Topic:Neonatal
Neonatal health in horses focuses on the study and understanding of the physiological and developmental processes that occur in foals from birth until they reach a few weeks of age. This field addresses various aspects of equine neonatal care, including the adaptation of the respiratory and circulatory systems post-birth, nutritional needs, and immune system development. Research often explores common neonatal conditions, such as neonatal maladjustment syndrome, sepsis, and failure of passive transfer of immunity, which can affect the health and survival of foals. This page compiles peer-reviewed research studies and scholarly articles that investigate the physiological development, common health challenges, and management practices associated with neonatal horses.
Distribution of SP- and CGRP-like immunoreactive nerve fibers in the lower respiratory tract of neonatal foals: evidence for loss during development. The lungs of neonatal foals contain many nerves immunoreactive for substance P and calcitonin gene-related peptide. These nerves are closely associated with the epithelium, bronchial and pulmonary vessels and the airway smooth muscle of all intrathoracic airways, including non-cartilaginous bronchioles. Activation of sensory nerves in the respiratory epithelium could thus potentially affect, via local axon reflexes, vascular and respiratory smooth muscle in neonatal equine airways. Nerves immunoreactive for these peptides are much more widely distributed within the lung than in adult horses; t...
Systemic candidiasis in four foals. Four foals were admitted to the neonatal intensive care unit in the first 2 days of life with problems related to birth hypoxia (neonatal maladjustment syndrome, renal failure, necrotizing enterocolitis) and sepsis. Foals were hospitalized for an extended period (35 to 70 days) and received treatment with several broad spectrum antimicrobial agents. Invasive monitoring and treatment procedures included intravenous catheterization, urinary catheterization, and parenteral nutritional and ventilatory support. In each foal, infections of undetermined cause developed, and systemic candidiasis was d...
Temporal changes in concentrations of amino acids in plasma and whole blood of healthy neonatal foals from birth to two days of age. Temporal changes, as well as differences in distribution, in concentrations of 24 amino acids in plasma and whole blood of neonatal foals were determined from birth to 2 days of age. In addition, differences in concentrations of amino acids in plasma between mare and foal pairs were determined at birth. Significant (P < 0.05) hypoaminoacidemia existed for 15 amino acids in plasma of foals at birth, compared with mares (paired t-test). Concentrations of 7 amino acids (aspartate, glutamate, glutamine, glycine, hydroxyproline, phenylalanine, proline) in plasma of foals were higher (P 0.05). S...
Characterization of a red blood cell antigen in donkeys and mules associated with neonatal isoerythrolysis. A red cell antigen of donkeys and mules was identified using antibodies in serum from a mare which produced a mule foal affected with neonatal isoerythrolysis (NI). Subsequently antibodies with similar activity were identified in the sera of other mares which had produced mule foals and were produced by immunization of horses with blood from donkeys. The antigen detected by these antibodies does not correspond to any recognized horse red cell alloantigen. This may be a xenoantigen since all donkeys (and mules) tested have shared this antigen and all horses tested have lacked the antigen. The r...
Pharmacokinetics of phenylbutazone in neonatal foals. Single doses (2.2 mg/kg of body weight) of phenylbutazone (PBZ) were administered IV to 6 neonatal horses (5 to 17 hours old at time of dosing). Plasma concentrations of PBZ and its metabolite oxyphenbutazone were monitored serially for 120 hours after drug administration. Pharmacokinetic variables were calculated, using 1- and 2-compartment open models. Descriptive equations from the best model for each foal were then used to derive model-independent variables describing PBZ disposition. Median volume of distribution at steady-state was 0.274 L/kg (range, 0.190 to 0.401 L/kg). Median terminal...
Pharmacokinetics of and serum thromboxane suppression by flunixin meglumine in healthy foals during the first month of life. Age and species reportedly affect the pharmacokinetic variables of nonsteroidal anti-inflammatory drugs. We determined the effect of age on flunixin pharmacokinetic variables in foals during the first month of life. We also estimated the physiologic activity of the drug in neonatal foals by determining the effect of flunixin on thromboxane production during clotting of blood taken from the foals. Flunixin disposition and clearance were determined after IV administration of 1.1 mg of drug/kg of body weight to 5 healthy foals when they were 24 to 28 hours, 10 to 11 days, and 27 to 28 days old. T...
[The development of the IgG concentration in the blood serum of newborn foals]. The aim of this study was to determine the course of the IgG concentration in blood serum of neonatal foals. A comparison of blood serum IgG concentration of the mares showed IgG values of 3356 +/- 671 mg/dl up to a maximum of 3579 +/- 766 mg/dl (means +/- s). In accordance with Eisenhauer (1981) and in contrast to Jeffcott (1974) no significant change of the IgG level in the blood serum of the mares could be observed during the test period. However, the IgG concentration in the colostrum of meanG = 11776 mg/dl during birth decreased considerably 96 hours later with meanG = 135 mg/dl. At birth...
Causes of abortion, stillbirth, and perinatal death in horses: 3,527 cases (1986-1991). Pathology case records of 3,514 aborted fetuses, stillborn foals, or foals that died < 24 hours after birth and of 13 placentas from mares whose foals were weak or unthrifty at birth were reviewed to determine the cause of abortion, death, or illness. Fetoplacental infection caused by bacteria (n = 628), equine herpesvirus (143), fungi (61), or placentitis (351), in which an etiologic agent could not be defined, was the most common diagnosis. Complications of birth, including neonatal asphyxia, dystocia, or trauma, were the second most common cause of mortality and were diagnosed in 19% of the...
Pharmacokinetics of cefotaxime in neonatal pony foals. Serum concentrations of cefotaxime and desacetylcefotaxime were measured in 1-week-old pony foals after IV administration of a single dose of cefotaxime. The cefotaxime disposition data conformed to a two-compartment model with elimination half-life of 0.60 hour. The combined cefotaxime and desacetylcefotaxime data was best described by a four-compartment model. The apparent half-life describing the disappearance of desacetylcefotaxime was 1.69 hours. Dosage of 40 mg/kg of body weight given IV every 4 to 6 hours for neonatal foals with gram-negative septicemia and every 2 hours for foals with ...
Some aspects of perinatal maturation and adaptation. Physiological challenges facing the perinatal individual are huge. This is partly because of the marked and abrupt change from the intrauterine to the extrauterine environment, but also because the physiological responses to that change depend upon systems whose maturation is affected markedly by birth. Perinatal maturation appears, therefore, both to precede and accompany the physiological adaptations required for neonatal survival. This review does not provide a comprehensive coverage of perinatal physiology but directs attention towards evaluating constraints on foetal and neonatal thermoge...
Post-transfusion survival of 50Cr-labeled erythrocytes in neonatal foals. Erythrocytes transfused allogeneically into mature horses have a short survival (less than 4 days) compared with an expected erythrocyte life span of 140-150 days. Yet, foals undergo transfusions for neonatal isoerythrolysis successfully. The authors have determined the survival of transfused erythrocytes in neonatal foals, using the stable isotope, 50Cr, to label the erythrocytes. Normal foals underwent transfusions with labeled erythrocytes from three sources: their own erythrocytes (autologous), the erythrocytes of their dam, and the erythrocytes of an unrelated castrated male. After transf...
Use of oral tolerance tests to investigate disaccharide digestion in neonatal foals. Oral tolerance tests were performed on 13 neonatal foals to determine their ability to digest disaccharides on d 1, 3 and 5 postpartum. Foals were assigned randomly to treatments consisting of 20% (wt/vol) solutions of either maltose, lactose, or sucrose, dosed at 1 g/kg of BW, or glucose, dosed at .5 g/kg of BW. After a 2-h fast, an initial blood sample was collected via jugular catheter. Foals were administered the appropriate solution orally, and blood was collected every 15 min for 1 h and then every 30 min for 3 h. Plasma glucose increased after dosing with lactose or glucose but not with...
Development of lymphocyte blastogenic response in the neonatal period of foals. The blastogenic response of lymphocytes and serum concentration of cortisol from eighteen foals were evaluated during various stages of the neonatal period. The results of blastogenic responses were expressed by a stimulation index (SI). Blastogenic response to three mitogens was lowest at birth (PHA: 1.17 +/- 0.02, Con A: 1.11 +/- 0.05 and PWM: 1.02 +/- 0.01), then increased gradually with slight variations postpartum. The serum concentration of cortisol was highest at birth (44.0 ng/ml) and decreased rapidly to 19.3 ng/ml within 1 week postpartum, and then was maintained at this level. The h...
Atresia coli in the foal: a review of six cases. Physical examination and exploratory celiotomy were performed on five neonatal foals presented with signs of acute colic. Atresia coli was confirmed in each foal during surgery. The most consistent finding on physical examination was the absence of meconium staining following repeated enemas. The large, transverse and/or small colon were involved in all foals. One eight month aborted foetus was submitted for necropsy and diagnosed as having atresia coli and congenital hydrocephalus. Atresia coli should be considered for neonatal foals with signs of acute colic.
Electrocardiographic findings during parturition and blood gas tensions immediately after birth in thoroughbred foals. In 101 newborn Thoroughbred foals and foaling mares, 45 fetal (FECGs) and 101 neonatal electrocardiograms (NECGs) were obtained to investigate neonatal arrhythmias and other parameters including changes in fetal (FHR) and neonatal heart rate (NHR). Moreover, umbilical arterial, venous and jugular venous blood gas tensions and pH immediately after birth were analyzed to compare with the type and the degree of neonatal arrhythmias. Before delivery, in 37 fetuses FHR gradually decreased while in 8 cases it increased after rupture of the chorio-allantois. Abnormal deliveries were related in 5 of t...
Palliative repair of aortic atresia associated with tricuspid atresia and transposition of the great arteries. Successful palliative repair of aortic atresia and hypoplastic aortic arch associated with tricuspid atresia in a neonate is described. The repair consisted of reconstruction of the hypoplastic aortic arch with an equine pericardial patch, division of the patient ductus arteriosus, connection of the pulmonary artery to the aorta, implantation of the proximal part of the ascending aorta into the main pulmonary artery, and anastomosis of a polytetrafluoroethylene graft 5 mm in diameter between the right ventricular outflow tract and the central pulmonary artery, which was transferred anteriorly ...
Metabolic changes in thoroughbred and pony foals during the first 24 h post partum. Metabolic rates, rectal temperatures and respiratory quotients (RQ) were determined during the first 24 h post partum in Thoroughbred and pony foals and in relation to environmental temperature. Both breeds had high metabolic rates (greater than 200 W/m2) during the first hour post partum when they were wet and shivering; by 4 to 24 h values were fairly steady at about 153 and 105 W/m2 for Thoroughbred and pony foals, respectively. At birth, rectal temperature was lower in Thoroughbred foals than in pony foals; values increased during the first hour, and then decreased. At 24 h of age, both br...
The distribution of ventilation-perfusion ratios in the lungs of a dysmature foal. The distribution of ventilation-perfusion (VA/Q) ratios, before and after 100 per cent oxygen, was studied in an induced-premature foal at 4 h and again at eleven days of age, using the multiple inert gas elimination technique. The major finding was an absence of low VA/Q ratios when breathing air, indicating that low PaO2 in the neonatal period was totally attributable to the right-to-left shunt. At 4 h of age the PaO2 was 5.48 kPa and the right-to-left shunt represented 33.4 per cent of the cardiac output. At eleven days of age the PaO2 was 9.76 kPa and right-to-left shunt was 10.1 per cent ...
A comparison of inulin, para-aminohippuric acid, and endogenous creatinine clearances as measures of renal function in neonatal foals. The glomerular filtration rate (GFR) was estimated in eight full-term neonatal foals by the single injection inulin plasma clearance method at two days of age, the continuous infusion plasma and urinary clearance methods at three days of age, and the 12-hour endogenous creatinine clearance method at four days of age. The effective renal plasma flow (ERPF) was estimated simultaneously by the single injection para-aminohippuric acid (PAH) plasma clearance method in the eight two-day old foals and the continuous PAH infusion plasma and urinary clearance method in the eight three-day old foals. Th...
Effects of intravenous xylazine hydrochloride on blood glucose, plasma insulin and rectal temperature in neonatal foals. The effects of intravenous xylazine hydrochloride on blood glucose, plasma insulin and rectal temperature were investigated in six foals at 10 and 28 days of age. These variables were also measured in three foals at 19 days of age when saline alone was injected. Rectal temperature fell significantly after 30 mins in both groups of xylazine treated foals and was still depressed after 120 mins. Hypothermia did not occur in the saline control group. There was no significant change in blood glucose or plasma insulin concentrations during the 120 mins following either xylazine or saline administrat...