Table 1:

Clinical severity scores^a

Severity score	Neurobehavioral abnormalities
0 = Normal	- No clinical signs
1 = Mild	- Mildly sedate but remains standing - May lie down briefly but quickly stands when stimulated - Readily returns to normal behavior with external stimulation
2 = Moderate	- Moderate sedation, appears to be sleeping but with abnormal roosting posture (i.e. head down on the ground instead of tucked behind wing) - Consistently lying down - Displaying piloerection - Eyes partially closed or glassy-eyed - May demonstrate ataxia - May have intermittent, generalized muscle tremors - Mildly increased respiratory effort - Clinical signs improve to mild with external stimulation but does not return to normal behavior
3 = Severe	- Clinical signs as noted in moderate but more severe - Severe sedation, minimally response to external stimulation - More consistent whole-body tremors - More severe ataxia - Unable to stand or ambulate on own
4 = Comatose	- Severe sedation, non-responsive to external stimulation - More consistent whole-body tremors - Laterally recumbent, unable to stand - Occasional regurgitation

^aClassification system for the clinical severity scores used to categorize the severity of neurobehavioral abnormalities observed after oral administration of imidacloprid in domestic chickens.