Progress in equine contraception

Progress in equine contraception

  BILLINGS–The American SPCA on April 16,  2012 granted $100,000 to the Science & Conservation Center in Billings,  Montana, maker of the contraceptive vaccine ZonaStat-H.   The grant is separate from an ongoing ASPCA subsidy of $50,000 per year for three years to help advance the center’s work.  “The center, on the ZooMontana grounds, will more than double the size of its training facility,”  reported Zach Benoit of the Billings Gazette.
ZonaStat-H is based on porcine zona pellucida,  extracted from the ovaries of slaughtered pigs.  The potential contraceptive use of PZP was discovered at the University of Tennessee in 1972. The Science & Conservation Center,  founded by veterinarian Jay Kirkpatrick,   has produced and tested PZP-based contraceptive vaccines since 1998.  The first such vaccine approved and registered by the EPA,  ZonaStat-H was in 2011 injected into about 1,600 free-ranging mares across the U.S.,  including the Pryor Mountains of Montana and the McCullough Peaks region of Wyoming.  ZonaStat-H has also been used to contracept about 85 animal species kept in zoos. “The Humane Society of the U.S. sponsored the registration,”  Benoit noted.
A rival product,  GonaCon,  is a vaccine based on antibodies to the hormonal triggers that produce the sex hormones estrogen, progesterone and testosterone.  GonaCon has also been tested on wild horses in the Pryor Mountains,  and on urban deer in New Jersey and Maryland.
In England,  Friends of the Dartmoor Hill Pony,  the Dartmoor Hill Pony Association,  World Horse Welfare,   and the pharmaceutical firm Pfizer are testing yet another approach to equine contraception, using an Australian product,  Tracy McVeigh of the Guardian reported on March 12,  2012.   About 20 mares are to be treated this year.  “There are thought to be fewer than 1,000 of the ponies left,  down from  25,000 in the 1930s,”  McVeigh wrote