to Premarin, by more than two to one respondents said they hadn't been told about cruelty-free plant-base and synthetic options. (Sixty three percent of respondents, or 309 women, said they hadn't been told that options were available while only 30 percent or 147 respondents said their doctors had shared this information with them.)

When respondents were told that tens of thousands of pregnant mares are forced to stand in small stalls, with a urine collection device hooked to them, for as many as six months out of every year to produce Premarin, a majority of respondents (53 percent or 255 women) said they would choose a plant-based or synthetic treatment as opposed to Premarin. That percentage increased to 54 percent (265 women) when respondents were told that the majority of foals born to these mares are sent to slaughter, their meat shipped overseas to Europe and Japan to be eaten.

Animal advocates, including members of United Animal Nations, have been working to spread the message about Premarin for years. However, they are fighting a long-established industry (Wyeth-Ayerst has been producing Premarin in Canada since 1942) and its close connections with the medical and insurance community. (Wyeth-Ayerst is currently facing an anti-trust lawsuit filed by a competitor, Duramed, based on the administrative rebates and fees it offers doctors and insurers who limit their prescriptions to Premarin.)

The industry also has increased its use and abuse of horses in recent years with the opening of a new "pregnant mares' urine" (PMU) plant in Minnesota by Natural Biologics. This company has applied for a permit from the U.S. Food and Drug Administration to produce a generic version of Premarin an is already contracting with more than 40 farmers throughout the midwestern United States to keep pregnant mares hooked to urine collection devices.

"The PMU industry has a vested interest in keeping women hooked on hormone replacement that is derived from horse urine," said Dr. Nancy Harrison, a UAN board member from San Diego. "Our goal is to ensure that women aren't kept in the dark about the needless suffering of the horses or about successful alternatives that would end their suffering."

"Wyeth-Ayerst is misleading and deceiving women by withholding important information," said Dr. Paula Rothman, a gynecologist specializing in reproductive endocrinology in the Atlanta, Georgia area who offers alternatives to Premarin to her patients. "We need to do a better job educating women about the needless suffering of PMU horses and the many safe, effective and more natural forms of ERT that would end the suffering of the innocent."