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.
Ousey JC, McArthur AJ, Rossdale PD.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...
Stewart JH, Rose RJ, Young IH, Costas L.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 ...
Brewer BD, Clement SF, Lotz WS, Gronwall R.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...
Robertson SA, Carter SW, Donovan M, Steele C.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...
Lavoie JP, Spensley MS, Smith BP, Mihalyi J.The uptake of colostral IgG and IgM, their serum half-lives, and the rates of endogenous synthesis of IgG and IgM were evaluated in 6 newborn foals fed bovine colostrum (principals) and 6 foals allowed to suckle their dams (controls). The principal foals were fed 400 ml of bovine colostrum (IgG, 10,000 mg/dl and IgM, 200 mg/dl) at 2-hour intervals, from 2 to 20 hours after foaling (total dose, 4 L). Serum IgG and IgM concentrations were determined by single radial immunodiffusion from birth to 98 days of age. At foaling, principal foals had no detectable serum equine IgG, but 1 control foal ha...
Saikku A, Koskinen E, Sandholm M.The glutaraldehyde coagulation test was adapted to foal serum to determine adequacy of the colostral-intestinal transfusion of IgG. The test is performed simply by mixing one volume of reagent with 10 volumes of serum and observing the coagulation time. The required glutaraldehyde concentration was established for various threshold levels of IgG as determined by radial immunodiffusion. The analysis consisted of 140 serum samples from foals. Sera with low IgG levels require high glutaraldehyde concentrations and vice versa. The 4 g/l threshold generally accepted for IgG adequacy, was achieved a...
Roser JF, Dudan F, Little TV, Livesay-Wilkins P, Hillman RB.Studies were undertaken to investigate the effects of oxytocin induction on prolactin release in term (Group II) and preterm (Group III) mares and to compare these effects to spontaneously foaling mares (Group I). Since physiological concentrations of prolactin in blood have not been measured in the neonatal foal, experiments were designed to monitor prolactin in the cord artery and jugular blood of the foals from all groups of mares. Although prolactin levels varied in term mares (Group I and II) during the last 11 days of pregnancy, an increase was observed between Day -6 and Day 0 (2.7 and ...
Dudan F, Hirni H.Since 1980 techniques specifically designed to treat human neonatal diseases have also started to be applied to ill or premature equine newborns. These techniques will be described and their application to the most common equine neonatal disorders will be discussed. Such techniques include: post-natal cardiopulmonary resuscitation, exogenous thermal support, administration of broad spectrum antibiotics after diagnostic studies, supplemental oxygen therapy and mechanical ventilation, intravenous fluid and electrolyte therapy, blood component transfusion and total parenteral nutrition.
Stewart JH, Young IH, Rose RJ, Costas L, Barko AM.The distributions of ventilation-perfusion ratios, and the effects of 100% oxygen administration on the distributions, were studied in 3 foals from 4h to 9 days of age, using the multiple inert gas elimination technique. The distributions were calculated from the pulmonary clearance of 6 inert gases following infusion into a peripheral vein of a solution containing the inert gases. The results from a total of 8 studies showed several consistent features. The major findings were (i) the absence of low ventilation-perfusion ratios, i.e. regions where blood flow was greatly in excess of ventilati...
Stammers JP, Leadon DP, Hull D.The fatty acid composition of the plasma free fatty acid, triacylglycerol and phospholipid fractions was measured in blood and milk samples taken daily from 3 mares and their foals on Days 1-9 post partum inclusive, and from a total of 12 mares and foals on Days 22, 30 and 51. A rise in the plasma concentrations of triacylglycerol and phospholipid similar to that well documented in other species occurred in the neonatal period. Alterations in the composition of the foal plasma phospholipid after birth lend support to the view that the placenta rather than the fetus could be responsible for the...
Bernoco M, Liu IK, Wuest-Ehlert CJ, Miller ME, Bowers J.Chemotactic and phagocytic responsiveness of peripheral blood polymorphonuclear leucocytes (PMNLs) from 11 foals were analysed immediately after birth (pre-colostral) and at different times after colostrum ingestion. The number of foal PMNLs per microscopic field that had migrated through the filter in chemotaxis and the number of yeast particles ingested per foal PMNL in phagocytosis were significantly lower when tested with foal plasma before colostrum ingestion (chemotaxis, 2.0 +/- 0.55 (s.e.m.); phagocytosis, 0.98 +/- 0.352) than in tests 4 or more days after colostrum ingestion (chemotaxi...
Thomas WP, Madigan JE, Backus KQ, Powell WE.Cardiopulmonary function was studied in 10 full-term healthy foals from birth to 14 days of age. Systemic and pulmonary haemodynamics were recorded in lateral recumbency via indwelling aortic and pulmonary artery catheters. Mean body weight increased from 45.4 +/- 2.4 kg on Day 1 to 70.6 +/- 6.1 kg on Day 14. All foals had a continuous murmur of patent ductus arteriosus for 3-6 days. From Day 1 (12 h old) to Day 14, heart rate increased (89 +/- 4 to 95 +/- 5/min), mean aortic pressure increased (87.7 +/- 1.9 to 100.3 +/- 3.2 mmHg), mean pulmonary artery pressure decreased (38.6 +/- 4.6 to 27.4...
Leadon DP, Jeffcott LB, Rossdale PD.Parturition was induced in 2 groups of mares, less than 300 (n = 49) and 300 to 320 days gestation (n = 31), by the administration of prostaglandin F2 alpha or fluprostenol and oxytocin. Foals were categorized into 4 groups according to their ability to adapt in, and survive, the neonatal period. Group A had no demonstrable coordinating reflexes, were weak from birth, and all died within 90 minutes. Group B had some righting reflexes, but had poor coordination and a weak suck reflex. They showed some improvement for about 2 hours, but all died within 9 hours. Group C foals had a good suck refl...
Koterba AM, Drummond WH, Kosch P.The basic concepts of diagnosis and treatment in the abnormal neonatal foal are presented. Methods of restraint, sedation, and general nursing care are discussed, as well as more specific techniques of respiratory and circulatory system support.
Becht JL, Semrad SD.Hematologic parameters change during the first 10 days of life. Erythrocytes increase in number but decrease in size and hemoglobin concentration. The PCV, hemoglobin, and platelet count also decrease. Total blood and plasma volume and, to lesser extent, erythrocyte volume decrease. Normal neonatal foals may have immature neutrophils (up to 5 per cent bands), and their early rapid rise in neutrophil numbers may be accompanied by a lymphopenia. Monocytes, eosinophils, and basophils are all absent or low initially. Infectious processes can cause rapid and variable changes in the leukogram. Howev...
Stewart JH, Rose RJ, Young IH, Costas L.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 ...
Dewes HF.Fractures of the central tarsal and/or third tarsal bones involving both limbs of six foals are described. Five of the subjects were born either premature or of twin pregnancies. Fractures occurred in the neonatal period and coincided with disablement. Features of behaviour, posture and gait are described, together with gross radiographic findings, bone ash determination and blood chemistry. Lesions observed on the articular faces of tarsal bones recovered from adult horses may have originated during the neonatal-period.
MacDougall DF.The proteins IgG and IgG(T) are the predominant immunoglobulins in equine colostrum. Their distribution and catabolism were studied in the newborn foal using an isotopic tracer technique. More precise quantitation of the absorption of these immunoglobulins from colostrum is now possible.
Young RL, Linford RL, Olander HJ.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.
Journal of biochemistryNovember 1, 1963
Volume 54 388-397 doi: 10.1093/oxfordjournals.jbchem.a127804
JOHKE T.This research article investigates the differences in acid-soluble nucleotides in the milk of various species including cows, goats, mares, and humans through different stages of lactation, and compares the nucleotide […]
El-Hage C, Gilkerson J.While well known as a zoonotic pathogen of birds, Chlamydia psittaci is less well recognised as a cause of abortion in mares and severe infection in foals. However, in the past decade it has been causing epizootics of both in south-eastern Australia, as Charles El-Hage and James Gilkerson explain.
Bernick A, Demattio LS, Wehrend A.Uroperitoneum is a typical disease of the newborn foal, which occurs rarely but regularly. Ultrasonography is considered the most important imaging method for diagnosing this disease. Thus far, only one older case series comprising 31 foals suffering from uroperitoneum has systematically listed results of ultrasound examinations. Objective: This paper presents the findings of an ultrasonographic examination of 34 foals with uroperitoneum in order to inform future interpretation of ultrasonographic data in suspected uroperitoneum cases. Methods: Ultrasonographic data of 34 neonatal foals up to ...
Morgan J, Curtis Shaw G, Weisman J, Cecere T, Carvallo-Chaigneau FR.A 2-d-old Warmblood colt was submitted for autopsy with a spectrum of bilateral ocular abnormalities. At postmortem examination, a constellation of lesions within the anterior segment included retention of ectodermal elements, compatible with choristoma. Ocular choristomas can be localized to different intraocular structures and are rare in equids. The morphologic features in our case were suggestive of abnormal corneal differentiation.
Magdesian KG.Knowledge of immunodeficiencies is crucial to neonatal medicine, in that they predispose to sepsis in the newborn and neonatal foal, as well as recurrent infections in older foals. The most common immunodeficiency in newborn and neonatal foals is failure of passive transfer, which is an example of an acquired immunodeficiency. Congenital or developmental immunodeficiencies may be transient or permanent, and can either affect the cell-mediated or humoral arms of immunity, and in some cases both. Affected foals often have chronic or recurrent respiratory or gastrointestinal infections, often wit...
Volding DM, Flores-Ahlschwede P, Cramer MJ, Landrock KK, Sayre KC, Welsh TH, Bordin AI, Piccione J, Cohen ND.To determine the effects of transfusion of Rhodococcus equi hyperimmune plasma (REHIP) on serum electrolyte and protein concentrations in neonatal foals. Unassigned: A prospective observational study of 355 privately owned Thoroughbred foals from 13 farms in New York and cross-sectional study of REHIP samples. Blood was collected immediately before and after transfusion of either 1 or 2 L of REHIP to foals, and serum samples were separated and frozen until tested for concentrations of sodium (Na), potassium (K), chloride (Cl), total protein (TP), albumin, and globulins. Samples (n = 90) of REH...
McGuire TC, Perryman LE, Banks KL.Following the descriptions of immunodeficiencies in horses beginning in 1973, there has been considerable effort to develop methods for differential diagnosis and to determine the cause and prevalence of the disorders. In addition, the equine immunodeficiencies, especially combined immunodeficiency, have been studied from a comparative viewpoint with the goal of finding information applicable to similar diseases of children. Coincident with the development of knowledge about the immunodeficiencies per se, considerable information about several aspects of immunology has been obtained. It is the...
Sonea IM, Bowker RM, Robinson NE, Holland RE.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...
Braun JP, Tainturier D, Bézille P, Raviart I, Rico AG.In goat and mare colostrum, gamma-glutamyltransferase (GGT) activity is relatively low (mean values are, respectively, 900 and 350 U/l). In the serum of newborns before suckling, GGT is also low (less than or equal to 28 U/l in goats and less than or equal to U/l in foals); then in goats GGT is much increased on the 1st day (mean = 127 U/l), and it decreases during the following days. In foals, serum GGT slowly but regularly increases for the first 5 days, then decreases. Such differences can be attributed to intestinal protein absorption capabilities which are selective in newborn foals and u...
Furr MO.Neurologic disease of foals is a diagnostic and therapeutic challenge for veterinarians. Disease conditions such as neonatal encephalopathy are seen as well as developmental and congenital defects, bacterial infections, and trauma. Neonatal encephalopathy can be considered a "syndrome" with a variety of causes resulting in a similar clinical presentation. These causes can be categorized as maladaptation, hypoxic/ischemic encephalopathy, and metabolic abnormalities, all leading to signs of cerebral and brainstem disease. Spinal cord signs may occasionally be seen, but these signs are usually ov...
Smith JE, Dever M, Smith J, DeBowes RM.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...
Zicker SC, Rogers QR.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...
Dudan F, Hirni H.Since 1980 techniques specifically designed to treat human neonatal diseases have also started to be applied to ill or premature equine newborns. These techniques will be described and their application to the most common equine neonatal disorders will be discussed. Such techniques include: post-natal cardiopulmonary resuscitation, exogenous thermal support, administration of broad spectrum antibiotics after diagnostic studies, supplemental oxygen therapy and mechanical ventilation, intravenous fluid and electrolyte therapy, blood component transfusion and total parenteral nutrition.
Tennent-Brown BS, Morrice AV, Reed S.Neonatal encephalopathy is the most common neurologic condition affecting newborn foals and shares similarities with perinatal asphyxia syndrome of human infants. In many cases of neonatal encephalopathy there is no obvious episode of acute or chronic hypoxia and other mechanisms likely play a role in the pathogenesis. Increased concentrations of neuroactive progestagens are found in affected foals; whether these molecules are protective, as has been suggested, or play a role in the pathogenesis is unknown. Neurologic diseases other than neonatal encephalopathy affect foals occasionally and sh...
Lanci A, Mariella J, Ellero N, Canisso IF, Dondi F, Castagnetti C.This study aimed to determine alpha-fetoprotein (AFP) concentrations in amniotic fluid, plasma of mares and respective foals: carrying normal pregnancies and delivering healthy foals (n = 20; Group 1); carrying apparently normal pregnancies and delivering sick foals (n = 15; Group 2); carrying high-risk pregnancies and delivering sick foals (n = 14; Group 3). High-risk pregnancy was defined by a history of premature udder development/lactation or increased of the combined thickness of the uterus and placenta, or vulvar discharge and/or mares' systemic illness. Sick foals were affected by...
