Dog Health, Responsible Breeding

Esterisol (Neutersol) back in the US – soon!

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.


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  • Reply Ruth August 17, 2011 at 8:36 am

    Very cool…..I’ll have to make a note to watch for it. We’re not neutering our pup yet for a variety of reasons, but may down the road choose to do so (I have no intention of breeding, but we’re thinking of showing). Not having to worry about putting him through surgery at whatever point that may be (since he’s already big enough to make man-handling him while unconsious really difficult) would be awesome!

    • Reply jan dykema January 8, 2013 at 6:55 pm

      I never quite understand this.. you don’t want to breed.. but you want to show. Dog shows are for evaluating breeding stock.. that is why the dogs must be natural ( or intact if you prefer). By the way he will not be unconscious.. he will be anesthetized.. and that can be dangerous for dogs. What is your reason for possibly neutering him anyway?
      As for this drug.. i think it is dangerous. in the wrong hands it could be lethatl to the continuation of many breeds…

      • Reply Joanna Kimball January 9, 2013 at 5:16 am

        Plenty of people don’t want to breed because of the responsibility of it. If it was just “I made really nice puppies,” I’d agree with you, but a responsible breeder always has to support owners, take back puppies, be the safety net for litters… years and years and years down the line. I know that whatever I do, wherever I move, what career path I go down, I am going to have to have a place to put multiple dogs in case they come back to me, an understanding family, a prepared spouse, and a charged cell phone. Lots of owners who love the show ring don’t want anything to do with the commitment of breeding.
        Joanna Kimball recently posted…Is the dog fancy at a tipping point?My Profile

  • Reply priscilla August 17, 2011 at 9:50 am

    I still havent fixed my male and was trying to decide when , hes almost 8months . Of course were not showing or breeding but what little ive read about leaving them intact is better.. . Hes already so big and muscular! but id hate to remove his chances of developing further..
    I bet the vets down here have not started using this method..but im asking..

  • Reply Ruff August 17, 2011 at 12:33 pm

    Why not just give them a vasectomy? They cauterize the tubes with lasers nowadays, and in some countries, it’s the only legal procedure for canine birth control– unless an emergency operation has to be performed because of pyometria.

    • Reply Ruff August 17, 2011 at 12:49 pm

      Vasectomy via laser cheaper than castration, only takes a few minutes for the vet to perform, doesn’t require anesthesia, recovery time is within a day and it leaves the testicles completely intact. There’s no allergic reactions as zinc-based solution will provoke, and it won’t engage the immune system as “zeutering” reports swellings after injections. Plus the potential health consequences of reducing hormone production by 40% to 50% won’t have to be followed up on.

      The only resistance is the myth dogs so-called “charged up” on estrogen and testosterone are harder to control.

      • Reply rufflyspeaking August 18, 2011 at 7:02 am

        I have no problem with vasectomy as a concept, but it’s expensive and most vets won’t do it without anesthesia (at least that I’ve ever found). It also retains the look and feel of a normal testicle, which is a problem in the show ring (since neutered dogs are not to be shown) and of course if the dog ever gets picked up by animal control you’ve got a heck of a job explaining that the dog isn’t intact.

        • Reply Sandeep Manchanda September 2, 2011 at 9:44 am

          Any sterilization method vasectomy or Esterilsol has the same issue with animal control. But microchip company databases can record the sterilization status to ensure such dogs are not accidentally castrated. Tattoos can also be used.

          Laser vasectomy is a valid option (especially without anesthesia) but not without its own pitfalls like autoimmune responses and cyst formations leading to other complications over time.

  • Reply Kamie August 21, 2011 at 1:15 am

    I will certainly be checking with my vet about this. I just CANNOT make a decision about neutering Ice. My breeder is willing to discuss it as long as I don’t breed him. He has NO boy dog bad habits… I can’t really come up with a reason to neuter him.

  • Reply Sandeep Manchanda January 20, 2012 at 1:48 am

    Availability of Zinc neutering is changed to 2nd quarter 2012. Waiting list is growing.

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