Effects of weight, litter size and parity of mother on the behaviour of the puppy and the adult dog

Abstract

During a 6-year period 867 8-week old German shepherd puppies were subjected to a behaviour test containing 10 different score groups. The weight at each tenth day up to 50 days of age was registered as well as litter size and parity of mother. All dogs were also tested at the age of 450–600 days. Puppies born during the first year and during the first 5 months of the second year (period 1) weighed 25% more at 50 days of age compared to those born during the last 7 months of year 2 and in year 3–6 (period 2). Puppy weight decreased with increasing litter size. Parity of mother had some effect on puppy behaviour however none on adult behaviour. Puppy weight affected the behaviour of puppies and adult dogs, however mainly in females. Larger female puppies were more active and explorative in the puppy test and scored higher for defence drive and hardness as well as in the concluding index value at adult age. Significant differences between period 1 and 2 were found both in the puppy test and in the test results of adult dogs. It is suggested that theses effects were caused by the change in material used in the whelping boxes. The corrugated cardboard used in period 1 was assumed to have an effect on the neonatal puppies similar to what previously have been described as early handling. The change in material used in the whelping boxes was also shown to affect growth in puppies. The effects were different in winter than in summer. It is also suggested that the behaviour of puppies is greatly affected by degree of maturation and that there may be differences in maturation due to gender and litter. It is also possible that maturation is affected by weight which then would explain the correspondence between weight and behaviour.