Case series of neonatal lamb diarrhea syndrome treated with an evidence-based protocol to reduce antibacterial use.

Neonatal diarrhea in lambs remains a major cause of morbidity and mortality worldwide, yet standardized evidence-based treatment protocols for this species are limited. This prospective case series describes the field outcomes of a practical treatment protocol based on early intervention, oral rehydration, and targeted antibacterial use on a commercial Lacaune dairy sheep farm. The protocol was applied to 103 diarrheic lambs out of 133 born over a 60-day period. Daily clinical assessment included fecal scoring, evaluation of bacteremia signs, hydration status, suckling reflex, and abomasal palpation. All lambs continued voluntary suckling and received oral electrolyte solution daily until recovery. Antibacterials and NSAIDs were administered when at least two bacteremia signs were present, while isolated pyrexia was treated with NSAIDs alone and prolonged diarrhea (> 5 days) with antibacterials only. Mean duration of diarrhea was 4.0 days. Tested diarrheic lambs showed co-infection with rotavirus and Cryptosporidium spp. Bacteremia-compatible signs were observed in 25% of cases, and dehydration in 19%. Approximately 15% of lambs initially presented with isolated pyrexia before developing additional signs compatible with bacteremia, highlighting the importance of close clinical monitoring. Plasma glucose, sodium and potassium concentrations remained statistically stable. There was a 2.9% mortality rate, with all deaths attributed to Escherichia coli bacteremia. Antibacterials were required in only 34% of lambs, indicating that clinical selection criteria may help reduce unnecessary antibiotic exposure. Under field conditions, this protocol was associated with favorable clinical outcomes and supports early intervention, close monitoring, and selective antibacterial use in neonatal lamb diarrhea.