The only FDA-approved nonsurgical sterilization drug for male dogs began shipping to U.S. veterinarians Monday nearly a decade after an earlier version exited the market.
The new drug, Zeuterin Injectable Solution, is a blend of zinc gluconate and the amino acid arginine. The manufacturer, Ark Sciences Inc. of Ventura, Calif., has trained and certified more than 400 veterinarians in the use of Zeuterin.
The procedure does not involve traditional neutering—the surgical removal of a dog’s testicles. Instead, Zeuterin is injected without general anesthesia directly into each testicle using a fine, 30-gauge needle. Sperm production ends within one to three days, and the testes ultimately shrink, the manufacturer stated.
The drug is indicated for male dogs ages 3 to 10 months and may be delivered under mild sedation.
“It’s a simple, one-time procedure that takes only minutes,” said celebrity veterinarian Marty Becker, DVM, who attended the product launch Monday at the Western Veterinary Conference in Las Vegas. “It is such an improvement over traditional castration that shelter operators and veterinarians are embracing it.”
Dr. Becker reported that Zeuterin is the first veterinary product he has endorsed.
Also present at the unveiling were McAllen, Texas, mobile veterinarian Amber Valinski, DVM, and Phil Nelson, DVM, Ph.D., the dean of Western University of Health Sciences’ College of Veterinary Medicine.
Dr. Valinski, who was certified in 2012, has performed 722 Zeuterin procedures.
“I made myself a believer that this product works, that it’s effective and that it’s safe,” she said.
Western University veterinary students have administered Zeuterin during their training.
“[Veterinarians] can go into areas where it’s difficult to sterilize … and reduce the risk to the patient and increase the effectiveness and efficacy of population control,” Dr. Nelson said.
Ark Sciences, which in 2011 began work on a U.S. plant designed for the manufacture of Zeuterin, initially is focusing on the drug’s mass use through animal shelters and spay/neuter clinics. The company also is conducting online and hands-on training to certify more veterinarians in the precise administration of Zeuterin—from measuring the testicles to injecting the drug.
The earlier drug, Neutersol, was produced by Addison Labs beginning in 2003 but fell out of favor by 2005 over training issues and side effects such as a high rate of testes inflammation.
Ark Sciences acquired the rights to Neutersol and then worked to earn FDA approval of the plant, rebrand the drug and train veterinarians.
An FDA clinical trial found Zeuterin to be safe, with a sterility rate of 99.6 percent. Minor reactions, such as testicular swelling and pain, were observed in 6 percent of the dogs within a week after injection. Adverse reactions may include vomiting, loss of appetite and lethargy, the manufacturer reported.
Ark Sciences acknowledged that sterilizing a dog with Zeuterin may not eliminate roaming, aggression and other behaviors commonly absent in castrated dogs. Zeuterin cuts testosterone levels by approximately half, the company added.
Marketing Zeuterin to animal shelters and spay/neuter clinics is the immediate goal as the drug gains veterinary acceptance. The SPCA of Central Florida this month announced free Zeuterin injections for 100 dogs at its Orlando and Sanford veterinary clinics.
“Having an injection available to sterilize male dogs, as opposed to traditional surgery, is truly revolutionary,” said Rebecca Rhoades, DVM, a certified animal welfare administrator and medical director of SPCA of Central Florida. “Increased efficiencies also allow us to sterilize many more male dogs with this procedure.”
The SPCA clinics later will offer Zeuterin sterilizations for $50.
Valinski believes the lower cost of Zeuterin procedures will appeal to veterinarians. Her expenses run about $13 for each procedure, plus the drug cost.
“We don’t need a surgical suite,” she said. “You don’t have [the] cost of your gloves, your sharps, your autoclaving, the tech cost with cleaning all your instruments, the prep time, the anesthesia cost.”