Around 1900 German public health institutions are populated with cattle, pigs, hor­ses, sheep and goats. The Department of Bacteriology and that one of Veterinary Medicine of the Imperial Health Office looked more like a farm house than a labora­tory and the Prussian Institute for Experimental Therapy had been enlarged with stable buildings around the turn of the century. In the Imperial Health Office and the Institute for Infectious Diseases life stock and veterinary medicine played an impor­tant role in German public health institutions: At the interface between life sciences and agronomy, veterinary knowledge and veterinary medicine was linked to national politics and national economy, agro- and food industry as well as the pharmaceutical industry, public health and risk policy. Linked to national and bio-economy, life stock was seen as valuable national (bio) capital. For these reasons the state engaged in veterinary medicine. In the public health institutions research was done to investigate the character, etiology and transmission paths of epizootics as well as to develop or to improve cures against animal diseases. In the Institute for Experimental Therapy sera and biologicals against animal diseases were controlled on their efficacy and their therapeutic impact.

In the public health institutions cattles, horses and pigs had a different and varying ontological status resulting from their different relations to humans. Cattles, sheep, pigs and horses had a status as commodities, as patients suffering from mostly fatal diseases like cattle plague, bovine tuberculosis, swine pest or food and mouth dis­ease. (Beyond that, horses were also seen as luxury goods and status symbols as well as working animals). And at the same time life stock was considered – first and foremost – as scientific objects in experimental settings, for instance to investigate the etiology and transmission paths of animal diseases, or to search for remedies against epizootics. Furthermore infected cows and pigs were feared as a public threat because it was unclear if pathogens that cause animal diseases could also infect humans. Especially the discussion about the transmission of bovine and hu­man tuberculosis around 1900 could be cited as an example for this issue. Finally, and due to fact that animals were susceptible to the same pathogens as humans, animals were also a source to produce small pox vaccines or a dispenser to produce serum against animal and human diseases. Serum against erysipelas made pigs happy – according to an advertising of the serum producer.

The paper will trace the different states of life stock in the public health institutes as scientific objects, as a public health threat, as a source for a remedy and as commo­dities. Moreover, the paper will follow the shifting ontological status and the conse­quences for the human-animal relationship.