Immunoglobulins G and lysozyme concentrations in canine fetal fluids at term of pregnancy

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.

Characterization and expression patterns of lysozymes reveal potential immune functions during male pregnancy of seahorse

Seahorses are one of the most amazing ovoviviparous fishes in the ocean because males, and not females, have evolved a brood pouch for incubating embryos. During male pregnancy, paternal seahorses need to develop effective immune protection for embryos in the brood pouch from potential infection by pathogens. Lysozymes (Lyz) are a group of antibacterial enzymes of the innate immune system that play an important role in resisting pathogen invasion. However, the immune function of lysozymes in the brood pouch of the pregnancy-lined seahorse (Hippocampus erectus) remains unknown. In this study, we found three different lysozymes in the lined seahorse: HeLyzC, HeLyzG1, and HeLyzG2. Synteny analysis revealed that HeLyzG1 and HeLyzG2 were generated by species-specific expansion rather than tandem duplication. Tissue expression patterns showed that the highest mRNA expression levels of the three lysozymes occurred in the brood pouches. Immunostimulation-induced expression analysis showed that all three HeLyzs in the brood pouches up-regulated their mRNA expression levels after Vibrio parahaemolyticus infection, but only the HeLyzG2 was upregulated after Poly(I:C) injection. Similarly, except for HeLyzC, upregulated expressions of HeLyzG1 and HeLyzG2 were found quickly in brood pouches injected with LPS. The upregulated levels of HeLyzC and HeLyzG2 in brood pouches during pregnancy were significantly higher than those in non-pregnancy, implying that seahorse lysozymes might function in the immune defense in brood pouches during pregnancy. In addition, the expression levels of HeLyzs were low in embryos in the brood pouch but significantly increased in neonates. This implies that embryos in the brood pouch might not necessarily express more lysozymes by themselves due to paternal immune protection. In conclusion, our study demonstrated that HeLyzs play an important role in immune protection during male seahorse gestation, and the synergistic effect of multiple HeLyzs may contribute to improved neonatal survival.

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.

Clinical Trial on the Usefulness of On-Site Evaluation of Canine Fetal Fluids by Reagent Test Strip in Puppies at Elective Caesarean Section

Simple Summary

In veterinary medicine, the availability of an easy tool for the immediate evaluation of biological fluids’ composition on site is desirable and beneficial as a first-line diagnostic instrument in many instances and in several animal species. The aim of the present study was to assess the usefulness of reagent urinary test strips marketed for urines for the on-field evaluation of fetal fluids’ composition in newborn dogs at elective caesarean section. From surviving newborns, a collection of 113 amniotic and 107 allantoic samples was performed, and 8 amniotic and allantoic fluids were collected from non-surviving newborns. All the fetal fluids were assessed by urinary test strips within 5 min from collection. Significant differences were found for both types of fluid between surviving and non-surviving puppies, and between medium/large and small-sized puppies. Differences were also depicted between amniotic and allantoic fluids within the surviving group. These results seem to suggest that the on-site analysis of fetal fluids’ composition by reagent test strips could represent a first-line tool for the evaluation of puppies and for the quick identification of puppies requiring special monitoring and assistance.

Abstract

The reagent urinary test strips (TS) marketed for urines represent the first-line diagnostic tool in many instances. Therefore, the aim of the study was to assess the usefulness of TS for the on-field evaluation of fetal fluids’ composition in newborn dogs at elective caesarean section. Of a total of 137 puppies born at term, 127 survived and 10 did not survive. One hundred and thirteen amniotic and 107 allantoic samples from surviving newborns were collected, and 8 amniotic and allantoic fluids were collected from the non-surviving newborns and assessed by strips. Significantly lower amounts of amniotic glucose and higher amounts of amniotic and allantoic nitrites, amniotic protein, allantoic urobilinogen, and amniotic bilirubin concentrations were found in non-surviving when compared to surviving newborns. In the surviving ones, higher specific gravity and bilirubin concentrations, and lower pH, were found in allantoic than in amniotic fluids. Higher amniotic and allantoic glucose concentrations, higher amniotic and allantoic pH, and lower amniotic and allantoic protein concentrations were found in medium/large- than in small-sized puppies. The TS allowed the quick evaluation of fetal fluids in puppies at birth. The differences between surviving and non-surviving puppies seem to suggest that the on-site analysis of fetal fluids’ composition by TS could represent a first-line diagnostic tool in the field of canine neonatology, allowing the quick recognition of puppies needing assistance as a complementary tool for clinical evaluation.

How Stressful Is Maternity? Study about Cortisol and Dehydroepiandrosterone-Sulfate Coat and Claws Concentrations in Female Dogs from Mating to 60 Days Post-Partum

In dogs, the phase from mating to the end of weaning lasts about 120 days and encompasses many aspects that, interacting, contribute to increase the allostatic load. The coat and claws, useful for long-term change assessments, have the advantage of being collectable without invasiveness. In the present study, the Cortisol (C) and Dehydroepiandrosterone-sulfate (DHEA-S) concentration monthly changes in the coat and claws were studied in female dogs from mating to the end of weaning to assess Hypothalamic-Pituitary-Adrenal (HPA) axis activation during pregnancy and the post-partum period. The results from 15 Dobermann Pinscher female dogs showed a trend of increase of the coat C from mating to 60 days post-partum, with significant changes between mating and parturition-60 days post-partum (p < 0.01) and between the 30-day pregnancy diagnosis (PD) and 30-60 days post-partum (p < 0.05). The claws C trend showed significant increases between mating and 30-60 days post-partum (p < 0.05) and between the PD and 60 days post-partum (p < 0.01). DHEA-S in both matrices showed non-significant changes. The results suggest that maternity could play a pivotal role in the HPA axis activation, with a subsequent chronic secretion of C determining an increase in the allostatic load in the mothers. Neither maternal parity nor litter size played a significant role in the accumulation of C and DHEA-S in both matrices.

Effect of Delivery by Emergency or Elective Cesarean Section on Nitric Oxide Metabolites and Cortisol Amniotic Concentrations in at Term Normal Newborn Dogs: Preliminary Results

Simple Summary

The high perinatal mortality rates in dogs are partly attributable to stress at parturition, with the production of cortisol (C), and related to the type of delivery, that is elective or emergency cesarean sections (ELCS and EMCS). Nitric oxide metabolites (NOs) are also related to the type of parturition (ELCS or EMCS), because of the different emotional and physical stresses experienced by the bitch in these two scenarios. The study aimed to assess the concentrations of C and NOs in the amniotic fluid of puppies delivered by ELCS or EMCS. In the amniotic fluid of the 32 puppies delivered by ELCS, C, and NOs concentrations were significantly lower than those found in the amniotic fluid of the 22 puppies delivered by EMCS. Lower C concentrations were found at increasing newborn viability assessed by Apgar score. Higher amniotic NOs concentrations were associated to increasing mother’s parity, puppies’ birthweight, and time of labor within the EMCS group. Due to the possible concurrence of several compartments (maternal, maybe placental, and fetal) to the final amniotic fluid composition, the definition of the role played by the three compartments in the higher C and NOs concentrations found in amniotic fluids collected from puppies delivered by EMCS than ELCS needs further clarifications.

Abstract

The neonatal response to stress was reported to be related to the type of delivery, that is elective or emergency cesarean sections (ELCS and EMCS, respectively). Nitric oxide (NO) is also reported to be related to uterine inertia, and high levels of NO metabolites (NOs) are associated with physical and emotional stress. The study aimed to assess the concentrations of cortisol (C) and NOs in the amniotic fluid of puppies delivered by ELCS or EMCS. In total, 32 puppies were delivered by ELCS and 22 by EMCS. ANCOVA showed an effect of the ELCS vs. EMCS on both amniotic NOs (p < 0.001) and C (p < 0.001) concentrations. Lower amniotic C concentrations were found at increasing Apgar score (p < 0.001). Higher amniotic NOs concentrations were associated to increasing mother’s parity (p < 0.001), puppies’ birthweight (p < 0.001), and time of labor within the EMCS group (p < 0.05). A positive correlation between birthweight and amniotic NOs concentrations was also found (p < 0.05) in the EMCS group. Due to the possible concurrence of several compartments (maternal, maybe placental, and fetal) to the final amniotic fluid composition, the definition of the role played by the three compartments in the higher C and NOs concentrations found in amniotic fluids collected from puppies delivered by EMCS than ELCS needs further clarification.

Apgar score or birthweight in Chihuahua dogs born by elective Caesarean section: which is the best predictor of the survival at 24 h after birth?

Background

In the dog, the correct management of parturition and the prompt neonatal evaluation and assistance can reduce the perinatal mortality rates that are particularly high in toy breeds. Newborn evaluation and factors addressing prognosis are pivotal to guarantee the correct neonatal assistance. Assessment of the Apgar score with viability classification and birthweight are recognized as predictors for neonatal survival in dogs, but breed-specific data are needed for a more feasible application in the dog species, in which wide differences among breeds are known. The present study aimed therefore to: (a) assess the role of Apgar score and birthweight as predictors for the survival of Chihuahua newborn puppies in the first 24 h of life; (b) to assess a cut-off of the Apgar score and birthweight values that can predict the survival of Chihuahua newborn puppies in the first 24 h after birth; (c) to assess the possible effect played by maternal parity, newborn gender and litter-size on Apgar score in Chihuahua newborn puppies, in order to provide breed-specific data for a better neonatal assistance.

Results

Data obtained from 176 normal developed Chihuahua puppies born by elective Caesarean section, showed that 62%, 28% and 10% of puppies were classified in the Apgar score classes 7–10, 4–6 and 0–3, respectively, with survival at 24 h after birth of 97%, 96%, 39%, in the three Apgar classes of viability, respectively. Apgar score was a better predictor for survival at 24 h after birth than birthweight (AUC 0.93, P < 0.0001; AUC 0.69, P < 0.01, respectively). Litter-size of 7 puppies/litter plays a negative effect on Apgar score. Apgar score is a better predictor of survival at 24 h than birthweight, and the best cut-off of Apgar score for survival at 24 h after birth is 4, with 96% sensitivity and 77% specificity.

Conclusions

The different proportion of “normal viable” and “less viable” neonates in comparison to other studies highlights that Chihuahua puppies born by elective Caesarean section should be carefully evaluated at birth to provide correct assistance.

Effect of breed body-size on leptin amniotic fluid concentrations at term pregnancy in dogs

Because of the need to improve the knowledge about canine perinatology, and given the major role of fetal fluids in sustaining the course of pregnancy and fetal development, an in-depth analysis to better understand the role of some hormones in these compartments is essential. Among all, leptin is recognized to play a key role not only on the energetic homeostasis, but also at multiple levels, influencing the control of reproduction, food assumption and metabolism. Even if in humans and other species it is reported the presence of leptin receptors during fetal development, very little is known about the canine species, in which the role of leptin still needs to be fully understood. The present study aimed to assess the amniotic fluid leptin (AFL) concentrations at term pregnancy in healthy dogs, and to evaluate the possible influence played by breed body-size (after assessment of correlation with maternal bodyweight and placental weight), or other maternal (age, parity, and the so-called "litter effect") and neonatal (gender, birth weight, litter size) parameters on AFL concentrations, analyzed by ELISA test. The study was performed on 90 healthy, viable and normal weighted puppies, 39 small-sized (adult body weight < 10 kg) and 51 large-sized (adult body weight > 25 kg), born by 29 purebred, healthy bitches, submitted to elective Caesarean section because of breed-related or individual high risk for dystocia. The results showed that the mean AFL concentration in the small-sized puppies was significantly (p < 0.05) higher in comparison to large-sized puppies (867.48 vs 698.42 pg/ml), while all the other studied parameters did not show to influence AFL concentrations. In conclusions, the present study showed significant higher at term AFL concentrations in small-sized as compared to large-sized breeds, suggesting an influence of breed body-size on fetal metabolism, as previously reported for NEFA and IGF-I.

Pregnancy-associated immune-mediated hemolytic anemia in a dog

OBJECTIVE

To describe the clinical presentation, diagnostic investigations, and outcome of a dog with pregnancy-associated immune-mediated hemolytic anemia.

CASE SUMMARY

A 6-year-old, pregnant Bichon Frise was presented due to lethargy, inappetence, and progressive regenerative anemia with spherocytosis. The dog had been recently receiving ranitidine and amoxicillin/clavulanate. An in-house saline agglutination test identified marked agglutination and a urinalysis identified hemoglobinuria. Thoracic and abdominal imaging, as well as infectious diseases testing, was unremarkable. The bitch started whelping shortly following hospitalization, and the anemia progressively resolved without any other intervention. Ranitidine and amoxicillin/clavulanate were re-introduced within the following 2 months but the anemia did not reoccur. In light of these findings, a diagnosis of pregnancy-associated immune-mediated hemolytic anemia was made.

NEW OR UNIQUE INFORMATION PROVIDED

Pregnancy-associated immune-mediated hemolytic anemia should be considered in female dogs that develop severe hemolytic anemia during pregnancy and may resolve spontaneously following parturition.

Some more about dogs: Proteomics of neglected biological fluids

We report in this manuscript what is known about the protein makeup of a selection of biological fluids in the domestic dog. The samples we review - amniotic and allantoic fluid, seminal fluid, saliva, bile, synovial fluid, tears - are still very poorly characterized in this species. For some of them we can present results from our own, mainly unpublished experiments. SIGNIFICANCE: The dog is one of the most widespread companion animals, and also of medical relevance as model species for some human diseases. Still, investigation of body fluids other than serum and urine is not so commonly undertaken, although - like in humans - also these sample types may have potential for diagnostic purposes. We compile published data about proteomes of fetal fluids, seminal plasma, saliva, bile, synovial fluid and tears, enriched by some yet unpublished data of our own (proteins of amniotic and allantoic fluid, tears). Closing gaps in our knowledge on dog proteins will further our understanding of (patho)physiological processes.

Changes in mucosal and serum immunoglobulin levels of California sea lions during early development

To date, most studies on pinniped immunoglobulins have focused on circulating antibodies. However, systemic and local immune activities differ in terms of maturation, intensity, and types of effectors that participate. Here, we examined levels of three immunoglobulin isotypes, IgG, IgM and IgA, in the blood and mucosal membranes of free-living California sea lion pups. We investigated whether age, body condition and sex influenced their concentration. Isotype levels varied among tissues, with age-related patterns that could be indicative of differential regulation along development. Serum IgG and IgA increased linearly with age, reaching adult levels at five months of age, while IgM remained unchanged. Mucosal isotypes tended to be low in newborns and remained so until five months of age. Regardless of age, pups with better condition tended to have higher anal IgG levels and higher genital IgA levels, suggesting that their synthesis and transport to the mucosal membranes is costly. Intersex differences were only observed in the genital mucosa, where all isotypes differed between male and female pups, regardless of age, presumably due to histological and anatomical differences.

Cortisol fetal fluid concentrations in term pregnancy of small-sized purebred dogs and its preliminary relation to first 24 hours survival of newborns

Along the perinatal period, in mammals, cortisol (C) plays a pivotal role in the final intrauterine fetal maturation and in the early neonatal adaptation. Because of the scarce knowledge about canine perinatology, the present study was aimed to assess the C concentrations in amniotic and allantoic fluids collected, without invasiveness, from small-sized, purebred newborn puppies born by elective cesarean section, at term of pregnancy. Possible correlations between fetal fluid C concentrations and maternal parity, litter size, birth weight, Apgar score, were evaluated. In addition, the possible effect of fetal fluid C concentrations on newborn survival at 24 hours of age, and the effect of the litter or the newborn gender on fetal fluid C concentrations were also assessed. The results, obtained from 50 born alive, normal-weight puppies, without gross physical malformation, showed that C concentration was higher in allantoic than in amniotic fluid (P < 0.01), even if a strong positive correlation between the two fluids C concentration was found (P < 0.0001; R = 0.83). Neither amniotic nor allantoic C concentrations were correlated to maternal parity, litter size, birth weight, and Apgar score. Interestingly, higher amniotic (P < 0.05), but not allantoic, C concentrations were found in puppies not surviving at 24 hours after birth. Therefore, it could be suggested that this parameter may be useful for the recognition, at birth, of puppies needing special surveillance during the first day of age. A significant (P < 0.001) effect of the litter in both amniotic and allantoic C concentrations was found. In conclusion, the present results showed that in small-sized purebred puppies, born at term by elective cesarean section, the exact fetal, maternal, or placental source contributing to fetal fluid C concentrations remains to be clarified. From a clinical perspective, however, the evaluation of amniotic C concentration at birth seems useful for the detection of puppies that need special surveillance during the first 24 hours of age, and should be coupled to the early newborn evaluation by Apgar score. However, the small total number of newborns, and especially of the dead puppies enrolled in the present study, suggests that further, more-focused investigations on a large number of subjects are needed before the method could be considered for application in the clinical practices.