A 15-point neurological score for foals was developed, and tested on foals (<8 days old) presenting to the Marion duPont Scott Equine Medical Center (n=75) and the Royal Veterinary College (n=11). The score consists of 2 scales, which are added together to provide the total score. The points and descriptors for the first scale are as follows: Bright, alert, nursing, follows mare (0); Depressed, nursing, follows mare (1); Depressed, nursing, wanders away from mare (2); Depressed, standing, not nursing, will not follow mare (3); Recumbent, able to maintain sternal recumbency part of the time, strong suckle reflex (4); Recumbent, unable to maintain sternal recumbency, suckle reflex (5); Recumbent, no suckle reflex, responds to finger in ear (6); Recumbent, no suckle reflex, legs extended most of the time and muscles tense (7); Comatose, muscles relaxed, no response to finger in ear (8). Foals with a physical cause of recumbency (e.g., flexural deformity) are scored on this scale as if they were standing. The second scale is as follows: No seizure activity (0); Single seizure of less than 10 seconds (3); Single seizure of more than 10 seconds or two seizures of less then 10 seconds (4); Multiple seizures (5); Status epilepticus (7). All scores were assigned at admission by a single investigator.
The median admission neurological scores for hospital survivors and non-survivors, and for blood culture positive and negative foals were compared with the Mann Whitney U-test. The correlation of admission neurological scores and arterial lactate concentrations (measured on a NOVA Stat profile M or CCX analyzer) and mean arterial pressure (measured indirectly with a tail cuff) was tested with Spearman's rho coefficient. Analysis of these data was performed using SPSS version 12. Results for all tests were considered significant if the p value was less than 0.05. The median neurological score on admission of all 86 foals was 4, and the range was from 0 to 12. The median score of survivors (2) was less than that of non-survivors (5) (p<0.001; n=86). There was no significant difference in median score between blood culture positive (4) and negative (3) foals (p=0.109; n=84). The neurological score was moderately correlated with admission lactate concentration (correlation coefficient 0.528, p<0.001, n=68), but only weakly correlated with mean arterial pressure (correlation coefficient −0.285, p=0.011, n=78). This neurological score is statistically associated with clinically important parameters (hospital survival, blood lactate concentration), and warrants further study, including investigation of inter-observer variation in scoring.