Toxoplasmosis, cat roundworm and cat scratch disease are caused by pathogens that depend on cats — pets or feral — for part of their life cycle. But these diseases can be passed to humans, sometimes with severe health consequences. In our study published in the journal Wildlife Research, we looked at the rates of these diseases in Australia, their health effects, and the costs to our economy. Based on findings from a large number of Australian and international studies, Australian hospital data and information from the Australian Bureau of Statistics, we estimate many thousands of people in Australia fall ill or sustain a minor injury as a result of cat-dependent diseases each year. Our estimations suggest more than 8,500 Australians are hospitalised and about 550 die annually from causes linked to these diseases. We calculated the economic cost of these pathogens in Australia at more than A$6 billion per year based on the costs of medical care for affected people, lost income from time off work, and other related expenses.