The arrival of the fridge as a common home appliance implied, among other consequences, the evolution of the place of the animals in the city. My grandma still had chicken under the kitchen sink in their third ground apartment, as during the Spanish post-civil war era this was still common (most urban dwellers came from rural areas, as her), and she had no fridge at home and retail was not up to the task of massive meat distribution. To be precise, at a given moment they bought a fridge, but power lines were not reliable enough…
Which leads us to a previous matter: the spread of electric energy. The generalization of electricity in the cities is a matter of little more than the last century, with a gradual growth: first light, and then an incremental growth of the rest of appliances. The urban family revenue had to grow to support buying new appliances, but power generation and transportation networks had to grow in terms of both capacity and reliability.
This expansion of electricity is central to the link between animals and humans in cities in many ways, and in Europe there is a clear example in the production and distribution of dairy products. Since Pasteur it is known that milk is an ideal place for pathogens to thrive, especially when time between milking and drinking grows and temperature is uncontrolled, so up to the generalization of railroads the strategy was to bring the cow as close as possible to the citizen. Cities as Madrid or Paris had at the end of the XIXth century a large amount of “vacheries”, small places in which cows were raised to produce milk for nearby populations, sometimes in ground floors or inner courts in what now are posh areas. Some examples as Louis Bonnier’s time architectures in ceramic tiles show the convergence with the expansion of urban hygiene.
The improvements as well in transportation as in refrigeration both on the offer side (industrial fridges) and the demand side (a fridge for every family) reduced with time the need for cows near families. Along with the end of urban horses due the car, this is a relevant evolution. It is worth thinking how in today’s polluted cities a quality milk production could happen, but anyway this urban story also had implications for rural areas: while the milk production in former times could only be exported as cheese, with power and fridges an industrialization of the milk industry ensued.
It would be interesting to see, in the recent context of avian influenzas, how the way in which humans and fowl evolves in Asian cities with fast GDP, infrastructure and population growth, as a century ago in North America or Europe.