Prediction of whelping date in large and giant canine breeds by ultrasonography foetal biometry

Neonatal-Maternal Bodyweight Ratio at Birth: An Indicator for First-Week Survival Prognosis in Canine Newborns

Objectives. In dogs, neonatal bodyweight (NBW) varies at birth. Size-specific reference values for NBW are essential to correctly manage newborns. The present study aimed to define a new tool to evaluate NBW that could be routinely applied in canine neonatology, promptly identifying puppies requiring more care. Methods. The records of 89 litters were retrospectively evaluated. Data were grouped according to maternal bodyweight (MBW) in five categories: toy (≤5 kg), small (5.1-9.9 kg), medium (10-24.9 kg), large (25-39.9 kg), and giant (≥40 kg) dogs. At birth, the NBW of 412 puppies, alongside their litter size (LS) and gender (G), were recorded. Neonatal mortality within the first week was considered. The influence of MBW, LS, and G on NBW and the effect of NBW on the 1-week outcome were evaluated using ANOVA (p < 0.05). The ratio between NBW and MBW expressed as a percentage (N-MBW%), was assessed for each puppy. Through Receiver-Operating Characteristic (ROC) curves, N-MBW% thresholds between puppies alive or dead at one week of age were calculated in each group. Results. The LS was different among groups, except for small vs. medium dogs. In small litters, N-MBW% was lower in medium-, large- and giant-sized dogs than in toy and small dogs. In medium and large litters, N-MBW% differed among the five groups. Male and female N-MBW% differed among the five groups. Only in large and giant sizes did LS affect N-MBW%, which was lower in a large LS. The N-MBW% was higher in healthy puppies than in those who died within one week. The ROC-derived N-MBW% thresholds were as follows: 4.5% in toy-, 3.2% in small-, 1.5% in medium-, 1.2% in large-, and 1% in giant dogs. Clinical significance. The ROC-derived N-MBW% thresholds can be used to cautiously identify puppies at increased risk for one-week mortality and may be helpful in clinical practice, representing a suitable parameter to give a prognosis on 1-week survival immediately at birth.

Preliminary Evaluation of Cortical and Medullary Echogenicity in Normal Canine Fetal Kidneys during the Last 10 Days of Pregnancy

The objective of this study was to assess changes in the echogenicity of the cortex and medulla of canine fetal kidneys in relation to days before parturition (dbp), maternal size and litter size. Monitoring of 10 healthy pregnant bitches (2-8 years old, 8.8-40.3 kg bw) was conducted from -10 to 0 dbp using ultrasound. A single renal sonogram was obtained by scanning in a longitudinal section the three most caudal fetuses. The mean gray level (MGL) and SD of a manually drawn region of interest (ROI) in the renal cortex and medulla were measured using the Fiji Image J software (Image J 1.51h, Java 1.6 0_24 64 bit). A linear mixed model taking into account the maternal size as a fixed effect, dbp and litter size as covariates and the bitch as a random and repeated effect was used. The regression coefficients (b) were estimated. Cortical SD (C-SD) and cortico-medullary SD (C/M-SD) were influenced by dbp, with a significant decrease at the approaching day of parturition (b = 0.23 ± 0.06, p < 0.001 and b = 0.5 ± 0.02, p = 0.038, respectively). Maternal size had a significant impact on C/M-MGL with differences observed in large-sized (1.95 ± 0.13) compared to small- (1.41 ± 0.10, p = 0.027) and medium-sized bitches (1.51 ± 0.09, p = 0.016). The C/M-MGL was influenced by litter size, showing a decrease as the number of pups increased (b = -0.08 ± 0.03, p = 0.018). C-SD and C/M-SD were exclusively affected by dbp, and not by maternal and litter size. This suggests their potential as valuable parameters, warranting further investigations in future studies.

Ultrasonography for the evaluation of pregnancy in the female canine

Ultrasonography can be used for canine pregnancy diagnosis, determination of gestational age, assessing foetal maturation and readiness for birth, monitoring high-risk pregnancies, assessing foetal distress, evaluating bitches in dystocia and foetal gender determination. As the quality and resolution of ultrasound machines have improved, the clinician's abilities to utilize ultrasound as an integral part of reproductive evaluation of all aspects of pregnancy have exponentially increased. This paper reviews the use of ultrasonography throughout pregnancy and the advances made in the interpretation of captured images.

Clinical use of the canine foetal kidney formula in dogs of different maternal sizes during the last ten days before parturition

Data concerning the use of the canine foetal kidney length (L) formula in the prediction of parturition timing are still lacking. In our study, we aimed to evaluate the accuracy of the L formula in predicting the parturition date during the last 10 days of pregnancy. Twenty-five clinically healthy pregnant bitches, aged 2-9 years and weighing 3.5-52.2 kg, were ultrasonographically monitored from -11 to 0 days before parturition (dbp). Kidney L was measured for the three most caudal foetuses, and the parturition day was estimated using the kidney formula, whose accuracy was calculated as the percentage of cases estimated (ranges of ± 1 or ± 2 days) on the actual parturition date. A K-proportions test was performed to identify differences in the accuracy among maternal sizes and the sex ratio of pups, and a two-proportions z-test was performed to identify differences between litter size classes (≤ 7 vs. > 7 pups) and time ranges (-11/-5 and -4/0 dbp). An accuracy of 35% within ± 2 days was found in the range of -11/-5 dbp and an accuracy of 30% within ± 2 days was found in the range of -4/0 dbp. The accuracy differed between small (53% ±1 day and 60% ±2 days) and large (10% within ± 1 and ± 2 days) bitches (P = 0.019 within ± 1 day, and P = 0.007 within ± 2 days). For small litter sizes, the accuracy was 38% within ± 1 day and 44% within ± 2 days, and for large litter sizes, it was 14% within ± 1 and ± 2 days. A threshold value was found between litter size classes within ± 2 days. The use of the L formula during the last ten days of pregnancy did not seem to warrant good accuracy in the prediction of parturition date. Further studies on different maternal sizes should be performed.

[Diagnostic Imaging during pregnancy of the dog]

Diagnostic imaging represents an important part during modern pregnancy management of the dog. Ultrasound has become the modality of choice for an early pregnancy diagnosis, enabling a verification as early as 17-20 days after LH surge. Furthermore an evaluation of fetal viability and development is possible as well as the depiction of malformations and an early assessment of fetal stress. Doppler imaging may also be of supporting value in this context . Using fetal maturity as well as measurements of fetal and extrafetal structures, a calculation of the gestational age and therefore the time of parturition is achievable. Radiographs of the caudal abdomen enable pregnancy diagnosis from the 43rd day after LH surge onward. In addition, an assessment of fetal size as well as litter size is possible. Both modalities allow for complementary statements concerning possible labor complications and possess supporting value concerning the decision of necessary obstetric intervention and further management in patients with dystocia.

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.

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.

Usefulness of Maternal and Fetal Parameters for the Prediction of Parturition Date in Dogs

An accurate parturition timing is of key importance for breeders and veterinarians in order to give professional assistance to parturition in dogs. However, pregnancy length calculated from the breeding date has a wide variability. Different parameters and formulas have been described and calculated, as well as their accuracy which is affected by various factors: stage of pregnancy, litter and maternal size. Therefore, the selection of the most appropriate parameter panel poses the challenge of weighing their influences and impact on the overall accuracy. The aim of this review is to analyze the parameters useful for parturition timing, especially their accuracy, and to propose the addition of fetal maturity and criteria for its evaluation to detect readiness for parturition. Parameters, as described in literature, are classified as: (i) maternal parameters, (ii) fetal parameters, (iii) ultrasonographic assessment of maternal and fetal heart rate and blood flow, (iv) parameters indicating fetal maturity. A focus on recently described parameters-such as fetal gastrointestinal motility and fetal lung development detected by quantitative ultrasound-is reported. Currently, the most accurate way to predict parturition day is represented by a prepartum progesterone drop, but the identification of a panel of ultrasonographic parameters combining their significance and their accuracy throughout pregnancy is still needed.

Pre- and Probiotics to Increase the Immune Power of Colostrum in Dogs

Wide differences in Ig concentration in canine colostrum have been reported. Thus, some litters can be at risk of passive immune transfer failure. Present study evaluated if supplementation with MOS, FOS, E. faecium and L. acidophilus along pregnancy increases colostrum quality. Twenty Great Dane bitches were divided into 4 groups. Control group (CG) received standard diet, only. Diet was supplemented with pre- and probiotics in other 3 study groups during: the last (1WG), last 2 (2WG), and last 4 (4WG) weeks of pregnancy, until parturition. Serum samples were collected at estrous (T0), supplementation beginning (T1), and parturition (T2). Colostrum was collected at C-section end. The IgG, IgM, and IgA were assayed on both matrices. In serum, IgG were higher at T0 than at parturition in all study groups and they significantly lowered from T0 to T1 in all groups. In colostrum, IgG and IgM were significantly higher in 4WG, while IgA already increased in 2WG group. Four-week pre- and probiotic supplementation resulted in the best immune properties of colostrum, as by the higher IgG, IgM, and IgA colostrum levels found in 4WG. Further studies would verify the exact mechanisms involved: pre-partum IgG mammary accumulation and B-cells GALT proliferation and mammary transfer. Further trials would verify whether these beneficial effects of pre- and probiotics on colostrum also lead to improved clinical conditions and immunological functions of newborns and puppies.

Pregnancy Effect on Echocardiographic Parameters in Great Dane Bitches

Simple Summary

In women, as well as in bitches, pregnancy is associated with the adaptation of the left ventricular function. Pregnancy mainly represents a status of increased volume load of the maternal heart driven by the need to supply an adequate blood flow through an augmented uterine perfusion to the developing fetuses. Consequently, cardiac morpho-functional changes are expected. Cardiac morphology and function in pregnant bitches that would develop complications may differ from those with a normal outcome. Thus, the assessment of the maternal cardiovascular function may be a useful screening tool to detect pregnancy complications in dogs. Few studies investigated the cardiac maternal adaptation in different gestational ages in dogs. Breed is a known source of variation in echocardiographic values; hence, the cardiac performance during pregnancy may also be prone to a breed-related variation. For these purposes, due to possible breed-related variations in cardiac parameters and function, and to the specific predisposition for myocardial diseases, echocardiographic changes along pregnancy in healthy Great Dane bitches were evaluated. A significant effect of the age of gestation on the increase of functional and diastolic parameters and on the decrease of systolic parameters was reported.

Abstract

Pregnancy is associated with adaptation of the left ventricular (LV) function. Due to differences between breeds in baseline echocardiographic values and specific predispositions for myocardial diseases, breed-specific echocardiographic parameters may be helpful to evaluate whether the systolic function varies during pregnancy. This study enrolled nine healthy Great Dane bitches with uncomplicated pregnancy. Echocardiographic M-mode and B-mode data were collected before ovulation and within 7 days of the predicted parturition term. Evaluated parameters were: LV dimension in diastole (LVd) and systole (LVs), end-diastolic (EDVI) and end-systolic (ESVI) volumes indexed to body surface area (BSA), end-diastolic (EDV) and end-systolic (ESV), end-point-septal-separation (EPSS), left atrium to aortic root ratio (LA/Ao), sphericity index (SI), ejection fraction (EF), fractional shortening (FS), stroke volume (SV), heart rate (HR), and cardiac output (CO). The ANOVA showed a statistical effect of the age of gestation (p < 0.01) on the increase of diastolic dimensions and functional parameters and on the decrease of systolic dimensions. The CO increase parallels the rise in SV and HR (p < 0.01). No statistical differences were observed for EPSS, LA/Ao, and SI. The changes in cardiac chambers and function are likely to reflect maternal adaptation to allow the fetal development in uncomplicated pregnancy. The present study provides specific echocardiographic values in uncomplicated pregnancy of Great Danes, showing that the systolic function is enhanced and that the increase in preload, observed during gestation, is the likely mechanism.

A Biotic Support During Pregnancy to Strengthen the Gastrointestinal Performance in Puppies

Up to 60% of neonates can be affected by gastroenteritis due to specific pathogens or aspecific polymicrobial interactions. The present study evaluated if a dietary supplementation with MOS, FOS, E. faecium and L. acidophilus in pregnancy may reduce gastroenteritis in puppies. Fifteen Great Danes were divided in 3 groups. The control group (CG) ate a standard diet. In 2 study groups, the diet was supplemented with pre- and probiotics during the last (1WG) and the last 4 pregnancy weeks (4WG). Up to 9 weeks, puppies were checked daily to identify first- or second- presentation gastroenteritis. Data were processed by χ² (P < 0.05). First-presentation gastroenteritis was more frequent in CG than in 1WG than in 4WG. Second-presentation gastroenteritis was more frequent in CG than in 1 and 4WG. Puppies from pre- and probiotics supplemented bitches were less prone to gastroenteritis. 1 or 4WG equally reduced second-presentation gastroenteritis in puppies, but 4WG was better than 1WG on first-presentation gastroenteritis. By entero-mammary link, supplemented bitches produced higher immune quality colostrum, thus puppies faced immunitary challenges better; moreover, maternal microbiota, positively altered by supplementation, was transferred to newborns, becoming more resistant to gastroenteritis. This information can be useful in clinical practice with the goal of preventing gastroenteritis in puppies and reducing its prevalence and severity.

Urinalysis in Great Dane Puppies from Birth to 28 Days of Age

Simple Summary

Still, nowadays, small animal perinatology is quite an unknown field of veterinary medicine. To help decrease the high mortality rates reported for canine newborns, veterinary practitioners should become more aware of neonatal physiology and pathology, focusing their attention on metabolic balance. It is impossible to discriminate healthy puppies from pathological littermates in the absence of reference ranges for specific parameters, which are obviously different from those of adults. Since blood samples are more difficult and dangerous to collect from newborns, practitioners could rely on urinary samples, easily gathered by the stimulation of the somato-vesical spinal reflex. The present research, based on 624 urine samples, offers results that can be used as references for the first-line evaluation of newborn Great Danes by dipstick rapid urinalysis. In healthy puppies, specific gravity and pH vary from birth to 28 days of age, while glucosuria and proteinuria are never reported. The present results, derived from a sample of single-breed puppies, can represent the starting point for a further multi-breed evaluation.

Abstract

Urinalysis, a common test in infants, could represent a suitable non-invasive clinical tool in puppies. In dog neonates, urine is easily collected by stimulating the somato-vesccal reflex. Information on urine characteristics during the neonatal period is missing. Beside instrumental laboratory analyses, the dipstick was proven useful for rapid urinalysis to evaluate specific gravity (SG), pH, leukocytes, nitrites, glucose, proteins, ketones, urobilinogen, bilirubin, and blood. The present study aimed to describe urinalysis features by the dipstick test and refractometer along the neonatal period. Urine samples (n = 624) were collected by manual stimulation from 48 healthy Great Danes, daily from birth to seven days, then twice a week until 28 days, to assess age-related changes (ANOVA, p < 0.05) and the possible effects of gender and litter (T-test, p < 0.05). The SG and pH significantly changed during the neonatal period. Other parameters did not vary significantly in relation to age. No significant differences were observed either among litters or between genders. The present study confirmed that canine kidneys are able to concentrate urine from the second week of age when the urinary SG started to be similar to adults, while pH still increased towards the typical values of adults at 28 days. Significant glucosuria and proteinuria were never detected. Dipstick urinalysis represents a useful first-line complementary tool in newborns clinical examination, providing information about systemic homeostasis.

Fertility outcome after medically treated pyometra in dogs

Cystic endometrial hyperplasia-pyometra complex (CEH/P) is a challenge in canine reproduction. Present study aimed to assess fertility after medical treatment. One-hundred-seventy-four bitches affected by CEH/P received aglepristone on days 1, 2, 8, then every 7 days until blood progesterone < 1.2 ng/mL; cloprostenol was administered on days 3 to 5. Records were grouped according to bodyweight (BW): small (< 10 kg, n = 33), medium (10 ≥ BW < 25 kg, n = 44), large (25 ≥ BW < 40 kg, n = 52), and giant bitches (BW ≥ 40 kg, n = 45). Age; success rate; aglepristone treatments number; relapse, pregnancy rates; diagnosis-relapse, -first, -last litter intervals; litters number after treatment, and LS were analyzed by ANOVA. Overall age was 5.14 ± 1.75 years, without difference among groups. Treatment was 100% successful, without difference in treatments number (4.75 ± 1.18), relapse (15/174, 8.62%) and pregnancy (129/140 litters, 92.14%) rates, intervals diagnosis-relapse (409.63 ± 254.9 days) or -last litter (418.62 ± 129.03 days). The interval diagnosis-first litter was significantly shorter (163.52 ± 51.47 days) and longer (225.17 ± 90.97 days) in small and giant bitches, respectively. Overall, 1.47 ± 0.65 litters were born after treatment. Expected LS was achieved in each group, as shown by ΔLS (actual-expected LS by breed, overall -0.40 ± 1.62) without differences among groups. Concluding, CEH/P affects younger dogs than previously described. Relapses were rarer than previously reported. Medical treatment with aglepristone+cloprostenol is effective and safe, preserving subsequent fertility, as demonstrated by negligible changes in LS.

Effects of Alfaxalone or Propofol on Giant-Breed Dog Neonates Viability During Elective Caesarean Sections

Attention must be paid to C-section anesthesia effects on mother and offspring. Alfaxalone induction results in improved puppy viability when compared to propofol. The present study aims to evaluate effects of alfaxalone or propofol induction for elective C-section on newborns, expressed as Apgar score and fetal fluids cortisol concentration. Anesthesia was induced with alfaxalone 3 mg/kg iv in 5 bitches (group A), and propofol 4 mg/kg iv in another 5 (group P), maintained with isoflurane. Amniotic and allantoic fluids were collected to determine cortisol concentration. Apgar score, litter size, newborn gender, birth-weight, maternal age, and parity were recorded. ANOVA, U Mann-Whitney test and ANCOVA assessed the effects of drugs on the Apgar score and fetal fluids cortisol. Thirty-six puppies were randomly selected for the study: 16 from group A and 20 from group P. Only the Apgar score significantly differed between groups. ANCOVA confirmed a significantly higher Apgar score in group A underlining the influence of fetal fluids cortisol concentrations, both resulting in covariates. Present results confirm the effect of anesthesia on the Apgar score of newborns, which is significantly higher for alfaxalone than propofol, suggesting the use of fetal fluids cortisol as a covariate. These findings could be a starting point for further investigations when less viable puppies are detected or expected, such as during an emergency C-section.

Effect of delivery management on first-week neonatal outcome: How to improve it in Great Danes

A different incidence of neonatal complications has been reported in several species according to the duration of the various labour stages and the type of delivery. Trauma associated with dystocia may result in the release of neonatal catecholamines and cortisol that negatively affect neonatal metabolism, thus survival. Aim of the present study was to assess how the first-week neonatal outcome is affected by a different management of parturition. Clinical records of 46 Great Dane litters from 8 different kennels were evaluated retrospectively. Data were grouped in 3 categories: vaginal delivery (VD), emergency C-section (ES), planned C-section (PS). The risk of stillbirth, early neonatal mortality and perinatal mortality was calculated at puppy and at litter level in each group. Data were statistically compared by the ANOVA and Chi-Square test (p < 0.05). Seventy-eight puppies were naturally delivered (VD), 120 experienced dystocia at birth that required emergency C-section (ES) and 105 came from planned C-section (PS). No statistical difference in neonatal bodyweight and litter size was observed among groups. In PS, both stillbirth and neonatal mortality resulted significantly lower than in VD and ES, resulting in the lowest observed perinatal mortality. The number of litters with stillbirth was significantly higher in ES than VD and PS. The number of litters with neonatal mortality resulted significantly lower in PS than VD and ES. The overall perinatal mortality in VD resulted statistically influenced from both stillbirth and neonatal mortality, while it resulted strongly affected by the high stillbirth in ES. No difference was observed for PS perinatal mortality. Present results, reporting a high incidence of dystocia as well as high perinatal and neonatal mortality, lead us to evaluate the opportunity to plan an elective C-section in Great Dane bitches, in order to minimize perinatal mortality.

Colour Flow Mapping examination: An useful screening test for the early diagnosis of ductus venosus patency in canine newborns

Ductus venosus (DV) closure plays a key role in hepatic circulation adaptation to postnatal metabolic function, and DV patency might develop a congenital portosystemic shunt (CPSS). The noninvasive Color Flow Mapping (CFM) examination, a validated method to diagnose CPSS in adult dogs, is routinely performed to assess DV closure after birth in humans. This study aimed to describe the feasibility of the ultrasonographic evaluation of the DV after birth and to determine its closure time in healthy Great Dane neonates. Patency of DV in serial Color Flow Mapping (CFM) examinations and bodyweight (BW) were recorded on Days 0-3-6-9 in 24 neonates that were classified as having patent (PDV) or closed ductusvenosus (CDV) basing on CFM signal presence/absence. Since the 3rd day, DV diameter was recorded. Data were analysed by ANOVA (p < 0.05). All dogs resulted healthy 1 year later. The number of PDV and CDV puppies at birth was not different on Day 3 (24 and 0 vs. 22 and 2, PDV and CDV, respectively), whereas it resulted different on Days 6 (24 and 0 vs. 14 and 10) and 9 (24 and 0 vs. 0 and 24); on Day 3, it was different compared to Days 6 and 9; on Day 6, it was different from Day 9. Reduction of DV diameter resulted positively related to neonatal BW growth. The CFM evaluation of DV closure after birth in Great Dane puppies represents a feasible technique. Present results suggest the time of functional closure in normal neonates within 9 days after birth. Thus, CFM examination, as an early screening test for DV patency evaluation, performed 10 days after birth, may identify suspicious dogs at risk that would require further investigations. Further studies are needed to deepen the role of a delayed closure in low bodyweight and preterm puppies.

Is the biparietal diameter of fetuses in late gestation too variable to predict readiness for cesarean section in dogs?

Correct assessment of readiness for cesarean section is essential for timing elective cesarean section during late pregnancy in the bitch. In humans, biparietal diameter is sufficiently precise and accurate and used in a clinical setting daily. The objectives of this study were to determine whether fetal biparietal diameter in late gestation in the dog could be used to predict readiness for cesarean section by having reached a minimum cut-off value and to correlate the biparietal diameter to birth weight. The biparietal diameter of 208 puppies in 34 litters from 31 English bulldog bitches and 660 puppies in 78 litters from 70 Boerboel bitches were measured immediately after delivery by cesarean section, performed at full term, using digital calipers. At the same time the birth weight of the same 208 English bulldog puppies and 494 of the same Boerboel puppies in 59 litters from 54 bitches was measured by means of an electronic scale. With a cesarean section, all the puppies in a litter are delivered simultaneously and readiness for cesarean section must be determined for a litter. The minimum, median and maximum biparietal diameter varied from 21.1 to 47.8, 32.9 to 50.0 and 34.2-58.2 mm, respectively, among English bulldog litters and from 18.4 to 48.7, 35.5 to 49.7 and 39.8-54.3 mm among Boerboel litters. This large variation suggests that biparietal diameter is too variable within and among litters to be useful as a means of determining readiness for cesarean section.

Specific fetometric formulas of ICC and BP for calculating the parturition date in the miniature breeds of canine

The aim of this study was to derive the growth curves of the inner chorionic cavity and the biparietal distance in miniature dog breeds by ultrasonographic fetometry and present new specific formulas for prediction of parturition date. In this study, foetal biometry parameters were obtained using serial ultrasonographic examinations in 24 pregnant bitches of six different miniature breeds (≤5 kg). The mating time was unknown. Overall, 25 inner chorionic cavity diameter (ICC) and 22 biparietal diameter (BP) measurements were taken. The relationship between ICC or BP growth and days to parturition was analysed by linear regression. The results showed a significant relationship between days before delivery and ICC or BP. The equations derived from the growth curves can be used in practical prediction of parturition date in miniature dog breeds.

Clinical use of fetal measurements to determine the whelping day in German shepherd breed bitches

The aim of this work was to use a linear regression model previously developed in a pilot study to calculate days before parturition (DbP) using inner chorionic cavity (ICC), biparietal diameter (BPD), crown-rump length (CRL), body diameter (BD) and deep portion of telencephalic vesicle (DPTV) in German shepherd dogs (GSD) with known ovulation day and then to test that model in bitches with unknown ovulation day. In our current study, a model for GSD bitches published in a previous report, proved satisfactory for ICC [DbP=44.76-(4.34×ICC)] and BPD [DbP=38.65-(12.86×BPD)]. We therefore used their model, but developed a new one for CRL, BD and DPTV. For ICC and BPD, we tested accuracy for more than 35days before parturition (ICC) and more than 15days before parturition (BPD). Measurements were taken on at least two fetuses during each ultrasound recording (US) of 22 GSD bitches with known (n=16) and unknown (n=6) ovulation days. The accuracy of the above model was 77-100% for ICC and 83-96% for BPD with a precision of ±1 and ±2days, respectively. Accuracy increased significantly when US was performed more than 35days before parturition for ICC and more than 15days before parturition for BPD. BD and CRL were the most accurate parameters (R²=0.95 and 0.85). In bitches with unknown ovulation day, BD accuracy was 71.4-100% with a precision of ±1day and ±2days, respectively. CRL and DPTV were less accurate (±1day, 60%; ±2days, 80% accuracy).