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: March 23rd, 2020
Oh man. This is going to make a lot of people in my field angry. Apologies to classmates and veterinarian friends!
I came upon a 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.
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 EIGHT 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 about FOUR TIMES. This is huge!! Major, major, industry shaking information as far as I can tell.
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.
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.
Hi Dr Dressler,
I have a 9-1/2 year old German Shepherd that I never neutered for various reasons. I’m now getting ready to move, and a number of landlords have specifically asked if he’s neutered, so I’m looking into it as I’m not really opposed to it. What are your thoughts on neutering at this age? I would, of course, want blood tests done beforehand, but assuming that all came out clear? My main concern is for his safety during surgery – I know I should have done it before now.
Also, would the face that he’s been unneutered for this long help decrease his chances of these prostate cancers that you mention in this article? Or is it an “all or nothing” deal? (If you know?)
Thanks so much!
Maggie
Dear Maggie,
I have no problem with neutering a dog of this age at all, as a matter of fact it makes a lot of sense! Just get the proper work up before hand and make sure they check the old prostate!
Best
D
[…] population study of neutering status as a risk f… [Prostate. 2007] – PubMed result Bladder and Prostate Cancer: Neutering Male Dogs Increases Risk "1. Castration of dogs increases total malignant prostate cancer by EIGHT times for some […]
Dr. Dressler, I really need your advice on what to do. My 11 year old schnauzer has an enlarged scrotum (one side has always been larger than the other side) that has hardened inside. One Vet recommended neutering as usual and sending off for results. The other Vet recommended neutering with a scaple and removing everything at the time of surgery. He said this was more involved than regular neutering but that is what he recommended. What do you recommend I do? What would you do if this was your dog? I need to know asap because I need to do something asap. Thank you. I am worried sick!
Dear Janice,
Well, this is a little tough since I don’t have hands on the dog. Neutering with a scalpel is a routine neuter, just FYI. I am wondering if he is talking about a scrotal ablation, where they remove the testicle sac along with the testicle. We cannot say what is correct without a crystal ball. If malignant, we might be happy we did a scrotal ablation too. If benign, it will be overkill.
I suppose if you want to limit the intervention, do the neuter plus scrotal ablation first off. Although it may be overkill, the odds of only having one surgery is higher. If malignant, it may be you would be looking at a second wider excision surgery to remove all the cells, if a simple neuter was done.
By the way, the scrotal ablation is not a huge procedure, so although it is more involved, it is not that difficult or risky if done properly. You might want to read the surgery part of the Guide if you have not done so.
I hope this helps
D
Our 9 year old Beagle was just diagnosed with prostate cancer. I am wondering why none of the sites I have looked at suggest the medication that my vet team suggested for him. They said that piroxicam, which I understand is an arthritis medication for humans, often acts to shrink (temporarily) the prostate gland making the dog more comfortable and better able to urinate and defecate. How come I could find nothing about that on the internet sites I looked at? Is this something anyone else has had recommended?
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Dr. Dressler,
may i ask who you can recommend to provide veterinary services in san fernando valley, ca ? someone who is credible, honest, and yet who is in this profession for the animals vs. the $ , as well….
appreciate it … please no one working w/ or for the VCA, please
thank you & best regards
Dear D,
I have no experience in this location I am afraid. The best things to do is ask other dog lovers. Go to dog parks, groomers, pet stores and see what people say.
Best,
Dr D
Dear Terry,
Two suggestions for your concerns…don’t move to Florida, and don’t neuter your dog.
While risks of bladder and prostate cancer are low overall, if it is YOUR dog who needlessly develops a painful and ofen fatal disease, it might seem a bit more important to you in the grand scheme of things.
Where are your suggestions to decrease the risk for the neutered dog developing cancer? Eliminate certain dietary agents? Toxic chemicals? Exposure to radiation?
We just don’t know. But we do know that one big risk factor to avoid…..castration. Just say NO!
I would like to see the one and only study from 2007 that shows that castrated males have an increase risk for developing bladder and prostate cancers. Do you have a link to an accredited website or can you tell me which journal or periodical it is from?
How old were the dogs in the study? What age were they neutered? Did they have any prostate or bladder problems prior to the castration? How long after castration did they get cancer? What type of cancer did the get? How many dogs were in the study? What breed were the dogs? Was there a history of cancer in the family? How long did the study go on for?
Also, do you think it is really a good idea that people with pets that have enlarged prostates and are obviously having urinary and defecation problems, think it is OK to not neuter their pet? In all fairness you might want to point out how the chances of the prostate shrinking increases dramatically after the dog is neutered. Maybe site one of the thousands of studies done on that subject.
People will believe anything they read on the internet, especially if it comes from someone with a good reputation, which it seems like you have. I had a hard time finding any negative feedback on you. You need to be careful how you present information on line. After reading some of the above posts I have no doubt that at least 2 of the dogs with enlarged prostates, that did not have a diagnosis of cancer, would have done better had they been neutered.
Your original discussion was about prostate, bladder cancer, and neutering of male dogs. There are posts about osteosarcoma and hemangiosarcoma. Neither of these have anything to do with castration. As a responsible veterinarian you should be correcting these people.
AND the Frontline issue??? Are you really supporting the idea that topical Frontline, not any other topical flea product, is causing cancerous tumors? Did any of these dogs ever receive an injection, like a vaccine, in that spot? I would love to see the study on the Frontline topic also. There are only thousands of studies and millions of dollars in research showing vaccine related tumors. So much research in fact that the protocol for administering vaccines changed 10-12 years ago so the incidences of tumors would decrease.
I look forward to seeing some of this research.
Dear Nicki,
For your review. I am sure you will find the publications below of good quality. You can access abstracts and in some cases the full papers on Pubmed.
Prostate. 2007 Aug 1;67(11):1174-81.
A population study of neutering status as a risk factor for canine prostate cancer.
Bryan JN, Keeler MR, Henry CJ, Bryan ME, Hahn AW, Caldwell CW.
Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, Missouri, USA. bryanjn@missouri.edu
As neutering as an ancillary treatment for prostatitis, benign prostatic hypertrophy, and prostatic abcess, these are topics for a different blog related to non-cancerous diseases of the prostate.
Vaccosarcomas, which occur at injection sites and sound like what you are referring to, are problems in cats but almost non-existent in dogs. There are some white blood cell issues related to vaccination, in particular vaccination of infants, that need attention in the context of canine and other species’ cancer development, but this information needs to be pieced together from multiple publications to see the big picture. I do not believe this is what you are referring to.
Some information on topical insecticides (generally) as a risk factor (different from concrete cause and effect, which is non-existent in cancer for any factor):
J Toxicol Environ Health. 1989;28(4):407-14.
Epidemiologic study of insecticide exposures, obesity, and risk of bladder cancer in household dogs.
Glickman LT, Schofer FS, McKee LJ, Reif JS, Goldschmidt MH.
Department of Clinical Studies, University of Pennsylvania, School of Veterinary Medicine, Philadelphia.
Osteosarcoma and early surgical sterilization:
Cancer Epidemiol Biomarkers Prev. 2002 Nov;11(11):1434-40.
Endogenous gonadal hormone exposure and bone sarcoma risk.
Cooley DM, Beranek BC, Schlittler DL, Glickman NW, Glickman LT, Waters DJ.
Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, Indiana 47907, USA.
Vet J. 1998 Jul;156(1):31-9.
Host related risk factors for canine osteosarcoma.
Ru G, Terracini B, Glickman LT.
Department of Animal Pathology, University of Turin, Italy. cea@to.iZS.it
Thank you for your interest in these topics
Best,
Dr D
have border colie 12 months why not to neuter.