Bladder and prostate cancer: neutering male dogs increases risk
Dr. Demian Dressler is internationally recognized as “the dog cancer vet” because of his innovations in the field of dog cancer management, and the popularity of his blog here at Dog Cancer Blog. The owner of South Shore Veterinary Care, a full-service veterinary hospital in Maui, Hawaii, Dr. Dressler studied Animal Physiology and received a Bachelor of Science degree from the University of California at Davis before earning his Doctorate in Veterinary Medicine from Cornell University. After practicing at Killewald Animal Hospital in Amherst, New York, he returned to his home state, Hawaii, to practice at the East Honolulu Pet Hospital before heading home to Maui to open his own hospital. Dr. Dressler consults both dog lovers and veterinary professionals, and is sought after as a speaker on topics ranging from the links between lifestyle choices and disease, nutrition and cancer, and animal ethics. His television appearances include “Ask the Vet” segments on local news programs. He is the author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity. He is a member of the American Veterinary Medical Association, the Hawaii Veterinary Medical Association, the American Association of Avian Veterinarians, the National Animal Supplement Council and CORE (Comparative Orthopedic Research Evaluation). He is also an advisory board member for Pacific Primate Sanctuary.
Updated: June 5th, 2019
Oh man. This is going to make a lot of people in my field angry. Apologies to classmates and veterinarian friends!
I came upon this study from the August, 2007 journal Prostate. Probably not what a lot of us would be reading in our spare time, but I am busy with upcoming info products for dog cancer owners and I dig through lots of publications.
Here is the study abstract. The short story is the following:
Data was gathered from North American Veterinary Hospitals on male dogs that had been neutered (testicles surgically removed, or castrated), to evaluate the trend that had been noted in some older articles that neutering increased prostate cancer.
Because, if this were the case (and this is my comment, not the authors’), it would seem ethics demand that owners of male dogs were advised of this before consenting to neutering surgery.
Here is what they found. Hold your hats, folks:
1. Castration of dogs increases total malignant prostate cancer by over 3 times for some prostate cancers (prostate adenocarcinoma). So the answer is yes, castration does increase prostate cancer in dogs (which goes against what I was taught).
2. Castration of dogs increases the most common type of bladder cancer (transitional cell carcinoma) by eight times. This is huge!! Major, major, industry-shaking information, or it should be.
So what does this mean to you are considering castration of your dog (or he is castrated)?
Here are some overall statistics: Roughly 1 in 3 dogs will be affected with some form of cancer, and approximately half of those will die of it, at least based on the treatments that have been available up to this point (I believe we can do a lot better with what I call Full Spectrum Care). Anyway, 1-2% of all cancers are bladder cancers, the most being transitional cell carcinomas (there are rarely other types of cancer that affects the bladder). So if we put all these above stats together and average them out, we are looking at a bladder cancer risk in castrated dogs of 2 percent.
For more helpful information and tools, get a copy of the Dog Cancer Survival Guide
Two percent is not a lot, but I neuter hundreds of dogs, and I see bladder cancer. Two percent happens! And the worst kind of cancer for your dog to get is…the one your dog gets, if you know what I mean.
Here is some information on bladder cancer in dogs.
Okay, the pundit gallery will argue.. but castration helps control the unwanted dog population, helps unwanted behaviors like aggression and territorial urination in undesirable locations, etc. Yes, yes, all true.
But, we must start informing owners of this, to use Al Gore’s phrase, inconvenient truth before they opt for castration of male dogs.
And that is one of the purposes of this blog!
Best to all,
Dr Dressler
Dr. Demian Dressler is internationally recognized as “the dog cancer vet” because of his innovations in the field of dog cancer management, and the popularity of his blog here at Dog Cancer Blog. The owner of South Shore Veterinary Care, a full-service veterinary hospital in Maui, Hawaii, Dr. Dressler studied Animal Physiology and received a Bachelor of Science degree from the University of California at Davis before earning his Doctorate in Veterinary Medicine from Cornell University. After practicing at Killewald Animal Hospital in Amherst, New York, he returned to his home state, Hawaii, to practice at the East Honolulu Pet Hospital before heading home to Maui to open his own hospital. Dr. Dressler consults both dog lovers and veterinary professionals, and is sought after as a speaker on topics ranging from the links between lifestyle choices and disease, nutrition and cancer, and animal ethics. His television appearances include “Ask the Vet” segments on local news programs. He is the author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity. He is a member of the American Veterinary Medical Association, the Hawaii Veterinary Medical Association, the American Association of Avian Veterinarians, the National Animal Supplement Council and CORE (Comparative Orthopedic Research Evaluation). He is also an advisory board member for Pacific Primate Sanctuary.
Thanks so much for this. I have an intact 2 year old male French bulldog, about 28 lbs, on a raw diet, who has an enlarged prostate. Of course everyone is telling me to neuter him, but I don’t want to (and not because we plan to breed — I just figure the hormonal system is there for a reason, right?)
Can you recommend anything to help shrink his prostate to normal size? I would really appreciate any information you might have on this. Thanks again!
Hello Dr.D,
I have a maltese who is about 6 years old and he is not neutuered. I’ve read articles that say a neutered dog lives longer than one that isn’t. Is that true? I’ve also read conflicting articles that say a dog is more likely to get prostate cancer. We have had him for about a year & a half now & hasn’t shown any negative behavior in terms of roaming or spraying. Please help me make the best decision for my pup.
Thanks.
Dear Jamie,
there are pros and cons to both neutering and not neutering. The standard conventional wisdom suggests to neuter. I do not always agree with the conventional wisdom, but each case must be considered separately.
Medicine is not always clear cut 🙁
D
Thank you Dr. Dressler for the info on spay and neutering. Unnatural can not be healthy. May I share it?
Dear T,
sure!
D
Hello Dr Dressler,
I was online doing some research on an issue my dog is having. Here it is.
I was just at my vets office in Wed with one of my working dogs. I had noticed some blood droplets prior. She did a rectal on him to only feel a “lump” on his prostate. We put him on Cipr 250mg’s BID. He will be 7 in May. He is also a GSD approx 92#’s. Not sure what onfo you need. I have also contacted a Repo Specialists and bringing him in next week for exam. Any thoughts? I am very concerned and not ready to loose this dog especially just yet. The Dr I am going to go see is Dr Jane Barber in NC. I am very concerned.
Thanks so much for all you do!
Dear Rebecca,
If the antibiotics don’t work you will want to have an ultrasound guided aspirate to get it tested and cultured. This is step two. Hang in there..
Best,
Dr D
I recently aquired a mixed puppy. He was a stray, but is the nicest dog out there. I am, of course keeping him. Everyone keeps telling me to get him casterated, because it will keep him healthier! So, if the information you are telling me is correct, which I believe it is…I shouldn’t get him casterated correct? He will not be a breed dog, but simply a nice house dog. He is brindle color and has the looks of a lab, mixed with some kind of plott hound. I want him to live a healthy life. If I watch him, to make sure he’s not out breeding other dogs; would you suggest not casterating him?
Dear Melissa,
castration is not a black and white issue. My general opinion is to wait until after 18 months of age unless there is a behavioral or medical reason for it sooner…
D
[…] prostate cancer and bladder cancer, both of which would be much worse than an enlarged prostate. Bladder and prostate cancer: neutering male dogs increases risk A population study of neutering status as a risk f… [Prostate. 2007] – PubMed result […]
Hi Dr. Dressler,
Your Sept ’08 post quotes a 3X increased risk of prostate adenocarcinoma for castrated dogs, while the Jan ’09 post quotes that risk as 8X. The Sept ’08 post quotes a risk of 8X higher bladder cancer for castrated dogs while the Jan ’09 post quotes a 4X higher risk. Can you please let me know which is accurate? Thanks!!
Thank you for your informative piece on neutering. I am a firm believer of not neutering my pet as I believe it is the owner’s responsibility to maintain the behavior, health and well-being of the pet just like nurturing and fostering a child.
If the owner isn’t willing to do this, then the person should not have a pet, under any circumstances. I have a 5 year old maltese, who has only mated with another dog once, under the supervision of both owners. Once again, it was the owners who control the situation.
🙂
Hi Dr. Dressler,
I notice that you have two entries on this topic. In one entry you state that bladder TCC is increased eightfold in neutered dogs. In the other entry you state three times increase. Then for prostate adenocarcinoma in one article you state 3 increase in neutered males and in the other article it is quoted as 8 times….am I misunderstanding something in your entries?
I cannot see ANY benefit to neutering males unless people want to alter some specific behaviors like marking….but I’d prefer the marking to needlessly increasing his risk of suffering from a painful and fatal cancer.
Here are the study results:
RESULTS: Neutered males had a significantly increased risk for each form of cancer. Neutered males had an odds ratio of 3.56 (3.02-4.21) for urinary bladder TCC, 8.00 (5.60-11.42) for prostate TCC, 2.12 (1.80-2.49) for prostate adenocarcinoma, 3.86 (3.13-4.16) for prostate carcinoma, and 2.84 (2.57-3.14) for all prostate cancers. Relative risks were highly similar when cases were limited to those with a histologically confirmed diagnosis.
I am struggling greatly with the decision of having my dog neutered after reading this, and from what Ive heard from most europeans, they seem to be very on track in general, our appt. is Monday, and I think Im going to cancel it.
On a separate note however, he tested positive for lyme antibodies on the 4dx (inexpensive test} and was treated right away with Doxy, Im thinking of paying the 148. dollars for a more comprehensive test to test his levels of lyme, apres doxy, to see where they are. So much seems to be done backwards…really frustrating, what is your opinion on this, and the use of Frontline. He is a small breed lhasa chihuahua mix, thank you, ariana of cambridge, ma.
I have a 2 y/o maltese whos is cryptorchid and no vet will take just one. We don’t want him to have px cancer or be incontinent. In adult males (its the same thing.. decreases life expectancy , fatigue etc…etc. Who can I get to remove just one (the undescended one.. obviously at risk due to it’s climate.
We are in Oklahoma,,,,Lawton,OK
thanks
Clint Kirk, D.O.
Dear Denise,
as always, always work under your vet’s guidance..as to your question, it is difficult to get the high amounts needed by feeding actual mushrooms. A little cooked shitake is one option.
Best,
DrD