Cognitive Decline in Older Dogs: Nutrition and Training Have No Impact

Aging causes an inevitable cognitive decline in humans, but also in their four-legged companions. In humans, however, it is possible to slow this decline through measures such as a specialized diet or mental stimulation. But according to a new study, this is not the case for pet dogs. A specific diet or prior training has no impact on age-related declines in dogs’ problem-solving abilities, sociability, boldness, and dependence.   In all mammals, aging is associated with physical and cognitive changes. And just as in humans, pets experience behavioral changes and progressive cognitive decline with age, resulting from a complex set of genetic and environmental factors. These changes may manifest as a decrease in curiosity or a decline in sociability, memory, or attention. The severity and symptoms of this cognitive decline often vary from one dog to another. Numerous studies in laboratory dogs suggest that an enriched diet or stimulation through training throughout the animal’s life could slow cognitive aging in dogs. However, few studies have sought to verify these findings outside the laboratory setting, in pets. To better understand aging in pet dogs, researchers from the University of Veterinary Medicine Vienna and the University of Liverpool assigned 119 pet dogs—all over 6 years old and of various breeds—either an enriched diet (containing nutrients such as antioxidants, omega fatty acids, phosphatidylserine, and tryptophan) or a control diet over a one-year period. They also asked the animal owners to share their experiences with training their dogs. After one year on the controlled diet, the researchers assessed the cognitive abilities and behaviors of the older dogs using a robust test called the Modified Vienna Canine Cognitive Battery (MVCCB). This tool could also be used to detect behavioral changes and cognitive deficits in older dogs more systematically. In fact, the analyses showed that, as a general rule, aging dogs experience a decline in problem-solving ability, sociability, boldness, and dependence. This was not the case for trainability or independence. And contrary to expectations, training experiences and an enriched diet do not appear to influence this cognitive decline. Further research will therefore be needed to determine whether and how training or diet can impact aging in companion dogs.