THE EFFECT OF CALORIC RESTRICTION ON THE BEHAVIOR OF PEN-HOUSED DOGS - TRANSITION FROM UNRESTRICTED TO RESTRICTED DIET

Thirty-nine dogs were assigned to four treatment groups for weight los s. Breed, sex and initial body condition were similar across groups. T reatments included 0, 25, 40 or 50% caloric restriction, based on calc ulated maintenance energy requirements for the dog's estimated ideal b ody weight. True maintenance energy requirements and actual caloric re striction were determined retrospectively. Dogs were videotaped simult aneously in the late afternoon, early morning, immediately before the morning feeding, and immediately after the morning feeding during the 3 days prior to initiating calorie restriction, and on days 1-2, 8-9 a nd 15-16 of calorie restriction. Overall activity levels varied signif icantly, with the direction of change depending on the size of dog, le vel of restriction, gender, and time on diet. Small breed male dogs, w hich were on the most severe restriction based on actual calorie needs as determined at the end of caloric restriction, showed an initial in crease in activity prior to feeding, followed by decreasing overall ac tivity as they continued on caloric restriction. Large breed male and female dogs, which were on less intense actual restriction, exhibited a slight increase in overall activity, deriving primarily from decreas ed sleep and increased sitting, standing and walking. An early (day 1) increase in focused barking by dogs on greater caloric restriction is followed by a significant decrease, In summary, severe caloric restri ction may be counter-productive by inducing decreases in activity. Inc reases in aggressive behavior are not typical, but may occur.