Zoonotic diseases emerging from human-animal interfaces including wildlife markets, factory farms, and habitat encroachment represent both public health crises and evidence of animal welfare failures in these systems.
Zoonotic disease emergence and animal welfare are linked through shared root causes: the conditions that create animal suffering including crowding, stress, and poor hygiene also create conditions favorable for pathogen emergence and amplification. Wildlife markets that cause acute welfare harms for captured animals simultaneously create pathogen spillover conditions. Factory farms that cause chronic welfare harms from crowding and environmental deprivation also create immunocompromised animals with elevated pathogen loads and evolutionary pressure toward more transmissible strains. Addressing these welfare failures is therefore simultaneously pandemic prevention strategy. The economic case for wildlife market reform and intensive farming welfare improvement is strengthened by the enormous costs of pandemic prevention and response, making animal welfare investment one of the highest-return public health interventions available.