Elective caesarean section (CS) is the safest means of delivering the litter in bitches in specific situations. Timeously performing elective pre-parturient CSs at a fixed time would be convenient and prevent emergency CSs and foetal demise. This review proposes a method of performing elective pre-parturient CSs which is safe for both the bitch and puppies. Brachycephaly, small litters and large litters, preceding litter delivered by CS and trial of labour after a preceding CS are identified as factors increasing the need for CS whereas emergency CS is identified as factor increasing foetal demise. The first day of cytological dioestrus more precisely predicts the day of onset of spontaneous parturition than the first day of the LH surge or the dates during oestrus on which progesterone (P4) first exceeds 6 nM or 16 nM. Foetal biparietal diameter at the time of onset of spontaneous parturition varies too much to accurately predict readiness for CS. During the last few days of gestation, P4 with cut-off concentrations at 15.8, 8.7 and 3.18 nM, but not plasma cortisol concentrations, hold promise as predictors of onset of parturition and when to perform pre-parturient CSs. A protocol associating medetomidine hydrochloride as premedicant with propofol as induction agent and sevoflurane as maintenance is safe for scheduled CS and yields good maternal and puppy survival rates at delivery, 2 hr and 7 days after CSs. Clinicians have to pay attention to the haematocrit of bitches at the time of cervical dilatation which is at the lower end of the normal reference ranges for non-pregnant dogs and to the decline in haematocrit during CS (as a proxy for blood loss) which is approximately 7% for both parturient (open cervix) and pre-parturient (closed cervix) CSs. Pre-parturient CSs can be scheduled and performed 57 days after onset of cytological dioestrus with puppy survival rates of 99%. Collectively, these studies provide a protocol to safely perform elective CSs in a large proportion of the obstetric population at a convenient time of the day but more research is required with larger numbers to establish whether this practice is routinely safe and safe in all breeds.

中文翻译：

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朝母狗预定的产前剖腹产。

选择性剖宫产术（CS）是在特定情况下将母猪分娩时最安全的方法。在固定时间及时进行选择性产前CS会很方便，并可以防止紧急CS和胎儿死亡。这篇综述提出了一种对产妇和幼犬都安全的进行产前CS的方法。短头畸形，小垫料和大垫料，由CS输送的前胎和在前CS以后的分娩试验被认为是增加对CS需求的因素，而紧急CS被认为是增加胎儿死亡的因素。与LH激增的第一天或发情期间孕酮（P4）首次超过6 nM或16 nM的日期相比，细胞学的发情期的第一天可以更准确地预测自发性分娩的开始日期。自发性分娩开始时胎儿的双顶径变化太大，无法准确预测CS的准备情况。在妊娠的最后几天，P4的临界浓度为15.8、8.7和3.18 nM，但血浆皮质醇浓度没有，预示着分娩的开始和何时进行产前CS。将盐酸美托咪定作为前药与丙泊酚作为诱导剂，七氟醚作为维持剂的方案对于计划的CS是安全的，并且在CS后2小时和7天分娩时可获得良好的母婴存活率。临床医生必须注意子宫颈扩张时母犬的血细胞比容在非怀孕犬的正常参考范围的下端，而在CS期间血细胞比容的下降（作为失血的替代指标）是产期（开放子宫颈）和产前（封闭子宫颈）CS的约7％。产前CS可在细胞性发情期开始后57天进行安排和进行，幼犬成活率为99％。总而言之，这些研究提供了一种协议，可以在一天的方便时间在大部分产科人群中安全地进行选择性CS，但是还需要进行更多的研究才能确定这种做法在所有品种中是否常规安全。产前CS可在细胞性发情期开始后57天进行安排和进行，幼犬成活率为99％。总而言之，这些研究提供了一种协议，可以在一天的方便时间在大部分产科人群中安全地进行选择性CS，但是还需要进行更多的研究才能确定这种做法在所有品种中是否常规安全。产前CS可在细胞性发情期开始后57天进行安排和进行，幼犬成活率为99％。总而言之，这些研究提供了一种协议，可以在一天的方便时间在大部分产科人群中安全地进行选择性CS，但是还需要进行更多的研究才能确定这种做法在所有品种中是否常规安全。