Pigeons, starlings, and other birds can transmit diseases to man via their droppings. The two major diseases that can be spread to people by bird droppings are psittacosis and histoplasmosis.

Psittacosis is an infectious disease caused by bacteria. The symptoms are high fever, severe headaches, and symptoms similar to pneumonia. The reservoir of psittacosis is principally pets birds, such as parakeets, but the disease can be found in pigeons. The mode of transmission is by inhalation of dust from infected droppings, and dust from the feathers of infected birds. Human cases are mostly sporadic. Although usually mild or moderate, human cases can be severe, especially in untreated elderly persons.

Histoplasmosis is a disease caused by the inhalation of the spores of a fungus. The disease is most often asymptomatic, but occasionally produces acute pneumonia or an influenza-like illness. The mode of transmission is the same as for psittacosis. Without treatment, some forms of the disease can be fatal.

Pigeons and other birds can be a potential disease threat when they roost inside of buildings. Birds roosting inside of a building can deposit large quantities of droppings within the structure, commonly in the attic spaces. The droppings and dust contaminated with droppings may not be contained within the attic spaces. The droppings and contaminated dust may find its way into the living spaces.

In order to prevent the spread of diseases from birds to people, it is important to prevent birds from roosting within the building. Birds can find their way into buildings through holes in the soffits, or in the roof. Repairing holes in soffits and roofs will prevent birds from entering. Birds which are already present within the building must either be exterminated or driven out.

After the birds have been eliminated from a building, and the means of entry have been blocked, all droppings within the building should be removed, and all spaces within the building that have been contaminated with droppings should be thoroughly cleaned. Sanitary precautions should be taken, and personal protective equipment should be worn by those persons doing the cleanup. At a minimum, respirators and gloves should be worn. Proper hygiene should be observed, such as hand washing, and laundering of clothing.

Public Health regulates bird infestations only within rental properties under Public Health Nuisance Regulation 2-93, Section 7D. In cases where birds have inhabited a rental property, the Public Health can order the property owner to initiate control measures. Public Health does not regulate bird populations in the outdoor environment.