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.
we have a 12yr old boykin spaniel, not neutered, who was recently diagnosed for an enlarged prostate, x-ray, antibiotics (7days) His symptoms were no appetitite and lethargic. His temp was 104 with .blood in his urine….He improved in days and took the antibiotic till gone.
We were not scheduled for a return visit and now three weeks later, no appetite again, vomited yesterday but doesn’t appear to be lethargic, walking fine, bowels ok. He did suggest being neutered but we are apprehensive about the surgery ,he is also on seizure med tho’ it is under control. My concern is do we go back to the vet with a urine sample. after reading the comments on your blog, should we suspect cancer. He is a very non-agressive dog and dearly loved.
thank you for your advice.
Dear Mary, This is a worrying time for you, of course. Should you suspect cancer? Better to suspect and have it confirmed or ruled out, than to live with the worry. Why are you worried about the neutering surgery? Due to his overall health or for some other reason? Often dogs who remain intact get on absolutely fine until later years when changes occur. If you vet has recommended the surgery, ask ‘why’? There will be a good reason which you need to consider. You may find some more information on the blog at https://www.dogcancerblog.com/blog/checking-your-dog-for-testicular-cancer/. If he has lost appetite and is vomiting again, another vet visit is recommended. Call in advance and ask if you need to bring a urine sample. There may be other things going on, but unless you get them checked, all you have is your imagination and a dog who is not 100%. Good luck, and give him a big cuddle from all of us.
Hello, we have a 7 year old corgi that has just been diagnosed with an inoperable bladder tumor and during the ultrasound they also believe that his prostate may be affected as well. They started him on piroxicam? We are meeting with the oncologist this week to discuss more the specifics and talk about options. Because he is a puppy mill survivor that was horribly abused and is traumatized we are reluctant to put him through cancer treatment. Are there dietary things we can do, alternative medicines, turmeric, etc.. that might be effective?
A couple of weeks ago my dog started to cry when trying to poop and it was coming out ribbon like. It was determined that he has a very enlarged prostate. He is ten and was neutered when he was a puppy. The vet did an x-ray which showed how large it actually was and it also showed mineralization. There were faint shadows also that appeared to be lymph nodes. She said that she was quite certain it was cancer. Is there any chance it isn’t cancer? He is pooping less despite using pumpkin and cat hair all medicine to help him along. He is still eating, drinking and peeing just fine. I don’t think he has any pain aside from when he tries to poop.
Dear Ann Marie,
I would suggest an ultrasound guided fine needle aspirate to confirm if there are doubts…
Best
Dr D
AnnMarie,
I recommend an abdominal ultrasound and an aspirate or biopsy to confirm.
All my best, Dr Sue
Dr dressler,
I recently purchased a golden retriever. He has an undescended testicle at 9 wks age, which the breeder said could drop as late as 13-16 wks. I’m curious about your opinion because they had kept him intending to be a show dog prior to learning this. I have never dealt with this before and have read that leaving the testicle in the abdomen can “significantly” increase cancer occurrence and other possible health related issues. We must have him neutered (purchase agreement), but I appreciate your feedback regarding this issue and whether it truly is a genetic flaw as another breeder stated to me when considering purchasing him.
Shelley brings up a good point. I am also curious about the numbers. If the absolute numbers are closer to 10,000,000, I’d say it’s a risk worth taking. As humans, we often make choices daily even when we know there is risk involved. When speaking specifically to decreasing a dog’s risk of getting prostate cancer then yes, based on the study, it makes sense for a vet talking about cancer to advise against neutering. What people must consider is the risks vs. the benefits. Intact dogs are more likely to roam, more likely to get hit by cars (because they are roaming), and more likely to be euthanized when they end up in the shelter as a stray. Having fostered homeless animals for the last three years who were rescued from the shelter, I can count on one hand the number we’ve received who came here without their dangly bits. The cancer argument is a strong one, and something that should definitely be taken into consideration when making such an important choice for your animals but please don’t let it be the only factor in your decision-making process.
Hi. My husband is curious to know what are the absolute numbers. The study just quotes relative numbers. For example, if the “normal” risk of getting cancer is 1 in 10,000,000 then an eight fold increase is only 8 in 10,000,000. Not much difference. The opposite is also true. If the “normal” risk is already high, say 1 in 100 then an eight fold increase would be very concerning – 8 in 100. My husband is always skeptical of studies that only report relative numbers. Would you know what the absolute numbers are?
my minature dacshund was neutered about 8 wks ago he is 8 and a half. when i brought him home all he did was lay around no appetite. took him back this week they are suspecting bladder and prostate cancer. They are doing an exploratory surgery tomorrow , to see if anything can be done. I dont want to loose my dog
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At what age should a mail dog be neuter to help to prevent cancer later in live?
I heard that 6 months to a year may not be a good time to and if so what is a good time
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Interesting. My neutered dog just past away from bladder and prostate cancer….