Zeutering vs. Neutering: The Controversy and an Opinion

Medical articles
Pomeranian resting in cone after neuter surgery

There’s a new way to sterilize male dogs you should know about. It involves a product called Zeuterin, whose trade name spawned the predictable verb “to zeuter” in reference to the act of rendering a dog sterile via injection with zinc gluconate (aka: “zeutering”).

Despite the fact that it’s been used successfully in many other countries, the drug has gotten plenty of push-back here in the US. Veterinarians and pet owners alike have expressed skepticism, disdain, and even downright revulsion at the very notion of this novel method.

Which makes little sense to me. After all, Zeuterin is simpler, safer, and much less expensive than its surgical alternative (i.e., castration):

  • No anesthesia is required.

  • It takes only seconds to administer.

  • It’s considered painless.

  • Complication rates are way below those for castration.

  • And it costs only $5 to $25 per pet.

Despite these benefits, controversy appears inevitable. Here’s why:

Zeuterin is administered as an injectable - directly into the center of each testicle. As such, pet owners have expressed a significant degree of shock and horror that this procedure should be undertaken at all, much less on a patient that remains wide awake. Men, in my experience, have been especially resistant (“You can’t tell me that doesn’t hurt!”).

Meanwhile, many of my veterinary colleagues have expressed similar skepticism over its painlessness. Though I've seen this done and observed no pain, suspicion that a dog might not be willing to remain calm throughout the procedure is commonly voiced within the vet set.

This fear of pain prevails despite the fact that we’ve amassed quite a bit of evidence to the contrary. I mean, we’re talking about a 28-gauge needle, not a scalpel. Sure, some soreness on par with what we’d expect after neutering is a possibility, but it’s not universally the case. All told, this is a breeze compared to traditional castration.

But that doesn’t mean those who condemn the approach don’t have legitimate concerns. Because Zeuterin doesn’t completely castrate dogs, some testosterone remains. Zeutered dogs retain about 50% of their testosterone, which means that, though rendered 100% sterile, they may still exhibit some of the frustrating behaviors that are often eliminated with castration. It also means they’re still at risk of suffering some conditions neutering eliminates.

But the news is not all bad on the testosterone front. Not at all. On the plus side, zeutered dogs will likely experience some of the benefits of testosterone, including a reduced risk of obesity and improved muscle tone overall (a boon for many in their arthritic geriatric years). A reduction in cruciate ligament disease and a reduced risk of certain cancers relative to neutered males are additional benefits testosterone reportedly confers.

Though I'd still rather castrate most of my male sterilization candidates whose owners report behavior concerns and (of course!) those for whom castration becomes a medical imperative (perineal hernias, benign prostatic enlargement, etc.), I’m more than willing to consider zeutering for clients who prefer their pets keep some testosterone to help hedge against certain risks.

Mostly, though, I believe this solution is best for shelter situations: It’s cheap. It’s easy. It’s effective. And those who adopt these pets can always choose to castrate later if they elect to do so after consulting with their veterinarians. What’s not to love?

After all, professional prejudice, present unpopularity, and personal aesthetics are no rationale for avoiding new technology. If that were the case, we'd still be living in a world unwilling to consider pet sterilization at all.

I know I sound somewhat grouchy but, to my way of thinking, it’s bad enough we have to deal with pet overpopulation as a result of public irresponsibility; dealing with the public's distaste for solutions to the problems it's created makes it that much harder to take.