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

Neonatal Clinical Assessment of the Puppy and Kitten: How to Identify Newborns at Risk?

Neonatal puppies and kittens have physiological and anatomical characteristics that differ from those of adult animals, which impacts the interpretation of physical examination and complementary tests. The veterinarian must be familiar with the clinical, laboratory, and imaging aspects observed in neonates. It is necessary to thoroughly evaluate the litter and the mother to notice the most subtle signs of illness and advise the owner to constantly monitor the newborns, quickly sending them to specialized care. This review describes how to perform clinical assessments of newborns systematically and recognize clinical signs of neonatal changes or affections in puppies and kittens.

Neonatal hypoglycemia in dogs-pathophysiology, risk factors, diagnosis and treatment

Hypoglycemia is the most common metabolic alteration in the clinical routine of newborn dogs, acting as a predictor of mortality in these patients. The neonatal dog shows hepatic insufficiency and homeostatic mechanisms not yet fully developed, with limited glycogen reserves and limited capacity to perform glycogenolysis and gluconeogenesis. These physiological particularities make newborn dogs particularly susceptible to hypoglycemia when of fasting, even for short periods. Several maternal and neonatal factors may be related to a higher risk of developing hypoglycemia in neonates. This paper reviews glycemic homeostasis, the pathophysiology of neonatal hypoglycemia, the main causes involved and the diagnostic and therapeutic approaches to this condition.

Maternal and neonatal cortisol and catecholamines throughout vaginal eutocia and C-section in dogs

Increased fetal cortisol is associated with catecholamine release, a primary factor for neonatal adaptive responses. However, relationship between canine peripartum cortisol and catecholamine is unknown. We aimed to compare serum adrenaline, noradrenaline and cortisol during peripartum in bitches and neonates of distinct obstetric conditions and to assess amniotic fluid cortisol concentration. Twenty females and maximum of three puppies per litter were allocated into Vaginal Eutocia (10 females; 17 neonates) and Elective C-section (10 females; 20 neonates) groups. Amniotic fluid was collected at delivery for cortisol concentration. Maternal and neonatal blood were collected prepartum, intrapartum, postpartum and 1h postpartum, and at birth, 30 and 60min, 12hs and 24hs, respectively, for cortisol, adrenaline and noradrenaline assessment. C-section determined higher noradrenaline throughout delivery and cortisol concentration from intrapartum through 1h postpartum, compared to vaginal birth. C-section maternal cortisol showed progressive increase from intrapartum onwards, while neonatal cortisol remained unchanged. No difference of maternal cortisol concentration occurred along whelping, whereas a significant decrease was verified for vaginal delivery puppies from birth until the 12hs. Puppies delivered vaginally had higher cortisol concentration at birth and 30min, compared to c-section puppies. There was a higher concentration of amniotic fluid cortisol in vaginal eutocia. In conclusion, c-section induces higher maternal stress during and after surgery, whilst vaginal delivery is a more neonatal physiologically stressful condition, contributing to better adaptation during transition.

Apgar scores in puppies following the induction of etomidate compared with alfaxalone or propofol for cesarean section

Background and Aim

The Apgar score is a useful assessment of neonatal viability in dogs. The Apgar score in puppies born by cesarean section can be lower than vaginal delivery because all anesthetic drugs can cross the placenta. Therefore, anesthetic drugs with minimal cardiorespiratory effect and rapid elimination are recommended for cesarean section. The present study aimed to compare Apgar scores in puppies born after the induction of etomidate, alfaxalone or propofol, and those maintained with isoflurane inhalation during cesarean section.

Materials and Methods

Thirty-six bitches were equally divided in the three anesthetic drug groups. Modified Apgar scores were assessed at 5, 15, and 60 min after delivery. Intraoperative vital signs and Apgar scores were compared using a linear mixed model and adjusted pairwise comparisons using Bonferroni analysis.

Results

A total of 125 puppies were included in this study. Age, body weight, litter size, type of surgery, delivery time, anesthetic and surgical duration, and intraoperative vital signs did not significantly differ between the groups. Puppies in the alfaxalone and propofol groups had significantly higher Apgar scores than the etomidate group in both elective and emergency surgery. In elective surgery, Apgar scores at 5 min after delivery did not differ significantly between groups. At 15 and 60 min after delivery, Apgar scores in the etomidate group were significantly lower than those in the other groups. In emergency surgery, Apgar scores were significantly lower in the etomidate group than in the alfaxalone group at all time points.

Conclusion

Induction with alfaxalone and propofol resulted in better outcomes with higher Apgar scores and neonatal viability than etomidate. Therefore, alfaxalone and propofol should be used as anesthetic induction drugs in both elective and emergency cesarean sections.

Apgar Score for Newborn Dog Viability Assessment: Differences between English and French Bulldogs Born via Cesarean Section

Even if largely used in canine neonatology, some questions about the Apgar Score (AS) arose. Notably, considering the breed-oriented modifications of the score are needed, slight changes of the score were reported for English (EBs) and French bulldogs (FBs). The present study aimed to evaluate the possible differences between neonatal viability of the two breeds assessed by AS in puppies born via cesarean section. The results obtained from 99 puppies born alive and without malformations (EB = 47, FB = 52) showed significant (p < 0.001) differences in the median AS (seven in EB vs. eight in FB), with Grimace (p < 0.05 for sub-score 0 and p < 0.001 for sub-score 2) and Attitude (p < 0.05) being differently sub-scored between the two breeds. In the 89 alive puppies at 7 days of age, the same difference in the median AS was observed (p < 0.001), and only Grimace was differently sub-scored between the two breeds (p < 0.05 for sub-score 0 and p < 0.01 for sub-score 2). These results suggest that low Grimace could be an intrinsic characteristic of EB newborns, but it could negatively affect the neonatal adaptation process of EBs, providing an indication for focused neonatal assistance. Neonatal mortality at 7 days of age was higher in EBs than in FBs (17 vs. 3.8%, respectively), which deserves further investigations. The study provides further evidence that breed-oriented ASs are needed for a better evaluation and assistance of purebred puppies at birth.

Hypoglycaemia management with a hypercaloric supplementation in neonatal puppies delivered by caesarean section

There is a high perinatal mortality rate in dogs, estimated at 20%, and one of the leading causes of this rate is hypoglycaemia. Therefore, we aimed to evaluate the efficacy of a hypercaloric supplement containing vitamins and amino acids in newborn puppies presenting hypoglycaemia at birth. Ninety-nine pups were divided into four groups: normoglycaemic caesarean section (NORMOCS), hypoglycaemic caesarean section supplemented with the hypercaloric (SUPLCS), hypoglycaemic caesarean section supplemented with glucose (GLICCS) and eutocic delivery (EUT). We evaluated the following parameters glycaemia, Apgar score, neurological reflexes and rectal temperature of neonates at the following moments 5 min (M5), 30 min (M30) and 60 min (M60) after birth. Brachycephalic dogs were 73.3% (22/30) of caesarean sections (c-sections). The puppy's average glycaemia represented about 90% of the maternal glycaemia, while 15.1% (14/99) of the neonates had hypoglycaemia (<90 mg/dL) at M0 and 46.5% (44/99) at M60. Only four neonates had glycaemia below 40 mg/dL at M30 but without showing any clinical signs. The puppy's fasting while waiting for the intraoperative period and the dam's anaesthetic recovery was considered risk factors for hypoglycaemia. There was no difference in mean blood glucose levels or vitality parameters among puppies from the SUPLCS and GLICCS. In conclusion, the hypercaloric supplement can be used as a replacement for glucose in hypoglycaemic puppies and it can also bring nutritional benefits for the puppy. The prepartum glycaemia of the dam is an important parameter to be measured, and the appropriate management of it reduces the chances of the puppies being born with hypoglycaemia.

Assessment of Vitality, Blood Profile, and Degree of Meconium Staining on the Skin in Newborn Dogs According to Its Birth Weight

Neonatal mortality in dogs reaches up to 40%. Due to the high rates, promptly detecting the causes and preventing newborns from dying are extremely important. Vitality evaluation, blood parameters, and the degree of meconium staining on the skin are valuable resources in canine perinatology. In this study, 435 puppies from 85 bitches close to parturition were recruited and divided into four quartiles according to the puppy's birth weight: Q₁ (127-200 g) n = 110 puppies, Q₂ (201-269 g) n = 108 puppies, Q₃ (270-388 g) n = 108 puppies, and Q₄ (389-464 g) n = 109 puppies. This experimental article aimed to report the effect of birth weight on the blood profile variables, the vitality of newborn puppies, and the meconium staining degree, integrating these three aspects. It was concluded that the weight of newborns was correlated with the degree of meconium staining, presenting more cases of severe meconium staining in the puppies of the highest birth weight group. The weight of the newborns was correlated with a higher number of stillbirths and alterations in the blood variables, showing the most severe cases of metabolic acidosis, hypoxia, and hypoglycemia in the puppies of the Q₄ quartile. On the contrary, no statistically significant correlations were found between the weight of newborns and vitality. Nevertheless, the analysis of the results showed that the most vigorous puppies were found at Q_1; however, at minute 60 after birth (AB), all the puppies in the four quartiles standardized their vitality scores.

Canine Pregnancy, Eutocia, and Dystocia

Veterinary care of breeding dogs begins before a breeding takes place, during prebreeding consultations, through matings, gestation, and delivery of newborns.

Canine Cesarean Section: Emergency and Elective

Canine Cesarean Section (CS) is primarily performed to increase survival of newborns and less commonly to save the life or reproductive future of the dam. Conducting proper ovulation timing to accurately predict the due date will allow a planned, elective CS as an excellent alternative to a high-risk natural whelping, and possible dystocia, for certain breeds and situations. Techniques for ovulation timing, anesthesia, and surgery tips are provided.

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.

Canine amniotic fluid at birth: From a discarded sample to a potential diagnostic of neonatal maturity

The definition of new reliable markers for neonatal maturity evaluation is crucial in canine clinical practice. Concerns about the safety of amniotic sampling in pregnant dogs have prevented its collection for diagnostic purposes. Moreover, amniotic fluid had been considered waste material until the latest studies reported amniocentesis as a reliable and safe procedure, even in the canine species. In our study, amniotic fluid (n = 63) collected at birth from ten dogs undergoing elective Caesarean sections at term was analysed to discover new potential indices of canine neonatal maturity. Based on gestational age, mothers and puppies were divided into two groups: the early group (≤65 days from luteinizing hormone (LH) surge, n = 5) and the late group (>65 days from LH surge, n = 5). Amniotic parameters of the lightest and heaviest puppy in individual/each litter, with a birth weight difference of at least 20% among littermates, were also compared. In particular, the content of lecithin, sphingomyelin, surfactant protein A (SP-A), cortisol, and pentraxin 3 (PTX3) in amniotic fluid, which is considered predictive of foetal development in humans, were investigated. Maternal serum SP-A and cortisol were also measured simultaneously. All amniotic parameters were detectable in canine amniotic fluid. Interestingly, the concentrations of different amniotic parameters correlated with each other. Lecithin was positively correlated with sphingomyelin (p < 0.0001), maternal SP-A (p < 0.0005), and the ratio of amniotic and maternal cortisol (p < 0.004). Amniotic SP-A was inversely correlated to maternal SP-A (p < 0.05), lecithin (p < 0.005), and lecithin-sphingomyelin ratio (p < 0.05). A positive correlation was also recorded between amniotic and maternal cortisol (p < 0.008). Considering that all puppies were born alive and mature, these data could provide a potential range of expected amniotic values in full-term new-born dogs. Furthermore, since gestational age was positively correlated with both maternal and amniotic cortisol (p < 0.0001) and amniotic PTX3 (p < 0.05), amniotic fluid seems to be an attractive, innovative, and minimally invasive matrix with potential diagnostic and prognostic utility for the investigation of canine maturity.

Is the Weight of the Newborn Puppy Related to Its Thermal Balance?

Hypothermia, a factor associated with neonatal mortality, can occur immediately after birth as a protective mechanism to prevent hypoxic damage in neonates, or to reduce the metabolic rate to improve the chances of survival in the first hours of life. The heat interchange through the superficial temperature of animals can be evaluated with infrared thermography (IRT). However, to date, there is no information on thermal windows in puppies. This study aimed to evaluate, with the use of IRT, the microcirculatory alterations in 8 different thermal windows identified at 7 different times in 289 newborn puppies assigned to different groups. Three thermograms were taken from four zones of each puppy: the facial, frontal, right lateral, and left lateral regions. Newborn puppies were grouped in 4 quartiles according to their weight: Q1 (126−226 g) n = 73, Q2 (227−330 g) n = 72, Q3 (331−387 g) n = 74, and Q4 (388−452 g) n = 70. A total of 8 thermal windows were considered at 7 evaluation times from Wet at birth until 24 h after birth (AB). Two-way mixed ANOVA within and between subjects’ design for each thermal window (eight models) was performed. Results revealed a positive correlation between the puppy’s weight and its ability to achieve thermostability in all the evaluated thermal windows. Statistically significant differences (p < 0.0001) between the 4 quartiles (Q1, Q2, Q3, and Q4) were found. The lowest temperatures were recorded when the pups were still wet and the highest at 24 h AB. Thermal windows with the highest temperatures were abdominal (34.234 ± 0.056 °C), thoracic (33.705 ± 0.049 °C), nasal (30.671 ± 0.110 °C), and upper left palpebral (34.066 ± 0.052 °C), while the lowest were thoracic limb brachial biceps (27.534 ± 0.051 °C), thoracic limb elbow (27.141 ± 0.049 °C), thoracic limb metacarpal (27.024 ± 0.062 °C), and femoral pelvic limb (27.654 ± 0.055 °C). Assessing the thermal response in newborn puppies can help identify drastic temperature reductions or deficient thermoregulatory compensation during the first hours of life, preventing the consequences of hypothermia.

Early Blood Analysis and Gas Exchange Monitoring in the Canine Neonate: Effect of Dam’s Size and Birth Order

Simple Summary

The complications that are observed during parturition are events that affect the vitality of the newborn and can also compromise their health by predisposing them to fetal hypoxia, increasing newborn mortality. Blood gas analysis to measure the main biomarkers associated with hypoxia evaluates the physiological and metabolic alterations derived from this state, and these could help identify if said markers respond to maternal or neonatal causes. This study aimed to assess the effect of the dam’s size, the birth order, and the presentation of blood gas alterations. Recognizing if these elements are intertwined may enhance newborns’ life expectancy by enabling the planning of a perinatal protocol to avoid serious metabolic consequences that are derived from prolonged hypoxia.

Abstract

In canines, size at birth is determined by the dam’s weight, which would probably affect the newborn’s viability due to litter size and birth order. Fetal hypoxia causes distress and acidemia. Identifying physiological blood alterations in the puppy during the first minute of life through the blood gas exchange of the umbilical cord could determine the puppy’s risk of suffering asphyxiation during labor. This study aimed to evaluate the effect of the birth order and dam’s size during spontaneous labor and the alterations during the first minute of life. The results indicate that the dam’s size and the birth order have considerable physiological and metabolic effects in the puppies, mainly in birth order 1 (BO1) in small-size dogs, while in the medium size, the last puppy presented more alterations, probably because of a prolonged whelping which could have fostered hypoxic processes and death. Likewise, with large-size dogs, intrapartum asphyxiation processes were registered during the first minute of life in any birth order.