A new product may change how you think about having your male dog neutered.

Marketed under the name ‚ÄúZeuterin,‚ÄĚ this product is an injectable solution of zinc gluconate used for chemically sterilizing male dogs. Forgoing the need for general anesthesia and surgery decreases the cost and time of the neutering procedure, and therefore this method may revolutionize our country‚Äôs overcrowded animal shelters, but is it a valid option for the average pet owner?

What is Zeuterin?

Zeuterin is FDA approved for use in young male dogs between the ages of three and ten months old. An injection is given into each testicle, inducing fibrosis and rendering the dog sterile. Studies have shown the product to be over 99% effective, though because all of the sperm may not be killed instantly, the manufacturer recommends waiting 60 days before exposing a ‚Äúzeutered‚ÄĚ dog to females in heat.

Zeuterin does not get rid of testosterone completely as traditional neutering does. Instead, it decreases the testosterone level to about half of that found in intact male dogs. Obviously, male dogs who are neutered with Zeuterin will keep their testicles, whereas traditionally castrated dogs do not.

Let’s go over some pros and cons of this method of neutering.

Zeuterin pros and cons



This is probably the MOST important pro. While sedation is sometimes used for the procedure, there is no need for general anesthesia and there are no incisions to worry about, therefore no dreaded e-collar.


Again, with no costly anesthesia time, the cost of the procedure will surely be less than a traditional neuter.

Effects of testosterone

Many owners like the appearance of dogs who are subject to continued amounts of testosterone ‚Äď they are generally a bit beefier in appearance.


Effects of testosterone

Because testosterone is still present, many of the behavior problems that are curbed with traditional neutering may still occur, including roaming, urine marking, aggression, and mounting behavior. Diseases that result from increased testosterone can still occur, including benign prostatic hyperplasia, bacterial prostatitis, testicular cancer, and perianal tumors.

Side effects

Like virtually all procedures, there are side effects. In the case of Zeuterin, side effects include testicular swelling, scrotal ulceration and/or bruising, testicular pain, and systemic signs like vomiting and inappetence. Overall, the complication rate is low at 1.1% of dogs.

Proof of sterility

Because the dog‚Äôs testicles remain, you might get some dirty looks from pet owners who are concerned about whether your dog is neutered or not. A ‚ÄúZ‚ÄĚ tattoo is recommended for dogs who are chemically sterilized. Microchips that contain reproductive status are also available.

Mating behavior

Dogs who are neutered with Zeuterin can still mount willing females, putting them at risk for transmissible venereal disease.

No one can tell you whether Zeuterin is right for your family. That's a decision you need to make. If it is something that interests you, have a discussion with your veterinarian to see if it is a good choice for you and your dog.

Jul 3, 2013
Pet Health

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