This is very, very good news.
Here’s the background: For a very long time scientists have known that sperm production in mammals is actually pretty fragile. The structure of the testicles is a lot like a huge mall parking lot; in each of the parking spaces baby sperm grow. As they mature they back out of the parking spots and join others in the narrow aisles, moving out to the larger roads and then to the superhighway and then hopefully into the great dark world to make some puppies.
Because everything depends on those little tubes, if you damage them they can’t make the baby sperm. And it turns out it’s very easy to damage them with a mild caustic agent, something that’s not very harmful to anything but those fragile little cells.
Rsearchers figured out that a perfect solution was zinc gluconate. Inject zinc gluconate into a testicle and two things happen – sperm production is drastically reduced and the sperm that are produced have poor motility (which means they can’t fertilize eggs) AND – because testicle tissue also converts the hormones the pituitary gland sends out into testosterone – the testosterone production of the dog dropped by 40%-50%.
This is, honestly, a fantastic thing. The dog can’t make puppies, but he’s still producing 50%-60% of his vital testosterone. The drop in testosterone is why so many serious dog people keep dogs intact even if they have no intention of ever breeding them. It’s just simply healthier. If we can remove the possibility of puppies without removing all the testosterone, it’s a great thing.
The zinc injection that was discovered was put on the market as “Neutersol” in the early 2000s – and promptly taken off again.
Neutersol was taken off the market not because the product didn’t work but because (in their opinion) it was such a breakthrough method that people didn’t adopt it fast enough and (in my opinion) because it was stupidly marketed. Most owners in the US don’t worry about the health problems of neutering; they worry about the price. Most serious dog people don’t worry about the price; they worry about the health problems. Neutersol was positioned at the same price as a surgical neuter, which was ridiculous – they wanted to use it as a cash cow even though nothing about it justifies the price. It’s a zinc gluconate solution in a syringe; you don’t need to use anesthesia. And at that time it was positioned for use only in a very narrow age range of puppies. So vets didn’t offer it as a low-cost alternative and most owners never heard about it, and by the time show breeders and performance owners were ready to say that a male had proven that shouldn’t have puppies (typically over a year old) the product was unavailable.
Esterilsol, which is the same thing branded by a different company, has been promised to solve both problems. They say they’re positioning it at 1/5 the cost of a surgical neuter and that it’s no longer age-specific. If that’s the case – if they can make this work – it’s a process that show breeders and performance breeders should JUMP ALL OVER.
I am hoping their promises are true; if they are, this could be a huge game-changer.
By the way, I happen to have access to one of the (comparatively) few dogs that was Neutersol-castrated; when we pulled my sister’s dog Wilson from the Hartford Pound and had him groomed we discovered that he had been Neutersol-injected. So I can tell you from experience that it leaves dogs with small but intact testicles; there’s no way (because I can hear this question coming) that a judge would think he was normal, but they do still exist. And Wilson “feels” more like an intact male than a neutered one, both physically in muscle tone and width of chest and pelvis and behaviorally. He can (and has) breed and tie but is not enthusiastic (with the exception of Ginny who, in her one and only heat cycle with us, drove Wilson to feats of manliness that shocked even him) and obviously no puppies come of it.
I’ll be watching for more news, and hopefully updates in the fall.