For those countries touched by the first wave of the industrial revolution, the period from the mid-eighteenth to the end of the nineteenth centuries saw rapid and significant changes across many domains of human and nonhuman life. These changes, as they affected human children and nonhuman animals, were the context for the emergence of the specific rationalities that continue to echo through contemporary relationships between these two groups, and between these groups and wider society. Between the sixteenth and nineteenth centuries there had been major but gradual change in humans’ relationships with nonhuman animals, but urbanization and industrialization heralded a much more rapid pace of change (Franklin 1999). The UK was the first country to experience urbanization and industrialization, from the mid-eighteenth century onwards. Elsewhere in Europe and the USA, the process started later but moved forward faster. The nineteenth century in particular saw unprecedented urban growth in the UK: at the start of the century less than 20 per cent of the human population lived in towns or cities with populations exceeding 10,000, and no provincial town or city (outside London) had a population exceeding 100,000; by the end of the century around three quarters of the human population lived in towns or cities exceeding 10,000 and 17 provincial towns or cities had populations over 100,000. During the century, the human population of the capital alone grew from 1.1 million to 7 million. This rapid change did not unfold in a planned or orderly fashion, but was chaotic and disorganized, and associated with a proliferation of public health hazards (Giddens and Sutton 2013, Szreter 2001). This transformation of public health since the eighteenth century was especially marked for infants and children. It was associated with a decrease in deaths from infectious diseases, which was observed across the human population, but this had particular significance for this group (McKeown 1977). Prior to the expansion of urban living, the majority of humans lived in rural locations in close proximity to nonhuman animals, and shared accommodation with them, especially during the winter months (Franklin 1999).