Are mixed-breed dogs healthier?
- Medical Mutts Service Dogs
- 3 days ago
- 5 min read
At Medical Mutts Service Dogs, we work with a special group of dogs—rescues. Many of the service dogs we train come from shelters or are surrendered by previous owners. These dogs often fall into the “mixed-breed” category, affectionately known as “mutts.” Some people assume that purebred dogs are better suited for the demanding role of a service dog, but emerging scientific evidence challenges that assumption—and supports what we've seen time and time again in our training facility.
A 2020 academic review titled Are Mixed-Breed Dogs Healthier than Purebred Dogs? compiled 25 years of research and came to a compelling conclusion: mixed-breed dogs not only live longer on average, but they are also less prone to many inherited diseases that commonly affect purebred dogs. For an organization like Medical Mutts, which places a strong focus on training service dogs who must stay healthy and active for years, this research is both encouraging and validating.
Let’s take a closer look at what the science says—and what it means for the future of service dog training.
The Longevity Advantage of Mixed-Breed Dogs
When selecting a service dog, longevity matters. These dogs are trained over several months, and their human partners rely on them for years to come. That’s why it's crucial to choose dogs with the best chance at a long, healthy life.
According to the research review, mixed-breed dogs live, on average, 1.2 to 1.3 years longer than purebred dogs. One large-scale study using cemetery data from Japan found that mixed-breed dogs under 10 kg lived an average of 15.4 years, while those over 10 kg lived 14.5 years. In contrast, many purebred dogs had shorter lifespans, with popular breeds like Golden Retrievers and German Shepherds averaging around 10–12 years.
Several factors influence lifespan, including gender, whether a dog is neutered or spayed, and—most notably—body size. Unlike most mammals, where larger size typically equates to a longer life, dogs show the opposite trend. Small dogs generally live longer than large dogs, likely because large breeds age more quickly and are more prone to age-related diseases.
Mixed-breed dogs, thanks to their genetic diversity, tend to avoid the extremes of body size and benefit from the overall health advantages that come with genetic variation. While size does matter, being a mixed-breed appears to offer a consistent longevity boost across weight categories.
The Health Benefits of Hybrid Vigor
The term “hybrid vigor,” or heterosis, refers to the increased vitality that comes from genetic diversity. This is one reason why mixed-breed dogs are often healthier than their purebred counterparts. The review highlights multiple studies showing that purebred dogs have a higher risk of developing inherited conditions. In fact, more than 370 genetic disorders have been linked to breed-specific traits in dogs.
One large-scale study involving over 27,000 dogs found that purebred dogs had a significantly higher prevalence of 10 inherited disorders, including:
Epilepsy
Hypothyroidism
Heart disease
Cataracts
Elbow dysplasia
Intervertebral disc disease (IVDD)
Allergic skin conditions
Mixed-breed dogs, by contrast, showed lower rates of these disorders, likely because they’re less affected by the inbreeding that can occur when trying to preserve specific breed characteristics.
This matters greatly in the context of service dogs, who are expected to be physically sound, responsive, and emotionally balanced over a long working life. Health issues can shorten a dog’s working years, increase veterinary costs, or even prevent a dog from finishing training.
At Medical Mutts, we carefully evaluate every dog for physical health and temperament before they enter our training program. Our experience—and now scientific research—confirms that many mixed-breed dogs have what it takes to succeed.
Behavioral Considerations: A Double-Edged Sword
Interestingly, the review notes that behavioral problems are one area where mixed-breed dogs can be more vulnerable. Studies showed that mixed-breed dogs were more likely than purebreds to be euthanized due to issues like aggression or separation anxiety. The reason? Predictability.
When you mix breeds with very different behavioral traits—such as a guarding breed with a companion breed—you might end up with a dog whose behavior is hard to anticipate. Owners sometimes realize too late that their dog’s energy level, reactivity, or temperament doesn’t match their lifestyle or expectations.
But this is exactly where structured service dog training programs make a huge difference. At Medical Mutts, every dog undergoes a thorough temperament assessment. Only those with the right combination of traits—calmness, focus, sociability, and low reactivity—move on to training. Many behavioral issues arise when dogs lack structure or guidance, and our training provides both.
With the right environment, many behavioral issues can be prevented or resolved, allowing mixed-breed dogs to shine.
Cause of Death: What the Research Shows
Another area examined in the review is cause of death. Purebred dogs were significantly more likely to die from organ disorders, heart disease, and cancer, while mixed-breed dogs were more likely to be euthanized due to behavioral issues or die in accidents.
For example:
Mixed-breed dogs had lower cancer-related mortality than many purebred breeds.
Certain breeds, such as Bernese Mountain Dogs and Golden Retrievers, had cancer mortality rates over 30%, compared to 12.6% in mixed-breeds (according to one study).
Mixed-breeds were also less likely to suffer from disorders of the liver, kidneys, and central nervous system.
On the flip side, behavioral issues and accidents—like car collisions—were more common causes of death among mixed-breed dogs. Some researchers speculate this is due to more mixed-breed dogs being off-leash or owned by less experienced handlers.
Again, training and structure make all the difference. The dogs at Medical Mutts are never casually placed. We match each dog with the right client and provide extensive coaching so that both dog and human succeed.
What This Means for Medical Mutts and You
We’ve always believed in second chances—and in the potential of every dog, regardless of breed. But this research reinforces that choosing mixed-breed rescue dogs isn’t just the ethical choice—it’s also a smart one.
Mixed-breed dogs offer:
Longer average lifespans, especially in smaller sizes
Lower risk of inherited disease and many chronic illnesses
A diverse gene pool that supports physical and cognitive health
Incredible potential for service work when paired with the right training
Our mission at Medical Mutts Service Dogs is not only to train reliable service dogs, but to do so in a way that saves lives—both human and canine. By choosing rescue dogs and giving them rigorous, compassionate training, we create partnerships that change lives.
Final Thoughts: The Science Supports What We’ve Always Known
For anyone still unsure whether a “mutt” can be a service dog, the answer is an emphatic yes. The science is in. Mixed-breed dogs are not only capable—they often bring longevity and resilience to the role.
At Medical Mutts, our dogs are proof of that. They come from a wide variety of backgrounds, but with training, structure, and love, they become focused, loyal, and life-changing partners.
Interested in getting a fully trained service dog or training your own? Visit Medical Mutts to learn more about our programs.
-- Jennifer Cattet
Founder and CEO, Medical Mutts Service Dogs
Comments