Relationship between fetal biometric assessment by ultrasonography and neonatal lamb vitality, birth weight and growth.

Ultrasonographic examination of pregnant ewes can enable the identification of perinatal abnormalities and establish prenatal assistance responsible for minimizing morbidity and perinatal mortality. Therefore, we aimed to evaluate the feasibility of a fetal biometric analysis by ultrasonography to predict neonatal vitality and lamb growth during the first month of life. A longitudinal study was conducted with 13 healthy ewes, subjected to ultrasonographic examination every 15 days from 60th day of pregnancy until lambing, evaluating thoracic diameter, abdominal diameter, biparietal diameter, humerus, femur and placentome length. At birth, 22 lambs were assessed through Apgar score at 5 minutes and after 1 hour. Measurement of body weight was also carried out immediately at birth and weekly during 30 days after birth. Thoracic diameter showed a significant increase between 91-105 days and 121-135 days. Conversely, abdominal diameter had a progressive growth until 106-120 days, and then, a steady development was observed. Biparietal diameter showed progressive growth only towards days 91 and 105. For the humerus length, we verified a significant increase between 106-120 days and 121-135 days, remaining unaltered onwards; while femur length continued to grow until lambing. The linear regression analysis between birth weight and biparietal diameter at 60-75 days was high (R2=0.96; P<0.0001; coefficient of variability of 3.3%). In conclusion, ultrasonographic analysis of fetal biparietal diameter at mid-pregnancy can be used as a predictor of lamb weight at birth. Moreover, assessment of femur length at final pregnancy can be employed for fetal and neonatal development estimation.

Calving duration and obstetric assistance influence pulmonary function of Holstein calves during immediate fetal-to-neonatal transition.

Neonatal immediate adaptation to extrauterine life depends mainly on adequate lung function, which is under the influence of previous fetal maturation and obstetrical condition, both acting to stimulate the efficient liquid removal from the pulmonary parenchyma during the immediate transition period. The objective of the present study is to identify chest radiographic changes of neonatal calves born under the influence of different duration of calving and obstetric assistance and correlate with clinical analysis and blood acid-base balance. Experimental groups were determined according to the duration of calving: 2 h (n = 16), 2-4 h (n = 16) and >4 h (n = 12), and additionally by two sub-groups: no-intervention calving (n = 22) and intervention calving (n = 22). Neonatal calves were evaluated for heart and respiratory rate at birth, 5 min, every 10 min until 90 min. Arterial acid-base balance was determined immediately after calving and thoracic radiographs were made at 10 min of life. Lung radiopacity was higher in the 2-4 hr Group compared to the 2 hr Group. When calving duration was greater than 4 hours, a significant respiratory depression was observed. Calving greater than 2 hours slower neonatal pulmonary clearance, 100% and 91.6% of the calves born in the 2-4 hr and >4 hr Groups, respectively, had mild to moderate lung parenchyma opacity. There was a positive correlation between lung radiographic changes and blood TCO2 and negative correlation between pulmonary opacity score and blood PaO2 and SO2. Hence, it is possible to infer that neonatal hypoxia during prolonged calving has an imperative influence on pulmonary fluid absorption in calves. In conclusion, calving greater than 2 hours impacts pulmonary function at birth, leading to altered lung gas exchange, pulmonary clearance, cardiac and respiratory pattern. Conversely, obstetric intervention when calving has duration greater than 4 hours is beneficial for neonatal oxygenation.

Redox, acid-base and clinical analysis of preterm and term neonatal lambs.

During pregnancy, fetal lambs are exposed to low oxygen tension. Thus, an effective antioxidant mechanism is partially developed which sensitizes fetus to oxidative stress. Consequently, term and preterm neonates are susceptible to molecular and cellular injury caused by oxygen species (ROS). This study aimed to evaluate the development of antioxidant enzymes and oxidative profile of preterm (135 days of pregnancy) and term (145 days of pregnancy) neonatal lambs, correlating with clinical analysis. Preterm lambs had significantly (P ≤ 0.05) lower score of vitality (4.00 ± 1.10), bradycardia (99 ± 34 bpm) and bradypnea (13 ± 10 mpm). However, both groups were normothermic and euglycemic. Preterm group had low blood pH (7.07 ± 0.10) and both groups had hypercapnia, more severe in preterm group (85.52 ± 18.65 mmHg). In addition, premature newborns had lower pO2 (10.67 ± 5.65 mmHg) and SO2 (6.17 ± 5.85%) values. No significant difference (P ≥ 0.05) on antioxidant enzymes and oxidative stress were verified among experimental groups, although glutathione peroxidase negatively correlated with Apgar score, heart rate, SO2 and pO2. Our data show that preterm neonates are less adapted to the odds of labor and to overcome the immediate changes of extra-uterine life. Furthermore, we verified an influence of glutathione peroxidase in controlling oxidative stress, which highlights mature enzymatic mechanisms of cell redox, even in premature lambs.

Cystic endometrial hyperplasia-pyometra syndrome in bitches: identification of hemodynamic, inflammatory, and cell proliferation changes.

Cystic endometrial hyperplasia (CEH)-pyometra syndrome is one of the most common diseases of noncastrated female dogs. However, determination of etiological mechanisms and differential diagnosis of CEH-pyometra syndrome are undefined. The aim of this study is to compare immunohistochemically the expression of cyclooxygenase-2 (COX-2) inflammatory mediator, Ki-67 antigen proliferation marker, vascular endothelial growth factor (VEGF-A) angiogenesis mediator and its FLT-1 and KDR receptors, and correlate with Doppler velocimetry of uterine artery and endometrial vascularization in bitches with CEH-pyometra syndrome. Bitches were allocated into CEH-mucometra Group (n = 13), Pyometra Group (n = 11), and Control Group (n = 8). Pyometra Group presented cytoplasmatic staining intensity for COX-2, VEGF-A, and FLT-1 and KDR receptors in luminal epithelium cells significantly higher compared to CEH-mucometra and Control groups. For the glandular epithelium, Pyometra Group had higher immunostaining score for VEGF-A and its receptors (FLT-1 and KDR). Hemodynamic indexes showed negative correlation with VEGF-A and its receptors as well as with COX-2. On the other hand, uterine vascularization score showed positive correlation in relation to immunostaining of COX-2, VEGF-A, and receptors in the endometrium luminal epithelium. In conclusion, uterus of bitches with CEH-pyometra syndrome show inflammatory process characterized by COX-2 expression, resulting in greater expression of proliferative Ki-67 marker as tissue response against the infectious agent. Furthermore, the increased VEGF-A expression and its receptors in CEH-pyometra reflect the increased blood flow and lower vascular resistance. Therefore, canine pyometra is characterized by an inflammatory, proliferative, and vascular disorder.

Estrogen and oxytocin receptors in the canine corpus luteum during pregnancy and parturition / Receptores de estrógeno e ocitocina no corpo lúteo durante a gestação e parto em cadelas

The expression of genes encoding the receptors for estrogen (ERαmRNA) and oxytocin (OTRmRNA) was studied in the corpus luteum during pregnancy and parturition in dogs. Real-time PCR was performed to quantify the levels of ERαmRNA and OTRmRNA in the corpus luteum of bitches during Early (up to 20 days of gestation), Mid (20 to 40 days) and Late Pregnancy (40 to 60 days), and Parturition (first stage of labor). The corpus luteum expressed mRNA for OTR, however ERα mRNA was not detected. There was a reduction of OTR mRNA expression in the corpus luteum from gestational Day 20 onward, which suggests an important role of OTR mRNA in the mechanism of pregnancy recognition in dogs. We concluded that the expression of OTR mRNA in canine corpus luteum vary over time, which support the idea that the sensitivity and response to hormone therapy can vary along the course of pregnancy and labor. Moreover, the canine CL lacks ERα mRNA expression during pregnancy.

A expressão dos genes que codificam os receptores de estrógeno (REα RNAm) e ocitocina (ROT RNAm) foi estudado no corpo lúteo de cadelas durante a gestação e parto. A técnica de PCR em tempo real foi realizada para quantificar a expressão do REα RNAm e ROT RNAm no corpo lúteo de cadelas durante o início (até 20 dias de gestação), meio (20 a 40 dias) e final da gestação (40 a 60 dias), e durante o parto (pródomos do parto). O corpo lúteo apresentou expressão do RNAm para o ROT, entretanto o RNAm para o REα não foi detectado. Houve redução na expressão do ROT RNAm no corpo lúteo a partir de 20 dias da gestação, indicando papel no mecanismo de reconhecimento gestacional em cadelas. Em conclusão, a expressão do ROT RNAm no corpo lúteo de cadelas apresentou variação ao longo do tempo de gestação, sugerindo que a resposta e sensibilidade à terapia hormonal pode variar conforme o momento da gestação e parto. Ademais, o corpo lúteo canino não expressa REα RNAm durante a gestação.

Avaliação clínica e hemodinâmica periparto de fêmeas bovinas da raça holandesa em diferentes condições obstétricas / Peripartum clinical and hemodynamic evaluation of Holstein cows under distinct obstetric conditions

As distocias na espécie bovina são normalmente corrigidas por manobras obstétricas, sendo a extração forçada um procedimento obstétrico de risco, podendo causar injúrias tanto maternas quanto fetais. Partos induzidos com administração de ocitocina exógena nas inércias uterinas podem levar ao comprometimento fetal pela hipotensão e bradicardia materna, pois a ocitocina participa de regulações endócrinas e neuroendócrinas de órgãos como o coração e rins. O objetivo deste estudo foi comparar as mensurações de frequência cardíaca (FC), pressão arterial não-invasiva (PA) e eletrocardiograma de fêmeas bovinas da raça Holandesa agrupadas segundo a condição obstétrica: eutocia (G EUT; n = 10); distocia com manobra obstétrica (G DIST; n = 10); inércia uterina com infusão de ocitocina (G OCT; n = 10); nos seguintes momentos: pré-parto, intraparto, pós-parto imediato e uma hora após o parto. Os traçados eletrocardiográficos denotaram ritmo sinusal normal em todos os períodos. Observou-se taquicardia em todos os grupos, sendo que apenas no G OCT a FC pós-parto (111 ± 23 bpm) elevou-se estatisticamente em relação ao pré-parto (94 ± 11 bpm). Houve acréscimo significativo da PA no intraparto do G DIST (PA média = 101 ± 24 mmHg), decorrente de contrações uterinas e abdominais mais intensas. As fêmeas bovinas do Grupo OCT não apresentaram aumento significativo da PA diastólica intraparto em relação ao pré-parto como observado nos G EUT e G DIST. Os resultados apresentados demonstram que a distocia com correção manual eleva a pressão arterial das fêmeas bovinas, enquanto a administração de ocitocina altera momentaneamente as variáveis hemodinâmicas com possível efeito bradicárdico e hipotensor intraparto, impondo adaptação circulatória materna frente às alterações do parto.

Bovine dystocias are commonly assisted through obstetric procedures. However, manual traction delivery can be a dangerous strategy for the treatment of dystocia as it may lead to maternal and fetal injuries. Use of oxytocin for uterine atonia or hypotonia to induce contractions may compromise fetal welfare due to maternal hypotension and bradycardia, because this hormone regulates renal and heart endocrine and neuroendocrine actions. The aims of this study were to compare heart rate (HR) measurement, non-invasive blood pressure (BP) and electrocardiograms records of Holstein cows during the first stage of labour, intrapartum, immediately after calving and one hour later of physiological birth and dystocia. The animals were allocated in: group EUT – eutocia (n = 10); group DYST – dystocia with obstetric assistance (n = 10); group OCT – uterine inertia treated with oxytocin (n = 10). The electrocardiograph tracing showed a normal sinus rhythm during all parturition. Tachycardia was observed in all groups, however, group OCT showed higher heart rate immediately after calving (111 ± 23 bpm) than prepartum evaluation (94 ± 11 bpm). During labor, DYST G presented significantly higher BP (Medium BP = 101 ± 24 mmHg), due to uterine and abdominal strengthened contractions. Group OCT cows didn't show significative elevation on diastolic BP during calving as occurred on EUT and DYST groups. The present results indicate superior blood pressure on manual traction delivery of bovine females, while oxytocin infusion altered transitorily hemodynamic variables with a possible bradicardiac effect and intrapartum hypotension and impose maternal circulatory adaptation during parturition.