(NEXSTAR) — Cancer is a common cause of death in dogs, but the likelihood of your canine developing the disease could be connected to their breed, new research suggests.
According to data from the American Veterinary Medical Association, nearly half of elderly dogs over the age of 10 will develop cancer.
A study published Wednesday in the journal The Royal Society found that large dog breeds, but not the largest, might be more prone to the disease.
The research is based on observations in both humans and dogs. Leonard Nunney, lead researcher and biologist at the University of California, Riverside, explained that previous studies have shown that taller individuals might have a higher overall risk of cancer.
For instance, in a substantial 2022 study conducted by John Hopkins Medicine, researchers found a possible link between height and colorectal cancer in humans. The co-author of the John Hopkins study, Dr. Elinor Zhou, said that “one possible reason for this link is that adult height correlates with body organ size.” Organs in taller adults tend to grow faster, he said, increasing the chances of mutations that could lead to the formation of cancerous cells.
This theory, however, does not necessarily apply to our furry companions, according to Nunney. He said that larger dogs, given their shorter lifespans, actually have a reduced risk of developing cancer when compared to medium-sized canines.
Out of 85 dog breeds studied, only flat-coated retrievers had a significantly higher risk of dying from cancer. Scottish terriers, Bernese mountain dogs, and bullmastiffs also showed a notable risk, more than 50% higher than expected.
The study also explored how inbreeding and genetic diversity impact the risk of developing cancer. Genetic diversity is defined as “the range of different inherited traits within a species,” the University System of Maryland noted on its website.
Research shows inbreeding reduces genetic diversity, and some dog breeds with low genetic diversity may have a higher risk of specific cancers.
Nunney said that flat-coated retrievers are particularly susceptible to a rare form of cancer known as sarcoma, which affects bones and soft tissues. Terriers, on the other hand, are more likely to develop bladder cancer.
Researchers used a two-step approach for the study. First, they analyzed data on how dogs from different breeds experience cancer-related deaths. Then, they examined factors related to cancer risk, like inbreeding levels.
Nunney told ABC News that the model used in this study can also help identify whether breeds are starting to see an increase in specific types of cancer in the future.