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Abstract: Oxytocin is used to induce and control parturition, nevertheless, the increase of uterine contractions decreases blood flow and gaseous exchange through the womb predisposing to intra-partum mortality. The objective of the present study was to evaluate the effect of oxytocin on myometrial activity, fetal intrauterine hypoxia and postnatal asphyxia in sows during farrowing. Hybrid (n = 120) sows approaching the time of farrowing were randomly assigned in two groups of 60 animals each. Group I (G1: control) was treated IM with saline solution and Group II (G2) was injected IM with oxytocin (1IU/6kg LW) as a single dose at birth of the first piglet. Both average number of myometrial contractions and intensity in G2 were greater (P < 0.01) as compared with G1. The mean of intra-partum stillbirths (IPS''s) and those where fetal cardiac frequency (FCF) or heart beats, could not be detected after birth, were greater (P < 0.01) in G2 as compared with G1. The average decelerations of FCF known as dips II, which indicate severe hypoxia, was greater in G2 (P < 0.01) as compared with that of G1. There was a greater (P < 0.01) number of intra-partum stillbirths, stained with severe meconium in G2 when compared with G1. Oxytocin treatment increased (P < 0.01) the number of pigs born alive with ruptured umbilical cords and those with different grades of meconium staining on their skin. It was concluded that administration of oxytocin at the onset of parturition increased the myometrial activity, decreased fetal cardiac frequency, predisposed the rupture of umbilical cords and the degree of meconium staining, and increased intra-partum mortality. [Copyright &y& Elsevier]

The objective of the present study was to evaluate in penned sows the effect of two commercial oxytocin products on umbilical cord pathology, degree of asphyxia and intra-partum mortality. This study included 120 sows divided in three groups of 40 animals with eight animals for parities one to five per subgroup, respectively. Group 1 (G1) or control received saline solution while oxytocin groups (G2) and (G3) were injected at the onset of fetal expulsion with two oxytocin products. The doses of oxytocin were as follow: Primiparous sows weighing less than 130 kg received 20 IU; multiparous sows weighing 130–180 kg received 30 IU, and those above 250 kg, 40 IU. Piglets born alive and/or dead were classified at birth using a subjective scale based on the degree of meconium staining on skin. Umbilical cords of intra-partum stillbirths (IPS) were classified as adhered or ruptured and subdivided into four categories: without pathological changes, edematous, congested and hemorrhagic. Result analyses revealed significant differences (P<0.01) between groups 1 and 2, and 1 and 3 regarding the following traits: expulsion interval (min) (X: G1 27.7; G2 22.6; G3 22.2), IPS with a severe stain degree (X: G1 0.10; G2 0.45; G3 0.50), IPS with ruptured umbilical cords (X: G1 0.07; G2 0.42; G3 0.47), and detectable heartbeats in IPS (X: G1 0.27; G2 0.25; G3 0.22). Treatment with oxytocin reduced the duration of the expulsion of the fetus, increased the number of IPS with ruptured umbilical cords and with severe meconium-stain degree and reduced the number of fetuses with inspiration attempts. Furthermore, the use of this hormone increased the need for obstetric assistance due to increased frequency of dystocia. [Copyright &y& Elsevier]

Abstract: In utero fetuses are evidently exposed to several factors that cause an interruption of the oxygen flow through the umbilical cord causing asphyxia leading to hypoxia and metabolic acidosis. These conditions are important causes of intra-partum and neonatal mortality. The main objective of this review is to provide current information regarding the pathophysiology of asphyxia in piglets around parturition; the physiological mechanisms invoked by affected piglets to compensate perinatal hypoxemia are discussed. This review also addresses some similarities and differences of asphyxia between piglets and other mammals, including human neonates. Metabolic acidosis and hypoxia are sequela to asphyxia and can cause profound health effects in postnatal performance because of an abnormal suckling, a reduced absorption of colostrum and inadequate passive transfer of neonatal immunity. Acidosis also cause hypothermia, increased mortality and reduced survival in neonates. One of the first deleterious effects of intrauterine hypoxia is the expulsion of meconium into the amniotic sac leading to meconium staining of the skin, and in severe cases, meconium aspiration into the lungs. Even though there have been technological changes and improvements in husbandry, piglet mortality due to asphyxia remains a major problem. One potential alternative to reduce neonatal mortality in pigs is the monitoring of fetal stress during birth and the implemention of strategies such as the Apgar score, that is often used in human pediatrics. It is also important to consider the physiological, behavioral and biochemical changes that take place during parturition which subsequently impact the vitality, maturity and development of neonatal pigs. Understanding the pathophysiology of fetal hypoxia should help practitioners and farmers implement more effective delivery techniques aimed at reducing neonatal mortality and improving postnatal performance. [Copyright &y& Elsevier]

Abstract: Two hundred sows were randomly assigned to intramuscularly receive 0.9% NaCl (group 1) or oxytocin 0.083, 0.11 or 0.17IU/kg (groups 2, 3 and 4, respectively) immediately after the expulsion of the first piglet. The overall duration of labor was decreased in a dose-dependent relationship. Time interval between piglets was decreased approximately 5min in groups 3 and 4 while sows in these groups exhibited approximately 10–20 contractions×10 births more than controls (P &#60;0.005). Duration and intensity of uterine contractions also showed a positive dose–response relationship. As an indicative of fetal distress, approximately 2.5 times more meconium-stained piglets were born to sows receiving the higher doses of oxytocin, but in the lowest dose significantly decreased. Oxytocin 0.083IU/kg significant decreased the mortality rate of piglets [OR 0.49 (95%CI, 0.26–0.92)]. In conclusion, we recommend the intramuscular administration of the lowest possible dose of oxytocin, which still decreases the duration of labor in sows. [Copyright &y& Elsevier]

One of the main functions of infrared thermography (IRT) consists in detecting temperature changes in organisms caused by variations in surface blood circulation. IRT is a useful tool that has been used mainly as a diagnostic method for various stress-causing pathologies, though recent suggestions indicate that it can be used to assess the block quality of certain body regions. In the field of anaesthesiology, IRT has been applied to brachial and epidural blocks, while in algology, changes in surface blood circulation associated with sympathetic activity have been investigated. Thermography has also been employed to complement pain level scales based on the facial expressions of patients in critical condition, or after surgery. In addition, it has been used as a tool in research designed to evaluate different surgical procedures in human medicine, as in the case of surgical burrs for placing dental implants, where IRT helps assess the degree of heating associated with bone devascularisation, reduction in vascular perfusion as a consequence of stroke, and changes in the autonomous nervous system, or the degree of vascular changes in flaps applied to burn patients. In veterinary medicine, thermography has brought several benefits for animals in terms of evaluating lesions, diseases, and surgical procedures. The aim of this review is to evaluate how IRT can be used as a tool in surgical procedures, cases of vascular change, and pain monitoring in veterinary medicine with an emphasis on small animals. • The detection of haemodynamic changes in vascular tissues by infrared thermography (IRT) is a reliable method for evaluating the functioning of the ANS (in cases of surgical and post-surgical pain). • IRT is not limited to detecting pathological changes (i.e. , those caused by disease or inflammation). • IRT allows specialists to identify changes in microcirculation caused by the use of drugs. [ABSTRACT FROM AUTHOR]