Evaluation of the foal survival score in a Danish-Swedish population of neonatal foals upon hospital admission.

This research assesses the Foal Survival Score (FSS), a system used to estimate the chances of survival for sick newborn foals within their first days of life, by applying it to a different population of foals in Denmark and Sweden. The evaluation demonstrates that with an optimal cutoff score of ≥6, the FSS moderately performs in determining foal survival prognosis, but suggests that the FSS may not work as effectively in different horse populations, advising caution against overestimation of its diagnostic potentials.

Objective and Methodology

• The research’s main aim was to evaluate the Foal Survival Score (FSS) — a system used for estimating the probability of survival in sick newborn foals less than four days old — and to determine how it performs when applied to an older population of foals and in a geographically different location from the original study.
• The researchers carried out a retrospective multicenter study involving 590 hospitalized neonatal foals aged 14 days or less from Denmark and Sweden, collecting data related to the identity, history, clinical examination, laboratory test results, necropsy findings, and outcomes.
• They compared scores and score variables between foals that survived and those that did not, using logistic regression. A receiver operator characteristic curve was utilized for calculating the optimal cutoff and its test parameters.

Results

• The study identified several factors which were significantly related to nonsurvival, namely prematurity, cold extremities, the presence of more than one infectious or inflammatory sites, as well as certain blood glucose concentrations and total white blood cell counts.
• The optimal cutoff for predicting survival was determined to be a score of ≥6. This resulted in a sensitivity of 78%, a specificity of 58%, a positive predictive value of 92% and a negative predictive value of 31%.
• The FSS was found to be equally effective in foals that were less than four days old and those aged between four and 14 days.

Conclusion

• The study concluded that using the optimal cutoff score of ≥6, the FSS moderately performs and can be effective in early prognosis of survival.
• However, the score’s performance varied in a different population compared to the original one on which it was formulated. The researchers hence caution against overestimating the potential of the FSS in diagnosing survival prospects and suggest assessing it under local conditions and populations.