As your playful puppy puts more years behind him, things start to slow down. He may not run as fast or bark at random strangers — and he may also experience dog dementia.
Some research has suggested that an enriched diet can help fight off cognitive decline in aging pet dogs. A new study tested that theory, casting doubt on whether a specialized diet is ultimately necessary for aging dogs.
For one year, researchers fed 119 pet dogs, all over age 6, one of two diets — either a control or an enriched diet. The enriched diet included nutrients like antioxidants, omega-fatty acids, tryptophan, and Phosphatidylserine.
After a series of tests, the scientists determined that the enriched diet did not make a significant difference when it comes to the six factors they evaluated:
- Activity independence
Previous training experience, which the researchers assessed based on reports from owners, also did not make a difference in dogs' aging brains. The findings were published Wednesday in the journal PLOS ONE.
Durga Chapagain, a researcher at Messerli Research Institute in Vienna, Austria, led the study. Chapagain explains that previous lab experiments suggested that diet can alter learning and memory in older laboratory dogs.
But while lab dogs are generally kept in a homogenous group with a standardized diet and housing type, there is much more variation in the lives of pet dogs. Chapagain's team wanted to determine how diet influences dogs outside of the lab.
"Those studies have claimed that these diets are very effective," Chapagain tells Inverse. "But we advocate that in order to claim whether or not these diets have any effect on dogs’ cognition and behavior, we need to test these diets in general dog population either pet dogs, working dogs, sports dogs, service dogs, therapy dogs, etcetera."
The new findings suggest that past work does not apply to all dogs — or render specific dog food brands effective for helping the brains of older dogs.
"We should be cautious to generalize the findings of laboratory dogs to all dog population and advertise that certain food brands are effective for pet dogs per se," Chapagain says.
With the new findings, the researchers hope to reach pet owners looking to do what they can to help their aging dogs.
Owners should monitor their dogs' health overall, and look out for early signs of aging – behavior changes are especially important to note, Chapagain says. They should still pay attention to diet and the amount of food served, feeding their pet according to what stage of life they're in, their activity levels, and how many treats they're getting.
It's also important to pay attention to what a brand claims, and whether or not those claims may be misleading, Chapagain says. The findings don't mean that enriched diets are wholly ineffective — but they leave room for doubt, and for further research.
"Feeding antioxidants and omega fatty acids won’t cause any harm to old dogs, as we know that in humans these components delay cellular aging," Chapagain says.
But dog owners "should not be misled with commercial diets with these components claiming to boost cognitive functions unless there is a proven study done to support this claim."
Abstract: Dogs demonstrate behavioral changes and cognitive decline during aging. Compared to laboratory dogs, little is known about aging in pet dogs exposed to different environments and nutrition. In this study, we examined the effects of age, an enriched diet and lifelong training on different behavioral and cognitive measures in 119 pet dogs (>6yrs). Dogs were maintained on either an enriched diet or a control diet for one year. Lifelong training was calculated using a questionnaire where owners filled in their dog’s training experiences to date. Before commencing the diet and after one year of dietary treatment, they were tested in the Modified Vienna Canine Cognitive Battery (MVCCB) consisting of 11 subtests to examine correlated individual differences in a set of tasks measuring general, social and physical cognition and related behaviors. Forty-two behavioral variables were coded and were subjected to principle component analyses for variable reduction. Twelve subtest level components and two Z-transformed variables were subjected to exploratory factor analysis which resulted in six final factors: Problem solving, Trainability, Sociability, Boldness, Activity-independence and Dependency. Problem solving, Sociability, Boldness, and Dependency showed a linear decline with age, suggesting that the MVCCB can be used as a tool to measure behavioral and cognitive decline in aged pet dogs. An enriched diet and lifelong training had no effect on these factors, calling attention to the fact that the real world impact of nutritional and other interventions in possibly counteracting the effects of aging, should be further investigated in pet dogs living under diverse conditions, in order to understand their ultimate effects.