While dogs make our lives immeasurably better, their own lives are heartbreakingly short compared with those of humans. As the late American writer Agnes Sligh Turnbull famously observed, this is their only fault.
And although losing a dog is clearly the worst part about having one, it is often preceded by another difficult phase: making major health-care decisions on behalf of a beloved senior canine.
In a new study, researchers from North Carolina State University propose a novel way to help people navigate this stressful process. They've developed a tool to help pet owners and veterinarians assess frailty in older dogs, potentially removing some uncertainty around these already-difficult choices.
Combined with a vet's evaluation of a senior dog's body and muscle condition, the new tool can reportedly predict likelihood of short-term mortality – that is, dying within six months – and offer pet owners helpful insight about their dog's health and quality of life.
“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 co-author Natasha Olby, a professor of gerontology at NC State.
“In humans, frailty correlates with disability and mortality, and we have tools for assessing frailty in humans,” Olby says. “However, this is an emerging field in dogs and there is a need for screening tools that can be applied easily.”
Olby is lead investigator for the canine neuro-aging program at NC State, where she and her colleagues are working to shed light on the mechanics of aging in dogs. A tool that can measure dogs' frailty would be valuable for multiple reasons, she explains.
A tool like this could help inform tough decisions faced by many owners of senior dogs, Olby notes. That could mean opting for aggressive treatment in less frail dogs, or it could mean palliative care or euthanasia – but potentially with more clarity and less guilt.
“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.”
Olby and her colleagues designed a questionnaire to be completed by pet owners to ascertain frailty in older dogs. It features questions about a dog's nutritional status, exhaustion, muscle weakness, social activity, and mobility, based on five “domains” also used in assessing human frailty.
Dogs scoring as impaired in three of the five domains are classified as overall frail, the researchers explain, and are nearly five times more likely to die within six months as dogs who don't meet the frailty criteria.
“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.
Part of the appeal, she adds, is also the simplicity.
“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,” Olby says.
This is still an early step, the study's authors acknowledge, but a necessary one. They hope their research will help get the ball rolling, leading to an increasingly complete understanding of how frailty manifests in dogs.
“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 study was published in Frontiers in Veterinary Science.
