A new method of neutering male dogs without surgery is gaining popularity, but some local veterinarians have concerns about its effectiveness.
In June, the Spay Neuter Assistance Program of North Carolina became the first organization in the state to practice “zeutering,” or neutering dogs by injecting the testicles with a zinc compound called Zeuterin.
The procedure does not require anesthesia and can be done in less than 10 minutes. Zeuterin is an appealing option for shelters looking to curb overpopulation, as well as for pet owners who take issue with traditional castration, said Laureen Bartfield, president and executive director of SNAP-NC.
Several local vets, however, say that they are uneasy about the new technique because they feel that it is too early to know the full range of effects Zeuterin could have.
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With Zeuterin, the dogs’ testosterone production drops to 40 or 50 percent rather than zero. Testosterone is linked to certain behavioral patterns, such as roaming and showing aggression toward other dogs, and neutering is often encouraged not only to sterilize dogs but also to change these patterns. Because Zeuterin does not cut off testosterone production completely, the behavioral change may not be as pronounced. For some dog owners, this might be preferable, Bartfield noted.
“This is attractive to some people that, for whatever reason, whether it’s cultural, whether it’s machismo, want male dogs to have testicles and have testosterone,” Bartfield said.
For most dog owners, however, maintaining this level of testosterone is likely not ideal, noted Michelle Hayes, a veterinarian at Spay Neuter Clinic of the Carolinas on Providence Road, which does not use Zeuterin.
“In my mind, you’re not reducing the major behavior that you want to get rid of,” Hayes said.
Veterinarians must be specially trained to administer Zeuterin, which became commercially available in February after being approved by the FDA. Vets from more than 70 clinics and animal hospitals across the country have been trained to perform the injection since it was introduced.
There are currently two North Carolina organizations with veterinarians licensed to offer the injection, according to the Zeuterin Network website. In addition to being offered at SNAP-NC, which maintains mobile clinics at 19 locations in the Triangle area, Zeuterin can be found at Total Bond Veterinary Hospital, which has five locations in and around Charlotte.
“Any alternative to surgical sterilization deserves attention,” said Mark Epstein, medical director of Total Bond. A complete absence of testosterone has been linked to health problems, he noted, and so Zeuterin’s capacity to neuter while allowing testosterone production could be a positive step forward.
Cary Bernstein, executive director of Spay Neuter Charlotte, said the drug has not been in the marketplace long enough for her to feel comfortable recommending it.
The fact that Zeuterin leaves dogs open to testicular cancer later in life, a possibility that is eliminated by traditional castration, is also a concern, Bernstein said.
But for older dogs or dogs with certain medical conditions, Zeuterin offers a chance to be neutered that otherwise would not be possible, Bartfield said. Anesthesia, which is used in traditional surgical neutering, is often unsafe for these dogs, and Zeuterin allows them to be neutered without the risk.