Equines pregnant mares

Many systemically administered estrogen products are available in the United States, but conjugated equine estrogens (CEEs), prepared from the urine of pregnant mares, is the most widely prescribed. Transdermal estrogen preparations are also available and usually are prescribed for patients who experience adverse effects, elevated triglycerides, or liver function abnormalities while taking an oral product. Transdermal preparations also have a lower incidence of venous thromboembolism than oral preparations.9... 

One of the most prolific natural sources of estrogenic substances is the stallion, which liberates more of these hormones than the pregnant mare or pregnant woman. The equine estrogens—equilenin and equilin—and their congeners are unsaturated in the as well as the A ring and are excreted in large quantities in urine, from which they can be recovered and used for medicinal purposes. 

I Oral Estrogen. Oral CEE has been available for more than 50 years. CEE is prepared from the urine of pregnant mares and is composed of estrone sulfate (50% to 60%) and multiple other equine estrogens such as equilin and 17a-dihydroequilin. ... 

Brendemuehl JP, Boosinger TR, Bransby DI, Kee DD, Schumacher J, Shelby RA, Putnam MR. The effects of short-term exposure to and removal from the fescue endophyte Acremonium coenophialum on pregnant mares. Proc Sixth Int Symp on Equine Reproduction 1994c, pp 11-12. 

Cross DL, Anas K, Bridges WC, Chappell JH. Clinical effects of domperidone on fescue toxicosis in pregnant mares. Proc Am Assoc Equine Pract 45 203-206, 1999. 

PMSG. Pregnant mare serums gonadotropin. Equine cyonin. Gormon. Eleagol. Priatin. Serotropin. Gestyl. Antostab. Many other names [9002-70-4]... 

Kosanke JL, Loch WE, Worth K, Ellersieck MR. Effect of toxic tall fescue on plasma prolactin and progesterone in pregnant pony mares. Proc Equine Nutrition and Physiology Symp. 1989, p 663. 

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