"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.
Todd ET, Hamilton NA, Velie BD, Thomson PC.Horses produce only one foal from an eleven-month gestation period, making the maintenance of high reproductive rates essential. Genetic bottlenecks and inbreeding can increase the frequency of deleterious variants, resulting in reduced reproductive levels in a population. In this study we examined the influence of inbreeding levels on foaling rate, gestation length and secondary sex ratio in Australian Thoroughbred mares. We also investigated the genetic change in these traits throughout the history of the breed. Phenotypic data were obtained from 27,262 breeding records of Thoroughbred mares...
Scheurer L, Bachofen C, Herteman N, Hilbe M, Wolfer N, Schoster A.This case series describes three cases of equine multinodular pulmonary fibrosis (EMPF) diagnosed at the Clinic for Equine Internal Medicine at the University of Zurich between 2012 and 2017. Current information on etiology and treatment options are presented. Two horses showed mild signs of chronic lower respiratory tract disease and one horse was presented with acute signs of disease including recurrent fever spikes and tachypnea. Diagnosis was achieved by physical examination, radiographic findings, and PCR testing for equine herpesviruses (EHV) of bronchoalveolar lavage (BAL) fluid or lung...
Wormstrand BH, Fjordbakk CT, Griffiths DJ, Lykkjen S, Olstad K.Growth cartilage is found in the articular-epiphyseal cartilage complex (AECC) and the physis. It has a temporary blood supply organised as end arteries. Vascular failure is associated with osteochondrosis, but infection can also obstruct vessels. The location of bacteria was recently compared to arterial perfusion, and the results indicated that they were located in the distal tips of AECC end arteries. Systematic perfusion studies were not available for comparison to the infected physes. Further studies may improve our understanding of infections and other pathologies. Objective: To describe...
Riley CB, Jenvey CJ, Baker FJ, Corripio A. To determine if an ELISA for measurement of IgA in equine serum could be used to measure concentrations of IgA in foal faeces and to determine correlations with concentrations in the milk of the dam. Faeces from 20 Welsh Cob and Welsh Pony foals and milk from their dams were collected within 12 hours (Day 0) and at 6 days after parturition (Day 6). On Day 6, faeces could not be collected from 2/20 foals, and milk samples could not be collected from 3/20 mares. An equine IgA ELISA validated for serum and plasma was used to measure concentrations of IgA in all samples in triplicate. The preci...
Iida A, Saito H, Amao A, Fujita T, Kato A, Ueda F.A nutritional supplement containing salacinol (NSS) was administered to Thoroughbred foals daily beginning 21 days after birth, and clinical signs and intestinal microbiota were analyzed. The average number of days for which foals exhibited a fever between 21 and 110 days after birth was determined. The number of days was significantly reduced, by approximately 1/3, in the NSS group compared with the control group. Furthermore, improved weight gain was observed in the NSS group compared with the control group. By analyzing the intestinal microbiota, it was determined that the ratio of Clostrid...
Baptista VDS, Guttmann PM, Rusca AC, Moreira da Silva K, Macieira DB, de Alencar NX, Lessa DAB.Ten mule foals were used to investigate serum IgG concentration. Blood was collected from mares and foals on the day following parturition (D1), at 48 and 72 hr after birth (D2 and D3), and on D7, D14, D21, D28, D35, D42, and D60. Serum IgG concentration was determined by zinc sulfate turbidity test and was above 400 mg/dl at all time points, except for one foal on D2. Mean values were above 800 mg/dl from D1 to D7 and at D60. The difference between mares and foals at each collection time was significant, except at D1. For all other days, foal IgG values were lower than the mare IgG values. Me...
Miagkoff L, Archambault M, Bonilla AG.To describe the antimicrobial susceptibility patterns of the most commonly isolated bacteria cultured from synovial fluid samples from horses with suspected septic synovitis treated at an equine referral hospital between May 1, 2008, and September 24, 2017. Methods: 131 synovial fluid samples from 108 client-owned horses. Methods: A retrospective medical record search was conducted to identify horses with suspected septic synovitis and results of synovial fluid bacterial culture and antimicrobial susceptibility testing. Data collected included signalment, known or suspected origin of synovial ...
Claes A, Cuervo-Arango J, Colleoni S, Lazzari G, Galli C, Stout TA.The success of invitro embryo production (IVEP) in horses has increased considerably during recent years, but little is known about the effect of the speed of invitro embryo development. Blastocysts (n=390) were produced by intracytoplasmic sperm injection of IVM oocytes from warmblood mares, cryopreserved, thawed and transferred into recipient mares on Days 3, 4, 5 or 6 after ovulation. The time required for invitro-produced (IVP) embryos to reach the blastocyst stage was recorded (Day 7 vs Day 8). The likelihood of foaling was affected by the speed of invitro embryo development and recipient...
Canisso IF, Ellerbrock RE, Wilkins PA.An 18-hour-old colt was presented for abdominal discomfort, preputial swelling, and frequent posturing to urinate. Examination of the scrotum confirmed 2 testes and no scrotal or inguinal hernia. Transabdominal ultrasound identified a distended bladder and no free fluid in the peritoneal cavity. Inspection of the preputial cavity revealed that the internal lamina of the prepuce was mostly attached to the glans penis. The preputial cavity was lubricated and manual traction was applied to detach the internal lamina of the prepuce from the glans penis. The colt urinated spontaneously 1 hour after...
Barton MH, Hart KA.The dynamic physiologic changes and unique diet during the neonatal period contribute to key differences in clinicopathologic test results of healthy foals relative to healthy adult horses. When reporting results, most diagnostic laboratories only provide reference intervals for mature horses. Thus, failure to recognize the unique differences that occur in foals relative to adult horses can lead to erroneous interpretation of neonatal clinical pathologic values. Thus, the main objective of this article was to review distinct features of common clinicopathologic tests in foals, relative to matu...
Kamr AM, Dembek KA, Gilsenan W, Bozorgmanesh R, Hassan HY, Rosol TJ, Toribio RE.Hypocalcemia is a common finding in critically ill equine patients. Parathyroid hormone (PTH) helps to maintain calcium homeostasis in hypocalcemic patients by promoting renal calcium reabsorption and bone resorption. Increased serum PTH concentrations have been reported in critically ill people and animals, including horses and foals. It is unknown whether increased secretion of PTH is associated with markers of bone turnover in hospitalized foals. The goals of this study were to measure markers of bone resorption (C-terminal telopeptide of type I collagen [CTX-I]) and bone formation (osteoca...
Souza JRM, Gonçalves PBD, Bertolin K, Ferreira R, Ribeiro ASS, Ribeiro DB, Rechsteiner SMDEF, Araújo RR, Pimentel CA, Pimentel AMH.The aim of the present study was to evaluate the correlation of age and heat cycle to determine reproductive efficiency in young and aged Thoroughbred mares bred on foal heat (FH) or on second heat (SH) after foaling. Embryo mortality (EmbM) was determined every time a mare was found open after a positive pregnancy diagnosis. Parturition to breeding interval, pregnancy rate (PregR) and EmbM rate were the dependent variables and the treatments were breeding on the FH or on SH. The cutoff age to obtain above-average probability for the EmbM was 10 years old. PregR in mares bred on FH was lower ...
Mortola E, Miceli G, Alarcon L, Azcurra M, Larsen A.In newborn foals the absorption of colostrum immunoglobulins in the small intestine is maximal up to 8 hours after birth and then progressively decreases to become null after 24 hours post-partum. Thus, equine practitioners need a simple, quick, inexpensive and reliable field test to identify foals affected by failure of passive transfer rather than an accurate method yielding quantitative results within the whole range of immunoglobulin concentrations. Objective: As the validity of the immunocrit method to detect failure of passive transfer in foals had not been evaluated before, the object...
Henry S, Sigurjónsdóttir H, Klapper A, Joubert J, Montier G, Hausberger M.Artificial weaning is a standard practice known to be one of the most stressful events in a domestic foal's life. Research has mainly focused on ways to alleviate weaning stress. However, there is still a need for more detailed research on what should constitute best practices with respect to animal welfare. The aim of this review is to address this issue by examining the natural weaning process. We first provide an overview of the scientific literature on the natural temporal dynamics of the dam-offspring bond in horses: it is to be noted that the natural process of weaning is little document...
Bergmann W, de Mik-van Mourik M, Veraa S, van den Broek J, Wijnberg ID, Back W, Gröne A.In Warmblood horses, degenerative joint disease is involved in cervical malformation and malarticulation (CVM). The degree of contribution of articular process joint (APJ) osteochondrosis (OC) is not clear. Objective: (a) To explore the presence of predilection sites for APJ OC in cervical and cranial thoracic vertebral columns of Warmblood foals and (b) to examine the correlation of such a site with the predilection site of CVM. Methods: Case series. Methods: Seven hundred APJ facets of C2 to T2 of 29 foals (11 months gestation to 12 months [median age 7 days; range 365 days; 95% confiden...
Gilday R, Richard H, Beauchamp G, Fogarty U, Laverty S.The administration of bisphosphonate medications, which target osteoclastic-bone remodelling, to juvenile and adult racehorses is a matter of debate owing to concerns that these molecules remain bound to the bone-mineralised matrix and may interfere with subsequent bone growth, adaptation to exercise and healing of bone microdamage in equine athletes. Osteoclasts participate in endochondral ossification, subchondral bone remodelling and bone repair. There is a knowledge gap on the role of equine osteoclast biology in the growth and maturation of joint surfaces and this information is important...
Tirosh-Levy S, Gottlieb Y, Mimoun L, Mazuz ML, Steinman A.Although the main route of transmission of is through tick feeding, transplacental transmission is also possible and may lead to abortion, or to the birth of a sick or carrier foal. The aim of this study was to evaluate the role of as a cause of abortions in Israel and the risk of foals being infected at a young age. Eight aborting mares were serologically evaluated for exposure to via the immunofluorescence antibody test (IFAT) and their aborted fetuses were evaluated using PCR and qPCR. In addition, five mares and their foals (aged 4-6 months) from a highly endemic farm were tested for i...
Mehdizadeh Gohari I, Unterer S, Whitehead AE, Prescott JF.The role of type A in canine acute hemorrhagic diarrhea syndrome and foal necrotizing enteritis is poorly characterized. However, a highly significant association between the presence of novel toxigenic and these specific enteric diseases has been described. These novel toxigenic strains produce 3 novel putative toxins, which have been designated NetE, NetF, and NetG. Although not conclusively demonstrated, current evidence suggests that NetF is likely the major virulence factor in strains responsible for canine acute hemorrhagic diarrhea syndrome and foal necrotizing enteritis. NetF is a be...
Cooper LG, Caffe G, Cerutti J, Nielsen MK, Anziani OS.Macrocyclic lactones are the most widely used drugs for the control of gastrointestinal nematodes of horses in Argentina. Ivermectin and moxidectin are used as broad spectrum anthelmintics and although there are several international reports on the resistance of Parascaris spp., the resistance status of the local nematode population is largely unknow. This report informs a case of suboptimal efficacy to both drugs to control Parascaris spp in foals in central Argentina. In February 2018, routine fecal parasite egg counts showed a moderate-high number of Parascaris spp eggs (mean = 680 eggs p...
Nagel C, Aurich J, Aurich C.Economic losses due to dystocia or neonatal death as well as animal welfare and ethical concerns demand a reliable prediction of parturition with the aim to improve survival of the dam and her offspring. In this review, estimation of gestational age by ultrasound and prediction of parturition based on clinical signs, behaviour changes and changes in body temperature, composition of mammary gland secretions as well as hormonal changes are discussed in comparison between horses and cattle. Based on the physiological changes associated with the end of gestation and onset of labor, several systems...
Arnold-Lehna D, Venner M, Berghaus LJ, Berghaus R, Giguère S.There is a lack of data on the efficacy of treatment of Rhodococcus equi pneumonia in association with an optimised selection of foals. Objective: To evaluate whether targeted treatment protocols resulting in decreased antimicrobial use impact foal mortality rates. Methods: Retrospective study. Methods: Three hundred and thirty foals with pneumonia per year were randomly selected from 2008 to 2016. All foals were examined once weekly from birth until weaning. A physical examination of the respiratory tract, body temperature, haematology and an ultrasonographic examination of the lungs was incl...
Wetzig M, Venner M, Giguère S.Given the importance of rifampin in treatment protocols for tuberculosis in people, its use in veterinary medicine is under increasing scrutiny in some countries and alternatives might be needed in the near future. Objective: This study was set up to evaluate whether azithromycin combined with doxycycline is effective for the treatment of bronchopneumonia in foals and noninferior to the combination of azithromycin and rifampin. Methods: This is a controlled, randomised and double-blinded clinical trial. Two hundred and forty foals on a farm endemic for infections caused by Rhodococcus equi wer...
Saliou G, d'Ablon X, Théaudin M, Saliou T, Bourassi S.Performing a brain computerized tomography scan (CT scan) on a foal requires specific equipment and anesthesia for large animals. However, the information obtained may demonstrate lesions responsible for the neurological deficits. Especially, CT scan findings may help to understand a mechanism of cerebral ischemia. Indeed, categories of cerebral ischemia are divided in three types: territorial infarctions (downstream of the territory of an artery), watershed infarctions (slow-flow at the junction of two arterial territories), and lacunar infarctions (small-vessel occlusions). Hypersensitivity ...
Wilkes EJA, Heller J, Raidal SL, Woodgate RG, Hughes KJ.Information regarding parasite control practices currently used on Thoroughbred and Standardbred studs in Australia is lacking. Anthelmintic resistance (AR) is a global problem which has implications for equine health and welfare. Objective: To identify parasite control practices currently used on horse studs in Australia and investigate the frequency of use of management factors that have been associated with the likelihood of promoting or delaying AR. Methods: Questionnaire study of equine parasite control on Thoroughbred and Standardbred studs in Australia. Methods: An online questionnaire ...
Theelen MJP, Wilson WD, Byrne BA, Edman JM, Kass PH, Mughini-Gras L, Magdesian KG.Antimicrobial treatment protocols for foals with sepsis that do not improve clinically often are adjusted based on bacteriological and antimicrobial susceptibility testing results from samples collected at hospital admission. Objective: To evaluate whether hospitalization for ≥48 hours affects bacteriological and antimicrobial susceptibility testing results. Methods: Two-hundred sixty-seven foals <30 days of age admitted to a neonatal intensive care unit and diagnosed with sepsis. Methods: Medical records were reviewed retrospectively to identify foals with sepsis and positive bacteri...
Saitua A, Becero M, Argüelles D, Castejón-Riber C, Sánchez de Medina A, Satué K, Muñoz A.Horse trainers often claim that exercise on a water treadmill (WT) leads to a greater muscle power and development compared to terrestrial locomotion, because of the greater viscosity of water compared to air. This research assesses locomotor changes measured with accelerometers fixed in the pectoral region and in the sacrum midline in six horses subjected to exercise sessions of 40 min duration on a WT without water (DT), and with water at the depth of fetlock (FET) and carpus (CAR) with velocities of 6 km/h and at the depth of stifle (STF) at 5 km/h. Another five horses performed the same ex...
Fouché N, Graubner C, Lanz S, Schweighauser A, Francey T, Gerber V.Four 2-month-old foals were presented to an equine hospital with acute kidney injury caused by Leptospira interrogans infection. Clinical signs were nonspecific and included lethargy, fever, and unwillingness to nurse. The most important hematologic and clinicopathologic findings were azotemia, anemia, thrombocytopenia, hyponatremia, and hypochloremia. The diagnosis was based on urinary real-time PCR, serology using a microscopic agglutination test, or both. The most important serovars involved were L. interrogans serogroup australis serovar Bratislava and Australis. Treatment consisted of IV ...
Hannan MA, Haneda S, Murata K, Takeuchi S, Cheong SH, Nambo Y.Until now, there have been no reports of foals born through embryo transfer after artificial insemination using frozen semen in Japan. The aims of this study were to develop a riding crossbred horse and evaluate the prospects of embryo transfer technology in multiplying horse population. In both donor and recipient mares, luteolysis was induced by the administration of 0.1 mg Cloprostenol to synchronize the onset of estrus, and ovulation was induced by administering 2000 IU human chorionic gonadotropin (hCG) or 0.75 mg Deslorelin. Frozen semen from an Irish Connemara pony stallion was used to ...
Álvarez-Narváez S, Berghaus LJ, Morris ERA, Willingham-Lane JM, Slovis NM, Giguere S, Cohen ND.The practice of prophylactic administration of a macrolide antimicrobial with rifampin (MaR) to apparently healthy foals with pulmonary lesions identified by thoracic ultrasonography (i.e., subclinically pneumonic foals) is common in the United States. The practice has been associated epidemiologically with emergence of R. equi resistant to MaR. Here, we report direct evidence of multi-drug resistance among foals treated with MaR. In silico and in vitro analysis of the fecal microbiome and resistome of 38 subclinically pneumonic foals treated with either MaR (n = 19) or gallium maltolate (...
Giosuè C, Alabiso M, Russo G, Alicata ML, Torrisi C.In Italy, the interest for jennet milk production has recently developed. An 18-month-long experiment was carried out on a jennet farm near Milo (CT), where 24 jennets, which derived from the Ragusana breed, were tested for milk yield and composition over an entire lactation period. The jennets were fed with hay and concentrate in a large paddock. From the 28th post-foaling day to the end of the lactation, the jennets were machine-milked twice a day with an in-between milking interval of 5 h. The milk amount from each jennet was recorded every 3 weeks and individual samples were collected and ...
Ringger NC, Giguère S, Morresey PR, Yang C, Shaw G.Neonatal hypoxic-ischemic encephalopathy (NHIE) is a disease affecting newborn foals for which there is no antemortem diagnostic test. Objective: Ubiquitin C-terminal hydrolase 1 (UCHL1) and the phosphorylated axonal forms of neurofilament H (pNF-H) are markers of brain injury in foals with NHIE. Methods: Thirty-three foals with a clinical diagnosis consistent with NHIE and 17 healthy foals. Methods: Retrospective study. Concentrations of UCHL1 and pNF-H in plasma were measured by ELISA. The performance of the assays for the diagnosis of NHIE was assessed by receiver operating characteristic c...
Hart KA, Dirikolu L, Ferguson DC, Norton NA, Barton MH.To compare daily endogenous cortisol production rate and the pharmacokinetics of an i.v. bolus of hydrocortisone between neonatal foals and adult horses. Methods: 10 healthy full-term 2- to 4-day-old foals and 7 healthy adult horses. Methods: Blood samples were collected from each horse every 15 to 20 minutes for 24 hours for determination of 24-hour mean cortisol concentration. Afterward, dexamethasone (0.08 mg/kg) was administered i.v. to suppress endogenous cortisol production. Twelve hours afterward, hydrocortisone sodium succinate (1.0 mg/kg) was administered as a rapid i.v. bolus and ser...
LeBlanc MM.Ascending placentitis is a common cause of premature birth, abortion and delivery of compromised, ill foals. Recent experimental models have investigated diagnostic procedures and treatment strategies in an attempt to improve live foal rate. Diagnostics such as transrectal and transabdominal ultrasonography are used to evaluate foetal well-being and placental separation, while measurement of plasma progestins or oestrogen identifies a stressed or hypoxic foetus. Treatment is directed at stopping spread of infection, maintaining uterine quiescence and blocking production of pro-inflammatory cyt...
Mallicote M, House AM, Sanchez LC.Diarrhoea is among the most common clinical complaints in foals. Aetiologies, diagnostic testing and recommended interventions for specific causes of enterocolitis are summarised. Many mild to moderately affected foals can be managed in an ambulatory setting, while others will benefit from more intensive care at a referral centre.
Smith BP, Robinson RC.Five out of 6 foals between 2 and 4 months old, on a ranch in northern California, developed pneumonia within a 3 week period in June and July 1978. Corynebacterium equi was recovered from each of the 5 foals by transtracheal aspiration. Clinical signs were variable but included increased respiratory rate, fever, cough, nasal discharge, harsh airway sounds over middle sized airways and wheezing over small airways. Cyanosis was present in the most severely affected foal. Radiographic findings included diffusely increased interstitial and peribronchial densities, areas of consolidation and, in 3...
Traub-Dargatz JL, Jones RL.A review of the literature describing clostridia-associated enterocolitis is presented. The bacteria, their toxins, and possible factors that interact to contribute to the pathogenesis of enterocolitis are described. Clinical signs associated with clostridia-associated enterocolitis, methods of diagnosis, treatments, and preventive strategies are discussed.
Gambini A, De Stefano A, Bevacqua RJ, Karlanian F, Salamone DF.Embryo aggregation has been demonstrated to improve cloning efficiency in mammals. However, since no more than three embryos have been used for aggregation, the effect of using a larger number of cloned zygotes is unknown. Therefore, the goal of the present study was to determine whether increased numbers of cloned aggregated zygotes results in improved in vitro and in vivo embryo development in the equine. Zona-free reconstructed embryos (ZFRE's) were cultured in the well of the well system in four different experimental groups: I. 1x, only one ZFRE per microwell; II. 3x, three per microwell;...
Olstad K, Ytrehus B, Ekman S, Carlson CS, Dolvik NI.It is presently unknown whether cartilage ischaemia plays any part in the pathogenesis of osteochondral fragmentation within the equine metatarsophalangeal joint, as no detailed studies on microcirculation in the area have been reported. Objective: To describe the developmental pattern of the blood supply to the epiphyseal growth cartilage in the metatarsophalangeal joint of foals. Methods: Eight Standardbred foals were sacrificed between birth and age 7 weeks to undergo a barium perfusion procedure to demonstrate vessels within growth cartilage canals of one hindlimb. The metatarso-phalangeal...
Dickie CW, Klinkerman DL, Petrie RJ.Two Quarter Horse foals from different premises died from enterotoxemia. Clostridium perfringens toxins alpha and beta were demonstrated in the foal's intestines by mouse protection tests. Clostridium perfringens type C was isolated from the intestines of each foal. Histologic examination revealed hemorrhage, necrosis, and massive numbers of C perfringens.
Johnson R, Ramos-Vara J, Vemulapalli R.This report describes the characterization of a Bartonella henselae abortion in an equine fetus by gross, histologic, immunohistochemical, ultrastructural, and molecular methods. Bartonella henselae can cause cat scratch disease, bacillary angiomatosis, bacillary peliosis, and endocarditis in humans and other animals. The bacterium has been isolated from several mammalian species but only recently from equids; however, it has not been linked to abortion in equids. An aborted equine fetus exhibited necrosis and vasculitis in multiple tissues, with intralesional Gram-negative short-to-spirillar ...
Sevinga M, Vrijenhoek T, Hesselinks JW, Barkema HW, Groen AF.This study was motivated by the hypothesis that the incidence of retained placenta (RP) in Friesian horses is associated with inbreeding. The objectives were to 1) calculate the inbreeding rate in the total registered Friesian horse population; 2) study the association of the inbreeding coefficient of the foal and the mare with the incidence of RP; and 3) study the heritability of RP in Friesian mares after normal foalings. Data from the total registered Friesian horse population from 1879 to 2000 (52,392 individuals) were collected from the registration files of the Friesian Horse Studbook. I...
Szeredi L, Tenk M, Jánosi S, Pálfi V, Hotzel H, Sachse K, Pospischil A, Bozsó M, Glávits R, Molnár T.Cases of equine abortion and perinatal foal losses were investigated in Hungary during a three-year period (1998-2000). Samples from aborted equine fetuses and newborn foals (total n = 96) were examined using bacteriological, virological, pathological, immunohistochemical (IHC), molecular biological and serological methods. The cause of abortion and perinatal foal loss was identified in 67/96 cases (70%); viral infection was found in 22 (23%), viral and bacterial coinfection in 1 (1%), bacterial infection in 23 (24%), protozoan infection in 1 (1%) and fungal infection in 2 cases (2%). Morpholo...
Roach JM, Foote AK, Smith KC, Verheyen KL, de Mestre AM.Pregnancy loss after Day 70 of gestation manifests as abortion, stillbirth or perinatal death. While previous studies have reported the diagnoses of laboratory submissions, none have quantified the incidence and causes of abortions, stillbirths and perinatal mortality at a population level. Objective: To report the incidence and causes of pregnancy loss after Day 70 of gestation in a cohort of Thoroughbreds. Methods: Retrospective cohort study. Methods: Outcomes of Day 70 pregnancies were collected from eight Thoroughbred farms over the 2013-2017 breeding seasons. Stud, veterinary and laborato...
Masri MD, Merritt AM, Gronwall R, Burrows CF.Developmental changes of the gastrointestinal tract were probably responsible for the changes in faecal composition during the first week of the foals' life, which resembled small intestinal ingesta of adult horses, suggesting a minimal colonic modification. Faecal composition at the time of foal heat diarrhoea was suggestive of a secretory-type diarrhoea, in that the electrolyte concentration accounted for most of faecal osmolality and the faecal pH was alkaline. After foal heat diarrhoea faecal composition slowly approached that of adult horses. These data suggest that foal heat diarrhoea is...
Oswald S, Peters J, Venner M, Siegmund W.Clarithromycin (CLA) is a well established macrolide antibiotic which is frequently used in therapy of airway diseases in foals. It is extensively metabolized by CYP3A4 resulting in the antimicrobial active metabolite 14-hydroxyclarithromycin (OH-CLA). Rifampicin (RIF) is often comedicated to prevent resistance and augment therapy. RIF is a known inducer for metabolizing enzymes and transporter proteins. Therefore, comedication might bare the risks of pharmacokinetic drug interactions which were investigated in a clinical trial. As no adequate method to determine CLA, RIF and their main metabo...
Overbeck W, Jäger K, Schoon HA, Witte TS.Endometritis constitutes a major problem in managing broodmares. The histological occurrence of polymorphonuclear neutrophils (PMNs) in the stratum compactum of the endometrium is accepted as the reference standard to diagnose endometritis in mares. The objective of this study was to determine the distribution of PMNs within different sampling locations of the uterus by cytological examinations and to compare it with PMN numbers in endometrial biopsies of the corresponding location. Cytological and endometrial samples were obtained from 37 uteri within 2 ± 1 hours after slaughter through smal...
Sevinga M, Barkema HW, Stryhn H, Hesselink JW.During the foaling seasons of 1999 and 2000, the incidence of retained placenta in 495 normal parturitions of 436 Friesian brood mares was studied. Retained placenta was defined as a failure to expel all fetal membranes within 3 h of the delivery of the foal. Furthermore, the sex of the foal, month of breeding, sire and dam's sire, age of the mare, and time of day of foaling, were studied as factors that might be associated with retained placenta in Friesian mares after normal foalings, and with gestational length. The analysis was carried out using marginal logistic regression, and mixed line...
Franke A, Kershaw O, Jenckel M, König L, Beer M, Hoffmann B, Hoffmann D.The article describes the isolation of a cowpox virus (CPXV) isolate originating from a horse. The skin of a foal, aborted in the third trimester, displayed numerous cutaneous papules. The histological examination showed A-type inclusion bodies within the lesion, typical for CPXV infections. This suspicion was confirmed by real-time PCR where various organs were analyzed. From skin samples, virus isolation was successfully performed. Afterwards, the whole genome of this new isolate "CPXV Amadeus" was sequenced by next-generation technology. Phylogenetic analysis clearly showed that "CPXV Amade...
Varrasso A, Dynon K, Ficorilli N, Hartley CA, Studdert MJ, Drummer HE.To develop and validate specific, sensitive and rapid (< 8 hour) diagnostic tests using polymerase chain reaction (PCR) for the diagnosis of abortion and respiratory disease caused by equine herpesvirus 1 (EHV1; equine abortion virus) and EHV4 (equine rhinopneumonitis virus). Methods: Primer sets based on nucleotide sequences encoding glycoprotein H (gH) of EHV1 and gB of EHV4 were designed and used in single round and second round (seminested) PCRs, and in a multiplex PCR for the diagnosis of EHV1 and EHV4 infections. Methods: Oligonucleotide primers were designed for each virus, PCR condi...
Pozza ME, Kaewsakhorn T, Trinarong C, Inpanbutr N, Toribio RE.Vitamin D is essential in calcium and phosphorus regulation, bone physiology, cell proliferation and epithelial integrity. Literature on vitamin D in growing horses is sparse, and the effect of age on vitamin D has not been evaluated in equids in the United States or in tropical countries. The goal of this study was to determine if there was an effect of age on serum 25(OH)D3 concentrations in equids in the US (Ohio/Kentucky) and Thailand (Chiang Rai and Kanchanaburi) during the same time of the year. Blood samples were collected from healthy ponies (n=21) and Thoroughbred foals (n=13), yearli...
Dawson DR, Nydam DV, Price CT, Graham JE, Cynamon MH, Divers TJ, Felippe MJ.To investigate the effect of opsonization of Rhodococcus equi with R. equi-specific antibodies in plasma on bacterial viability and phagocyte activation in a cell culture model of infection. Methods: Neutrophils and monocyte-derived macrophages from 6 healthy 1-week-old foals and 1 adult horse. Methods: Foal and adult horse phagocytes were incubated with either opsonized or nonopsonized bacteria. Opsonization was achieved by use of plasma containing high or low concentrations of R. equi-specific antibodies. Phagocyte oxidative burst activity was measured by use of flow cytometry, and macrophag...
The paper is a report from a workshop discussing equine endometritis, a condition affecting horse fertility. The event was held in honor of Professor John Hughes and his significant contributions […]
Ryan C, Giguère S.The objectives of this study were to compare relative vaccine-specific serum immunoglobulin concentrations, vaccine-specific lymphoproliferative responses, and cytokine profiles of proliferating lymphocytes between 3-day-old foals, 3-month-old foals, and adult horses after vaccination with a killed adjuvanted vaccine. Horses were vaccinated intramuscularly twice at 3-week intervals with a vaccine containing antigens from bovine viral respiratory pathogens to avoid interference from maternal antibody. Both groups of foals and adult horses responded to the vaccine with a significant increase in ...
Alanazi AD, Mukbel RM, Alyousif MS, AlShehri ZS, Alanazi IO, Al-Mohammed HI.In the last decade, Parascaris spp. resistance to anthelmintics has been recorded in many countries. In Saudi Arabia, there are limited data available on Parascaris spp. resistance to anthelmintics. Objective: To determine the current status of ivermectin, abamectin and praziquantel combined, and fenbendazole resistance to Parascaris spp. in horses in Saudi Arabia. Methods: Three hundred and forty-one foals from eleven different farms were examined by faecal egg count (FEC). The foals were all Arab horses aged 17.2 ± 4.5 (SD) months. Ivermectin (n = 46 foals), abamectin and praziquantel combi...
Chaffin MK, Cohen ND, Martens RJ, O'Conor M, Bernstein LR.To determine the chemoprophylactic effect of gallium maltolate on the cumulative incidence of pneumonia caused by Rhodococcus equi infection in foals. Methods: 483 foals born and raised on 12 equine breeding farms with a history of endemic R equi infections. Methods: Group 1 foals were treated with a placebo and group 2 foals were treated with gallium maltolate (approx 30 mg/kg, PO, q 24 h) during the first 2 weeks after birth. Foals were monitored for development of pneumonia attributable to R equi infection and for adverse effects of gallium maltolate. Results: There were no significant diff...
Folmar CN, Cywes-Bentley C, Bordin AI, Rocha JN, Bray JM, Kahn SK, Schuckert AE, Pier GB, Cohen ND.The bacterium Rhodococcus equi can cause severe pneumonia in foals. The absence of a licensed vaccine and limited effectiveness of commercial R. equi hyperimmune plasma (RE-HIP) create a great need for improved prevention of this disease. Objective: Plasma hyperimmune to the capsular polysaccharide poly-N-acetyl glucosamine (PNAG) would be significantly more effective than RE-HIP at mediating complement deposition and opsonophagocytic killing (OPK) of R. equi. Methods: Venipuncture was performed on 9 Quarter Horses. Methods: The ability of the following plasma sources to mediate complement com...
