Scientific Results: A review of frailty instruments in human medicine and proposal of a frailty instrument for dogs

August 14, 2023 - 5 minutes read

Posts in our Scientific Results series introduce recent papers published in the scientific literature by members of the Dog Aging Project research team. Follow this series to learn more about the scientific questions we’re asking, the kinds of results we’re getting, and what it all means for you and your dog.

Who worked on this research?

Rachel L. Melvin
Audrey Ruple
Elizabeth B. Pearson
Natasha J. Olby
Annette L. Fitzpatrick
Kate E. Creevy

Where was it published?

Frontiers Veterinary Science

What is this paper about?

This paper is about frailty – a complex syndrome associated with aging that has become important in human healthcare and research. When humans experience loss of emotional and physical reserves, they are less able to bounce back from stressors. Frailty, even more than chronological age, is associated with increased risk of negative health outcomes and death. There are many different ways to measure or determine frailty in humans, and this paper gives a brief review of frailty in human medicine and research. Assessing frailty is important because while we cannot reverse chronological age, we can intervene to reduce or even reverse frailty. And hopefully, this will be true for dogs as well.

Although frailty has been successfully measured in mice, rats, and small controlled populations of dogs, there is not a widely used frailty instrument available in veterinary medicine. This paper outlines the importance of a frailty instrument in the growth of geriatric veterinary care. We then propose a plan to develop a short, easy-to-use, low-cost, low-tech frailty instrument – FIDo (Frailty Instrument for Dogs) to be utilized by general practitioners.

What do these results mean for me and my dog?

Our Dog Aging Project Pack members, by participating in surveys, cognitive games, and other activities, are contributing data that will help inform the creation of FIDo. Our surveys and activities are repeated annually so that data can be compared year to year, so as the members of the Pack age chronologically, we can track changes in resilience and health. One day, we would like to produce a frailty instrument that will be available for use by your primary care veterinarians, which will help them care for your companion.

Where can I learn more?

Melvin RL, Ruple A, Pearson EB, Olby NJ, Fitzpatrick AL and Creevy KE (2023) A review of frailty instruments in human medicine and proposal of a frailty instrument for dogs. Front. Vet. Sci. 10:1139308. doi: 10.3389/fvets.2023.1139308


Over the last few decades, frailty has become a pillar of research and clinical assessment in human gerontology. This complex syndrome, characterized by loss of physiologic reserves leading to decreased resilience to stressors, is of critical importance because it predicts higher risks of poor health outcomes, including mortality. Thus, identifying frailty among the elderly human population has become a key focus of gerontology. This narrative review presents current scientific literature on frailty in both humans and animals. The authors discuss the need for an accessible frailty instrument for companion dogs suitable for general use in veterinary medicine and the advances that would be facilitated by this instrument. A phenotypic frailty instrument for companion dogs, utilizing components that are easily collected by owners or in the general practice setting, is proposed. The authors elaborate on the domains (physical condition, physical activity, mobility, strength, cognitive task performance, and social behavior), factors that will be included, and the data from the Dog Aging Project that inform each domain.