Zeuterin

Zeuterin (zū-tur-in) is a U.S. Food and Drug Administration approved injectable compound for sterilizing male dogs aged three months to ten months without the removal of the testicles; the male hormone testosterone continues to be produced in limited quantities following the injections. Manufactured by Ark Sciences, it became available in the United States on February 17, 2014. Zeuterin consists of sterile water, zinc gluconate, and the amino acid arginine and produces infertility in male dogs by chemical disruption of the testicle; it is intended as an alternative to surgical neutering. Before being allowed to administer Zeuterin, veterinarians must complete a five-hour course teaching them the correct location and manner to inject the drug. Properly administered, Zeuterin is considered to be 99.6% effective when given to dogs three to ten months of age. Outside of the United States it is also known by the trade name Esterilsol.

An earlier version of the drug, called Neutersol, was manufactured in the US from 2003 to 2005 before being taken off the market. It was developed by Pet Healthcare International, Inc. and was approved by the FDA for small puppies in 2003. In 2005 however, Pet Healthcare International severed ties with its manufacturing partner Addison Biologicals, and production of the drug stopped. Neutersol had been expected to be reintroduced into the market by early 2009, but that plan stalled and Ark Sciences acquired the intellectual property to this method of sterilization. Neutersol is contraindicated in cases of cryptorchidism, pre-existing scrotal dermatitis, testicular diseases and malformations, and drug hypersensitivity on Neutersol components.

Currently, the manufacturer, Ark Sciences, Inc. is in the process of restructuring and has temporarily suspended distribution of Zeuterin.