3 Best and Worst Medical Interventions for Dog Longevity

3 Best and Worst Medical Interventions for Dog Longevity

Note: This article about the best dog tests and medical interventions for dog longevity is the fourth in our series on life extension for dogs. We’ve previously looked at dog dental health, the best dog longevity diet, and the best exercise for dog longevity. Sign up for the rest of the series, including a deep dive into supplements and medicines, top dog products, and the full dog life extension guide!

A trip to the vet’s office is pretty much inevitable when you own a dog. 

Whether it’s for an annual checkup, preventative bordetella shots, or something more serious (like an ultrasound test to detect a beer koozie lodged in their large intestine that requires surgery to remove—ask me how I know…), your pup is going to need some kind of medical procedure or test during their lifetime.

The question I had while researching dog longevity was: which specific medical procedures and tests should I get for my dog if I want to improve his lifespan?

best and worst medical interventions for dog longevity

From looking into it, the main tests and medical procedures you may want to consider for your dog are the following:

  • Dog DNA tests (including biological age tests)
  • Dog cancer detection tests
  • Gonadectomy (spaying/neutering)

I’ll get into each of these dog tests and surgeries, and whether, when, and where to get them, below.

Note: Save the Dog Aging Project!
One of the best sources for research studies on dog longevity has been the Dog Aging Project, an NIH-funded study of over 45,000 dogs that’s already provided landmark insights into how to make dogs (and eventually people!) live longer. Unfortunately, as of publication in 2024, NIH is threatening to pull the funding for this crucial scientific endeavor. Please help save the Dog Aging Project by signing this petition: https://actionnetwork.org/petitions/support-the-continuation-of-the-dog-aging-project You can also donate directly to the project here: https://give.uwmedicine.org/give/?source=doggie
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Best canine DNA test kits for longevity

Dogs are at risk for several genetically-inherited diseases, many of which you can help them manage if you know which ones they are prone to.

One such example, which we covered in our article on exercise for dogs, is a very serious condition known as exercise induced collapse (EIC). It can strike up to 14% of some breeds, like labrador retrievers, and often leads to death. If you know your dog has it, there are some simple steps you can take to protect them, including limiting intense exercise. EIC is caused by a mutation of the DNM1 gene and, luckily, there are now consumer genetic tests for dogs that can detect it.

They can detect a whole host of other health issues as well, like risk for toxicity of different minerals, hemophilia, and a rare condition that could cause your dog to bleed out during a routine operation, and so I plan on getting one for our dog, Kipling, ASAP.

Three top dog DNA tests for health, which I’ve verified test for the EIC DNM1 gene mutation are:

Another type of DNA test that may help you improve your dog’s longevity is a biological age test.

Dog age tests

While we’ve covered these type epigenetic age tests for humans at length, dogs are emerging as a new target to use them to understand aging.

Dog biological age tests use DNA methylation (a complex organization of chemical compounds called methyl groups on the DNA that changes as you age) to determine their biological, vs. chronological age.

For instance, your dog may be three years old based on when they were born, but have a biological age of five years old, indicating they are aging faster than they should (likely due to being unhealthy).

Knowing this, you can alter your dog longevity routine to hopefully give your pup more years.

dog age test

Research from Steve Horvath, one of the first inventors of the biological age test in humans, has shown that a lot of DNA sequences are conserved across species, and so they can build a dog epigenetic age test in much the same way they can build one for humans. 

And they did! MyAgingTests, the consumer arm of Horvath’s Clock Foundation created a dog biological age test which uses a saliva swab to collect DNA.

Several other companies now also have dog DNA age tests using methylation, so you have some options to choose from, including:

Cancer tests for dogs

When it comes to dog longevity, the biggest risk seems to be cancer. 

Malignant tumors account for up to half of all deaths of elderly dogs, making dogs about ten times more likely to be diagnosed with cancer than humans each year. My childhood dog, a black lab named Truffles, died of tongue cancer at only eight years old.

dog cancer tests
She was a very sweet dog. Ball-obsessed like most labs.

As with humans, detecting cancer early is key to improving the survival likelihood for afflicted dogs. For instance, switching to a targeted therapeutic diet may increase cancer survival rates in dogs.

Many veterinarians recommend starting cancer screening in dogs around 6-8 years old, depending on breed. However, breeds with increased cancer risk like labradors, German shepherds, Bernese mountain dogs, and rottweilers may want to start as early as four. 

Since Kipling, as a Swiss mountain dog, is closely related to the Bernese, I plan to start screenings for him after he turns four this November.

While traditional methods for detecting cancer in dogs should absolutely be part of your arsenal, including physical examinations, standard blood work (especially looking at inflammation markers like CRP), ultrasounds for prostate cancer starting at “approximately at 40% of [your dog’s] expected longevity,” and even X-rays (since also, low-dose radiation could extend dog lifespan), there are some newer dog tests which may help detect even more types of cancer early.

In our article about detecting cancer in humans, we wrote about a (then) new method called a multi-cancer early detection test, also known as a “liquid biopsy.”

Malignant tumors account for up to half of all deaths of elderly dogs, making dogs about ten times more likely to be diagnosed with cancer than humans each year.

These tests take a blood sample, and then sequence the free-floating DNA in that sample to see if any of it indicates cancer elsewhere in the body.

Now, the same type of test has been developed for dogs, and validated via a clinical trial of 1,000 dogs, finding a detection rate for three of the most aggressive dog cancers (lymphoma, hemangiosarcoma, osteosarcoma) of 85.4%, and an overall sensitivity of 54.7%. 

Two different companies currently have liquid biopsy tests for dogs on the market. Both of these tests can be ordered directly by any veterinarian, so it’s worth talking to yours about possibly getting one annually, or even every six months, for your dog.

The tests, and how to order them, are described on their websites:

An even newer test to watch that is not yet on the market, is a urinalysis cancer test for dogs, with research on it just published in 2024.

Interestingly, cancer also plays a key role in the question of when to neuter your dog.

Pros and cons of neutering your dog

The big question many dog owners have about dog medical procedures, of course, is the question of neutering/spaying.

Most everyone in the U.S. gets their dogs spayed or neutered, while in Europe it’s much less common, and in Norway it’s actually illegal unless the health of the dog is in danger.

There’s been a lot of conflicting advice on “gonadectomy,” as it’s called, over the years. Oftentimes veterinarians and dog breeders will even have contradictory recommendations around when, or if, to get your dog spayed or neutered.

My wife and I experienced this with Kipling. Everything we’d read about Swissies and other giant breed dogs said to wait until two, even two-and-a-half years before considering getting them neutered, while our vet said it was fine to do it after six months.

when to neuter a puppy

So I was already curious about why the recommendations varied so greatly, and then I started to look into it and found research studies suggesting neutered and spayed dogs may be at increased risk for all kinds of health issues.

The burning question in my mind as I pored over scientific papers was:

Do neutered dogs live longer?

The science is mixed, but also time-dependent. There seems to be a pretty clear switch around the year 2000 or 2001. Most of the research before that time recommended early neutering and spaying for dogs, while the more recent research all seems to point to early neutering/spaying or, indeed, neutering at all, having adverse effects on the health and longevity of dogs.

Of course, the further nuance here is that a lot of this is sex- and breed-dependent, and many smaller breed dogs don’t experience the adverse effects of early neutering that large breeds do.

As a 2017 literature review concluded,”there currently is no single recommendation regarding gonadectomy that would be appropriate for all dogs.”

So let’s look at the different possible complications individually.

Neutering and spaying may increase osteoarthritis risk

I covered some of the recent research in our article on dog exercise, when I said the science pointed to earlier spaying/neutering (under about seven months old) as increasing risk for joint injuries and joint disease like osteoarthritis. Recall those conclusions:

  • “Neutered individuals were significantly more likely to have a joint disease compared to entire individuals in all studies that explored neutering as a risk factor” from a 2020 systematic review.
  • “Gonadectomy, and younger age at gonadectomy were significantly associated with higher risks of osteoarthritis” from a 2023 study of over 131,000 dogs.
  • “Gonad removal during the 24-month developmental period is adversely associated with three measures of susceptibility—increased incidence of CCL rupture, multiplicity (bilateral rupture), and accelerated time to initial CCL failure.” From a 2023 study on rottweilers.
  • “Compared to intact dogs, dogs who were ≤ 6 months at gonadectomy had increased risk for orthopedic injury” from a 2019 study of golden retrievers.

The conclusion that early neutering is a risk factor for joint disease seemed pretty universal, but a later neutering for small breed dogs doesn’t seem to give them the same issues: “Small-dog breeds seemed to have no increased risks of joint disorders associated with neutering.” 

But it’s not just arthritis and joint injury that spaying/neutering too early can negatively impact.

Early neutering may increase cancer risk

Cancer is a little more nuanced than osteoarthritis risk when it comes to the effect of neutering and spaying.

While several studies have shown neutering/spaying, especially done early, increases your dog’s risk for deadly cancers like hemangiosarcoma, some studies in female dogs have shown it may decrease the risk for mammary cancer. 

Like much of science, this is currently an open debate and not settled one way or the other.

A 2019 review emblemized this dichotomy, as it suggest both that, “For cancers having an inherited component, there is a generalized trend for an increase in risk associated with neutering across breeds and sexes,” but also, “For diseases that involve the reproductive system, such as mammary, or testicular cancer, neutering has a profound effect on reducing and/or eliminating the incidence.”

And dog breed, sex, and size seem to be highly correlated with increased cancer risk from neutering. A 2020 study on 35 different dog breeds found that, while some large breed dogs like female labradors were 2-4 times more likely to get cancer after neutering, “in only two small breeds (Boston Terrier and Shih Tzu) was there a significant increase in cancers.”

That study suggested that relatively few breeds are impacted by an increase in cancer rates after neutering, but those that are get significantly more cancer.

Relatively few breeds are impacted by an increase in cancer rates after neutering, but those that are get significantly more cancer.

Other studies have found both male and female dogs are at increased risk for certain cancers after being neutered.

For instance, a 2020 population study of a database of over two million dogs found that, “neutering is associated with development of splenic [hemangiosarcoma (HSA)] and HSA in general in both male and female dogs.”

A 2014 survey found: “Dogs gonadectomized at ≤ 6 months, between 7 and 12 months, or at > 12 months of age had significantly increased odds of developing mast cell cancer, lymphoma, all other cancers, all cancers combined, and fear of storms, compared with the odds for sexually intact dogs.” 

In golden retrievers, a 2013 study noted, “Almost 10 percent of early-neutered males were diagnosed with [lymphosarcoma (LSA)], 3 times more than intact males.” While, “There were no cases of [mast cell tumor (MCT)] in intact females, but the occurrence was nearly 6 percent in late-neutered females.”

Again in golden retrievers, “a greater proportion of spayed females died of cancer compared to intact females” according to a 2018 study.

And while in females spaying may protect against mammary cancer, the evidence actually appears weak, according to a 2012 systematic review.

In males, a 2002 study found that, “Castration increased the risk of [prostate carcinoma]” (i.e. prostate cancer).

Relatedly, many intact male dogs may be at higher risk for other prostate diseases like benign prostatic hyperplasia and prostatitis. But these seem like fairly benign and treatable conditions, including with antibiotics.

cryptorchidism and neutering dogs
Kipling’s neighbor friend, Paul, has cryptorchidism and will likely need to be neutered to prevent cancer and other health risks later in life.

However, male dogs with cryptorchidism, or undescended testicles, get testicular cancer at 13 times the rate of intact dogs with descended testicles. This may mean neutering a male dog with cryptorchidism could prevent testicular cancer, though you likely still want to account for age and breed before you do.

One 2013 study found both that neutered dogs had increased cancer risk, but that they also lived longer than intact dogs. This is confusing and makes me think that the study may not have adequately corrected for things like household income.

One impact of neutering that we know to be highly correlated with both osteoarthritis and cancer risk, as well as shortened longevity in dogs, is obesity.

Neutering and spaying may increase obesity risk

Neutering your dog changes their hormones and metabolism, and if you keep feeding them the same amount of food as before, they may be at increased risk of weight gain.

A 2019 study of service dogs noted that, “Compared to intact dogs, all gonadectomy age categories showed increased risk for the development of overweight/obesity.”

Similarly, a 2013 study of over 1,900 dogs concluded, “Gonadectomized dogs had a greater risk of being overweight than did sexually intact dogs, but this risk was not influenced by age at gonadectomy.”

And a 2022 study found, “Dogs that were neutered, female, and considered middle-aged or senior were at increased risk of overweight and obesity.”

As we covered in our article on the best diet for dog longevity, for dogs, overweight and obesity has a huge negative impact on their health and lifespan. It’s associated with all kinds of injuries, diseases, disorders, even cancers. Possibly the worst thing you can do for your dog’s longevity is to allow them to become obese and stay that way.

Do neutered dogs live longer? Longevity data is mixed

Interestingly, the research that actually looked at how neutering impacts dog longevity directly seems fairly inconclusive.

This may be because there isn’t much of it (I could only find a few studies with longevity as an endpoint), or because breed, age, and sex are such confounding factors in how neutering affects dog health.

A couple population studies found that neutering was associated with a longer lifespan, including the confusing 2013 study mentioned in the cancer risk section above, as well as a 2020 study looking at the records of over 20,000 dogs. 

But the second study even noted in its discussion section that, “it is possible that in our dataset, being gonadectomized acts as a proxy for better husbandry and veterinary care for these dogs, which in turn might have influenced our results showing a higher life expectancy associated with gonadectomy.”

But they add, “However, the large effect size in females is indicative that at least female gonadectomy does have a substantial beneficial effect on lifespan.”

neutering large dogs
Look! I broke it! Aren’t you proud?”

Some research on rottweilers specifically seems to suggest that intact dogs live longer than neutered/spayed ones.

A 2023 study found, “Male and female Rottweilers neutered before 1 year of age demonstrated an expected lifespan 1.5 years and 1 year shorter, respectively, than their intact counterparts. Broadening this analysis to include animals neutered before the age of 4.5 years produced similar results.”

Another study on female rottweilers, from 2017, noted that being intact for longer was “associated with an overall longevity advantage—a 33% decrease in mortality, living 17 months longer than females with shorter ovary exposure.”

However, this effect may be limited to certain breeds like rottweilers, as a 2016 controlled trial of labrador retrievers found that, “Gender and age at neutering were not associated with longevity” (either negatively or positively).

So to me, the data on neutering and longevity appear inconclusive.

Special consideration for spaying female dogs: Pyometra uterus infections

One additional thing to be aware of, if you have a female dog, is that not spaying them can increase the risk of a uterus infection called pyometra, which can be deadly.

Pyometra has a 10% to 20% mortality rate even with treatment, and tends to occur in older dogs, often after the age of eight. While emergency spaying is the preferred treatment, certain antibiotics also seem quite effective.

My testing and neutering plan for Kipling

So, after all this research do I plan to get Kipling neutered?

I’m currently leaning towards no, unless he shows signs of some disease associated with being intact, like testicular cancer.

If Kipling were a smaller dog, or female, or had an undescended testicle I might have a different answer here. But because he is a giant breed, already known for joint problems, and similar in size to rottweilers where studies showed a longevity benefit to remaining intact, I think for now we’ll hold off on getting him neutered.

But I do plan to get him a dog DNA test soon, and am considering one of the below dog genetic test kits:

I also plan to start testing him for cancer around four years old (in another year or so) and doing this either annually or every six months as finances allow.

I’ll make sure he gets an annual ultrasound for prostate cancer, plus one of the following canine cancer blood tests:

Finally, I’ll probably wait on doing a dog biological age test for Kipling until he’s older, maybe after age five, since I’m not sure at his young chronological age it will tell us much.

When I do, I’ll check out the following:

Next week we’re diving into dog longevity supplements

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Get notified when we publish new posts!

Note: Save the Dog Aging Project!
One of the best sources for research studies on dog longevity has been the Dog Aging Project, an NIH-funded study of over 45,000 dogs that’s already provided landmark insights into how to make dogs (and eventually people!) live longer. Unfortunately, as of publication in 2024, NIH is threatening to pull the funding for this crucial scientific endeavor. Please help save the Dog Aging Project by signing this petition: https://actionnetwork.org/petitions/support-the-continuation-of-the-dog-aging-project You can also donate directly to the project here: https://give.uwmedicine.org/give/?source=doggie

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