"Foals" encompasses a stage in the lifecycle of equines with distinct physiological and developmental characteristics. Foals are young horses, typically under one year of age, undergoing rapid growth and development. They require specific nutritional, health, and management practices to support their transition to adulthood. This page compiles peer-reviewed research studies and scholarly articles that explore the growth, development, health challenges, and management practices associated with foals and horses, providing insights into their care and welfare across different life stages.
Bertone AL, Park RD, Turner AS.Radiographs of 23 foals (35 forelimbs) with carpal region angular limb deformities, which later were corrected by hemicircumferential transection of the periosteum and periosteal stripping, were evaluated as to geometric and morphologic abnormalities. Geometric evaluation included deviation angle and deviation pivot point. Morphologic abnormalities were categorized as: asymmetric width of the distal radial physis; asymmetric width of the distal radial epiphysis; carpal bone collapse or fracture; carpal bone hypoplasia; carpal bone displacement; and metacarpal bone displacement. Fifty-seven per...
Sims LD, Tzipori S, Hazard GH, Carroll CL.Two foals aged 35 and 48 h from 2 Thoroughbred studs died several hours after developing clinical signs of depression, severe haemorrhagic diarrhoea and dehydration. Both foals had an acute haemorrhagic enteritis extending from the anterior jejunum to the terminal ileum which was characterised histologically by villus necrosis. Necrotic villi were surrounded by large numbers of rod-shaped Gram positive bacteria. Clostridium perfringens was recovered from the intestines of both foals and the isolates were considered to be C. perfringens type C. Other cases of diarrhoea were also observed in foa...
Van der Lugt JJ, Coetzer JA, Jordaan P, Marlow CH.Tyzzer's disease was diagnosed histologically in two foals, a 4-week-old Thoroughbred cross and a 6-week-old Arabian foal. Clinically both foals were in good health prior to a short illness lasting only a few hours. The liver lesions in both foals were characterized microscopically by multiple foci of necrosis. Variable numbers of elongated slender intracytoplasmic bacilli resembling Bacillus piliformis were demonstrated within hepatocytes bordering the necrotic foci.
McClure JJ, Addison JD, Miller RI.Oral candidiasis and bacterial septicemia were diagnosed in 8 foals that had laboratory and/or pathologic evidence of immunodeficiency. Two foals suffered solely from complete failure of passive transfer of colostal immunoglobulins. Six foals had evidence of immune defects but did not meet the criteria for diagnosis of any of the currently recognized primary equine immunodeficiency syndromes. All six of these foals died or were euthanatized due to bacterial infections. One foal with failure of passive transfer recovered and the other died of a mesenteric torsion before the effect of treatment ...
Foil L, Stage D, Adams WV, Issel CJ.The occurrence of tabanid feeding between mares and foals was observed. When mares and foals were observed freely moving within a pasture situation, foals had 2.43% (4 flies in 77 observations vs 297 flies in 139 observations) of the tabanid feeding occurrences of the mares. This difference in tabanid burden varied due to herd size, herd location, and tabanid species. Lower tabanid burden of foals was indicated as a practical protective mechanism against pathogenic agents mechanically transmitted by tabanids, such as equine infectious anemia virus.
de Oliveira AC, Rosenbruch M, Schulz LC.The morphology of asteroid bodies in equine arteries is demonstrated by light microscopy as well as by scanning and transmission electron microscopy combined with chemical analysis. Asteroid bodies first occur in horses at four weeks of age in all investigated tissues except the esophagus and always are located in the subendothelial space. The number, shape, ultrastructure and chemical composition of asteroid bodies differ markedly--depending on the age of the horse. Asteroid bodies are round and smooth in foals, but are shaped irregularly and have several projections and marked stratified cal...
Issel CJ, Adams WV, Foil LD.Progeny of a band of horses, positive by the agar-gel immunodiffusion (AGID) test for equine infectious anemia (EIA) antibody, were observed through their weaning over a 4-year period. Sentinels (AGID test-negative) were allowed to mingle with EIA-infected mares and their foals in pasture situations in an area with high populations of potential vectors. Of 27 adult sentinels, 8 (30%) seroconverted in annual rates ranging from 0% to 75%. In contrast, only 2 of 31 (6%) foals weaned became infected. Difference in infection rates between adult sentinels and foals was significant (chi 2, P less tha...
Shamis LD, Auer J.Complete ulnas and fibulas were found in a 10-month-old Welsh Pony examined because of severe flexural deformity, with carpal and tarsal valgus deformities, in all limbs. Presence of these normally vestigial structures is considered a form of atavism. At one week of age, periosteal transection was performed for the angular deformity, resulting in no improvement. When performing this procedure, the authors recommend transection of these vestigial structures if present.
Richardson DW.The common conditions affecting the urogenital tract of the neonatal foal and their medical and surgical management are described. Early recognition and treatment of serious abnormalities are necessary for a successful outcome in the equine neonate.
Klein L.A brief discussion of those aspects of neonatal physiology that pertain to anesthetic risk and selection of anesthetic techniques is followed by discussion of suggested techniques for anesthetic management in healthy foals. Preoperative preparation and management of foals with selected serious surgical conditions are also considered.
Gajadhar AA, Caron JP, Allen JR.Cryptosporidium oocysts were identified by phase contrast microscopy on smears from flotations of greenish-yellow pasty feces obtained from two foals. One foal, a one week old Percheron was recumbent, anorectic and lethargic, believed to be the result of a septicemia of undetermined etiology. Despite therapy and nursing care the animal died. Using light and electron microscopy, numerous stages of Cryptosporidium sp. were seen protruding from the surface of epithelial cells of intestinal villi. The other foal, a six week old Arabian had a mild diarrhea. The diarrhea and passage of oocysts event...
Latimer CA, Wyman M.This discussion of normal and abnormal findings on routine ophthalmic examination of the foal should prove useful to the equine practitioner who must provide counsel to the concerned owner and/or breeder. Early diagnosis and treatment of ocular abnormalities improve the prognosis for continued function and aid determination of the significance of lesions observed in later life.
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.
Frymus T, Degórski A, Kowalski B, Crisman M.
Summary:
Serum lysozyme (LZM) activity and nitroblue tetrazolium (NBT) reduction capacity of circulating phagocytes were determined by the lysoplate technique and the microquantitative method, respectively. As blood donors 47 clinically normal Arabian foals ranging in age from 6 hours to 22 days and their 40 dams were used.
A significantly (p < 0.05) lower serum LZM activity was found in foals older than 24 hours, compared with the mares (40.84 U/ml ± 15.32 and 48,96 U/ml ± 17.9, respectively), but the LZM/phagocyte ratio was similar in foals and mares.
Circulating phagocytes from...
Reef VB.Cardiac disease in the equine neonate occurs infrequently. Murmurs are often heard in foals and are not considered significant unless they persist beyond 4 days of age. Congenital cardiac defects are the most common form of primary cardiac disease in the foal, with ventricular septal defects occurring most frequently. Other neonatal foal diseases such as ruptured bladders, white muscle disease, neonatal respiratory distress syndrome, and septicemia have secondary cardiac involvement.
Koterba AM, Brewer B, Drummond WH.Foal septicemia is a major cause of neonatal morbidity and mortality. In order to improve success rates, earlier diagnosis and treatment are essential. This article stresses methods to prevent and treat infections in the compromised equine neonate.
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...
Adams R, Mayhew IG.The responses of apparently healthy newborn foals to neurologic testing differ significantly from those of adult horses. These responses and the diagnostic techniques pertinent to neurologic problems are reviewed as a basis for evaluation of the compromised neonatal foal. The more frequently encountered neurologic diseases are discussed in a problem-oriented format. These clinical problems include behavioral abnormalities, convulsions, changes in consciousness, blindness, ataxia without loss of strength, ataxia with weakness and paralysis, and the floppy foal.
Beech J.Despite major advances in our knowledge and ability to treat respiratory diseases in neonatal foals, neonatal respiratory medicine is still in its infancy. It is hoped that this article may serve as a guideline for diagnosis and treatment. Specific antibiotic regimens and emergency procedures are covered in other articles in this symposium. Because management factors play a critical role in the pathogenesis of respiratory disease, education of clients as to their importance would help both prophylactically and therapeutically. The necessity of very careful monitoring of neonates, which is crit...
Crowell-Davis SL, Houpt KA, Carnevale J.The feeding and drinking behavior of 11 mares and 15 foals living on pasture with free access to water was recorded during 2,340 15-min focal samples taken over 2 yr. Lactating mares on pasture spent about 70% of the day feeding. Foals began feeding on their first day of life. As they grew older, they spent progressively more time feeding, but still spent only 47 +/- 6% of the time feeding by 21 wk of age. Foals fed primarily during the early morning and evening. While grass formed the major proportion of the diet of both foals and mares, they also ate clay, humus, feces, bark, leaves and twig...
Vaala WE.Other therapeutic agents used in foals for specific diseases are discussed elsewhere. The marked effect of species, age, and degree of maturity on drug metabolism in the neonate reinforces the danger of interspecies extrapolation of pharmacology, the need for information specific for the foal, and the necessity for monitoring drug levels in the individual. Suggested antimicrobial doses are listed in Tables 3, 4, and 6. Recommended doses of anticonvulsants and sedatives are listed in Table 8 and in the article "Intensive Care of the Neonatal Foal." The following are recommendations for drug the...
Naylor JM, Bell R.Orphan foals are best reared by fostering them onto a brood mare of appropriate size. If no foster mother is available, they can be reared on 2 per cent fat skimmed cow's milk fortified with dextrose at the rate of 20 gm per L. This should be slowly increased from 10 per cent of body weight at 1 day of age to 25 per cent of body weight at 10 days of age. The amount should then be held constant until weaning. Alternatively, foals can be reared on milk replacers. Manufacturers' feeding instructions rarely mimic the milk intake obtained by a foal nursing her dam, and problems have been observed i...
Koterba AM, Drummond WH.Provision of adequate nutritional support to the sick neonatal foal is a vital part of intensive care; frequently, however, it is very difficult to accomplish. In this article, current recommendations concerning both enteral and parenteral nutrition are discussed.
Palmer JE.Few foals escape gastrointestinal disease during the first weeks of life. Diarrhea is an extremely common problem; fortunately, however, it is usually mild and self-limiting. When it is not, the underlying cause is often an infectious agent, such as rotavirus or Salmonella spp. Our understanding of many of the infectious agents causing neonatal diarrhea is far from complete. Gastric and duodenal ulcers are a less common disease of neonatal foals. There has been an apparent increase in the incidence of ulcer disease in foals during the past few years. The most effective way of decreasing seriou...
Leitch M.Angular limb deformities are not uncommon in foals. Mild angular deviation due to laxity of supporting soft tissues often resolves spontaneously. However, external splinting or casting may be needed in severe cases or in those that do not resolve. When incomplete ossification of carpal or tarsal bones is the cause of the limb deformity, external support is mandatory to prevent further deformation and abnormal development of the bones. When epiphyseal and metaphyseal abnormalities cause axial deviation, surgical intervention is usually necessary. Circumferential periosteal transection and/or tr...
Falcon J, Smith BP, O'Brien TR, Carlson GP, Biberstein E.Thirty-nine foals with pneumonia were admitted to the Veterinary Medical Teaching Hospital at the University of California, Davis. Corynebacterium equi was recovered from each of them on bacteriologic culture of transtracheal aspiration specimens or lung specimens at necropsy. The foals were divided into 2 groups. Group I consisted of 20 foals that died because of C equi pneumonia and were subsequently necropsied. Group II consisted of 19 foals that were treated and discharged from the hospital. Radiography was performed on all foals. Clinical signs included increased respiratory rate, fever, ...
Hong CB.Three cases of congenital polyalveolar lobe (pulmonary hamartoma) were diagnosed in female Thoroughbred foals. Foal 1 was born at full term but died shortly afterwards. Foal 2 was aborted at the seventh month of gestation. Parturition was induced at the tenth month of gestation in foal 3 because it developed hydrops of the amnion and ascites. In all three foals, the polyalveolar lobe occurred on the right side and affected the entire right lung. In each case, the right lung formed a tumour-like mass, and expanded into the left chest cavity. The lung masses were pink to dark red and spongy to r...
Rumpel AS, Alievi MM, Jardim Filho JO, Rozo CAC, Schuster LAH, da Silva AV, Ferreira MP.Physical activity has been widely investigated in horses to elucidate locomotion characteristics and behavior. However, research in real environment of training stables is limited. The objective of this study was to evaluate the effect of training regimen on night time physical activity of racehorses. Physical activities of twenty animals were monitored during the night time using accelerometers. The animals were compared in terms of training regimen: horses subjected to training on continual days, and horses subjected to training on intermittent days; age and sex were also considered. The var...
Baker SJ, Gerring EL.Impedance epigastrography was used to measure gastric emptying rates on two occasions in each of three foals. After smoothing of the raw data, emptying of water appeared to obey an exponential model. The mean emptying rate constant (SEM) was 0.171 +/- 0.038 min-1 (mean emptying half time 4.9 +/- 1.0 min).
Lezica FP, Filip R, Gorzalczany S, Ferraro G, de Erausquin GA, Rivas C, Ladaga GJ.In the present study, we determined the incidence and effects of season and weather on clinical manifestations of endophyte-infected ryegrass toxicity, performed chemical detection and pharmacological bioassays on ryegrass extracts, and conducted trials on: (i) effects of domperidone or metochlopramide on ovarian inactivity induced by endophyte-infected ryegrass; (ii) efficacy of buspirone or dihydrochloro phenyl piperazine (m-CPP) for preventing suppressed milk production induced by endophyte-infected ryegrass; and (iii) efficacy of domperidone to induce ovulation during winter anestrus. Mare...
Jaworska J, Tobolski D, Janowski T.The failure of the maternal immune system to recognize fetal antigens and vice versa due to MHC similarity between the foal and its dam might result in the lack of placental separation during parturition in mares. The aim of the study was to investigate the influence of MHC similarity between a mare and a foal on the incidence of retained fetal membranes (RFM) in post-partum mares. DNA was sampled from 43 draft mares and their foals. Mares which failed to expel fetal membranes within three hours after foal expulsion were considered the RFM group (n = 14) and mares that expelled fetal membranes...
ALEXANDER F, BENZIE D.1. The disposition and surface relations of the alimentary tract of the foal have been studied radiographically.
2. The rate of progress of a barium meal through the digestive tract was determined. The barium traversed the stomach and ileum of the weaned foal faster than that of the suckling foal, but was longer retained in the cæcum and ventral colon of the weaned foal.
Young DR, Richardson DW, Nunamaker DM, Ross MW, Tulleners EP.The medical records of 9 foals less than 4 months old, with fracture of the tibial diaphysis, were reviewed. Open reduction was accomplished by use of 3 approaches; however, a cranial approach was preferred and was used in 7 foals. Two dynamic compression plates were implanted in all foals except the first of this series. The technique of plate luting was used in 7 foals and appeared to improve the ability of implants to resist failure. Complications after surgery included partial or complete failure of fracture fixation (n = 3 foals), osteomyelitis (n = 2 foals), angular limb deformity (n = 2...