Neurologic dysfunction in newborn calves: understanding neonatal encephalopathy in clinical practice

Abstract

Neonatal encephalopathy (NE), a clinically important syndrome causing neurologic dysfunction in newborn calves, contributes to early-life morbidity and mortality. Affected calves exhibit impaired adaptation to extrauterine life, including delayed or absent respiration, difficulty standing, and ineffective nursing, compromising colostrum intake, passive immunity transfer, and overall viability. NE reflects a clinical presentation rather than a specific etiologic diagnosis and may result from hypoxic-ischemic injury, metabolic disturbances, trauma, infection, or intoxication. Historical terms such as ‘dummy calf’ and weak calf syndrome lack diagnostic precision and should be interpreted cautiously. Neonatal maladjustment syndrome, derived largely from equine and human literature, represents a proposed mechanistic subset of NE, potentially involving persistent neurosteroid activity but remains speculative in calves. Emerging hypotheses, including neurosteroid persistence and maternal gut microbiome influences, may contribute to neonatal maladaptation but require further validation. Management is primarily supportive whereas prevention should focus on dystocia reduction, timely obstetric intervention, and optimized periparturient and early neonatal care. Clarifying terminology and understanding underlying mechanisms is essential to improve clinical decision-making and research interpretation.