New Tool Can Assess Elderly Dogs’ Frailty
For Immediate Release
Researchers from North Carolina State University have developed a tool that can aid owners and veterinarians in assessing an elderly dog’s frailty. The tool – when coupled with simple assessments of body and muscle condition by the veterinarian – can predict likelihood of short-term (within six months) mortality and provide important data to owners faced with treatment and quality-of-life decisions for their aging dogs.
“In humans, we classify frailty as a physical or physiological state associated with loss of strength, slow walking speed, weight loss, exhaustion and reduced activity – which is what happens as your body starts winding down,” says Natasha Olby, Dr. Kady M. Gjessing and Rahna M. Davidson Distinguished Chair in Gerontology at NC State.
“In humans, frailty correlates with disability and mortality, and we have tools for assessing frailty in humans. However, this is an emerging field in dogs and there is a need for screening tools that can be applied easily.”
Olby is the primary investigator for NC State’s canine neuro-aging program, which seeks to understand the mechanisms involved in the canine aging process.
“We were motivated to develop a frailty phenotype, or set of common characteristics, in part because we think frailty may be altering outcomes for some of the dogs in our clinical trials,” Olby says. “The other motivation is that we see frail dogs every day – and the condition is not well-described.
“One of the most common questions veterinarians receive from owners trying to decide on treatments for elder dogs is, ‘How long will my dog live?’” Olby says. “If we could develop a phenotype that is reasonably predictive of short-term mortality, it could be helpful for owners who are faced with treatment decisions.”
The researchers developed a frailty screening questionnaire that asked owners questions about their dog’s nutrition status (which included overall body condition and appetite), exhaustion/energy level, mobility, muscle condition and social activity. These five “domains” are also used in human frailty assessments.
They then validated the tool against two dog populations: 39 dogs that were current participants in Olby’s neuro-aging study, and 198 dogs aged 10 years and older who were not enrolled in the neuro-aging study.
Dogs that were classified as impaired in three of the five domains were considered frail and were twice as likely to die within six months as dogs that were not frail.
“Of course, the reality is that you never really know how long a dog will live, but this questionnaire coupled with body and muscle condition scores is good at predicting six-month mortality,” Olby says. “And it is an easily deployable screening tool that doesn’t require any lab work – a veterinarian can assess body and muscle condition with simple palpation.”
The researchers are hopeful that this screening tool will lead to more complete phenotypes for canine frailty.
“It is definitely still a work in progress, but this screen is a simple tool that owners and veterinarians can use as a starting place for discussing care options for elderly dogs,” Olby says.
The work appears in Frontiers in Veterinary Science and was supported by the Kady M. Gjessing and Rahna M. Davidson Distinguished Chair in Gerontology. Olby is the corresponding author. Former NC State postdoctoral researcher Katharine Russell is the first author. Former resident Gilad Fefer, current resident Alejandra Mondino and NC State professors Emily Griffith, Korinn Saker and Margaret Gruen also contributed to the work.
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Note to editors: An abstract follows.
“Establishing a clinically applicable frailty phenotype screening tool for aging dogs”
DOI: 10.3389/fvets.2024.1335463
Authors: Katharine J. Russell, Alejandra Mondino, Gilad Fefer, Emily Griffith, Korinn Saker, Margaret E. Gruen and Natasha J. Olby, North Carolina State University
Published: Sept. 24, 2024 in Frontiers in Veterinary Science
Abstract:
Introduction: Frailty is a well-defined clinical syndrome in humans caused by accumulation of impairments which result in loss of reserve capacity and increased vulnerability to disability, dependence, and death. Dogs are of particular interest in studies of frailty due to the similarities they share with people in their environment, lifestyles, and age-related diseases.
Materials and methods: The aim of this study was to develop a frailty phenotype, based on previously validated measures in dogs, which could be easily applied in the clinical setting, and which was predictive of all-cause, short term (6-month) mortality. The study was conducted in two phases. In phase 1, a retrospective cohort of 51 dogs was used to identify and evaluate potential measures for the five domains of frailty. This information was then used to develop a simple frailty phenotype based on examination findings and owner directed questions. In phase 2 of the study, this phenotype was evaluated in a prospective cohort of 198 dogs aged 9years or older from multiple different specialty and primary care services to determine how the phenotype performed across a diverse canine population.
Results: The developed frailty phenotype was predictive of all-cause, short-term mortality independent of age, sex, or weight (hazard ratio = 4.71; 95% CI, 2.66–8.8). Of the covariates evaluated only breed was significant, with purebred dogs having 1.85 times higher mortality than mixed breed dogs (95% CI, 1.04– 3.31). The frailty phenotype performed similarly across all hospital services from which patients were enrolled.
Conclusion: Based on these findings, the defined frailty phenotype represents a valuable screening tool for early risk identification and intervention and can aid in clinical decision making for owners and veterinarians. Additionally, it will promote further research into the understanding and treatment of frailty in dogs.
