Which Dog Lives the Longest? Smaller Dogs Have Longer Lives

Being mixed breed versus purebred, spay/neuter status, and regular dental cleanings at the vet, are also linked to lifespan.

A happy black mixed breed dog lies in the grass and looks at the camera. The dog has a yellow collar and there is a ball in front of them.
Body size is the most important variable in predicting life span, but mixed breed dogs live longer than purebreds. Photo: Lunja/Shutterstock

By Zazie Todd, PhD

This page contains affiliate links which means I may earn a commission on qualifying purchases at no cost to you.

Is it true that mixed breed dogs live longer than purebreds? And that the size of a dog is linked to their lifespan? 

A study of over 2 million dogs attending veterinary clinics in the US answers some recurring questions about lifespan and dogs. The research, by Dr. Silvan Urfer (University of Washington) et al., analysed data from over 169,000 dogs in this cohort that died or were euthanized within a three-year period.

In all size groups (small, medium, large, and giant), mixed breed dogs live longer than purebred dogs, although the difference is not that large. The study found that, on average, a mixed-breed dog lives for 14.45 years compared to 14.14 years for a purebred dog.

For purebred dogs there was some variability in lifespan according to the breed. For example, amongst the breeds the scientists classified as giant, Great Pyrenees live longer (11.55 years) than Great Danes (9.63 years), with the mastiff, St. Bernard, and cane corso in between.

Small dogs had a longer median lifespan at 14.95 years than giant dogs at 11.11 years. Medium size dogs lived 13.86 years on average, and large dogs lived 13.38 years. (N.B. This study used a four-point size classification, compared to other studies that use a five-point scale).

The dog’s body size was the most important variable in predicting life span, more important than whether or not the dog was purebred. Small purebred dogs live longer than large or giant mixed breed dogs.

The dachshund is the longest lived at 15.2 years, and the Great Dane has the shortest median lifespan.

The shih tzu and Chihuahua also live longer than 15 years on average (median lifespan 15.08 and 15.01, respectively).

America’s most popular dog, the Labrador retriever, has a medium lifespan of 13.27, while the golden retriever has a medium lifespan of 12.93. Also in the large breed category, the German shepherd dog lives until 12.46 on average.

The study also found that, up until the age of 15 years, there was a lifespan advantage for dogs that were spayed or neutered. This was particularly the case for female dogs, who lived for 14.35 years compared to 13.77 if sexually intact.

For male dogs, the difference was much smaller, although still statistically significant: neutered male dogs lived until 14.15, compared to 14.09 for a sexually intact male. For dogs that lived longer than 15 years, spay/neuter status made no difference.

Another finding is that regular dental cleanings (under anaesthetic at the vet) were associated with an increased lifespan for dogs over 2 years old. The scientists say that one dental cleaning was associated with an almost 20% reduced risk of death.

There could be a direct association between good dental health and good general health, but this may not be the full story. It could also be that the kinds of dog owners who get their pet’s teeth cleaned also have other behaviours that may affect their pet’s lifespan.

There was a small association between the frequency of anal gland expression and lifespan. This was unexpected and the reason is not clear. but again may reflect the owner taking care of the dog's health.

The researchers had expected frequent vet visits to be associated with a longer lifespan, but instead the reverse was the case. This suggests that frequent visits are more often associated with health problems than with preventive health care. This does not seem surprising since a healthy dog may only be taken to the vet once a year.

Given the very large number of dogs in the study, the researchers took steps to avoid the risk of spurious statistical findings, including restricting the analysis to a few hypotheses they had developed in advance and using a conservative significance level.

Although it is not a representative sample, because the data included dogs who were not insured as well as those that were, the results are probably a good reflection of the general American dog population.

For mixed breed dogs, the analysis of the effects of body size could only include those for whom a breed was listed (e.g. ‘Labrador cross’), in order to classify them. This means that mutts for whom no breed was obvious were excluded from this section of the analysis.

As well, it is not possible to infer causal relationships from this data. For example, we do not know why smaller dogs tend to live longer than bigger dogs.

The data used records from a large veterinary chain, Banfield Pet Hospitals, across the United States, hence the size of the sample. The use of a large dataset like this is very promising for research on canine health.

The results are broadly in line with earlier studies, although an advantage for neutering in male dogs has not always been found.

Another recent study (with one co-author in common) found that being overweight has a significant effect on dogs’ lifespan.

Although most of the factors looked at in this study (body size, type of dog) cannot be changed, dog owners can take care of their dog's teeth. More research is needed because this study cannot show causality, but tooth brushing and dental scalings as recommended by the vet may help prolong your dog's life. 

If you want to learn how to teach your dog to let you brush your teeth, I recommend the online course Healthy Smiles: At home dental care for dogs and cats from DogKind.

Do you brush your dog's teeth?

Urfer, S. R., Wang, M., Yang, M., Lund, E. M., & Lefebvre, S. L. (2019). Risk Factors Associated with Lifespan in Pet Dogs Evaluated in Primary Care Veterinary Hospitals. Journal of the American Animal Hospital Association

As an Amazon Associate I earn from qualifying purchases. As an Etsy affiliate and Marks and Spencer affiliate, I earn from qualifying purchases.

Follow me!