By persisting indoors for months or years on rugs or furniture, certain chemical pesticides may present the potential for adverse effects. When applied outdoors, these same chemicals, plus others registered for outdoor use only, can drift indoors through open windows, contacting a caged bird kept nearby, or they can gain access from air intake ducts or be carried indoors on shoes. Birds and/or their environments may be treated with cholinesterase inhibitors such as the insecticide carbaryl (recommended for mite control) or outdated remedies such as the toxic substance paradichlorobenzene (found in moth crystals) used around cages. Further, the effects of multiple chemical exposures can be additive or even synergistic, with greater likelihood of adverse reactions occurring as a result.
Due to concern over West Nile virus, chemical pesticides may be broadcast from an aircraft or from a land-based vehicle in an effort to reduce mosquitoes. Pet birds (and other sensitive individuals) can be protected from contact with these sprays by closing windows and air intake ducts when the application occurs. If possible, a pet owner should obtain information from local governments, professional pest control companies, landscapers or neighbors who apply pesticides as to time, place, and nature of the pesticide product being sprayed close to the home. Greater surveillance of marketed products is needed to collect adverse reaction information. This is especially important for products used in the home and applied to pet animals, such as those products with fipronil and imidacloprid as active ingredients.
Reference: "Clinical Avian Medicine - Vol I and II" by Harrison and Lightfoot