Did you know you and your dog age similarly? Mapping canine aging at the molecular level
At Loyal, we believe that understanding how dogs age at the molecular level is key to helping them live longer, healthier lives. That is why our science team conducted the first study of its kind – measuring 18,314 biomarkers in 40 dogs. This research was recently published in Geroscience, a peer-reviewed scientific journal focused on the biology of aging. Building upon previous research on human aging patterns, our results reveal striking similarities between how dogs and humans age. Through publishing our findings, we hope to contribute to the scientific community’s collective understanding of the aging process, while furthering our own ability to develop new medicines to treat aging.
What makes this study different
We measured two layers of information in 40 dogs simultaneously: gene expression and protein levels. These two layers paint a picture of cellular activity: gene expression captures which genes are turned on or off, while protein abundance reveals the activity of the molecular workhorses those genes produce. Scientists refer to this sort of study, where information about multiple cellular processes is captured at the same time, as “multi-omics” (Multi-, as in multiple, and -omics, meaning the large-scale study of biological molecules).
This was the first multi-omic study of gene expression and protein abundance in dogs, giving us an unprecedented view into canine aging biology.
Applying this dual approach to blood samples from dogs spanning a wide age range – from spry young adults around 3 years old, all the way up to proper old-timers pushing 14 – we uncovered 816 genes and 40 proteins that significantly changed with age.
Two patterns jumped out
These pathways exhibited significant changes in activity during aging in dogs.
Two major themes emerged from our data: declining DNA repair and rising inflammation.
As dogs age, we observed broad reductions in DNA repair pathways – the cellular maintenance crews responsible for fixing damage to the DNA inside each cell. This mirrors what scientists have observed in aging humans and other animals, where accumulated DNA damage is considered one of the fundamental drivers of aging.
At the same time, we found that the immune system becomes more active with age, with increased expression of signaling molecules called cytokines and interleukins that drive inflammation. This pattern, often called "inflammaging," is a hallmark of human aging and has been linked to age-related diseases from arthritis to cognitive decline. Seeing these same inflammatory signatures in aging dogs connects the dots between what we know about human biology and what's happening in our canine friends.
Why does this matter for dogs – and humans?
When we compared our canine findings to large-scale human aging studies, the overlap was striking. The gene expression changes we observed in dogs mirrored several human hallmarks of aging, including genomic instability (the accumulation of damage to DNA over time), telomere attrition (the shortening of protective caps on chromosomes), and loss of proteostasis (the breakdown of the cell's ability to maintain functional proteins). These findings underscore the central role of these pathways in aging and reinforce the shared biology between dogs and humans.
This overlap between dog and human aging patterns isn't just academically interesting – it means insights from human studies can inform canine interventions, and vice versa.
Looking ahead
This study – along with other recent Loyal publications on frailty and metabolism in dogs – has strengthened our understanding of canine aging and aids our development of products to give us more time with the dogs we love.
And this is just the beginning. From here, we can look at larger and more diverse cohorts as well as longitudinal tracking to watch how individual dogs change over time.
To explore the full findings, read our paper or browse the interactive data we’ve made publicly available.
Sources
Koch, Z., Graves, J.L., Annan, S. et al. Multi-omic analysis of canine aging uncovers conserved aging pathways. GeroScience (2025). https://doi.org/10.1007/s11357-025-02029-2
López-Otín, Carlos, Maria A. Blasco, Linda Partridge, Manuel Serrano, and Guido Kroemer. 2023. “Hallmarks of Aging: An Expanding Universe.” Cell 186 (2): 243–78.
Franceschi, Claudio, Paolo Garagnani, Paolo Parini, Cristina Giuliani, and Aurelia Santoro. 2018. “Inflammaging: A New Immune-Metabolic Viewpoint for Age-Related Diseases.” Nature Reviews. Endocrinology 14 (10): 576–90.
McKenzie, B., Peloquin, M., Graves, J.L. et al. Changes in insulin, adiponectin and lipid concentrations with age are associated with frailty and reduced quality of life in dogs. Sci Rep 15, 5380 (2025). https://doi.org/10.1038/s41598-025-89923-z
Chen, F.L., Ullal, T.V., Graves, J.L. et al. Evaluating instruments for assessing healthspan: a multi-center cross-sectional study on health-related quality of life (HRQL) and frailty in the companion dog. GeroScience 45, 2089–2108 (2023). https://doi.org/10.1007/s11357-023-00744-2
McMahon, J.E., Graves, J.L., Tovar, A.P. et al. Translational immune and metabolic markers of aging in dogs. Sci Rep 15, 14460 (2025). https://doi.org/10.1038/s41598-025-99349-