Premarin TM is produced by Wyeth-Ayerst Laboratories , a subsidary of American Home Products . It is used to reduce the symptoms of menopause in women or women who have had a hysterectomy. This year, approximately 75,000 mares throughout North Dakota and Canada will be impregnated and confined to cramped stalls so their estrogen-rich urine can be collected. Most of the foals will be killed before their first birthday. For six months, while their bodies are producing the most estrogen, these mares are unable to take more than a step or two in any direction, turn around, or even lie down comfortably.
Lameness often develops.
They are also denied free access to water so that their urine will yield more concentrated estrogens. This can lead to renal and liver problems and cause the mares to struggle and injure themselves during water-distribution times to get to the water they so desperately crave. So that they can be put right back into production the next winter, the mares are reimpregnated within days of giving birth. Fertile mares may go through this same grueling cycle year after year for more than twenty years. A few are kept for stud or to replace their worn-out mothers.