DNA research explains why large dog breeds age faster

A study published in the journal Science suggests that the shorter lifespan of large dog breeds compared to smaller ones is linked to accelerated biological aging at a molecular level.

Researchers analyzed blood samples from hundreds of dogs, including participants from the Dog Aging Project. The findings indicate that large dogs exhibit higher activity of LINE1, which are self-replicating DNA elements known as jumping genes. These elements can copy and insert themselves into different parts of the genome, accelerating the biological clock.

In larger dogs, the chemical markers that regulate these jumping genes tend to disappear more rapidly with age. This process causes the biological age of a large dog to potentially exceed its chronological age. The study noted that for every year a dog's biological age exceeds its actual age, the risk of death within the following two years increases by approximately 15 percent.