The following timeline is based on documents found during keyword searches at epa.gov.
2009 – The EPA publishes a Fact Sheet classifying the product as a restricted-use pesticide, for use on female deer. The label indicated there is a chance that some animals will become permanently sterile.
2013 – The EPA registers GonaCon Equine as a restricted-use pesticide, naming USDA APHIS as the registrant, complete with PPE requirements and directions for use. Same product, but rebranded.
2015 – The EPA amends the registration, correcting the label and confidential statement of formulation (CSF). Still classified as RUP.
2017 – The EPA drops the restricted-use designation. Still assigned to USDA APHIS.
2019 – The EPA registers the product to Spay First as GONACON Immunocontraceptive Vaccine – EQ for commercial sale and use.
The product interrupts ovulation and infertility can be achieved for up to four years in mares treated with a primer and booster, according to a 2018 report by CSU.
Spay First is a 501(c)(3) nonprofit based in Oklahoma.
GonaCon EQ is not available for private use but you don’t need a diploma from the Billings School of PZP Darting and Public Deception to apply it.
Western Horse Watchers Association 