Dear Dr. John,

My boyfriend and I share in the ownership of a nine-month-old Brittany Spaniel. He is slightly hyperactive to say the least. Our difference in opinion comes down to whether we should neuter our dog. Are there any negative side effects? My boyfriend is convinced that this would make our dog lazier and fatter and take away his high level of energy. Frankly, slowing him down some might not be such a bad idea. I have always heard and believed that it was advisable to neuter male dogs much like it is important to spay a female dog. I’m convinced that this is a bit of a macho thing. Lastly, how soon should we have this done if we are to go forward in agreement on the subject? B.V.

Dear B.V.,

For a very long time, the benefits of neutering male dogs have been well understood. I list the following in no specific order of importance. The benefits include eliminating the risk of testicular cancer, greatly reducing any chance of prostatic disease such as hypertrophy or neoplasia, prevention of perineal hernias and local tumors, reducing the pet population, decreased aggression, decreased hyperactivity, makes training easier, reduces likelihood of roaming or running off, and decreases marking behaviors.

Neutering also increases lifespan by 1-3 years and one study showed a 13.8 % longer lifespan. Typically, the recommendation is to neuter male dogs at six to nine months of age. Frankly, I think your dog will benefit by being neutered at any age, but I would proceed sooner rather than later so I hope you can agree to do this. Brittany Spaniels are high energy dogs and reducing the dog’s hyperactivity might be desired. As to your boyfriend’s points, your dog will not get lazier or fatter if neutered because of neutering alone. As for negative side effects, you cannot breed a dog once the dog is neutered, and some more recent studies have suggested an increased incidence of joint disease. I always wonder if men opposed to neutering their male dogs feel the same way about spaying their female dogs but that’s the veterinarian in me speaking. Good luck in resolving the issue!

Dr. John de Jong owns and operates the Boston Mobile Veterinary Clinic. He can be reached at 781-899-9994