Comment from Linda Wilkinson
AnonymousSupportIndividual
Summary: An individual supports Tirza Eden's petition requesting that the FDA take jurisdiction over GonaCon-Equine and ZonaStat-H (PZP). The commenter argues that these products act as selective chemical sterilants that threaten genetic diversity and wild horse welfare, citing specific scientific studies and the Assateague Island herd as evidence.
I strongly support the Citizen Petition by Tirza Eden calling for FDA jurisdiction over GonaCon-Equine and ZonaStat-H (PZP).
The petition provides clear evidence that these products function as selective chemical sterilants in practice. Genetic factors determine response to GonaCon (Thompson et al. 2023), and long-term PZP use creates heritable non-response patterns (Eggert et al. 2010). Nuñez et al. (2017) confirms lingering fertility suppression even years after treatment stops. The Assateague Island herd illustrates this — despite halting PZP a decade ago, only a small group of mares produce foals annually and now over half the herd traces to the only non responder to PZP treatments — Carol’s Girl.
These outcomes threaten genetic diversity and wild horse welfare. I urge the FDA to take jurisdiction and require comprehensive safety, efficacy, genetic, and welfare evaluations.