Early Experience, Maternal Care and Behavioural Test Design : Effects on the Temperament of Military Working Dogs

Sammanfattning: Domestication has resulted in animals with broad variations between as well as within breeds, which allows for the selection and breeding of animals for preferred traits. This selection has affected both the genotypes and phenotypes of animals. In dogs, it has allowed for breeding for different purposes, such as companionship or the performance of specific tasks, e.g., herding, hunting, searching and protecting. Each of these types of working dogs has specific traits that are, in part, controlled by genes; however, genes are not solely responsible for the variations in the traits of an individual. The environment also plays a role, which has been studied in rodents and primates in recent decades. For instance, it has been shown that the amount of maternal care that a rat receives as a pup affects its temperament later in life; the more maternal care, i.e., licking, grooming and arched-back nursing (LG-ABN), that a rat receives, the more stress resistant, less reactive and more explorative it will be as an adult. However, the question is whether this is also true for dogs, and the investigation of how temperament in dogs is affected by environmental factors early in life is the main objective of this thesis. Three of the studies presented in this thesis focused on investigating the general parameters, particularly maternal care, that influences offspring behaviour to contribute to the understanding of temperament development in military working dogs. One of these studies concentrated on the environmental factors that influence dogs early in life, and the results indicated that some factors, such as parity, litter size and birth season, affect temperament later in life. Another study investigated how females take care of their young, and the results demonstrated that females consistently vary in their maternal style during the first three weeks postpartum and that this variation affects the temperament of the offspring. The third study focused on factors in the home environment, and the results showed that dogs approved through the evaluative temperament test were significantly associated with being hyperactive or restless and having difficulty settling down in the home environment. However, those dogs were also left home alone for more hours in a day than non-approved dogs. To be able to operate functionally, a military working dog needs to possess certain traits, or a certain temperament, and a vital characteristic is the way it responds to and copes with stress. This was investigated during an evaluative temperament test used to select dogs suitable for further training. Surprisingly, the results showed that the dogs approved for further training had significantly higher levels of salivary cortisol both before and after the test compared with the non-approved dogs. These findings may be of profound importance for understanding individual variations in behaviour and improving breeding schemes for working dogs.