Association of age and body condition with physical activity of domestic cats (Felis catus)

Physical activity contributes up to 30% of the total daily energy expenditure of domestic cats (Felis catus) and, therefore, can play an important role in the prevention and reduction of obesity and may impact macronutrient digestibility. An age-related decline in physical activity in domestic cats has been observed, however, scientific data is scarce. The aim of this study was to examine the relationship between physical activity, cat age and body condition score. A secondary aim was to determine whether physical activity level influenced apparent macronutrient digestibility. Using accelerometers, the physical activity of 138 domestic shorthair cats grouped housed in identical outdoor pens was measured. Cats were divided into five age groups: kitten (n = 10), junior (n = 37), prime (n = 30), mature (n = 33) or senior (n = 27), and physical activity data was collected from each cat for seven consecutive days. One cat was randomly chosen from each age group as a control and its physical activity was measured for the entire 11-week period. Body condition score of the cats was assessed in the same week that physical activity data was collected. A decline in physical activity with age was found, although this decline was not linear. Cats in the kitten and junior age groups had the highest physical activity. Compared with the younger age groups cats in the prime age group showed a significant reduction physical activity, which then remained constant in the mature and senior age groups. An overall decline in physical activity with an increasing body condition score was found. To investigate whether physical activity influenced apparent macronutrient digestibility, a subset of six cats from the junior and prime age groups were selected at the end of the activity assessment period. Cats were individually housed, fed a commercially available wet canned diet, and had ad libitum access to water. No effect of physical activity on apparent macronutrient digestibility was found.