Social Stress and Animal Welfare

As animal welfare issues become increasingly important in public consciousness, studying them has also become more important in veterinary science as it applies to animal farming. While much of the past research on animal health and welfare has focused on the physical health of farm animals, veterinary scientists are also beginning to look closely at the influence of social stress. The animal species that are most commonly raised on farms and used for food are generally social animals that tend to live in groups. It’s easy to see how the cramped conditions and other “management practices” of factory farming not only increase the risk of disease transmission, but can also be incredibly stressful for animals.

Of course, social stress and physical stress are not mutually exclusive. As this editorial in a special issue of The Veterinary Journal notes, “an increased risk of disease may not simply be due to an increased concentration of pathogens, but also due to social stress making them more susceptible to infection.” Currently, this is a major gap in the field of animal welfare, and one “that would benefit from future experimental and epidemiological research.” To underscore why further research would be important, the editorial authors note that the “Five Freedoms” related to animal welfare are nutrition, health, environment, behaviour and mental states, and that “three of these domains can be directly and negatively affected by social stress, namely, health, behaviour and mental states.”

Concern about these links is one aspect of an overall shift away from emphasizing prevention of negative welfare toward a focus on promoting positive welfare, which includes positive social interaction. In addition to understanding the links between social stress and farmed animal management practices, the editorial notes there is also “a need for a better understanding of the social interactions that occur between animals.” Some researchers propose using “social network analyses” to look at direct interactions as well as indirect links, something the authors here refer to as “friends of friends” of farmed animals.

Overall, this editorial may provide some encouragement for farmed animal advocates, especially those interested in improving animal welfare conditions on farms. “Good animal welfare implies both physical fitness and a sense of wellbeing,” note the authors, and “at the very least, all farm animals should have a life worth living (from the animals’ point of view).” This editorial, and the special issue of The Veterinary Journal that it accompanies, point to new directions in recognizing the cascading negative effects of factory farming. If we recognize that such concentrated animal farming is devastating for animals physically as well as socially, and that those two factors are exacerbated by each other, we need to question whether or not such a system can be justified.