In this large scale cross-sectional study we investigated the development and aging of various cognitive functions in pet dogs; social (social learning, perspective taking and communication), physical (spatial properties, and means-ends connections) and general cognition (learning, memory and problem solving), as well as basic control processes (motivation, inhibition, persistency, flexibility, and attentiveness). In order to avoid variation of data resulting from breed differences, one single breed, the Border collie was used. One hundred dogs were divided into seven age groups (from 6 months to 14 years) and tested in a cognitive task battery of 12 tests. The results from specific tests within the battery demonstrate the relevant stages of the development and aging of various cognitive functions over the lifespan, as well as the role of basic processes in cognition. We also investigated the possible influence of sex, past and current training, and neuter status on the performance of Border collies in cognitive tasks. In the future, accurate measures of canine cognitive development can then be applied to develop predictions and possible treatments to enhance cognitive development, delay cognitive decline, and to help to earlier detect cognitive abnormalities in typical family dogs. This study is of particular importance for comparative psychology, as it is one of the first to address lifespan cognition in a social species which shares our living environment, and finally, it also has significant practical relevance; as cognitive changes can affect quality of life, trainability, learning and problem solving abilities, and the human-animal relationship.