"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.
Conner ME, Darlington RW.Fecal samples from 86 foals with diarrhea were examined by electron microscopy during a 2.5 year period. Of these, 26 (30%) were positive for rotavirus. All of the cases were found in epizootic areas. The disease was produced in an experimental foal by inoculation via stomach tube of a bacteria-free fecal filtrate containing rotavirus. Examination of postmortem tissues from the duodenum and jejunum of 2 naturally infected foals and an experimentally infected foal revealed replicating virus in the intestinal epithelial cells. A limited survey of complement-fixing antibody to rotavirus in horses...
Pemberton DH, Thomas KW, Terry MJ.The prevalence of hypogammaglobulinaemia in 82 young foals was determined. Twelve foals were considered clinically abnormal at birth and ten died within two weeks. All of these foals were hypogammaglobulinaemic. Seven (10%) of the other 70 apparently normal foals were hypogammaglobulinaemic despite having suckled normally. Three of these foals developed significant disease and one died at one month of age. Rapid detection of foals with low serum immunoglobulin levels was achieved by adapting the zinc sulphate turbidity test to partially evacuated blood collection tubes. This permitted test to ...
Wesson JA, Miller KF, Ginther OJ.Plasma FSH and LH response to a synthetic GnRH analog was measured in adult ovariectomized pony mares (OVX) and in pony foals (<70 days of age) during late spring (May-June). FSH and LH responded in a similar fashion (200% increase) in the OVX mare, which is different from other reports for intact mares. There was a greater mean response to a comparable dose of GnRH in the prepubertal foal for both FSH (500%) and LH (900%) than in the OVX mare. There was a positive correlation between age and the maximum FSH response to GnRH in male and female foals. The LH response was positively correlate...
Lew AM, Hosking CS, Studdert MJ.Tests for T- and B-cell quantitation and immune function were developed, and their application in the diagnosis of primary severe combined immunodeficiency disease (CID) in Arabian foals was investigated. Foals with CID had severe lymphopenia and had small or zero numbers of B cells, as shown by immunofluorescence of surface immunoglobulin (Ig), erythrocyte-antibody-complement rosetting, and staphylococcal protein A rosetting. Serum IgM was undetectable in four CID foals 25 to 71 days old. Demonstrable antibody responses were not elicited in CID foals by phage phi X-174, a potent antigen in no...
Barth AD, Barber SM, McKenzie NT.A two month old Thoroughbred filly was presented with signs of depression, grinding of the teeth, frothing of the mouth and abdominal pain. These signs had persisted for two weeks despite treatment with mineral oil, dioctyl sodium sulfosuccinate, meperidine and antibiotics. A variety of diagnostic tests were done, the only abnormal finding was a stress leukon. On exploratory laparotomy the stomach was dilated with fluid and gas and the pyloric canal was constricted. Pyloroplasty resulted in correction of the condition. The etiological possibilities are discussed. This is believed to be the fir...
Perryman LE, McGuire TC, Torbeck RL.The capacity of cells from thymus, liver, spleen, mesenteric lymph nodes, peripheral blood, and bone marrow to respond to in vitro phytolectin and allogeneic lymphocyte-stimulation was determined in 16 pony fetuses 61 to 200 days old (gestational age). Phytolectin-responsive cells were detected in the thymus at the 80th gestational day, peripheral blood at 120 days, lymph node at 160 days, and spleen at 200 days. Mixed lymphocyte culture-responsive cells were detected in thymus at 100 days and in the spleen at 200 days (gestational age). Immunoglobulins (Ig) M and IgG were quantitated by radio...
Greenwood RE, Simson AR.An outbreak of ataxia and paralysis on a Thoroughbred studfarm is reported. The cause of the disease was attributed to equid herpesvirus (EHV1) infection which stemmed from a single 10-month abortion on the studfarm. Stallions, mares and foals were all affected but the most serious clinical signs occurred in the mares. there were 35 out of 39 mares, 2 out of 4 stallions and 5 out of 39 foals which exhibited signs of ataxia. Nine mares became recumbent and died or were euthanased. Treatment with betamethasone and antibiotics was given. The outbreak was contained to one area of the stud apart fr...
Maylin GA, Rubin DS, Lein DH.A survey of selenium and vitamin E concentrations in horses was conducted at four breeding farms in New York. There were no significant changes in mean blood selenium concentrations in horses at the three sampling dates whereas vitamin E concentrations underwent seasonal fluctuations. The mean blood selenium concentration in this survey for horses fed local feed was 7.7 microgram/dl. Horses fed commercial feed had a mean blood selenium concentration of 15.6 microgram/dl. A 0.94 correlation coefficient was found between blood glutatione peroxidase activity and blood selenium concentrations in h...
Stick JA, Boles C.Three foals with chronic cough, bilateral nasal discharge, and pneumonia were found to have a subepiglottic cyst as the inciting cause. Consistent findings were dysphagia and aspiration pneumonia, in addition to the abnormal respiratory noise usually found in the adult horse with a subepiglottic cyst. Histologic examination of the cysts suggested their origin was traumatic rather than embryonic.
Prescott JF, Johnson JA, Markham RJ.Four month-old foals were infected orally with 75 mL of a suspension of 5.0 x 10(8)Corynebacterium equi per mL. Two foals were killed after ten days and had scanty number of C. equi in the caeco-colic lymph nodes. No C. equi were recovered from the other two foals, killed 20 days after infection. No gross pathological change was detected in these four foals, although mild microscopic lesions were seen in the ileum of one foal. Results of lymphocyte blastogenesis using peripheral blood lymphocytes and C. equi antigens showed, however, that lymphocytes became sensitized to C. equi following this...
Crandell RA, Mock RE, Lock TF.Bovine herpesvirus 1247 (one dose) was given subcutaneously to five pregnant pony mares between 227 and 319 days of their gestations. There were no adverse clinical reactions, and the virus was not recovered from nasal swabs collected during a 2-week period after vaccination. Four ponies foaled full-term, live, healthy foals. The foal of the fifth mare (No. 1) was found dead, but on the basis of the pathologic and virologic examinations, the virus was not considered to be the cause of the death. At 3 weeks after vaccination, the pregnant pony mares had a 13- to 250-fold increase in serum antib...
Perryman LE, McGuire TC.Between January 1973 and September 1979, 2,092 horses and ponies were evaluated for immunologic disorders. A total of 418 abnormalities were detected in 416 (20%) of the animals tested. Disorders encountered were failure or partial failure of colostral immunoglobulin transfer from mare to foal (228 cases), combined immunodeficiency (159 cases), selective immunoglobulin M deficiency (19 cases), agammaglobulinemia (3 cases), transient hypogammaglobulinemia (2 cases), and lymphosarcoma (7 cases). Four conclusions were drawn from the study. (1) Immunologic abnormalities occur commonly in horses an...
Perryman LE, Torbeck RL.A 3-year prospective breeding trial was designed to verify the mode of inheritance of combined immunodeficiency (CID) in Arabian horses. Twenty-six mares that had previously produced foals with CID were mated to a stallion that had sired foals with CID. Of 53 foals obtained, 15 (28.3%) had CID. The ratio of female to male foals was 28:25, and the ratio of female CID to male CID foals was 8:7. The results of this trial confirmed a suggestion that CID in Arabian horses is inherited as an autosomal recessive trait.
Arnbjerg J.With reference to previous reports on hypocalcemia in horses special attention is given to the principal symptoms such as anxiety, increased muscular tension, esp. of the musculature of the extremities, in severe cases leading to ataxia, and to a pulse-synchronized respiration (Synchronous Diaphragmatic Flutter). The time of appearance of the symptoms are much more variable than it is the case for hypocalcemic agalactia in cows. Furthermore the condition has been reported in foals as well as in geldings. Thus the triggering factor seems to be somewhat different from that of agalactia. Hypocalc...
Thomas KW, Pemberton DH.Components of plasma or serum, including immunoglobulins, were concentrated two-fold by freezing then collecting 40-50% of the initial volume during thawing. This concentrated plasma (or serum) was administered intravenously to treat hypogammaglobulinaemic foals and calves. An adaptation of this method suitable for field use is described.
Pashen RL.Levels of the major circulating metabolite of prostaglandin F-2 alpha, 13, 14 dihydro-15-oxo-prostaglandin F-2 alpha (PGFM) were measured during the induction of foaling using small (2.5-10 iu) intravenous doses of oxytocin. PGFM levels rose rapidly in all animals within 15 min of injection and were associated with typical signs of second stage labour. Because these small doses of oxytocin are effective in successfully triggering parturition it is suggested that higher doses (40-120 iu) used to induce birth in other studies are unnecessary and could be potentially dangerous to the foetal foal....
Urch DL, Allen WR.The efficacy of orally administered fenbendazole on lung and intestinal parasitism in equids was investigated in a mixed herd of pony mares, jenny donkeys and foals. A single dose of 7.5 mg fenbendazole/kg body weight effectively removed intestinal parasites from the ponies, donkeys and foals, but higher doses and repeated treatments failed to eliminate lungworm infections in donkeys. The finding of eosinophilia proved useful in detecting lungworm infections in donkeys.
Holland PS, Brumbaugh GW, Ruoff WW, Brown SA.Plasma pharmacokinetics of ranitidine HCl were investigated after intravenous (i.v.) and oral (p.o.) administration of drug to six healthy foals. Twelve- to sixteen-week-old foals received 2.2 mg ranitidine/kg i.v. and 4.4 mg ranitidine/kg p.o. Concentrations of ranitidine were determined using normal phase high performance liquid chromatography. Plasma concentrations of ranitidine HCl declined from a mean of 3266 ng/mL at 5 min to 11 ng/mL at 720 min after administration. The profile of the plot of concentrations of ranitidine HCl vs. time was best described by a two-exponent equation for two...
Retteg Pauls S, Jottini S, Takai S, Venner M, Wohlsein P.A 3-month-old female trotter foal was euthanized due to severe dyspnoea. Pathomorphologically a chronic granulomatous to necrotizing pneumonia was found and Rhodoccocus (R.) equi was isolated microbiologically. An immunohistological method using a murine monoclonal antibody against a 15-17 kDa antigen of virulent R. equi was established in formalin-fixed and paraffin-embedded tissue sections using various antigen retrieval techniques to optimize the staining results. Microwave treatment was most suitable for the demonstration of bacterial antigen localized predominantly in intralesional macrop...
Mendoza FJ, Perez-Ecija RA, Estepa JC.Emphysema of lymph nodes is a rare finding that has been described in different anatomical locations and related to specific diseases in different animal species. Herein is described a foal with Rhodococcus equi infection that presented with emphysema and granulomatous inflammation of the bronchial and mediastinal lymph nodes. This is the first report of emphysematous lymphadenitis in a horse.
Parker WG, Sullivan JJ, Larson LL.The diagnostic value of rectal palpation and immunological assay of PMSG was tested at different stages of pregnancy in mares inseminated with frozen semen in three separate studies. The results were based on foaling success and particular attention was paid to the numbers of inconsistent results obtained by the two tests. Generally, the number of false positive diagnoses was lower for the immunological assay than for palpation in early pregnancy (Days 40 to 60) and the relationship became reversed later in gestation.
Eizema K, van der Wal DE, van den Burg MM, Dingboom EG, Everts ME.An optimal developed musculoskeletal system is vital for the performance of the horse. Previously, we showed that in the m. gluteus medius from adult untrained horses, identical mRNA and protein expression patterns were found in the majority of fibres. However, co-expression of IIa and IId/x myosin heavy chain (MyHC) was substantially more common at the protein than at the mRNA level, suggesting a transcriptionally controlled fine-tuning of these 2 genes. Objective: To analyse the MyHC transcripts and proteins (including the cardiac alpha isoform) in the same muscle during post natal developme...
Littlejohn A.The arterial oxygen tension (PaO2) in clinically normal newborn foals at 1300 m above sea-level is considerably lower (less than 60 mmHg) than in similarly aged foals at lower altitudes. This figure is further reduced to less than 50 mmHg without adverse effect in newborn foals at 1300 m maintained under pentobarbitone anaesthesia for prolonged periods. Measurement of O2 dissociation curves indicates that haemoglobin becomes saturated at a lower blood O2 tension in newborn foals than adult horses.
Miyakoshi D, Higuchi T, Ikeda H, Sato M, Yoshimura S.To report a surgical technique and an outcome for the repair of a displaced, transverse scapular body fracture with locking compression plates (LCPs) in a colt. Methods: One 5 month old Thoroughbred colt. Methods: Case report. Methods: A colt sustained an unstable, comminuted, transverse fracture of the scapular body. Three 4.5/5.0 mm LCPs were used with 6.5 mm cancellous screws, 4.5 mm cortex screws, and 5.0 mm locking head screws. Implants were removed 2 months after surgery. Results: Surgical site infection was identified by purulent discharge at the distal aspect of the suture li...
Wohlsein P, Harps O, Trautwein G.The clinical history, clinical, pathological and immunohistological findings of a four-month-old foal with generalised pemphigus foliaceus are presented. The typical lesions of this autoimmune skin disease are described and discussed.
Firth EC, Goedegebuure SA.The long bone ends of foals with infectious disease were sawn into sagittal slabs, washed and inspected. Tissue suspected to be abnormal on the basis of change of colour and consistency was radiographed, and then decalcified and examined histologically. The exact site of 140 focal osteomyelitis lesions from 18 foals was determined. There were more lesions in the epiphysis than the metaphysis. Epiphyseal lesions were in specific sites within a given epiphysis, and in most epiphyses the lesions were at the site of thickest cartilage. Metaphyseal lesions in the metacarpal, metatarsal and distal r...
Palmer JE.Cardiac arrest in foals is generally secondary to other serious systemic diseases. Although it can often be anticipated, a clear plan is vital to success. Establishing cardiac output through chest compressions is the most important first step. This step should be followed by ventilation, drug therapy, identifying the nonperfusing cardiac rhythm, and following a preplanned treatment algorithm. Birth resuscitation requires special treatment considerations. The clinician should be prepared to perform resuscitation any time a birth is attended.
Nieth J, Köhler K, Wehrend A.Two cases of an innate hyperplastic goiter in foals as well as the sonographic evaluation of the hyperplastic gland are presented. One foal displayed skeletal deformities in the form of a mandibular prognathism and forelimb contractures in addition to the swollen thyroid gland. Because of a poor prognosis, the animal was euthanized. The second foal was premature and displayed respiratory signs. Under symptomatic therapy, the goiter regressed within a few weeks.
McClure JM.This article provides an overview of general health care management procedures commonly dealt with by racetrack practitioners. Although some of the conditions discussed are similar to those observed in a non-racetrack practice, the manner in which they are approached usually varies because of the unique circumstances encountered in the racetrack setting.
Fries RC, Clark-Price SC, Kadotani S, Stack JP, Schaeffer DJ, Lascola KM.To compare measurements of left ventricular volume and function derived from 2-D transthoracic echocardiography (2DE), transesophageal echocardiography (TEE), and the ultrasound velocity dilution cardiac output method (UDCO) with those derived from cardiac MRI (cMRI) in healthy neonatal foals. Methods: 6 healthy 1-week-old Standardbred foals. Methods: Foals were anesthetized and underwent 2DE, TEE, and cMRI; UDCO was performed simultaneously with 2DE. Images acquired by 2DE included the right parasternal 4-chamber (R4CH), left apical 4- and 2-chamber (biplane), and right parasternal short-axis...
Huricha , Kawai M, Inose Y, Yamada F, Ninomiya S.In this study, we investigated maternal effects on the growth of Hokkaido native horses kept outdoors throughout the year. We used the data on body weight (BW), height at withers (HW), heart girth (HG), and cannon circumference (CC) of 517 foals during the first year of life to (1) examine the growth patterns by comparing six linear mixed models and (2) analyze the maternal effect on BW, HW, HG, and CC for each month by estimating variance components. The segmented polynomial third-order regression equation was selected as the best model for all the traits. The estimated proportion of variance...
Laan TT, Spoorenberg JF, van der Kolk JH.Intake of Rumex, a plant genus of the Polygonaceae family, probably led through the assimilation of oxalic acid, to hypocalcaemia in a four-week old foal. This foal was presented with muscle rigidity and a stiff gait. Both the total and ionized calcium concentrations were low, 1.38 mmol/l and 0.54 mmol/l respectively. The foal was treated with a total of 150 ml of a 20% calcium solution IV. The foals neuromuscular signs resolved within a few hours after receiving calcium solution.
Lovell JD, Stabenfeldt GH, Hughes JP, Evans JW.The levels of progesterone and total progestins increased during late pregnancy and then fell dramatically during the last few days before parturition, although birth occurred in the presence of significant amounts of plasma progesterone. Oestrogen levels decreased slowly but insignificantly until birth occurred, and then remained at a low level until the post-partum oestrus 10 to 12 days later. Total 11beta-hydroxycorticosteroids were unchanged from Day 45 before to Day 15 after birth. The endocrine pattern of one ovariectomized pregnant mare during the last month of gestation was similar to ...
Wehrend A, Meyer W, Herfen K, Bostedt H.A case of congenital (Erythro)keratoderma variabilis in a newborn foal is described. The clinical and histological findings are presented.
Buening GM, Perryman LE, McGuire TC.Serum concentrations of immunoglobulin M (IgM) and immunoglobulin G (IgG) can be determined in the horse with a satisfactory degree of accuracy, using commercially available reagents. Selected lots of anti-human IgM can be used in precipitation tests to detect and quantitate equine IgM. Commercially available anti-equine IgG tended to overestimate the amount of IgG in single radial immunodiffusion tests. Even with these limitations, commercial reagents can be used to differentiate immunodeficiency disorders of foals, including combined immunodeficiency and failure of passive transfer of colost...
Baird AN, Taylor JR, Watkins JP.Radiographically, osteolysis of the physis consistent with a septic physitis was observed in 3 foals. The foals were treated with surgical debridement and antimicrobials. Two of the horses were sound for use as adults; the third was euthanatized due to concurrent infectious arthritis and septicemia.
Boakari YL, Alonso MA, Riccio AV, Affonso FJ, Losano JDA, Nichi M, Belli CB, Fernandes CB.Information about mule physiology is scarce. Glucose and lactate serve as prognostic tools in neonates; thus, real-time evaluations would be beneficial. Our main objective was to measure glucose and lactate concentrations from healthy mule and equine foals from birth to 720 hours. Glucose and lactate concentrations were evaluated with a benchtop Randox Daytona analyzer (LAB) using plasma and with an Accutrend Plus system (ACP) using whole blood. Data were analyzed using PROC MIXED (P < .05), intraclass coefficient correlation and Bland-Altman analysis. Glucose and lactate concentrations fro...
Hultgren BD.Pulmonary lobar hypertrophy was diagnosed in a 4-hour-old Quarter Horse full-term foal that had respiratory arrest shortly after birth. The gross and microscopic appearances were consistent with polyalveolar lobe, a congenital anomaly of human infants.
Jimenez MM, Kirker-Head CA, Jakowski RM, O'Callaghan MW.Hypoplasia affecting both hind limbs was observed in a neonatal foal. Scintigraphy aided in establishing diagnosis and prognosis. Radiography revealed an abnormally shaped middle phalanx and lack of the distal phalanx and navicular bone in the right hind limb, with an abnormally shaped distal phalanx and navicular bone in the left hind limb. Scintigraphic findings were closely correlated with the radiographic findings. Radiographic and scintigraphic findings were confirmed at postmortem examination.
Pye J, Spriet M, Dow P, Katzman S, Murphy BG.To describe clinical, imaging, gross, and histopathological abnormalities associated with osteochondral necrosis of the femoral condyles in foals and identify features suggestive of a common pathogenesis. 8 Thoroughbred foals euthanized with a presumptive diagnosis of necrosis of the femoral condyles. Postmortem CT was performed on all distal femoral epiphyseal samples. The articular epiphyseal cartilage complex (AECC) of affected distal femurs was examined grossly and histologically, focusing on lesions of interest identified on CT images. 7 foals were between 9 and 23 days old at the time of...
Komosa M, Flisińska-Bojanowska A, Gill J.1. In six foals and their mothers (of Standard breed) diurnal changes in the haemoglobin level, red blood cell number and mean corpuscular haemoglobin during the first 13 weeks of foal life were studied. 2. Studies begun when a foal reached 7 days of age and were repeated every two weeks till 13 weeks of foal life. Blood was taken every 6 hr in foals and every 4 hr in mares. 3. No diurnal rhythmicity in parameters studied either in foals or in mares was found. 4. Decrease of haemoglobin level in lactating mares (14.0-12.5 g/100 ml) without changes in red blood cell number were observed. Mean c...
Ghaeli T, Karimi B, Kojouri GA, Dehkordi RR, Ahadi AM.One of the initial responses of the host's innate immunity of newborns against pathogens is the use of oxidative enzymes. This study aimed to evaluate changes in serum xanthine oxidoreductase (XOR) activity, the leukocyte myeloperoxidase (MPO) and XOR genes expression, and some biochemical parameters in healthy Darehshuri newborn foals up to 60 days of life. Blood samples were collected from 16 foals at 1, 7, 15, 30, and 60 days and used for detecting XOR activity, biochemical parameters, and also gene expression by real-time RT-PCR. High activity of XOR was observed at birth, explained by phy...
Clayton HM, Duncan JL, Dargie JD.The mechanisms involved in the pathophysiological disturbances associated with the presence of mature Parascaris equorum in the small intestine were investigated with radioisotopic techniques. The results suggested that, compared with worm-free controls, infected foals had a reduction in gut motility, an increase in the body solids ratio, a lowering of the body pool of albumin and a decreased ability to incorporate dietary methionine into plasma protein.
Valdes-Martinez A, Eades SC, Strickland KN, Roberts ED.We describe the echocardiographic findings in a 4-day-old thoroughbred foal with an aortico-pulmonary septal defect. The foal had labored breathing, cyanotic mucous membranes and a continuous grade 5/6 heart murmur with point of maximal intensity over the base of the heart on the right side. Echocardiographically, there was a large communication between the aorta and the pulmonary artery just dorsal to the base of the heart. The cardiac anomaly seen during the echocardiographic exam was confirmed at necropsy where a large communication between the two great vessels was observed. These findings...
Markel MD, Meagher DM, Ford TS.A 3-month-old Quarter Horse filly stepped on a fence staple and developed navicular bone osteomyelitis of the right hindfoot. A 1.5-cm spherical portion of medullary cavity containing purulent material was debrided and flushed with 0.9% NaCl solution. Cancellous bone was collected from a caudal sternebra and placed into the defect. The solar defect had filled with granulation tissue and was epithelialized 6 weeks after surgery. At 6-month follow-up evaluation, the navicular bone defect had healed and the foal was sound on the limb. Cancellous bone grafting may have merit for the treatment of n...
Bukowiecki CF, van Ee RT, Schneiter HL.A comminuted scapular fracture in a foal was treated surgically by use of 2 dynamic compression plates. The plates were applied upside down, so that the convex surface of the plate faced the bone. At 5 months after surgery, the plates were removed, and the foal recovered without complications.
