These dog breeds have a higher chance of getting cancer, study shows

Cancer is a leading cause of death in dogs.

But the risk of cancer varies substantially by breed.

Evaluating dogs by factors like breed, size and life expectancy, a new study published in Royal Society Open Science and authored by evolutionary biologist Leonard Nunney sought to find answers about canines and cancer.

It turns out that large, but not the largest, dog breeds have an increased risk for cancer. That's because the biggest dogs typically have a shorter life span, and die before they contract the disease. A medium-sized dog is likely to live longer and more likely to contract the illness.

The miniature pinscher, a toy breed ranging in weight from 8-13 pounds, has about a 4% risk of dying from cancer. But a Bernese mountain dog, which can weigh anywhere from 70-115 pounds, has a 55% risk of cancer mortality, according to the study.

It is not always size, however, that dictates the risk. And certain breeds are susceptible to specific kinds of cancers.

"Of 85 breeds in more than one dataset, only flat-coated retriever showed significantly elevated cancer mortality, with Scottish terrier, Bernese mountain dog and bullmastiff also showing notable risk (greater than 50% over expected)," said the study. "Analysis of breed clades suggested terriers experience elevated cancer mortality."

The Scottish terrier, which is a small breed, showed elevated risk for bladder cancer. Flat-coated retrievers have a higher risk of getting soft tissue sarcoma — specifically histiocytic sarcoma — which is a rare but aggressive cancer that commonly occurs in bones, joints, skin and lungs, according to the University of Pennsylvania School of Veterinary Medicine.

About 6 million dogs are diagnosed with cancer each year, according to the National Cancer Institute.

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