J. A. Rodrigues

Neonatal clinical evaluation, blood gas and radiographic assessment after normal birth, vaginal dystocia or caesarean section in dogs.

This study aimed to standardize signs and diagnostic criteria of respiratory function in newborn puppies delivered normally or after dystocia and caesarean operation. A total of 48 neonates were allocated into groups: eutocia (n = 20), dystocia (n = 8), caesarean (c)-section (n = 20). Neonatal health was assessed using the Apgar score and body temperature was determined at 0, 5 and 60 min after delivery. Venous blood gases (pO(2) and SO(2)) was measured immediately and 60 min after delivery, and a thoracic radiograph was made between 0 and 5 min of life. The c-section group had significantly lower Apgar scores at birth and 5 min. Hypothermia was present at 5 min in the eutocia and c-section groups, and at 60 min in all groups. The eutocia group had an irregular respiratory pattern in 78% of puppies at birth, 27.7% at 5 min and 21% at 60 min compared with 87.5%, 62.5% and 12.5% of the pups in the dystocia group where there was irregular respiratory rhythm, moderate to intense respiratory sounds with agonic episodes. The c-section group had respiratory alterations in 70%, 45% and 16% of puppies at 0, 5 and 60 min, respectively. Radiographic abnormalities were present in 17% of the pups in the eutocia group, 25% of the pups in the dystocia group and 30% of the pups in the c-section group, respectively. The c-section group had significantly lower SO(2) values at 60 min than at birth. All puppies had hypoxaemia, but a significant decrease was observed in the c-section group. Newborn puppies had tissue hypoxia and irregular respiratory pattern at birth. Caesarean-section puppies had lower vitality; however, all developed satisfactory Apgar scores at 5 min of life, regardless of the obstetric condition.

Acid-base changes in canine neonates following normal birth or dystocia.

There are limited data concerning blood gas parameters in neonatal dogs. Knowledge of the normal physiology may facilitate effective therapeutic intervention and potentially reduce neonatal mortality. This study examined acid-base parameters in pups born at normal parturition (n = 27) compared with those born after obstetrical assistance or caesarean operation (n = 13) and those born following oxytocin (OXY) administration for treatment of uterine inertia (n = 11). Pups were subjected to an objective scoring method of neonatal health adapted from use in humans (the Apgar score) at birth and again at 5 and 60 min after birth. Venous blood samples were collected at 5 and 60 min after birth for evaluation of blood gas parameters. At birth, all pups had low Apgar scores and a mixed acidosis. The base excess was lowest for pups delivered after OXY administration. The Apgar score improved for all pups after 5 min of birth and there was an improvement in carbon dioxide tension, base excess and venous blood pH at 1 h, although in all pups a metabolic acidosis persisted. These data provide an important insight into neonatal physiology and the variability of blood gas parameters in pups born at normal and abnormal parturition and provide the basis for clinical decision making following dystocia.

Influence of Ascorbic Acid and Glutathione Antioxidants on Frozen‐Thawed Canine Semen

Poor sperm viability post-thaw has resulted in constant research into methods of cryopreservation of canine semen. One factor that may be involved in poor viability is sperm oxidative stress caused by excessive formation of reactive oxygen species. The present study was performed in order to evaluate the effect of different concentrations of ascorbic acid (AA) and glutathione (Glu) added to an extender for the freeze-thawing of dog sperm. Semen from five mature dogs was collected and frozen in two studies. Prior to and after freezing, sperm motility, morphology and membrane status were examined. In addition, sperm motility was examined up to 120 min after thawing to evaluate thermo-resistance. In study I, semen was collected twice from each dog. On both occasions, semen was divided into three aliquots: control, Glu 1 mM and Glu 5 mM. In study II, semen was collected twice and divided into three aliquots; control, AA 50 microM and AA 250 microM. Initial sperm motility was significantly higher in sperm diluted with AA 50 microM; sperm longevity, however, measured by a thermal-resistance test (TRT), was higher for Glu treatments. Higher concentration of Glu produced significant improvement in TRT and membrane status, whereas higher concentration of AA had a negative impact in sperm longevity. Antioxidant supplementation to semen freezing extenders improved semen quality post-thaw. Moreover, Glu had the most beneficial effect when supplemented at 5 mM.

Peripartum haemodynamic status of bitches with normal birth or dystocia.

There has been limited investigation of parturition in the bitch and there is little information published on clinical and obstetrical examination other than opinion and anecdote. While there are substantial data on haemodynamic and vascular changes during normal parturition in humans, little is known about the physiological events in the dog. This study was aimed at maternal haemodynamic changes occurring during normal parturition and to investigate how these were modified in bitches with dystocia (DYST) treated either medically or via assisted delivery and caesarean operation. Three groups of 10 bitches were investigated; those with normal parturition, those with DYST corrected by manipulative assistance or caesarean operation and those with uterine inertia treated by oxytocin administration. Heart rate, systolic and diastolic blood pressure, electrocardiogram and blood glucose concentration were measured pre-partum, intra-partum, immediately after parturition and 1 h later. Heart rate was high at all times throughout the study and the majority of bitches had normal sinus rhythm. Blood pressure was generally within the normal range, and although systolic and diastolic blood pressure was highest during the intra-partum period and sometimes during the immediate post-partum period, there were no significant differences between groups. All bitches had blood glucose concentrations within the normal range throughout the study although pre-partum concentrations were statistically lower than many of the other time periods. The study provides useful physiological data that will facilitate monitoring and clinical management of bitches throughout normal parturition and DYST.

Association between birth conditions and glucose and cortisol profiles of periparturient dairy cows and neonatal calves

Parturition in cattle is a stressful event for both the dam and the offspring. Stress and pain can alter the energy profile of calves and calving cows, producing a metabolic imbalance at birth. This study aimed to assess the effects of dystocia and oxytocin and calcium infusion on metabolic homeostasis in dairy cows and calves. Thirty Holstein cows and their calves were divided into three groups: an eutocia group (n=10), in which no calving assistance was needed; a dystocia group, which required mild-to-severe obstetric assistance (n=10); and a uterine inertia group, which was treated with oxytocin and calcium (n=10). To assess serum cortisol and blood glucose levels, blood samples were collected during the peripartum period from cows and during the first hour since birth from calves. All groups were hyperglycaemic following parturition. Infusion of oxytocin and calcium resulted in lower maternal glucose concentrations and lower levels of stress than in cows in the dystocia group. Birth condition was significantly associated with blood glucose and cortisol concentrations in calves. Glucose concentration was lower in calves born with oxytocin and calcium infusion than those born with fetal extraction. In conclusion, assisted calving with fetal extraction causes important metabolic changes for the dam and calf. Conversely, the practice of oxytocin and calcium infusion for hypotonic cows has no harmful effects on metabolic balance and can be safely employed as a medical treatment.

Effect of dystocia and treatment with oxytocin on neonatal calf vitality and acid-base, electrolyte and haematological status

Under adverse obstetrical conditions, appropriate supervision and assistance during the immediate neonatal period are of the utmost importance, especially for weak calves. The aim of this study was to establish the effects of dystocia and oxytocin infusion on neonatal vitality, acid-base balance, and electrolyte and haematological homeostasis of dairy calves. Data were collected for 30 Holstein calves which were allocated to three groups: normal calving (n = 10); dystocia with mild to severe obstetric assistance (n = 10); and uterine inertia treated with oxytocin (n = 10). All 30 calves exhibited normothermia at birth, but had a significant decrease in body temperature after 60 min. Dystocic calves had lower Apgar scores than calves in the other two groups, and had respiratory and metabolic acidosis. Calves from normal calvings had normal blood pH, but base excess below the reference range. The mean partial pressure (Pa) of oxygen of calves whose dam had been treated with oxytocin was lower than that of calves from normal calvings. In all experimental groups, there was improvement in metabolic status in the first 60 min postpartum as PaCO2 values significantly decreased. All calves had normonatraemia, normokalaemia and normochloridaemia during the study period, but calves born to dams treated with oxytocin had a higher sodium concentration than those in the two other groups.

The influence of the obstetrical condition on canine neonatal pulmonary functional competence

OBJECTIVE To compare the influence of the obstetrical condition on neonatal respiratory performance, to estimate surfactant synthesis through lecithin and sphingomyelin ratio (L/S) in amniotic fluid of pregnant bitches and correlate the L/S with the respiratory condition during the first hour of life. DESIGN Prospective randomized study. SETTING University veterinary teaching hospital and private referral centers. ANIMALS In accordance to the condition at birth, puppies from 25 healthy bitches aged 2-6 years were allocated into: Eutocia Group--EUT (n = 19 neonates and 14 bitches); Dystocia Group--DYS (n = 8 neonates and 5 bitches) and Elective Cesarean Section Group--CS (n = 12 neonates and 11 bitches). INTERVENTIONS Amniotic fluid was drawn from amniotic sac and lecithin (L) and sphingomyelin (S) were measured by high performance liquid chromatography to obtain the L/S ratio. Neonatal physical examination was performed at 1, 5, and 60 minutes after delivery, and included the assessment of respiratory rate (RR) and respiration effort (RE). MEASUREMENTS AND MAIN RESULTS CS group had significantly lower amniotic L/S ratio when compared to EUT and DYS. There were no significant differences between vaginal groups (EUT versus DYS) in respect to L/S ratios. RE of eutocic neonates improved promptly, while RE of DYS and CS groups improved only 1 hour following birth. Moreover, amniotic L/S ratio positively correlated with RR after 60 minutes. CONCLUSIONS We identified a possible influence of the delivery method on the final surfactant maturation process. Thus, neonates born by elective CS prior to the onset of expulsive uterine contractions should have their respiratory parameters carefully monitored. Additionally, we propose that assessment of respiratory parameters 1 hour following birth can serve as a practical means to indirectly estimate pulmonary maturation (ie, surfactant synthesis) in puppies.

Avaliação do estresse oxidativo em cavalos de trote através da mensuração de malondialdeído (MDA) e glutationa reduzida (GSH) eritrocitária

O estresse oxidativo, decorrente de uma atividade fisica, leva a peroxidacao lipidica de membranas celulares, alem de danos proteicos e em acidos nucleicos, e um dos produtos finais desta reacao e o malondialdeido (MDA). A glutationa reduzida (GSH), considerada um antioxidante multifuncional, esta presente no plasma e principalmente nas hemacias e tem importância pelo fato de ser um dos indices da capacidade total antioxidante do corpo apos um estresse oxidativo. Com o objetivo de avaliar o estresse oxidativo em diferentes condicoes de treinamento fisico, determinaram-se a concentracao de MDA serico e GSH eritrocitaria em 45 cavalos da raca American Trotter e mesticos divididos em tres grupos: G1 (sem treinamento), G2 (ate 6 meses de treinamento) e G3 (treinamento ha mais de 12 meses). Observou-se que o MDA teve um valor significativamente menor no grupo de animais sem treinamento fisico. Nao houve diferenca estatistica significante para GSH corrigida pela Hb e para GSH corrigida pelo VG entre os grupos analisados, mas houve uma aparente tendencia a maiores valores no G2, no qual o sistema antioxidante esta em fase de adaptacao ao treinamento fisico constante e suas consequentes injurias. Conclui-se que a atividade fisica acarreta danos celulares frente ao estresse oxidativo, mas o sistema antioxidante tem papel fundamental nesta homeostasia observando uma adaptacao as injurias causadas pelos radicais livres.