The shipment of PMU (pregnant mare urine) mares from farms in the United States and Canada was put on hold in February until after the foaling season, unless the shipping distance is very short.

The reason, says Nat Messer IV, DVM, Dipl. ABVP, associate professor at the University of Missouri, and a member of an advisory board created by Wyeth Industries in Brandon, Manitoba, is because the mares are in late-term pregnancy and there is concern that long-distance travel will put both mare and foal at risk.

The mares are in the marketplace because Wyeth Laboratories has developed a new low-dose estrogen product that uses pregnant mare urine as the basic component. The lower-dose hormone replacement product requires far less pregnant mare urine than did its predecessor product.

When the PMU program was at its peak, there were 437 farms with 47,000 mares “on line” and producing pregnant mare urine. That number, by the end of next year, will have been reduced to 11,700 mares