The best way to prevent toxicoses by pesticides is to thoroughly and completely wash and scrub fresh foods before giving them to your bird. Cases of pesticide poisoning are very difficult to diagnose. Another, more common cause of contaminated food is bacteria. Often soaked foods contain a tremendous number of bacteria that can overwhelm your bird's immune system, in fact water and high water content foods are the number one cause of high bacterial exposure in pet birds. The other cause of contaminated food is mycotoxin tainted food.
Mycotoxins are chemicals produced by certain varieties of molds and fungi.
Often, the mold or fungi is no longer visible when the toxins are ingested, so these toxicities too are difficult to spot, but food can be tested for the presence of mycotoxins. The most common mycotoxins affecting grains are aflatoxin, ochratoxin, vomitoxin, and T2 toxin. The most commonly implicated foods with mycotoxins are poor quality peanuts and peanut butter, breads, meats, cheese, and grains. If a food smells moldy or certainly if mold is seen, the food should be discarded and not fed. Though the list of harmful foods may seem ominous, if clean, well stored foods are fed to birds, they very rarely develop food toxicoses.