R. Morrison

Associations between obesity and physical activity in dogs: a preliminary investigation

OBJECTIVES To assess whether obesity has any association with objectively measured physical activity levels in dogs. METHODS Thirty-nine dogs wore Actigraph GT3X accelerometers (Actigraph) for 7 consecutive days. Each dog was classified as ideal weight, overweight or obese using the 5-point body condition scoring system. Total volume of physical activity and time spent in sedentary behaviour, light-moderate intensity physical activity and vigorous intensity physical activity were compared between body condition categories. RESULTS Valid accelerometry data were returned for 35 of 39 dogs recruited. Eighteen dogs were classed as ideal weight, 9 as overweight and the remaining 8 as obese. All dogs spent a significant proportion of the day sedentary and obese dogs spent significantly less time in vigorous intensity physical activity than ideal weight dogs (7 ±3 minute/day versus 21 ±15 minute/day, P=0·01). CLINICAL SIGNIFICANCE Obesity is associated with lower vigorous intensity physical activity in dogs, as is also thought to occur in humans. These preliminary findings will help inform a future, larger study and may also improve our understanding of the associations between obesity and physical activity in dogs.

A 6-month observational study of changes in objectively measured physical activity during weight loss in dogs

OBJECTIVES To evaluate long-term changes in physical activity and sedentary behaviour during weight loss in dogs. METHODS Sixteen overweight and obese dogs undergoing a 6-month calorie-controlled weight-loss programme wore Actigraph GT3X accelerometers (Actigraph, FL) for three consecutive days each month for the duration of the programme. Total volume of physical activity and time spent in sedentary behaviour, light-moderate intensity physical activity and vigorous intensity physical activity were extracted from the accelerometer data and compared from baseline to month 6. RESULTS Valid accelerometry data were returned for 14 of 16 dogs. Mean percentage weight loss over 6 months was 15% of initial bodyweight. There was no marked increase in any of the physical activity outcomes or reduction in sedentary behaviour. CLINICAL SIGNIFICANCE Substantial weight loss was not associated with a spontaneous increase in physical activity or reduction in sedentary behaviour. Although the dogs in this study lost a substantial amount of bodyweight without a measured increase in physical activity, dog owners should still be encouraged to facilitate increased physical activity in their dogs owing to the wide range of benefits associated with physical activity other than weight loss.

Correlates of objectively measured physical activity in dogs.

To increase physical activity (PA) levels in dogs and to better evaluate their energy requirements, there is a need to understand which factors or correlates are associated with PA and/or sedentary behaviour. Improving our understanding of these correlates also has implications for prescribed energy requirements in dogs. PA was measured using accelerometry in 62 dogs from two common breeds (Labrador retrievers and Cocker spaniels). Five potential correlates (age, sex, breed, neuter status, body condition score) were tested for associations with total volume of PA, light-moderate intensity PA, vigorous intensity PA and sedentary behaviour. Age and breed were associated with total volume of PA, light-moderate intensity PA and sedentary behaviour in the final models. Age was associated with vigorous intensity PA. The final models explained 60%, 40%, 63% and 44% of variance in total volume of PA, light-moderate intensity PA, vigorous intensity PA and sedentary behaviour, respectively. These results should improve understanding of the variation in energy requirements of dogs, as well as the development of age and breed-specific diets and the prevention and treatment of canine obesity.

Use of accelerometry to investigate physical activity in dogs receiving chemotherapy

OBJECTIVES To perform a preliminary study to assess whether single-agent palliative or adjuvant chemotherapy has an impact on objectively measured physical activity in dogs. METHODS Fifteen dogs with neoplasia (treatment group) wore ActiGraph™ accelerometers for 5-day periods before, during and after receiving single-agent adjuvant or palliative chemotherapy. Mean 5-day total physical activity and time spent in three different intensities of activity (sedentary, light-moderate and vigorous) before, during and after receiving chemotherapy were compared to a group of 15 healthy dogs (control group). Results were also compared within the treatment group across time. RESULTS Prior to chemotherapy, treated dogs tended to be less active than control dogs. Treatment group dogs were slightly more active at restaging than they were prior to treatment but had similar activity levels to control dogs. Marked effects of chemotherapy on physical activity were not detected. Physical activity was slightly lower in treated dogs during chemotherapy when compared to control dogs but there was a slight increase in physical activity of treated dogs during chemotherapy when compared with pretreatment recordings. There was little change in the mean 5-day total physical activity between treated dogs during chemotherapy and at restaging but a mild decrease in time spent sedentary and increase in time spent in light-moderate activity at this comparison of time points. CLINICAL SIGNIFICANCE Single-agent adjuvant or palliative chemotherapy had minimal impact on physical activity levels in dogs with neoplasia.