Relationship between clinical signs and postmortem test status in cattle experimentally infected with the bovine spongiform encephalopathy agent

Table 5 Relative frequency of clinical signs at neurological examinations over time post inoculation compared to control cattle

Study	1	1	1	1	2	2
Groups	1 g	100 g	1 g	100 g	4	2
Postmortem BSE diagnosis	Pos	Pos	Neg	Neg	Pos	Neg
*Behaviour*
Nervous or apprehensive in corridor	↑↑↑	↑↑↑		↑↑↑	↑↑↑
Nervous entering milking parlour	↑↑↑			↑↑↑	---	---
Kicked out during examination	↑↑	↑↑		LI	LI	LI
Nervous/head shy in crush	↑	↑↑↑			↑↑↑
Vocal free				↑↑↑
Crush refused or entered reluctantly	LI	LI	LI	LI	↑
Yawning						↑↑↑
*Sensation*
Startle during examination once	↑↑↑	↑↑↑		↑↑↑	↑↑↑
Startle during examination repeatedly	↑↑↑	↑↑↑	↑↑	↑↑↑	↑↑↑
Clipboard test abnormal ≥1	↑↑↑	↑↑↑			↑↑
Clipboard test abnormal >2	↑↑↑	↑↑↑
Over-reactivity to sound once		↑↑↑		↑↑↑
Over-reactivity present once/2 tests		↑↑↑		↑↑	↑↑
Over-reactivity present >2/2 tests		↑↑↑			↑↑↑
Over-reactivity to sound >2		↑↑↑			↑↑
Flash test abnormal >2		↑↑↑			LI
Flash test abnormal ≥1		↑↑↑				↓
Stick test: kicking	LI	LI	LI	LI	↑↑↑
Head tests nervous	LI	LI	LI	LI	↑↑
Head restraint nervous	LI	LI	LI	LI		↓
*Movement*
Tremor	↑↑	↑↑↑		↑↑	↑↑↑
Ataxia or hypermetria	↑↑	↑↑↑			↑↑↑

Groups were compared with undosed controls (study 1) or saline-inoculated controls (study 2).
↑= greater/↓ = lower hazard rate than controls, with P<0.001 (three arrows), P = 0.001-0.01 (two arrows) and P>0.01 and <0.0125 (four comparisons) or <0.0167 (three comparisons) (one arrow). Blank cell: no significant difference; low incidence (LI): signs too rare in at least one of the groups to calculate a P-value.
Only signs that were significantly differently displayed compared to controls are listed. Groups are omitted if none of the signs were significantly different compared to controls.
Not shown is the comparison of signs between controls and cattle inoculated with tissue of expected infectivity (group 3, study 2) because there was no significant difference for any of the signs.

ISSN: 1746-6148