Time-dependent changes and prognostic value of lactatemia during the first 24 h of life in brachycephalic newborn dogs

Comparison of Propofol and Alfaxalone as Anesthesic Drugs in Bitches Undergoing Ovariohysterectomies (Healthy Bitches and with Pyometra) and Cesarean Sections

This study evaluated the efficacy and safety of two anesthetic agents, alfaxalone and propofol, on maternal physiological parameters (heart and respiratory rates, blood pressure, and temperature) on either ovariohysterectomies or cesarean sections in bitches. A total of 34 healthy and pyometra-affected females (classified as ASA II), were induced with IV propofol (4 mg/kg), while 35 females, both healthy and pyometra affected, were induced with IV alfaxalone (1 mg/kg). For cesarean sections, females (ASA II) were induced with propofol (n = 14) or alfaxalone (n = 14). Additionally, the neonatal viability and modified Apgar score were recorded at 5, 60, and 120 min post-delivery. There were no significant differences in the physiological parameters when comparing the use of propofol and alfaxalone in bitches undergoing ovariohysterectomies, regardless of their health status, nor when comparing cesarean sections. It was observed that bitches induced with propofol occasionally required an additional dose for maintenance of the anesthesia. Neonatal mortality rates were similar for both groups; however, alfaxalone was associated with higher neonatal viability as indicated by the Apgar scores. The findings suggest that both anesthetic protocols are effective and safe for use in canine reproductive surgeries, with no major differences in basic physiological parameters' alteration or neonatal outcomes between the two agents.

Emergency cesarean section in dogs: Usefulness of amniotic fluid biochemical parameters and placental morphology as indicators of neonatal viability

In recent years, special attention has been paid to the analysis of fetal fluids and placental histopathology to identify parameters that can be used as indicators of maternal reproductive quality, embryonic viability, and fetal and neonatal health. Newborn health reflects the functioning of the fetal adnexa and its relationship with maternal tissues. Therefore, evaluating these components is promising for the early detection of newborns at risk. This study aimed to detect the biochemical characteristics of the amniotic fluid (AF) and histopathological characteristics of the placenta for comparison between canine neonates born by elective (EL) and emergency (EM) cesarean sections (CSs) and associate the results with neonatal viability in the first 24 h. A total of 38 neonates born by ELCS (n = 19) and EMCS (n = 19) were selected. AF was collected to analyze the concentration of its biochemical components [alanine aminotransferase (ALT), alkaline phosphatase (ALP), creatinine, urea, total protein, albumin, total and direct bilirubin, lactate, glucose, potassium, chloride, calcium, and sodium]. Histopathological processing of the placenta was used to describe the lesions and identify the arrangement of collagen fibers using hematoxylin-eosin and picrosirius staining. There was an increase in ALP activity (P = 0.035) and the concentrations of lactate (P < 0.001) and potassium (P = 0.031), and a decrease in chlorides (P < 0.001) in the AF of neonates in the EMCS group. The comparisons between the groups did not show differences between the presence and extent of lesions in the placenta; however, a difference was observed in the arrangement of collagen fibers in the placental structure. A comparison between AF and histopathological findings showed a negative correlation (r = -0.609, P = 0.003) between glucose concentration and the presence of necrosis in the placental labyrinth. It was observed that the composition of the AF changed owing to the influence of the type of cesarean, possibly caused by prolonged hypoxia in cases of dystocia. ALP activity and lactate, potassium, and chloride concentrations in the AF might be explored as markers of neonatal health in EMCS. Under the conditions of this study, no correlations were found between the placenta's histopathological characteristics and the neonates' viability.

Differences in selected blood parameters between brachycephalic and non-brachycephalic dogs

Introduction

Cranial and upper-airway anatomy of short-nosed, flat-faced brachycephalic dogs predisposes them to brachycephalic obstructive airway syndrome (BOAS). Periodic apnoea increased inspiratory resistance, and an inability to thermoregulate effectively are characteristic of BOAS, but internationally accepted objective markers of BOAS severity are missing. The objective of this study was to compare the selected blood parameters between non-brachycephalic (NC) and brachycephalic (BC) dogs, exploring the possibility of developing a blood test for BOAS severity grading in the future.

Methods

We evaluated blood biochemistry, complete blood cell counts, red blood cell (RBC) indices, reticulocyte counts, a blood-born marker of intermittent hypoxia (glutathione, NO production), RBC hydration, deformability, and blood markers of metabolic changes and stress between BC (n = 18) and NC (meso- and dolichocephalic, n = 22) dogs.

Results

Reticulocyte counts and the abundance of middle-fluorescence immature reticulocytes were significantly (p < 0.05) higher in BC dogs compared to NC dogs. BC dogs had significantly more NO-derived NO2 - /NO3 - in plasma than NC dogs. RBCs of BC dogs were shedding significantly more membrane, as follows from the intensity of eosin maleimide staining, and had a significantly higher mean corpuscular hemoglobin concentration than NC dogs. Intracellular reduced glutathione content in RBCs of BC dogs was significantly lower, while plasma lactate was significantly higher in BC dogs compared to NC dogs. Plasma cholesterol and triglycerides were significantly lower, and cortisol was significantly higher in BC dogs compared to NC dogs. Eosinophil counts were significantly lower and the neutrophil-to-lymphocyte ratio was higher in BC dogs compared to NC dogs.

Discussion

Taken together, our findings suggest that the brachycephalic phenotype in dogs is associated with alterations at the level of blood cells and, systemically, with oxidation and metabolic changes. The parameters identified within this study should be further investigated for their potential as objective indicators for BOAS.

Biochemical factors affecting newborn survival in dogs and cats

The importance and implications of small animal neonatology were underestimated until recent times. Despite the recent increasing interest for this branch of veterinary medicine, however, perinatal mortality rates in canine and feline species remain high, representing an important challenge for the clinician. In this perspective, the prompt identification of newborns requiring additional and tailored assistance becomes a key to reduce the perinatal losses in small animals. To achieve this goal, clinical and laboratory findings must be carefully evaluated. This paper focuses on biochemical parameters and their reported influence on neonatal survival, guiding through the evaluation of canine and feline newborn laboratory analyses, with a thorough discussion about the use of different biological material in these subjects. Beside blood, other biological material, such as urines and fetal fluids proved to be interesting for the identification of possible prognostic markers, thanks also to their easy and safe collection. However, the correct reading-through the results must consider many variables such as type of delivery, anesthesia protocol in case of Caesarean section, age of the newborn at samples collection, and for blood analysis, also the type of blood, site of collection, modality of collection and storage must be considered. Notwithstanding the recent progress in literature, for most of the parameters more research is needed to define cut-off values with certainty.

Is an epidural component during general anaesthesia for caesarean section beneficial for neonatal puppies' health and vitality?

Regional centro-axial block is a recommended technique for uncomplicated caesarean section in human medicine. Since the application of regional anaesthesia as the only technique in veterinary medicine is impractical, the objective of the study was to assess and compare the epidural component of caesarean section (CS) on maternal and fetal outcomes. Bitches (n = 36) undergoing elective CS were enrolled in this study. Females were randomly assigned into two groups: Gr I (Isoflurane, n = 20) and Gr IE (Isoflurane plus Epidural, n = 16). Anaesthesia was induced with propofol, and maintained with isoflurane in oxygen. In the IE group, epidural anaesthesia was also performed using lidocaine. The maternal intraoperative parameters were compared at three time points: T1 - just before the skin incision, T2 - after the last puppy removal, and T3 - at the end of surgery. At least 100 mcl of mixed umbilical cord blood was collected for gas analysis. The modified Apgar scoring system (AS) was used to objectively score newborn health and vitality immediately after birth (0 min), 5 and 20 min after birth. Systolic, diastolic, and mean blood pressure were lower in the IE group at T1, T2, and T3 compared to I group (p < 0.05). In the combined anaesthesia group blood pressure remained stable but low at all time points. Throughout surgery, the IE group required a lower concentration of isoflurane (p < 0.05). The median values of the umbilical blood gas results were found to be similar (p > 0.05) in both investigated groups. The initial results of the Apgar score were comparable in the I and IE groups (p > 0.05). However, subsequent AS measurements revealed significant differences between both groups. Puppies from the IE group received better AS scores at 5 and 20 min compared to the I group (median AS 8 and 9 vs. 5 and 8, respectively). The results obtained demonstrated that epidural anaesthesia administration reduced the requirement for isoflurane in dams undergoing caesarean section and despite episodes of maternal hypotension did not affect the results of neonatal umbilical blood gas. Furthermore, newborns from the epidural anaesthesia group improved more quickly postnatally, developing a satisfactory condition in a shorter time.

Refining the APGAR Score Cutoff Values and Viability Classes According to Breed Body Size in Newborn Dogs

The Apgar score (AS) represents a key tool for neonate assessment, but the possible breed effect on AS in newborn puppies has never been investigated. Therefore, data from 234 dog litters born by caesarean section, grouped according to breed body size (BBS) (small, medium, large), were evaluated. Live-birth puppies were assessed through AS within 5 min of delivery, and classified in viability classes: 0−3 severely distressed, 4−6 moderately distressed, 7−10 not distressed. Statistical analysis evaluated possible differences of AS and viability class according to BBS, and between BBS and puppies’ mortality. Results showed no differences in the distribution of mortalities among BBSs. However, an effect of BBS on the AS was found, with small-sized puppies being the most represented in the severely distressed class, but having the best survival chance compared to large-sized newborns. Through receiver-operating-characteristics analysis, the AS new cutoff values for survival and for death <24 h and 24 h−7 days of age were identified, and the viability classes were redefined, with a narrower class of moderately distressed puppy specific for each BBS. In conclusion, the refining of the AS in dog species is imperative, with cutoff values and viability classifications that must be adapted to the BBS.

Canine Neonatal Assessment by Vitality Score, Amniotic Fluid, Urine, and Umbilical Cord Blood Analysis of Glucose, Lactate, and Cortisol: Possible Influence of Parturition Type?

Simple Summary

Parturition as a stressful event may influence puppies’ neonatal morbidity and mortality. The purpose of this study was to investigate the impact of parturition type on stress in newborn puppies, their weight gains, and survival in the first week postpartum. One hundred and twenty-three puppies were divided into three groups: vaginal parturition, emergency, and elective cesarean section. The Apgar score was assessed 5, 15, and 60 min postpartum, and samples of amniotic fluid, umbilical blood, and urine were collected for lactate, glucose, and cortisol concentration measurements. Although emergency cesarean section puppies had the highest cortisol concentration of all groups, their Apgar score at 5 min postpartum was comparable to the vaginal parturition group, which had the highest lactate levels. There were no significant differences between groups regarding relative growth rate. The type of parturition had no impact on puppies’ survival in our study, but supportive treatment was provided for non-vital puppies in stress. Non-invasive analysis of amniotic fluid and/or urine could help in the assessment of the neonatal vitality.

Abstract

The objective of this study was to investigate the impact of parturition type on vitality in newborn puppies, their weight gains, and survival in the first week postpartum. One hundred and twenty-three puppies were divided in three groups: vaginal parturition (VP), emergency (EM-CS), and elective cesarean section (EL-CS). Apgar scores were assessed 5, 15, and 60 min postpartum. Lactate and glucose concentrations were measured in amniotic fluid and umbilical blood; cortisol concentrations were measured in amniotic fluid and puppy urine. Puppies’ weight gain was tracked daily for 7 days postpartum. Apgar score at 5 and 15 min was significantly better in the VP group. EL-CS puppies had significantly lower umbilical blood and amniotic fluid lactate concentrations compared to the VP group, which also had higher umbilical blood lactate concentration than EM-CS puppies. The cortisol concentration in the amniotic fluid and in urine differed significantly between the groups, with the highest concentration in the EM-CS, followed by the VP group. Glucose concentration in amniotic fluid was higher in the VP group than EM-CS group. The type of parturition had no impact on puppies’ weight gain or their survival at birth; however, supportive treatment was provided for non-vital puppies. Non-invasive analysis of puppies’ fluids could help in the assessment of the neonatal vitality.

Umbilical Cord Blood Gas Parameters and Apgar Scoring in Assessment of New-Born Dogs Delivered by Cesarean Section

Simple Summary

The article presents the results of the clinical evaluation and umbilical cord blood analysis obtained from newborn pups delivered by the elective Caesarean section. In human medicine both the umbilical cord blood and Apgar score were proved to provide valuable information on neonatal status. In veterinary medicine very few reports concerning the relation between the clinical neonatal assessment (Apgar score) and umbilical cord blood parameters exist. All puppies show mild respiratory acidemia regardless the Apgar scores result. The lactates were not elevated whereas all the puppies with low Apgar sores had higher glucose and mortality rates. Only pups with low initial Apgar scores were at risk of death within first 24 h. Adaptation to the extra-uterine life is crucial and any practical improvement in neonatal diagnostics and care would be beneficial for newborn puppy survival.

Abstract

The article presents the results of the clinical evaluation (Apgar scores, AS) and umbilical cord blood gas analysis (UCBGA) obtained from clamped umbilical cords of newborn pups delivered by the elective Caesarean section. The study was planned as a controlled clinical study, the newborns were allocated into one of the groups, I—critical neonates (severe distress, AS ≤ 3), II—weak neonates (moderate distress, AS 4–6) and III—healthy neonates (no distress, AS ≥ 7). The following parameters were evaluated: pH (pH units), carbon dioxide partial pressure (pCO₂; mmHg), oxygen partial pressure (pO₂; mmHg), actual bicarbonate (cHCO₃⁻; mmol/L), total carbon dioxide (cTCO₂; mmol/L), base excess of extracellular fluid (BE(ecf); mmol/L), base excess of blood (BE(b); mmol/L), oxygen saturation (csO₂; %), lactate (Lac; mg/dL), hematocrit (Hct; %PCV), hemoglobin (cHgb; g/dL), glucose (Glu; mg/dL), ions (Na, K, Ca, Cl). The majority of puppies had low AS at birth (AS 4–6 in 38.1% and AS ≤ 3 in 57.1% of the neonates), but most of them (85.7%) improved by the 20th min. reaching AS of 7 and more. Moreover, puppies with lower AS (≤ 3) were at higher risk of death within the first 24h (20.8% did not survive). The positive correlation was found between Apgar score measured at 0 min and pH (r = 0.46, p = 0.01), and between Apgar score (at 0 min) and base excess in whole blood measured [BE(b)] r = 0.36, p = 0.03). Whereas, a negative correlation was detected between Apgar score at 0 and 5th min and glycemia (r = −0.42, p = 0.05, r = −0.34, p = 0.02 respectively. Overall, the puppies with higher glucose levels had lower Apgar scores and were at higher risk of death. Furthermore, in our study, the newborn puppies had mild acidemia with elevated pCO₂ levels and the HCO₃ at the lower range of normal limits, suggesting the mixed component in the acidemic state. Adaptation to extra-uterine life is crucial and any practical improvement in neonatal diagnostics and care would be beneficial for newborn puppy survival.