New research has unveiled unexpected insights into cancer risk among dog breeds, challenging the common belief that larger dogs are more susceptible to the disease. Published on Tuesday in Royal Society Open Science, the study conducted by evolutionary biologist Leonard Nunney at the University of California, Riverside, disproves the notion that the largest dogs face the highest cancer risk.
Contrary to human patterns, where larger bodies are generally expected to be more prone to cancer, the research indicates that, in dogs, large breeds (though not the largest) exhibit the highest cancer risk. Nunney explains the vast size range in dog breeds, from chihuahuas to mastiffs or Great Danes, as a key factor in this unexpected finding.
Surprisingly, big dogs, which tend to have shorter lifespans, actually have a lower risk of developing cancer compared to medium-sized dogs due to their shorter life expectancy. Some breeds identified as particularly prone to cancer include flat-coated retrievers, Bernese mountain dogs, and Westies. Flat-coated retrievers are especially susceptible to a rare type of sarcoma that develops in bones and soft tissues.
Notably, terriers, including the Scottish terrier, have a higher likelihood of developing cancer than anticipated based on their size. Terriers, in general, show a higher incidence of bladder cancer, according to Nunney.
The study brings a silver lining, revealing that not many breeds are excessively prone to cancer. Insights into genetic mutations causing cancer in dogs indicate that while inbreeding in a breed’s ancestry may shorten its lifespan, it does not necessarily increase the overall cancer risk.
This research opens the door for future applications, with the model used offering a tool to determine if specific breeds are experiencing an increase in a particular type of cancer. Nunney emphasizes that dogs serve as an excellent model for understanding genetic changes that may make certain breeds more susceptible to specific cancers. This breakthrough contributes valuable information to canine health and genetics research.
