Behavioural and cognitive changes in aged pet dogs: No effects of an enriched diet and lifelong training

Abstract

Dogs demonstrate behavioural 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 behavioural 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 behaviours. Fourty two behavioural 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 behavioural 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.

Leveling the playing field in studying cumulative cultural evolution: Conceptual and methodological advances in nonhuman animal research.

“…When dealing with many aging captive nonhuman primate populations, we must consider the effects of their cognitive abilities, motivation, and participation in experiments that vary across the life span because these will ultimately have consequences on the conclusions we draw. Whether animals attempt and persist at tasks, for example, can decline with age (Barbary macaques, Macaca sylvanus ; Rathke & Fischer, 2020), whereas perseveration with known solutions or strategies can increase (rhesus macaques; Lai et al, 1995; e.g., on aging and cognitive decline in other species, see Chapagain et al [2020] for dogs, Kapellusch et al [2018] for rats, and Kwapis et al [2020] for mice). Openness, linked with cognitive performance, also changes over the chimpanzee life span—with males in particular decreasing over adulthood (Rawlings et al, 2020).…”

Age‐related cognitive impairments in domestic cats naturally infected with feline immunodeficiency virus

“…Most often, researchers treat age as a continuous variable. 54,85 However, there are also several studies that analyzed age as a categorical variable. 13,14,64,86,87 The current study used both methods.…”

Successful and Unsuccessful Brain Aging in Pets: Pathophysiological Mechanisms behind Clinical Signs and Potential Benefits from Palmitoylethanolamide Nutritional Intervention

“…Laboratory beagle dogs have been involved in aging studies since the mid-1990s, and behavioral changes compatible with pathological aging were indeed identified [ 16 ]. However, the laboratory aseptic conditions and requirement for pre-test training lowered the possibility to apply the same lab tests to client-owned pets [ 17 ], thus hampering our understanding of age-related changes in the complex field of inter- and intra-specific social interactions, as well as the effect of environment on the development of pathological aging [ 9 , 18 , 19 ]. Nonetheless, laboratory beagles have been the first dog breed in which neuropathological changes similar to those observed in human beings suffering from sporadic Alzheimer’s disease (AD) were reported [ 20 ].…”