Why big dogs age faster

Where it stands as of Nov 9, 2026

Researchers analyzing DNA methylation across the genomes of 894 dogs in the Dog Aging Project found a broad loss of methylation with age, especially in mobile jumping-gene sequences called transposons. More than 40% of LINE1-associated genome regions lost methylation as dogs aged, and LINE1 activity may explain part of the size and lifespan pattern. The authors say it is not the whole explanation.