A 9-year-old show pony mare became acutely lame following removal of a bone sequestrum of the distal phalanx of the right thoracic limb. The mare also suffered from ongoing right dorsal colitis secondary to previous long-term nonsteroidal anti-inflammatory drug (NSAID) use. To avoid further NSAID use, a protocol for caudal epidural administration of morphine and detomidine in an increased volume was used to provide analgesia to the thoracic limbs. A total volume of 50 mL (0.2 mL/kg bwt) was administered over approximately 90 s. Immediately following the injection, the pony collapsed into lateral recumbency and experienced an apparent generalised seizure characterised by loss of consciousness and frantic paddling of all four limbs. The pony recovered rapidly without intervention, and no residual neurological deficits were noted. The epidural analgesia resulted in a marked improvement in comfort levels. The speed of injection is thought to have caused a change in epidural and intracranial pressures resulting in a generalised seizure and highlights the importance of administering large volumes slowly.

中文翻译：

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小马尾侧硬膜外注射吗啡和地托咪定后推定全身性癫痫发作

一头 9 岁的表演小马在移除右胸肢远端指骨的骨死骨后变得严重跛行。母马还患有继发于先前长期使用非甾体类抗炎药 (NSAID) 的持续右侧背侧结肠炎。为了避免进一步使用非甾体抗炎药，使用了增加剂量的吗啡和地托咪定尾端硬膜外给药的方案来为胸肢提供镇痛。在大约 90 秒内施用了 50 mL (0.2 mL/kg bwt) 的总体积。注射后，小马立即侧卧，并出现明显的全身性癫痫发作，其特征是意识丧失和四肢疯狂划动。小马在没有干预的情况下迅速恢复，没有发现残留的神经功能缺损。硬膜外镇痛显着改善了舒适度。注射速度被认为会导致硬膜外和颅内压的变化，从而导致全身性癫痫发作，并强调了缓慢注射大量药物的重要性。