Neonatal puppy survival after planned caesarean section in the bitch using aglepristone as a primer: A retrospective study on 74 cases

Canine Amniotic Fluid at Birth Holds Information about Neonatal Antibody Titres against Core Vaccine Viruses

There is a growing interest in the composition of amniotic fluid (AF) in both humans and animals. In addition to its nutritional and protective functions for the foetus, current knowledge demonstrates that AF also serves advanced diagnostic, prognostic, and therapeutic roles. Newborn dogs have an underdeveloped immune system, making them highly susceptible to dangerous pathogens such as canine parvovirus (CPV-2), canine infectious hepatitis virus (CAdV-1), and canine distemper virus (CDV), thus exposing them to a high risk of mortality in the first weeks of life. Immunoglobulins G (IgGs) represent the only antibody isotype capable of crossing the placenta in a small amount and have been detected also in canine AF. The primary aim of this study was to investigate the reliability of AF collected at birth as a marker of passive immunity in canine species. For this purpose, total and specific IgGs against CPV-2, CAdV-1, and CDV were investigated and quantified in both maternal plasma and AF collected at the time of caesarean section. The vaccination status of the bitches was also taken into consideration. Since the immune system can be influenced by gestational age, with preterm infants having immature innate and adaptive immunity, IgG concentrations were correlated with amniotic lecithin, sphingomyelin, cortisol, surfactant protein A, and pentraxin 3 levels. In a previous study from our group on foetal maturity these molecules were measured in the same samples. Finally, correlations between their amniotic content and neonatal outcomes were investigated. This study demonstrates that AF analysis at birth can provide valuable insights into neonatal immunity in puppies, offering a non-invasive method to detect potential early health risks, for improved puppy care and management.

Assessment of Vcheck® analyzer for rapid progesterone concentration measurement including recommendations for achieving the optimal breeding time in bitches

Background and Aim

Serum progesterone concentration plays critical role in determining the optimal breeding time in bitches and diagnosing reproductive-related issues. This study aimed to conduct a comparative analysis of serum progesterone results obtained from commercial point-of-care immunological analyzers, namely, Vcheck®, with those obtained using chemiluminescent microparticle immunoassay (CMIA). Our overarching goal was to evaluate these analyzers' accuracy and establish standardized guidelines for optimal breeding timing.

Materials and Methods

Ninety-four serum samples from bitches were analyzed using the Vcheck® analyzer and compared with CMIA. Thorough documentation included the mean, standard deviation, 95% confidence interval (CI), and minimum and maximum values of serum progesterone concentrations. Furthermore, Pearson's correlation coefficient, Lin's concordance correlation coefficient, and the bias correction factor were meticulously recorded.

Results

The mean progesterone concentration measured using the Vcheck® analyzer was significantly lower than that measured using CMIA, with a mean difference of 1.26 ng/mL of serum. The Bias correction factor was 0.935, which was nearly 1.00, indicating that the line of best-fit was on the perfect line of agreement, providing insight into the measurement accuracy. Pearson's correlation coefficient, a measure of precision, was also close to 1 (0.939), confirming the reliability of the data. Furthermore, Lin's concordance correlation coefficient was 0.877, indicating a fair overall agreement between the Vcheck® and CMIA methods. These results support the validity of the Vcheck® analyzer's results. The present study was developed by aligning with established CMIA guidelines and adapting them using the range and 95% CI derived from each set of results, ensuring a standardized and rigorous approach.

Conclusion

The Vcheck® analyzer provides a rapid assessment of serum progesterone concentration in bitches, with results comparable to those measured using the CMIA technique. However, when considering the use of the Vcheck® analyzer, it is recommended that the results should be interpreted carefully and the interpretation guidelines should be followed. In conclusion, Vcheck® provides a reliable and convenient method for veterinarian practitioners to measure canine progesterone levels in a clinical/hospital setting.

A Precision Assessment of a Point-of-Care Immunological Analyzer for Swift Progesterone Measurement and Guidance for Determining the Optimal Breeding Time in Bitches

The measurement of serum progesterone often varies due to different laboratory methodologies and individual canine characteristics. In this investigation, serum progesterone outcomes obtained from a commercial point-of-care immunological analyzer, designed for efficient serum progesterone assessment in bitches, were compared with results derived from chemiluminescent microparticle immunoassay from reference laboratories in Thailand. Our thorough documentation encompassed various parameters: mean, standard deviation, 95% confidence interval, and minimum and maximum serum progesterone concentration values. Additionally, we meticulously recorded the Pearson's correlation coefficient, Lin's concordance correlation coefficient, and the bias correction factor. Interestingly, there was no significant difference (p > 0.05) in the means obtained by the point-of-care immunological analyzer and chemiluminescent microparticle immunoassay. The Pearson's correlation coefficient between the point-of-care immunological analyzer and chemiluminescent microparticle immunoassay stood at 0.957, with Lin's concordance correlation coefficient for point-of-care immunological analyzer recorded as 0.949. Furthermore, the bias correction factor was established at 0.991. This investigation followed established chemiluminescent microparticle immunoassay guidelines, modified to incorporate the mean and 95% confidence interval as criteria for optimal breeding time using the point-of-care immunological analyzer. In conclusion, the commercial point-of-care immunological analyzer emerges as a valuable tool, aiding in precisely determining the optimal timing for natural mating or artificial insemination in bitches.

Canine Neonatal Health

This article provides a high-level overview of canine neonatal health for clinicians to use as a mental framework so that when presented with a canine neonate it is easier to construct a logical and systematic clinical approach that is less overwhelming. As early detection of the at-risk neonate results in earlier intervention, and improved health outcomes, there will be a focus on pro-active care. Where appropriate, other articles in this issue will be mentioned for a more in-depth discussion of specific areas. Key points will be highlighted throughout the text.

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.

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.

Ultrasonographic changes in fetal gastrointestinal motility during the last ten days before parturition in dogs

Fetal gastrointestinal motility (FGM) was suggested as useful to assess fetal maturity. Our study aimed to quantify FGM in relation to days before parturition (DBP), maternal size, and sex ratio of pups. During the last ten days of pregnancy, 23 clinically healthy pregnant bitches of 16 different breeds ranging in age from 2 to 9 years and body weight from 3.5 to 56.8 kg were monitored twice. The fetal intestine was observed in longitudinal and transversal scan on 3 of the most caudal fetuses in both uterine horns. Gestational age was counted backward from parturition day. The number of fetuses showing FGM was recorded in time in I (-11/-5 DBP) and II (-4/0 DBP). A Mann-Whitney test was performed to analyze variations of FGM% in relation to time and parity. A Kruskal-Wallis test was performed to identify variations of FGM% in relation to maternal size and sex ratio. Statistical significance was set at α = 0.05. A total of 147 FGM observations on 50 ultrasonographic monitoring points were performed. The FGM% was higher during time II compared to time I (median: 33%, range 0-100% vs. 100%, range 33-100%; P < 0.0001). FGM% was higher in small compared to large size bitches (median: 100%, range 67-100% vs. 67%, range 0-100%; P = 0.01). FGM% was not affected by parity and sex ratio. As previously reported, a significant increase in FGM% was observed in the last five DBP. FGM observation may be influenced by the maternal size, with easier evaluation in small size bitches, as well as ultrasound equipment and positioning.

Risk factors for neonatal mortality prior to hospital discharge in brachycephalic and nonbrachycephalic dogs undergoing cesarean section

OBJECTIVES

To compare neonatal survival to discharge rates between brachycephalic and nonbrachycephalic dogs undergoing cesarean section (c-section) and identify risk factors for neonatal mortality.

STUDY DESIGN

Retrospective study.

ANIMALS OR SAMPLE POPULATION

A total of 480 puppies from 90 bitches undergoing 106 c-sections.

METHODS

Medical records of c-sections performed between January 2012 and September 2021 were reviewed. Data collected included brachycephalic versus nonbrachycephalic breed, elective versus emergency c-section, litter size (c-section and total [including those born prior to and via c-section]), and neonatal survival to discharge. A generalized linear mixed model (univariable and multivariable) was performed to evaluate variables versus neonatal survival.

RESULTS

Overall neonatal survival to discharge was 93.1% (447/480); survival was similar between brachycephalic and nonbrachycephalic breeds (p = .221, 202/213 [94.8%] brachycephalic survival, 245/267 [91.8%] nonbrachycephalic survival). Puppies delivered via elective c-section were more likely to survive compared to emergency c-section (p < .001, 238/240 [99.2%] elective survival, 209/240 [87.1%] emergency survival). Puppies delivered in larger c-section litters were more likely to survive (p < .004) compared to smaller litters. Total litter size had no effect on survival.

CONCLUSION

Brachycephalism had no effect on neonatal survival. Puppies delivered via elective c-section were more likely to survive compared to puppies delivered via emergency c-section.

CLINICAL SIGNIFICANCE

Outcomes following c-section are similar between brachycephalic and nonbrachycephalic breeds. While it is preferable to encourage selective breeding for bitches that are able to whelp naturally, elective c-section should be considered in bitches at high risk for dystocia to maximize neonatal survival.

Parameters in Canines After Cesarean Sections

This study evaluated fertility in canines after cesarean section and compared it with natural parturition. Parameters, such as the time of the next heat after the first parturition or cesarean section, the heat which was used for another breeding attempt, whether it was successful, the number of puppies that were born, and the necessity of another cesarean section were examined. The study relied on questioning patient owners at a University clinic. A Google online form was also used. Information for 261 dogs from different breed groups was included, of which 119 bitches were in the cesarean section group, and 142 were in the natural parturition group. In total, 93 ± 2.7% [LSMeans ± standard error (SE)] and 91.12 ± 3% (LSMeans ± SE) of the bitches became pregnant after cesarean section and natural parturition at the first breeding attempt. There was no significant effect on the breed group or whether the bitch had undergone a cesarean section before (p = 0.8 and p = 0.63). Bitches, which underwent a cesarean section, were more likely to have further cesarean sections performed (p < 0.001). However, neither the breed groups (p = 0.17), whether the bitch had undergone a cesarean section (p = 0.59), nor the number of previous parities had any effect on the number of puppies born (p = 0.95). The breed group bulldogs had a high proportion of cesarean sections. Only 42.11% of the bulldogs had a natural parturition as the first included parturition and only 31% gave birth naturally thereafter.

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.

Verifying the placement and length of feeding tubes in canine and feline neonates

Background

Tube feeding is a common procedure in neonatology. In humans, tube misplacement reportedly occurs in up to 59% of all cases and may lead to perforation in 1.1% of preterm intubated neonates. While numerous studies on optimal tube placement have been performed in human neonates, current recommendations on tube feeding in canine and feline neonatology are based, at best, on studies performed in adult animals. Herein, we aimed to test ultrasonography as a tool to verify tube placement in puppies and kittens and to compare different anatomical predictive markers used in human, canine and feline neonates.

Results

The predictive tube length when held bent between the last rib and the mouth may induce trauma compared to when held straight. A strong positive linear correlation was observed between birthweight and gastric cardia localization. Ultrasonography findings were similar to coeliotomy findings. Stomach volume was less than 2 mL per 100 g in the less-than-one-day-old studied puppies (n = 25) and kittens (n = 28).

Conclusions

A weight-based equation was calculated to help predict appropriate tube placement. Ultrasonography can be used to control gastric tube placement, and neonates less than one-day-old have a smaller stomach capacity. Further studies are required to evaluate whether more-than-one-day-old puppies follow the same linear correlation with their weight. Further in vivo studies are warranted to determine the gold standard procedure for tube feeding in neonatal puppies and kittens.

Evaluation of surface plasmon field-enhanced fluorescence spectroscopy for rapid measurement of progesterone concentration in bitches

OBJECTIVE

To compare progesterone (P4) concentrations measured with surface plasmon field-enhanced fluorescence spectroscopy (SPFS) and chemiluminescence immunoassay (CLIA) in serum and plasma samples of client-owned bitches of various ages and breeds and to determine reference ranges for P4 concentrations at various stages of the estrous cycle.

SAMPLES

102 serum samples and 104 plasma samples.

PROCEDURES

In experiment 1, 1 aliquot each of serum and plasma was analyzed for P4 concentration by use of SPFS incorporated in a veterinary-specific point-of-care immunologic analyzer and CLIA. In experiment 2, serum collected from bitches in various stages of the estrous cycle was analyzed for P4 concentration by use of SPFS to establish reference ranges for each stage.

RESULTS

In experiment 1, P4 concentrations measured by SPFS and CLIA were highly correlated (serum, r = 0.966; plasma, r = 0.968). In experiment 2, ranges of serum basal (proestrous) P4 concentrations (n = 114) and P4 concentrations at the estimated time of ovulation (76), during pregnancy or diestrus (107), and during the prepartum period (50) measured with SPFS were 0.42 to 1.46 ng/mL, 3.69 to 7.85 ng/mL, 11.73 to 28.24 ng/mL, and 1.54 to 3.22 ng/mL, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

Because serum and plasma P4 concentrations measured with SPFS were highly correlated with those measured with CLIA and ranges of serum P4 concentrations measured with SPFS for each of phase of the estrous cycle were well-defined for the large sample size, veterinarians may be able to accurately use this veterinary-specific point-of-care immunologic analyzer with SPFS methodology to determine P4 concentrations of bitches in their daily practice.

Progesterone receptor blockers: historical perspective, mode of function and insights into clinical and scientific applications

Antigestagens (antiprogestins) are functional competitors of progesterone (P4) that prevent P4 from mediating its biological functions either by suppressing its production or blocking its function. Among the latter are progesterone antagonists, competitors of P4 binding to its nuclear receptor PGR, which have found application in both human and veterinary medicine, in particular in small animal practice for the prevention of nidation and the interruption of pregnancy. Depending on their mode of action, progesterone receptor antagonists can be divided into 2 classes. Class I antagonists bind to the PGR but fail to induce its binding to promoters of target genes (competitive inhibitors). Class II antigestagens, including aglepristone used in veterinary medicine, bind to the PGR, activate its association with a promoter, but interfere with the downstream signalling cascades, e. g., by recruiting transcriptional repressors. They act thereby as transdominant repressors exerting negative effects on target gene expression. Importantly for experimental sciences, as active antagonists, class II antagonists do not require the presence of the natural ligand for their action. Besides their clinical application, antigestagens are used in research for investigating P4-dependent physiological and pathological processes. Here an overview of the history and the current usage of progesterone receptor antagonists in veterinary medicine and research is presented.

Dystocia after Unwanted Mating as One of the Risk Factors in Non-Spayed Bitches-A Retrospective Study

Simple Summary

This is an article presenting the clinical data on the incidence of difficult labour in dogs being mated without owners’ intentions (accidental mating, unplanned breeding). Despite the widespread availability of spaying and its safety, unplanned and unwanted pregnancies in dogs are still a frequent concern. Unfortunately, in 8.3% (76/914) of cases, they result in difficult labour and deadly complications for the dam and her litter. Better owners’ education about the importance of neutering their pets and understanding of the benefits of early spaying by animal shelter managements and by breeders selling pets might improve the situation in the future. On the other hand, in such cases, it seems to be justified to advise the termination of pregnancy through spaying or the use of abortifacient drugs, despite the ethical concerns, because waiting for natural delivery could cause unnecessary suffering both to the bitch and her unborn puppies.

Abstract

This article presents a retrospective study on dystocia cases in bitches that were unintentionally mated and carried an unwanted pregnancy in the last 39 years. The evaluated medical records include 76 cases of difficult labour, which is 8.3% of 914 dystocia cases recorded during the period. Of these bitches, 38.2% (29/76) were 8 years, and 18.4% (14/76) were younger than 12 months. In 67/76 cases (88.2%), conservative (pharmacological and manual) obstetrical assistance proved to be unsuccessful, and caesarian section (CS) had to be performed, in contrast to the remaining recorded cases of dystocia (in which the pregnancy was intended and expected) when CS was performed significantly less often, in 71.5% (599/838) of cases. In unplanned pregnancies, 46.6% (110/236) of delivered pups were dead compared to only 26.4% (864/3273) dead pups in planned pregnancies. p value < 0.05 was considered significant. Despite the widespread availability of the spaying procedure nowadays and its safety, unplanned and unwanted pregnancies in dogs are still a concern in clinical practice. However, throughout the years investigated here, we observed an apparent decrease in the occurrence of dystocia after unintended mating, with much less recorded cases from year 2004 (71 vs. 5). Most probably, this is due to the increasing popularity of surgical castration in both females and males, and rising societal awareness of its importance, giving hope that some improvement in the welfare of dogs has already been achieved.

Triplex doppler ultrasonography to describe the uterine arteries during diestrus and progesterone profile in pregnant and non-pregnant bitches of different sizes

Hemodynamics of uterine vascularization is modified throughout pregnancy to meet the increasing demand of the growing fetuses and triplex doppler ultrasonography is widely used in human medicine to study the uterine arteries and assess the fetal and placental conditions. The aim of our study was to confirm this observation in the bitch, to evaluate differences between bitches of different sizes and to study abnormal pregnancies. Forty-four bitches were monitored during the estrous period to determine ovulation and every 10 days from ovulation to 50 days post-ovulation: the resistivity (RI) and pulsatility (PI) indexes of the right uterine artery were measured as well as usual assessment of fetal development and follow up of the luteal function. Thirty-three out of forty-four bitches were pregnant, including 6 abnormal pregnancies (resorption of more than 10% of the embryos). We also divided them in four weight categories: 8 were small (<10 kg), 13 medium (10-25 kg), 13 large (>25-40 kg) and 10 were giant breeds (>40 kg). We observed that RI and PI decreased over time and were significantly lower for pregnant bitches compared to non-pregnant ones from 30 days post-ovulation. In contrast, RI and PI did not significantly vary with the size of the bitches and we could not determine a significant impact of abnormal pregnancies either. In conclusion, we found no significant difference related to the size of bitches in the RI and PI. The only significant difference between pregnant and non-pregnant bitches was observed from 30 days post-ovulation.