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Canine Neutering
Health benefits of neutering
Neutering
When to Neuter
Neutering and Urinary control
also see Aggression
also see Dominance Aggression
also see Male Dog
also see Reproduction
Evaluating the health benefits of neutering your dogQuestion: As a subscriber, I would like to ask Dr. Mike the following questions.
Have any medical studies been conducted to evaluate the health benefits
of neutering your dog? I have heard repeated claims that neutered pets
are healthlier and happier. Beyond the benefits of eliminating the
possiblilty of testicular cancer and reproductive drive and perhaps the
elimination of some male to male aggressiveness is there any evidence of
other health benefits? Also is there any negative health effects
associated with the reduced levels of testosterone after neutering?Thanks, Corinne
Answer: Corrinne-
There have been a few studies evaluating the effects of castration on
dogs, usually either concentrating on behavioral effects or effects on
prostatic disease.These are the most commonly mentioned benefits, by veterinarians, of
castration in dogs:Decreased aggression (supported by studies)
Decreased urine marking (supported by studies)
Decreased roaming (neither supported nor refuted by studies)
Reduction in benign prostrate hypertrophy (supported by studies)
Reduction in prostatic infections ( could not find supportive studies)
Elimination of testicular cancer (no studies -- obvious
conclusion)
Rural practitioners add less chance of being hit by cars and shot by angry
female dog owners (no studies)These are the most common worries among pet owners:
Personality changes such as decrease in "maleness" or courage (not
supported or refuted)
Weight gain (studies show that a percentage of castrated males gain weight
- the exact
percentage and rate of weight gain vary from study to study)These are two concerns that dog breeders have that rarely are mentioned by
pet owners:Increased risk of prostate cancer (no conclusive studies -- but it is
clear that there is no protective effect
associated with castration)
Increased risk of orthopedic disorders / conformation problems (no studies
directly relating castration and orthopedic disorders but studies
do show that increased weight gain during growth can cause
problems with hip dypslasia, so by combining weight gain and
orthopedic studies some risk is likely)To sum this up, I think that it is much harder to make a clear case for the
health benefits of castration in male dogs than it is for the health
benefits of spaying female dogs, except if you factor in euthanasia due to
unwanted activities like urine marking that are often helped by castration.There was a study done which showed a small increase in the risk of
prostatic cancer in castrated males but the statistical significance and
study size were both small. It does seem clear that castration does not
help to prevent prostate cancer, though. It does help in prevention and
treatment of benign prostate hypertrophy. This seems like it might not be
a big deal, given the "benign" in the name, but when the hypertrophy is
significant this disorder is a problem.We do not think that there is much appreciable change in personality in
dogs that are castrated, although some owners disagree. In our experience
it rarely helps with aggression unless the owners are willing to undertake
a behavioral modification program, as well. We do think that it cuts down
on roaming, if castration is done before the dog goes off to seek females
in the first place, which also cuts down on fight wounds, gunshot wounds
and injuries from being hit by cars -- all of which can also be avoided by
supervision or containment of male dogs, as well.I think that the risk of orthopedic problems in dogs allowed to gain
excessive weight when growing is real. It is important to control weight
gain in all growing dogs, but especially in those that are neutered and
show an increased tendency towards weight gain.The effect of testosterone reduction on other hormonal systems is not well
studied, or at least not in the mainstream publications for general
veterinary practitioners. I suspect that this is an area in which more
research will be done in the future since more sensitive assays are being
developed for measuring canine hormones all the time and because
medications are being developed, such as selegiline (Anipryl Rx) which
have direct effects on hormonal regulatory mechanisms.While we have not studied this in our practice, I am nearly certain that we
could make a good case for neutered pets living longer. But this may be a
function of the fact that at the current time there is an emphasis on
neutering pets and an general feeling that it is the responsible thing to
do --- so the pet owners who are responsible type people feel an obligation
to do this and they also take better care of their pets.If you have questions about other health benefits or adverse effects of
castration that I missed, please feel free to write again.Mike Richards, DVM
4/18/2000
Q: My daughter also has a Dobe. He is 1 1/2 yrs old. Should he be neutered?
Of course, it is later than it should have been, but now she is getting some
flack from "experts" regarding why neuter him.He has never been with a female ; ) and she does not intend to breed him.
What are the benefits/risks of neutering. Your quick reply is appreciated
since he is schedule for the "snip" on 3/27.Regards, Michelle
A: Michelle-
I think that most veterinarians think that neutering male dogs is usually a
good idea. It helps with some behavioral problems and it reduces the risk
of benign prostate hypertrophy later in life. It eliminates the possibility
of testicular cancer. It reduces the incidence of fight wounds, hit by car
trauma and other injuries associated with looking for and finding female
dogs in heat. Male dogs are less likely to urine mark if they are neutered.
Neutering also reduces the risk of perianal adenomas ( a tumor that occurs
around the rectum later in life).Neutering is an irreversible procedure so it is important that everyone
involved in the decision making by comfortable with the choice to neuter.
When there are disagreements it seems acceptable to me to wait, since most
of the benefits do not appear to be affected too much by later neutering.
The exception might be wandering behavior. Once dogs establish a habit of
roaming, for whatever reason motivates them, it is hard to break that
habit. It is better to neuter early when this is likely to be a problem.Some dogs do gain weight after being neutered. Overall, the difference in
obesity percentages between neutered and intact males is a 5 to 10%
increase in obesity in intact males. This is the only disadvantage, other
than a slight risk of anesthetic problems, that I know of to neutering.If there are specific reasons for not neutering that people are giving your
daughter, I would be glad to try to find information on those specific
reasons.Mike Richards, DVM
3/22/99
Q: We have 2 male black lab puppies who are 4 months old. We have no interest in either breeding or showing them. What is the earliest age when we can safely have them neutered?
A: Larry- The recommended age for neutering any male is 6 mos. There have been some studies about neutering before 6 mos. of age and so far there do not seem to be any adverse effects with neutering this young but standard practice is to wait until 6 mos. - before sexual maturity begins.
Moe Richards, DVM
Neutering and urinary control problems
Q: Doc, perhaps you could tell me; (1) what is the absolute earliest age a Black Lab should be neutered? (2) is there a veterinary standard age of maturity a dog should reach before he is neutered? (3) can neutering cause a dog to have poor bladder control? (4) will my dog outgrow this problem (he's about five months old and house broken,...... until he gets excited)? thanks a bunch.
A: There is not a lot of data on the effects of spaying dogs and cats at younger ages than the "traditional" 6 months that has actually been published, at least that I am aware of. There are reports of two or three places studying the effects of early spay and neuter at the present time and I have seen references to data from these studies but am not aware of published data. I am only aware of one study of long term effects of spaying and neuter dogs at 7 months of age that followed the dogs for their entire lifetime. In this study, there were no problems attributable to spaying or neutering at this age other than a slight increase in the likelihood of estrogen dependent incontinence in female dogs. A lot of vets are spaying pets at 4 months of age pretty routinely now and humane organizations have been spaying animals in their care as early as 8 weeks for several years. Soon, there will be enough of these early spay and neuter patients and they will be old enough to figure out if there are long term effects. At present, no one is reporting any problems as far as I can tell.
So, to answer your questions. I don't know what the earliest age for safe neutering is. I only know that it is safe at 6 months or older. I believe the veterinarians reporting that they are having no problems with neutering as young as 8 weeks of age, but I can't support their claims with objective studies. Personally, if there was a strong need to neuter younger, such as exists at humane societies, I would have no qualms about it. I wouldn't neuter my own pet prior to five or six months of age, though.
I am not aware of problems with male dogs neutered young developing urinary incontinence. I have not seen any increase in the incidence of male dogs that are neutered over male dogs that are not neutered. I don't think that neutering your dog will make a urinary control problem worse.
There are two causes of incontinence that may explain your puppy's "problem". The first is submissive urination.
Puppies that have very submissive personalities tend to urinate small amounts when greeting people or when someone makes sudden movements or assumes a dominant position, even inadvertently. These puppies are generally showing other submissive signs, such as head down postures or rolling over. It can help to just ignore these puppies at first and let them get used to your presence in the house prior to greeting them. Many dogs will outgrow this behavior but some do not. For some dogs, treatment with anti-anxiety medications or phenylpropanolamine can be helpful. Unfortunately, not all dogs will respond to medical therapy or behavioral therapy for this condition. Strategically placed throw rugs or plastic runners are the next line of defense since the behavior often occurs at predictable times and places.
Some puppies can not control urination when they are very excited. They just get so worked up that they leak urine. Most puppies will outgrow this problem, too (at least based on the ones we see). Some dogs don't, though. We have some success treating these dogs with phenylpropanolamine. It seems to give them just enough control to get them through the excitement. It doesn't always work, though. I have never tried any other therapy for this condition. I think this is because I practice in a rural area and it is easy for my clients to adjust to making these dogs "outside dogs" and living with the problem. If there is an animal behaviorist in your area, your vet may be able to refer you to him or her for help with this problem.
In any case, I don't think neutering will help or hurt with either one of these behaviors.
Hopefully, he'll outgrow whatever problem is bothering him.
Mike Richards, DVM
Last edited 12/05/02