Relationship between physical activity, energy intake and body condition in companion dogs

Abstract: Obesity is a common nutritional disorder of companion dogs and can cause several health and welfare problems. Many studies focus on the nutritional aspect i.e. the effect of energy intake on overweight in dogs, whereas there are few studies on the physical activity aspect i.e. the effect of energy expenditure on weight management in dogs. An understanding of how amount and type of physical activity affects a healthy dog’s body condition could increase knowledge of dogs´ requirement of physical activity in order to avoid overweight, and thereby reduce the risk of dogs developing weight-related health problems. This study aims to assess the relationship between physical activity, energy intake and body condition in companion dogs, as well as differences in physical activity habits (gait, duration, distance, speed, heart rate, leash use) between overweight and non-overweight dogs. Thirty-one companion dogs from Sweden and Finland were included in this study. Questionnaires were used for the owner to record the dog’s feed intake, walks and other physical activities during seven consecutive days. General information about the dog and its habits of physical activity was received through an oral interview with the owner. Measurements of Body Condition Score (BCS), bodyweight and wither height were obtained by the student. Based on the dog’s habits for physical activity received from the questionnaires, two representative walks were chosen to be repeated for data collection. Polar® heart rate monitor was used to measure heart rate (HR), distance and speed during the walks. Possible effects of habits for physical activity and energy intake on the dog’s BCS and/or HR was statistically analysed in SAS 9.4. Results showed that non-overweight dogs used more trot (61% vs 45%) and gallop (18% vs 7%), less walk (the gait, 20% vs 47%), had higher speed (4.5 km/h vs 3.8 km/h) and spent less time on leash (43% vs 74% of walking duration) during walks than overweight dogs (P<0.05). Also, tendencies for walks with higher intensity (higher HR) and longer distances was seen for non-overweight dogs compared to overweight dogs (P<0.1). However, no significant difference in duration of walks was found between overweight and non-overweight dogs. Dogs walked at a high intensity (average HR above the total sample populations average) used less walk (the gait, 24% vs 44%), more gallop (18% vs 8%) and had a lower BCS (5.1 vs 5.9) than dogs walked at a low intensity (P<0.05). No relationship was found between energy intake and body condition. In conclusion, this study indicates that there is a relationship between physical activity and body condition in this population of companion dogs. However, the internal validity might be affected by the small sample population and, therefore, further studies are required.