Use of cardiac troponin I (cTnI) levels to diagnose severe hypoxia and myocardial injury induced by perinatal asphyxia in neonatal dogs.

Prolonged perinatal asphyxia and subsequent severe hypoxia are the main causes of mortality in neonatal dogs in the first days of life. In medicine, specific cardiac biochemical markers, such as troponin I, are used to diagnose ischemic and nonischemic myocardial injury in asphyxiated newborns after birth. Thus, the objectives of this study were to compare the levels of cardiac troponin I (cTnI) between asphyxiated and nonasphyxiated newborn dogs and evaluate the correlations of cTnI levels with the modified Apgar score, the levels of oxygen saturation, blood glucose, and lactatemia, and blood gas parameters. This study aimed to determine the possible use of cTnI as a marker of severe hypoxia and myocardial ischemic injury in neonatal dogs. Fifteen animals in a eutocic vaginal delivery group (VG), 15 animals in a cesarean section group (CG), and 13 animals in a hypoxia (asphyxiated) group (HG) were evaluated. The animals in the asphyxiated group were from dystocic deliveries and born by vaginal delivery or cesarean section. All groups were evaluated at birth and after 60 min. The newborns in the VG and CG exhibited mixed acidosis (respiratory acidosis due to increased partial pressure of CO2 (pCO2) and metabolic acidosis due to reduced pH and bicarbonate (HCO3) levels, base excess/deficit in the extracellular fluid compartment (BEecf), and increased lactate levels) due to transient physiological hypoxemia at birth. The cTnI levels in the VG and CG were within the reference standards for healthy dogs. No correlations between cTnI level and the other parameters were observed in the VG and CG. Newborns in the HG exhibited prominent mixed acidosis (p < 0.05) due to severe hypoxemia. The Apgar score and blood gas parameters showed that these dogs were born asphyxiated, and they presented low vitality and the need for resuscitation maneuvers. The cTnI levels in the HG were significantly higher than those in the VG and CG (p < 0.05) and above the reference standards for healthy dogs, which indicated ischemic myocardial injury. The cTnI level was negatively correlated (p < 0.05) with the parameters Apgar score, heart rate, peripheral oxygen saturation (sO2) level, reflex score, and total carbon dioxide (TCO2) level and positively correlated (p < 0.01) with lactate level. This study showed that asphyxiated newborn dogs have higher serum cTnI levels than nonasphyxiated newborn dogs; thus, the cTnI can be used as a marker of severe hypoxia and ischemic myocardial damage in newborn dogs.

Neonatal sepsis in dogs: Incidence, clinical aspects and mortality.

The neonatal period in dogs remains associated with high mortality rates. Sepsis is the main cause of neonatal losses during the first three weeks of life. Additionally, failure in the clinical assessment and early diagnosis of sick newborns is still common, leading to inadequate care, which contributes to a high mortality rate. Thus, the objective of this study was to describe the incidence of sepsis in canine newborns, the clinical aspects involved, the main isolated bacterial agents and mortality rates to facilitate clinicians' early recognition of this condition. Of the 152 litters and 762 neonates evaluated, 14.8% (113/762) had sepsis or septic shock, and the mortality rate among affected puppies was 25.6% (29/113). Among the puppies with sepsis that died, early mortality (0-2 days of age) occurred in 69% (20/29) of affected neonates, and late mortality (3-30 days of age) occurred in 31% (9/29) of affected neonates. Significant differences (p < 0.0001) in clinical parameters (heart and respiratory rates, blood glucose, body temperature, peripheral oxygen saturation and reflexes) were noted among healthy neonates and neonates with sepsis and septic shock. The main and most relevant clinical signs were apathy, a reduced sucking reflex, diarrhea, the neonatal triad, failure to gain weight, bradycardia, dyspnea, cyanotic mucous membranes, body erythema, reduced peripheral oxygen saturation, cyanosis and tissue necrosis in the extremities. The mother may have been the main source of infection for 87.6% (99/113) of neonates with sepsis. Most infections were transmitted during pregnancy (68%, 77/113) in cases of neonatal sepsis. The major source of infection for neonates was the uterus, followed by breast milk and maternal oropharyngeal secretions. The most frequently isolated bacterial agent was Escherichia coli, accounting for 25.6% (29/113) of sepsis cases. The morbidity and mortality of neonatal sepsis in dogs is high. The clinical evaluation and diagnosis of sepsis in neonates differ from those in adult animals. Thus, knowledge of the neonatal particularities of sepsis is essential for proper clinical management and greater survival of these patients.

Assessing the accuracy of imputation in the Gyr breed using different SNP panels.

The aim of this study was to evaluate the accuracy of imputation in a Gyr population using two medium-density panels (Bos taurus - Bos indicus) and to test whether the inclusion of the Nellore breed increases the imputation accuracy in the Gyr population. The database consisted of 289 Gyr females from Brazil genotyped with the GGP Bovine LDv4 chip containing 30 000 SNPs and 158 Gyr females from Colombia genotyped with the GGP indicus chip containing 35 000 SNPs. A customized chip was created that contained the information of 9109 SNPs (9K) to test the imputation accuracy in Gyr populations; 604 Nellore animals with information of LD SNPs tested in the scenarios were included in the reference population. Four scenarios were tested: LD9K_30KGIR, LD9K_35INDGIR, LD9K_30KGIR_NEL, and LD9K_35INDGIR_NEL. Principal component analysis (PCA) was computed for the genomic matrix and sample-specific imputation accuracies were calculated using Pearson's correlation (CS) and the concordance rate (CR) for imputed genotypes. The results of PCA of the Colombian and Brazilian Gyr populations demonstrated the genomic relationship between the two populations. The CS and CR ranged from 0.88 to 0.94 and from 0.93 to 0.96, respectively. Among the scenarios tested, the highest CS (0.94) was observed for the LD9K_30KGIR scenario. The present results highlight the importance of the choice of chip for imputation in the Gyr breed. However, the variation in SNPs may reduce the imputation accuracy even when the chip of the Bos indicus subspecies is used.

Incidence of congenital malformations and impact on the mortality of neonatal canines.

Canine congenital malformations are structural or functional abnormalities of organs present at birth that possibly interfere with the viability of newborns, thus contributing to neonatal mortality. This study evaluated and described the incidence of congenital malformations in neonatal dogs and determined the mortality rates among those affected. Of the 178 litters and 803 newborns included in the study, 24.7% (44/178) of the litters presented neonates with congenital malformations. The total rate of neonates that presented malformations was 6.7% (64/803). The total mortality rate in newborns with congenital defects was 5.4% (44/803), representing 68.7% (44/64) of the deaths observed among those affected. The early (0-2 days old) and late (3-30 days old) mortality rates among the affected neonates were 61.4% (27/44) and 38.6% (17/44), respectively. In total, 27 malformations were recorded, and the most common congenital defects were cleft palate 2.8% (23/803) and hydrocephaly 1.5% (12/803), either alone or associated with other malformations. The malformations were recorded in 15 breeds: Pug, Miniature Pinscher, Rottweiler, Pitbull, French Bulldog, English Bulldog, Dachshund, Labrador Retriever, Lhasa Apso, Poodle, German Spitz, Yorkshire Terrier, Shih-tzu, Brazilian Terrier and mixed breed. One case of exposure to a teratogenic agent was reported, but no maternal exposure to teratogens during gestation was reported with the other litters. The occurrence of congenital defects may be related to genetic factors since the highest incidence of malformations (84.4%) was observed in purebred dogs.