Neutering Male Dogs: Should You or Shouldn't You

By Ed Frawley  |  Last modified: May 21, 2026

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I get many emails asking if they should neuter their dogs. Neutering animals is an important income stream for many vets, which is why so many vets will advise you to neuter. The fact is unless your male dog is a monorchid (only has one testicle), you should not neuter your dog (male or female).

I used to argue that neutering would cure dominance or aggression problems if the neutering was done before 1 year of age. I have since learned that I was dead wrong. Those people are going to have to read my article on Dealing with a Dominant Dog and follow the directions there.

What Dogs Should Be Neutered

I used to believe that neutering would prevent older male dogs from developing prostate problems. Studies have since proven me wrong on that issue too.

Working dogs that are born with one testicle should be neutered but not until they are 2 years old. If these dogs are not neutered, they run the risk of developing testicular cancer at about 5 years of age. Neutering before 2 years is going to affect the dog's fight drive and working ability. Neutering after 2 years is not going to affect the dog's working ability.

I have come to believe that neutering our dogs causes so many health issues with the dogs that it's simply not worth the risk. Watch the video below and form your own opinion. I can tell you that we don't and won't neuter our dogs unless medically necessary.

Leerburg's general recommendation regarding spaying or neutering is to avoid the procedure if possible, but if you decide to proceed, wait until your dog is completely physically and mentally mature. While we do not recommend routine spaying or neutering due to documented health issues associated with early procedures, we acknowledge that medical exceptions exist and emphasize the importance of weighing the risks and benefits for your individual dog. Potential complications that may warrant the procedure include life-threatening conditions such as pyometra in females, testicular torsion or retained testicles in males, severely enlarged prostates that impair urination or defecation, and testicular cancer. Leerburg encourages owners of intact dogs to maintain regular veterinary examinations to monitor for these issues as their dogs age. Ultimately, this represents Leerburg's general guidance based on our experience, and you should consult your veterinarian to make the best decision for your individual dog's health and circumstances.

Dr. Becker: The Truth About Spaying and Neutering

Dr. Karen Becker, a proactive and integrative wellness veterinarian, discusses all about neutering or spaying in pets.

PDF Transcript of The Truth About Spaying and Neutering

Research Support: 2022 Behavioral Study on Castration

A 2022 questionnaire study by Kriese et al. published in the journal Animals provides empirical support for nuanced decision-making on spaying and neutering. The study surveyed 386 dog owners about behavioral changes following castration and found that while castration can resolve many undesirable behaviors in male dogs, the arguments for and against neutering should always be considered on an individual basis.

Behavioral Improvements After Castration

The study found significant reductions in several behaviors associated with sexual drive and territoriality:

• Roaming decreased from 26.68% to 10.61% of dogs
• Mounting behavior decreased from 55.44% to 27.46% of dogs
• Urine marking decreased from 52.59% to 38.86% of dogs
• Aggression toward other dogs decreased from 20.98% to 13.99%
• Aggression toward other animals decreased from 16.06% to 10.62%

Behavioral Concerns After Castration

The study also documented some unintended consequences of castration that dog owners should be aware of:

• Fear of unfamiliar dogs/humans increased from 13.47% to 18.65%
• Sound phobias increased from 10.62% to 17.10%
• Overall activity levels decreased significantly, with hyperactive dogs decreasing nearly three-fold (from 19.17% to 6.74%)

Study Conclusion

The researchers concluded: "While castration can resolve many undesirable behaviors in male dogs, the arguments for and against neutering should always be considered on an individual basis." This aligns with Leerburg's recommendation to weigh the individual circumstances of each dog before making this permanent decision.

Reference: Kriese, M., Ku?niewska, E., Gugo?ek, A., & Strychalski, J. (2022). Reasons for and behavioral consequences of male dog castration—A questionnaire study in Poland. Animals, 12(15), 1883. Link

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About Author

Ed Frawley

Ed Frawley is the founder and owner of Leerburg.com and has been producing professional dog training videos since 1982. Over the years, he has collaborated with some of the most respected dog trainers in the country. His body of work includes 194 full-length training DVDs and 95 comprehensive online courses. In addition to these, he has produced and published over 4,000 short training videos available free of charge on Leerburg.com and across the company's social media platforms.

Ed and his wife, Cindy—also a professional dog trainer—bred working-line German Shepherds and Belgian Malinois for more than 35 years. Although they retired from breeding in 2009, they had produced over 300 litters by that time.

Ed also served as a K9 handler for the local sheriff's department for 10 years, working in partnership with the West Central Drug Task Force. During his time in law enforcement, he handled multiple narcotics and patrol dogs and conducted more than 1,000 K9 searches. If you want to learn more about Ed, read about his history here.

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