Larger dogs show signs of faster molecular aging than smaller dogs

Science reports that researchers analyzed 1,640 DNA methylomes from 894 companion dogs. Larger and male dogs showed accelerated epigenetic aging patterns, while dogs whose methylation-based ages exceeded expectations had higher mortality risk. In larger dogs, age-related methylation loss at transposable elements—DNA sequences that can move within a genome—was 31% stronger than in smaller dogs. The researchers identify those elements as potential contributors to the size–lifespan link.