What is Premarin®?
How many PMU farms exist and where are they located?
How is the estrogen-rich urine for Premarin® obtained?
How many horses are involved in PMU production,
 and how are they acquired?
What happens to unproductive mares?
What happens to the foals of PMU mares?
Are there additional humane concerns?
Is the quantity of feed and water sufficient?
Is the PMU industry's Code of Practice adequate to
address these welfare concerns?
What are the prospects for addressing these cruelties
through new laws or government regulations?
Are there acceptable alternatives to Premarin®
for estrogen replacement therapy?
My doctor says that other estrogen replacement drugs have not
been proven to be as safe as Premarin®. Is this true?
What can concerned individuals do to reduce
the suffering of horses on PMU farms?
 
Click here to go back to our Frequently Asked Questions
 

Q. What is Premarin®?
A.  As the name implies, Premarin® is a conjugated estrogen product extracted
from pregnant mares' urine (PMU). It is manufactured by Wyeth-Ayerst Laboratories,
Inc., and is most commonly prescribed for estrogen replacement therapy (ERT) to
relieve hormonal deficiency symptoms associated with menopause or hysterectomy.
More recently, it has been prescribed to help prevent osteoporosis and heart disease.
Premarin® is the most widely used ERT drug, marketed for more than 50 years,
and currently administered to more than nine million American women.
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Q. How many PMU farms exist and where are they located?
A.  There are an estimated 500 PMU farms in North America, with the vast majority
located in the prairie provinces of western Canada. About 30 PMU farms exist in
North Dakota, near the Canadian border, and more have reportedly been established
in Minnesota. Almost all PMU farms are under an exclusive contract to provide
pregnant mares' urine to Wyeth-Ayerst Laboratories. Because the market for ERT
drugs is expected to expand dramatically as millions of women from the "Baby Boom"
generation enter menopause, it is likely that the number of PMU farms will increase proportionately.
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Q. How is the estrogen-rich urine for Premarin® obtained?
A.  Mares enter the collection barns in September and remain until March or April.
Each mare is kept tethered in a narrow stall with a rubber cup positioned over her
vulva to collect the urine flow. The cup is held in place by overhead supports and a
partial body harness. The tether and collection apparatus greatly restrict movement,
and the mare is unable to turn around or take more than a step or two in any direction.
If the tether is too short, she may even be unable to lie down comfortably.
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Q. How many horses are involved in PMU production,  and how are they acquired?
A.  PMU mares are obtained from a variety of sources. Most of the farm managers
buy or breed their own horses. A few lease pregnant mares from rental stables and
rodeo stock companies, as estrogen collection occurs only during off-season months.
Reliable estimates indicate there are at least 50,000 production mares on PMU farms,
accounting for the births of approximately 40,000 offspring annually. When the number
of breeding stallions, immature mares, replacement mares, and their foals are added,
the total is considerably greater than 100,000 horses.
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Q. What happens to unproductive mares?
A.  PMU mares may be used for several consecutive years—provided, of course,
that they become pregnant again during the brief summer breeding season.
But because there is a serious overpopulation of horses throughout North America,
and PMU mares are often untrained and difficult to handle, there is little demand for
them once they have outlived their usefulness as estrogen producers. Typically,
barren or unproductive mares are sent to the slaughterhouse.
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Q. What happens to the foals of PMU mares?
A.  Foals are allowed to nurse and be with their mothers for only three to four months—
instead of the normal six-month period. When the time comes for the mares to return
to the collection barns, the farmers dispose of surplus foals. A few female foals may be
kept for future PMU production, and some farmers even breed registered horses in
hopes of selling the foals as riding prospects. Thousands of remaining foals are sent
to unsheltered feedlots until they reach a desirable market weight. There they are
slaughtered and their carcasses shipped to Europe and Asia for human consumption.
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Q. Are there additional humane concerns?
A.  Inspection reports document a number of significant problems. PMU mares are
confined to individual stalls for approximately 6 months of their 11-month pregnancy.
These normally active animals are given very little, if any, exercise. They cannot interact
naturally with other horses. They are usually not given adequate bedding material that
would cushion and insulate the cold, hard floors on which they are forced to stand or lie.
Observers report that the mares exhibit an abnormally high frequency of leg injuries,
and edema in the chest and legs. Grooming is neglected and hooves are seldom
trimmed. PMU producers may wait too long to seek professional veterinary
care for serious illnesses and injuries.
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Q. Is the quantity of feed and water sufficient?
A.  While the quality and amount of feed provided is considered appropriate,
pregnant mares may receive considerably less water than they would normally drink.
In fact, the drug company recommends that PMU farms use automatic watering systems
that distribute water at timed intervals and in carefully measured amounts. In the past,
it was commonly reported that water was restricted in order to increase the concentration
of estrogens by volume of urine and thereby reduce shipping costs. The pharmaceutical
company now claims that the water restriction policy has been modified; however, they
remain unwilling to allow humane organizations access to the farms to verify such changes.
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Q. Is the PMU industry's Code of Practice adequate to address these welfare concerns?
A.  No. The Code of Practice was adopted only after Wyeth-Ayerst came under
considerable attack from Canadian animal protection groups. Developed in
conjunction with agricultural consultants, the code offers corporate recommendations
for sanitation, housing, equipment maintenance, feeding, etc. But it is not a law and
its provisions are deemed voluntary. PMU farmers have generally been given
considerable leeway by the drug company inspectors to deviate from the
recommendations. Even strict adherence to the code would not ensure that horses
are treated humanely. For example, the code recommends exercise, but does not
specify the frequency or amount of exercise necessary. The code also condones
the premature separation of mares and foals, but fails to address the humane disposition
of unwanted foals and unproductive mares.
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Q. What are the prospects for addressing these cruelties
through new laws or government regulations?
A.  Not very good. Years ago, PMU farming was primarily situated in the Canadian
provinces of Ontario and Quebec. When animal-protection groups opposed the
mistreatment of horses and PMU farms faced the certainty of regulatory reform,
the entire industry simply moved its operations to the more accommodating provinces
of western Canada. Given this history, if stringent regulations were enacted, PMU
farms would likely relocate to other areas or to developing countries where there may
be even less ability to influence the care the horses receive. PMU farming occurs in only
two states in the U.S., so there is unlikely to be sufficient support for federal legislation.
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Q. Are there acceptable alternatives to Premarin® for estrogen replacement therapy?
A.  There are a number of plant-derived or synthetic estrogens that the U.S. Food
and Drug Administration has approved as safe and effective for ERT. Some
physicians believe that certain alternative estrogens may, in fact, be superior to
Premarin® in terms of both performance and patient tolerance. And, because these
estrogens are derived from plant materials such as Mexican yams and soybeans,
or are synthesized in the laboratory, they do not promote the direct and continuing
suffering of horses.
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Q. My doctor says that other estrogen replacement drugs have not
been proven to be as safe as Premarin®. Is this true?
A.  Because Premarin® has been on the market longer than any of the other
estrogen replacement drugs, many of the long-term studies on estrogen
replacement therapy evaluated Premarin® specifically. For this reason, however,
some of the long-term disadvantages of estrogen use have also been noted—
including the increased risk of developing uterine and breast cancer—
which apply to the use of Premarin®.
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Q. What can concerned individuals do to reduce the suffering of horses on PMU farms?
A.  First, you can educate yourself and others about the mistreatment of horses used
for the manufacture of Premarin®. Because this is an important health care issue,
women should thoroughly discuss treatment options with a physician. Together,
 the doctor and patient can evaluate possible dietary changes and exercise programs
that may minimize hormonal deficiency symptoms and help prevent osteoporosis
and heart disease. If it is determined that estrogen replacement therapy is appropriate,
the use of a plant-derived or synthetic ERT drug offers an ethical alternative to Premarin®.
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