Larger Dogs Develop More Diseases as they Age, Shortening Their Lifespans

Posted on Categories Discover Magazine

It is no surprise that our canine companions age faster than humans. Some studies have found that our pups are similar in age to a 30-year-old human by the time they reach their first birthday. By four, the dog is nearing human middle age at 52.

A new study suggests a dog’s body size, age, and weight may influence the health ailments your pup may develop over time. The find, published today in PLOS ONE, is part of a more extensive nationwide study of how dogs age over time and its effects on their bodies.

Differences Between Small and Large Dogs 

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Larger dogs in the study developed more health issues like cancer, bone and muscle diseases, stomach, ear, nose, and throat issues, infectious diseases, and neurological conditions. Smaller breed pups, on the other hand, developed eye issues and cardiac and respiratory diseases. However, pattern risks of these diseases varied based on the dog’s size and where they are in their lifespans.

Reports of skin issues among the dogs also increased with their age, from 7 percent for puppies to 37 percent in senior dogs. Skin issues also increased when comparing small and larger dogs, with only 26 percent reported in small canines and 33 percent in larger breeds.

Read More: The Origins of Dogs

Understanding Aging in Dogs 

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Researchers analyzed this data collected by the The Dog Aging Project. The citizen science project relied on thousands of dog owners across the U.S. to submit data on their furry friends. Its goal is to understand, explain, and improve the effects of aging on dogs.

For this study, researchers looked at data from 27,541 dogs in the U.S. In the pool of good puppers, the team included 238 different breeds in the study.

When looking at the prevalence of each health ailment, a dog’s sex, weight, whether the dog was purebred or of a mixed breed, where the dog lived, and health statuses were all noted and considered.

Read More: What Old Dogs Can Teach Us About Aging

Why Do Larger Dogs Live Shorter Lives? 

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One study examining 56,000 dogs of 74 different breeds found that larger dogs age faster than smaller ones. As larger dogs mature from being a puppy to young adults, they undergo rapid changes and weight gain, which can result in a risk of musculoskeletal diseases like hip dysplasia.

Larger dogs are also more likely to die from cancer. This may be because larger breeds grow faster than smaller dogs, leaving the dogs more susceptible to age-related illnesses and abnormal cell growths faster. A different study found that larger dogs like Great Danes may be susceptible to cancers because their bodies can’t keep up with the selective breeding for these extreme sizes.

Read More: Why Do Small Dogs Live Longer Than Large Dogs?

Longer Lifespans? 


Still, the new study’s results do not confirm a relationship between a dog’s age and disease but may still uncover the health problems larger dogs may experience over time. The finding does help researchers get closer to understanding why larger dogs have reduced lifespans when compared to their smaller doggo friends.

Read More: Can Dogs Get Sick? How to Keep Your Dog Healthy

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