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