Health Hazards of Pigeons
Both humans and animals can be affected. The disease is transmitted to humans by airborne fungus spores from soil contaminated by pigeon and starling droppings (as well as from the droppings of other birds and bats). ... On occasion, the disease can cause high fever, blood abnormalities, pneumonia and even death.
Pigeons make the very air you breathe highly toxic with bacteria and spores. Doctors say that pigeon droppings, loose feathers and the dust they shake when fluttering their wings is the cause of an alarming spread of Asthma and upper respiratory illnesses.