Tiny power plants inside horses’ cells appear to work less efficiently in senior horses, potentially contributing to some of the health problems that come with getting older, according to equine researchers in Poland.

Their new research review shows that these “energetic hubs” undergo many of the same age-related changes in horses as they do in humans. Understanding such changes could eventually help veterinarians better prevent, manage, and treat age-related health problems—helping senior horses stay healthier longer, say Maria Puchalska, DVM, and Olga Witkowska-Piłaszewicz, DVM, PhD, researchers from the Warsaw University of Life Sciences Faculty of Veterinary Medicine in Poland.

The Connection Between Mitochondria and Aging

Horses are living longer thanks to improvements in veterinary care and changing attitudes about keeping retired horses as companions, creating a growing population of seniors that need good geriatric care. Yet scientists still know relatively little about the cellular changes behind equine aging and age-related disease, Puchalska says.

Scientists have been investigating a possible connection between mitochondria and aging since the 1970s. Today, researchers know that mitochondria not only produce most of the energy cells need to function but also help regulate inflammation, cell repair, and cell death. When mitochondria stop working properly, the effects can ripple through entire tissues, experts say.

Decades of studies in humans have shown that mitochondrial function changes with age, and mitochondrial dysfunction is now considered one of the biological hallmarks of aging. More recently, scientists have been finding similar trends in horses, according to Puchalska and Witkowska-Piłaszewicz.

Various research teams have already discovered signs of mitochondrial decline in older horses, particularly in skeletal muscle and oocytes (egg cells), she says. Researchers have also investigated whether mitochondrial dysfunction plays a role in conditions that affect many older horses, including osteoarthritis, equine metabolic syndrome, and pituitary pars intermedia dysfunction (PPID). Puchalska says they’re now beginning to suspect mitochondrial problems could contribute to muscle weakness, inflammation, and slower recovery after exercise.

Reviewing the Research

Scientists still don’t know how much mitochondrial dysfunction contributes to these conditions or to age-related decline more broadly, she says. To see where the evidence stands to date, Puchalska and Witkowska-Piłaszewicz carried out a review of relevant research. They investigated the relatively few studies on mitochondrial aging in horses and compared those papers with the broader body of research in humans.

The duo found that aging horses show many of the same mitochondrial changes seen in aging humans, including reduced function, changes in mitochondrial structure, and a declining ability to make new mitochondria and clear away damaged ones. Puchalska says that overlap gives researchers clues from human aging research about which processes might be worth investigating—and eventually targeting—in senior horses.

Even so, research in horses remains limited, making it too early to know exactly how these changes contribute to age-related health problems or how best to target them, she reports.

Managing Mitochondrial Dysfunction

Exercise might help offset some of the changes that occur in mitochondria as horses age, Puchalska and Witkowska-Piłaszewicz explain. In one study, for example, exercise training partially improved mitochondrial impairments in older horses. Regular low- to moderate-intensity exercise might therefore be beneficial. “However, the training program must be tailored to the individual animal, as an overly intense regimen may compromise the horse’s welfare,” Witkowska-Piłaszewicz says.

Some supplements might eventually prove useful, although research is still preliminary, she adds. “Overall, L-carnitine and multi-ingredient formulations currently provide the most promising results,” she explains. “But the evidence is still insufficient to recommend any specific supplement solely for protecting mitochondrial function in all senior horses.” Owners should discuss supplements with their veterinarians, Puchalska and Witkowska-Piłaszewicz caution.

In humans, some signs of mitochondrial dysfunction in blood cells are associated with frailty, so future research might investigate whether similar markers could help assess frailty in older horses, the team says. Eventually, such blood-based markers might help veterinarians monitor senior horses’ mitochondrial health.

If validated, such a test might help veterinarians detect subtle changes and adjust a horse’s care earlier, the researchers say. Developing reliable biomarkers is difficult, however, and could take considerable time.

Importantly, owners should never simply write off changes such as muscle loss, lethargy, or lameness as inevitable signs of old age, Puchalska and Witkowska-Piłaszewicz warn. Regular veterinary checkups can help identify health problems that might otherwise go unnoticed in senior horses.

Reference

Puchalska M, Witkowska-Piłaszewicz O. Mitochondrial dysfunction in equine ageing: Current evidence and clinical implications for geroscience. Equine Vet J. 2026. https://doi.org/10.1002/evj.70189

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  • Christa Lesté-Lasserre is a science journalist specialising in animal health and behaviour, life sciences, and evolutionary processes. Her articles and stories have appeared in major science magazines and literary reviews in multiple languages across the globe. Based in France's greater Paris area, Christa holds an MA from the University of Mississippi and a BA from Baylor University in Texas, complemented by postgraduate work in life sciences at the University of Paris René Descartes.

    A Pulitzer Center grantee for her coverage of the COVID-19 pandemic for Science magazine and recipient of American Horse Publications awards for her articles on equine behaviour, Christa focuses on shaping scientific studies into the stories they tell.

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