Most new and emerging human diseases come from animal populations, and among these, viruses – especially influenza viruses – are the most dangerous. Viral transmission and mortality can be very high. Influenza pandemics have previously killed many millions of people. Pigs and poultry are readily infected and can transmit disease to people. Intensive pig and poultry farms include large animal groups of low genetic diversity, who are crowded together, often in unhygienic conditions. Resultant chronic stress compromises immune systems. These environments are fertile breeding grounds for the emergence of new influenza pandemics and other dangerous diseases. To protect both human health and animal welfare, intensive pig and poultry farms should not be permitted, especially at large-scale, or in close proximity.
Mace JL and Knight A (2023). Influenza risks arising from mixed intensive pig and poultry farms, with a spotlight on the United Kingdom. Front. Vet. Sci. 10:1310303. https://doi.org/10.3389/fvets.2023.1310303.