There are dozens of organophospates found in thousands of products on the market, with uses ranging from nematicides to external parasiticides. These products come in spray, powder, and granular forms, with granular forms being readily eaten by songbirds or other birds and mammals foraging in treated fields. These affected animals are then consumed by raptors. It is possible that spraying a field before a rain will cause pooling and run-off that could affect birds bathing, swimming, or drinking that water. There have even been incidences of illegal use of these pesticides to lace carcasses with the specific goal of poisoning scavengers.
Organophosphate insecticides are harmful to nerve cells.
If this neurotransmitter is not broken down, it builds up at nerve endings, and the poisoned animal is continually stimulated, eventually dying of respiratory failure. Sub-lethal doses can cause weakness, uncoordinated movements, inability to stand, rigid paralysis, clenched talons, rapid respiration, muscle twitching, rapid alternating contraction and dilation of the pupil and other eye spasms, and even the absence of the pupillary light reflex. Blood tests later confirmed organophosphate poisoning. Within four days the eagle regained some use of its legs and within eight days, it could stand. It continued to improve, and after 16 days, it was transferred to the Chintimini Wildlife Rehabilitation Center in Corvallis, Oregon.