Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Bostedt H, Lehmann B, Peip D.Based on a group of 33 mares infected with mastitis, data regarding the time of appearance, the clinical symptoms and the bacteriological causes of the disease were evaluated. The cases were distributed as follows: 27.3% before delivery, 24.2% immediately after delivery (until the third day), 12.1% during the middle and late stages of lactation, 9.1% immediately after the weaning of the foal and 27.3% outside the lactation period of non-pregnant mares. The clinical picture is described. In the majority of the cases, both halves of the udder were infected. The analysis of the bacteriological re...
Dawson J, Lees P, Sedgwick AD.Equine polymorphonuclear (PMN) and mononuclear (MN) leucocytes were separated on Percoll gradients and used to study the chemoattractant properties of the polar ether-linked phospholipid, platelet activating factor (PAF). Six concentrations of PAF ranging from 1 ng/ml to 100 micrograms/ml were studied in each of two in vitro assay systems, the agarose microdroplet and a microfilter technique. Very significant (p less than 0.01) increases in the movement of both PMN and MN cells were obtained with most concentrations of PAF. In two instances there was no apparent concentration-response relation...
Anderson RR, Nixon DA, Akasha MA.1. Blood samples were obtained from seven species of mammals: horses, cattle, sheep, goats, pigs, guinea pigs and rats for determination of total and free thyroxine and triiodothyronine. Total thyroxine in the order listed above in ng/ml was: 15, 60, 79, 185, 53, 45 and 79. Free thyroxine in pg/ml was: 5.9, 10.0, 19.2, 32.1, 21.7, 6.7 and 51.3. 2. Total triiodothyronine in pg/ml was: 677, 1290, 979, 3170, 760, 317 and 1747. Free triiodothyronine in pg/ml was: 3.22, 4.40, 2.60, 6.74, 2.74, 2.42 and 10.88. 3. Percent free thyroxine was high in rats and low in guinea pigs, while percent free trii...
Koterba AM, Kosch PC, Beech J, Whitlock T.To investigate the mechanism underlying the polyphasic airflow pattern of the equine species, we recorded airflow, tidal volum, rib cage and abdominal motion, and the sequence of activation of the diaphragm, intercostal, and abdominal muscles during quiet breathing in nine adult horses standing at rest. In addition, esophageal, abdominal, and transdiaphragmatic pressures were simultaneously recorded using balloon-tipped catheters. Analysis of tidal flow-volume loops showed that, unlike humans, the horse at rest breathes around, rather than from, the relaxed volume of the respiratory system (Vr...
McClure JJ, Koch C, Powell M, McClure JR.Associations were sought between ELA A1-A10 and W11 antigens and the presence of laryngeal hemiplegia, arytenoid chondritis, umbilical hernias and cryptorchidism in Thoroughbreds and/or Quarter Horses. No significant associations were detected between laryngeal hemiplegia and any ELA antigen in Thoroughbreds. The association between arytenoid chondritis and A9 was significant with a relative risk (RR) of 15.6 and aetiologic fraction (EF) of 0.80 in Thoroughbreds. There were apparent associations based on RR between A4 and A5 in Quarter Horses with umbilical hernias (RR = 7.5 and 6.1 respective...
Bowling AT, Scott AM, Flint J, Clegg JB.Four minor haplotypes that produce abnormal haemoglobin phenotypes in horses have been characterized. Two of them, AIIb and V, are copy number variants with, respectively, one and three alpha genes instead of the normal complement of two. The AIIa and C haplotypes, on the other hand, each have two alpha genes but, as a result of probable gene conversions, they now encode identical, though haplotype specific, globins. Two out of 60 unrelated and phenotypically normal horses studied had an unusual triplicated rearrangement in the embryonic zeta-gene locus. Each of these variants appears to have ...
Serteyn D, Deby-Dupont G, Pincemail J, Mottart E, Philippart C, Lamy M.Arachidonic acid cyclooxygenase metabolites, thromboxane B2 (TXB2), prostaglandin E2 (PGE2) and 6-keto-prostaglandin F1 (6-keto-PGF1) were measured in horses where anaesthesia was maintained with halothane. Two horses suffering from postanaesthetic myositis were compared with four normal horses. TXB2 and PGE2 levels were higher in mixed venous blood drawn from the myopathic horses. An increase of TXB2 and PGE2 levels appeared when myopathic horses were rolled into dorsal recumbency after a prolonged period of lateral recumbency. One hour after the end of anaesthesia, TXB2 had continued to incr...
Adams R, Koterba AM, Brown MP, Cudd TC, Baker WA.The medical records of 20 neonatal foals in which exploratory celiotomies were performed for gastrointestinal disease were reviewed. In all 20 foals, persistent pain and/or progressive abdominal distension were the primary clinical findings influencing the decision to operate. However, ancilliary laboratory data were important to the proper medical management of these foals during anaesthesia and following surgery. Surgical diagnoses of the 20 foals included ileus (nine foals; 45 per cent), small colon obstruction (five foals; 25 per cent), large colon displacement (three foals; 15 per cent), ...
Thorén-Tolling K.Serum alkaline Phosphatase isoenzyme (ALP) activity was measured by agarose gel electrophoresis in horses, Swedish half-breds and trotters, of varying age and during different conditions of training. Thus the effects of aging and growing on the isoenzyme activities from birth up to about 3 years of age was studied. The influence of training during the first year of life on the ALP isoenzyme pattern was also evaluated. Furthermore the isoenzyme pattern in adult horses suffering from different kinds of diseases was studied.
In newborn and very young horses normally two different isoenzyme fra...
Smith CM, Steffey EP, Baggot JD, Dunlop CI, Farver TB.Inhalation anesthetics decrease the clearance of some drugs that are eliminated by renal excretion. The purpose of the study reported here was to investigate the effects of halothane anesthesia on the pharmacokinetics and urinary excretion of gentamicin sulfate, using the horse as a model. Using a crossover design, pharmacokinetic values after a single IV dose of gentamicin (4 mg/kg) were compared in halothane-anesthetized and unanesthetized horses. Compared with unanesthetized horses, the anesthetized horses had significant decreases in total body clearance (P less than 0.01) and apparent vol...
Edmunds DH, Whittaker DK, Green RM.The progress of artificial caries-like lesions created in human, bovine, equine, and ovine enamel has been studied. Lesions were produced by exposure to an acid gel system or by 5-day exposure to a sequential batch culture technique using Streptococcus mutans NCTC 10832. Longitudinal ground sections were prepared. The lesions were of similar appearance in all species when examined in polarized light. The depth in human enamel was approximately half that in the animal species. Microradiography confirmed subsurface demineralization in all four species. Similar depth ratios were seen in the scann...
Bowling AT, Wictum E.A fourth allele at the horse erythrocyte phosphohexose isomerase (Phi) locus was proposed to account for phenotypes observed after starch gel electrophoresis and enzymatic staining of red cell lysates from American Saddlebred and Tennessee Walking Horse breeds. The gene was rare, having an estimated frequency of 0.009 in 949 Saddlebreds tested.
Lyons ET, Drudge JH, Tolliver SC.During 1986, fecal specimens were collected 1 or more times from each of 164 horse foals (158 Thoroughbred and 6 mixed light horse type), ranging in age from 0 to 252 days, on 13 farms in central Kentucky. To detect natural infection with Eimeria leuckarti, feces were examined for oocysts. Oocysts were found in 67 (41%) of the foals on 11 (85%) of the farms. The earliest age at which oocysts were first detected was 15 days (1 foal); the latest age was 123 days (1 foal). The mean age for the first appearance of oocysts in the feces of the 67 foals positive for E leuckarti was approximately 70 d...
Sambraus HH.Due to motorization the heavy horses, in particular draught horses and carriage horses, were deprived of their "raison d'être". At present therefore, they mostly are found in small livestocks. The past few years they regained some significance through their work in the forests, as an attraction in tourism or somewhere else. In German speaking countries approximately 15 horse breeds must be considered to be threatened in their existence. Breeding history, appearance, use and geographical distribution of 12 of them are discussed in this article.
de Paz Cabello P, Chamorro CA, Sandoval J, Fernandez M.The mechanical papillae of the horse and cow were studied by scanning electron microscopy in order to determine their morphostructural characteristics and the differences between the two species. The horse has only thin, small and interlaced filiform papillae, while the cow shows robust and more ordered filiform papillae. Furthermore, the cow tongue presents conical and lenticular papillae surrounded by a papillary groove. A characteristic distribution of stratified scales and channeled tracts is observed in conical and lenticular papillae but not in the filiform papillae. The morphostructural...
Principato M.Listed and described herein are the main macroscopic lesions produced along the whole digestive tract of free-ranging horses by larvae of the five Gasterophilus spp., occurring in Umbria, a region of central Italy: Gasterophilus intestinalis, Gasterophilus nasalis, Gasterophilus pecorum, Gasterophilus inermis, Gasterophilus haemorrhoidalis. Lesions are classified on the basis of their sizes and shapes and the host's anatomic sites infested, and they are examined in relation to the developmental stages of larvae causing them. The examination of the lesions shows that it is very difficult to dif...
Kent MG, Elliston KO, Shroeder W, Guise KS, Wachtel SS.In situ hybridization with a cloned banded krait sex-specific repetitive DNA probe (Bkm) indicates a high concentration of Bkm sequences on the horse Y chromosome in both normal XY males and XY sex-reversed females. Lesser, but still significant, concentrations of Bkm sequences were mapped to horse chromosomes 3, 4, and 30.
King SS, Evans JW.Follicular growth, circulating estradiol concentrations and endometrial prostaglandin F2 alpha (PGF2 alpha) production were measured to determine whether there is an interrelationship among these factors associated with luteolysis. Follicular growth was monitored by rectal palpation every other day during diestrus in 16 mares. Plasma estradiol was determined for daily samples during all estrous cycles. Endometrial tissue was removed for PGF2 alpha analysis by radioimmunoassay on d 10, 12, 14 or 16 during several normal cycles and after d 30 during spontaneously prolonged cycles. Circulating es...
Gold JJ, Heath IB, Bauchop T.Vegetative and reproductive stages of Caecomyces equi gen. nov., sp. nov. isolated from the horse caecum were examined by light and electron microscopy. This organism, which is similar to isolates known as Sphaeromonas communis, produces uniflagellate, uninucleate zoospores whose perikinetosomal structures, i.e. circumflagellar ring, spur, struts and scoop, are similar in many respects to those described in species of Neocallimastix. Microtubular roots extend basally from the spur and associate with hydrogenosomes and the nucleus. Another group of microtubules radiates laterally in a fan-shape...
Carroll CL, Huntington PJ.Three hundred and seventy two horses of varying breeds, height and fatness were weighed and measured for height at the withers. They were assessed for condition score by adaptation of a previously published method. The heart girth and length of 281 of the horses were also measured. Weight of horses was highly correlated (P less than 0.001) with height (r2 = 0.62), condition score (r2 = 0.22) and girth2 x length (r2 = 0.90). Nomograms were constructed to predict weight from height and condition score, and girth and length measurements. Weight can also be accurately estimated from the formula: (...
Hurtig MB, Fretz PB, Doige CE, Schnurr DL.The mechanisms and completeness of equine articular cartilage repair were studied in ten horses over a nine month period. Large (15 mm square) and small (5 mm square) full-thickness lesions were made in weight bearing and nonweight bearing areas of the radiocarpal, middle carpal and femoropatellar joints. The horses were euthanized in groups of two 1, 2.5, 4, 5 and 9 months later. Gross pathology, microradiography, and histopathology were used to evaluate qualitative aspects of articular repair. Computer assisted microdensitometry of safranin-O stained cartilage sections was used to quantitate...
Marais J, Masty J.Scanning-electron-microscopic examination of corrosion casts was used to investigate the microcirculation of the coronary border of the equine hoof. Numerous peg-shaped capillary plexuses derived from arterioles extended distally from the dorsal branches of the digital arteries parallel to the hoof wall. The plexuses varied in length and consisted of a fine network of interconnected capillaries that converged to join a centrally situated venule. These centrally situated venules within the papillary plexuses gave rise to a vast venous plexus deep to the coronary band.
Hänni K, Hesford F, Lazary S, Gerber H.Genomic DNA isolated from 20 horses was digested with up to six restriction endonucleases and subjected to southern blot hybridization analysis using various human class II alpha- and beta-chain cDNA probes. A high degree of restriction fragment length polymorphism (RFLP) was found for the DQ alpha, DP beta, DQ beta and DR beta probes, about 20 polymorphic bands being detected for each. DR alpha showed 2-4 polymorphic bands, whereas no evidence for DP alpha-like genes was found. A number of correlations of RFLPs with individual alloantisera were apparent.
Potempa J, Korzus E, Silberring J, Dubin A.1. Noncatalytic protein component (NPC), a strongly acidic protein (pH = 4.5) was separated from native horse leucocyte elastase 1. 2. This protein reduces elastinolytic properties of elastases: 1 and 2A probably by decreasing their isoelectric points. 3. A possible regulatory role of this protein may be inferred from a higher affinity of elastase 1 to NPC rather than to elastin.
Kopp E, Mayr B, Schleger W.The expression of nucleolus organizer region (NOR) activity in diploid cells was investigated in a model mammalian hybrid system, the hinny (female ass x male horse), by sequential Ag-NOR and chromomycin A3/distamycin A/DAPI (CDD) staining ion lectin-stimulated peripheral blood lymphocytes. In the majority of cases we found non-expression of the horse-derived NOR chromosomes in the hinny. However, in one case there was strong NOR expression on horse-derived chromosome no. 1.
Cross DT, Ginther OJ.Uterine contractions in 8 nonpregnant and 13 pregnant mares were studied using ultrasonography. A 1-min video tape recording was made of longitudinal real-time images of the uterine body. An overall uterine contractile activity score (0 = no or minimal activity to 4 = maximal activity) was assigned to each video tape segment. There was a day effect (P less than .01) and an interaction (P less than .01) of reproductive status X day. Uterine activity scores were highest on d 14 to d 18 (d 0 = day of ovulation) for nonpregnant mares and on d 10 to d 14 for pregnant mares. Uterine activity scores ...
Satoh M, Higuchi T, Inoue S, Miyakoshi D, Gotoh T.Assessment of the cricoarytenoideus dorsalis muscle (CAD) in horses using a transesophageal ultrasound, computed tomography, or magnetic resonance imaging is available in a limited number of hospitals. This study assessed the ease of ultrasonographic imaging of the CAD using an external transcutaneous technique in horses. After confirmation of the CAD in the cadavers, ultrasonography in twenty live horses was carried out using a transcutaneous approach. In live horses, ultrasonographic imaging of the CAD was possible by pushing the larynx from the opposite side with the other hand. It is belie...
O'Callaghan MW.When performed on selected clinical cases, ventilation/perfusion scintigraphy provides valuable additional information on regional lung function that is not obtainable from conventional thoracic radiographs. This is particularly true of horses with EIPH, COPD, and those suspected of having some form of small-airway disease. For horses with EIPH, the presence of a perfusion deficit on the scan is considered a key prognostic sign, because it is likely in these cases that irreversible bronchial arterial takeover has occurred in the affected areas of lung. Findings from horses with COPD have impro...
Immonen I, Cuervo-Arango J.The reproductive management of mares for frozen semen artificial insemination (AI) can be costly and labor intensive. Predicting the exact time of ovulation can be challenging even when ovulation-inducing drugs are used. The main objective of this retrospective study was to determine whether there was an effect of interval between examinations to detect ovulation on likelihood of pregnancy and early embryonic loss in mares after postovulatory breeding with a single straw of frozen/thawed semen. The second objective was to determine the efficacy of two different drugs (human chorionic gonadotro...
Harris PA, Marlin DJ, Scott CM, Harris RC, Mills PC, Michell AR, Orme CE, Roberts CA, Schroter RC, Marr CM.Four horses (H, J, N and M) undertook a simulated competition exercise test (CET), designed to simulate physiological and metabolic stresses of the Speed and Endurance (S & E) test of a 3-day-event, under 3 different environmental conditions: 20 degrees C/40% relative humidity (RH) (cool, dry [CD] 2 sessions); 30 degrees C/40% RH (hot, dry [HD]) and 30 degrees C/80% RH (hot, humid [HH]) (Marlin et al. 1995a). Venous blood samples for electrolyte and total protein (TP) determinations were collected from indwelling catheters at predetermined time points throughout each CET and initial 30 min...
Groman EV, Schultz RM, Engel LL, Orr JC.In the reduction of 17beta-hydroxy-5alpha-androstan-3-one to the 3beta-alcohol, horse liver alcohol dehydrogenase utilizes the 4-pro-R hydrogen of NADH whereas the 3(17)beta-hydroxysteroid dehydrogenase of Pseudomonas testosteroni utulized the 4-pro-S hydrogen. These observations provide an exception to the rule proposed by Alworth and Bentley that with regard to the paired methylene hydrogens at C-4 of NADH and NADPH "the stereospecificity of a particular reaction is fixed and does not vary with the source of the enzyme preparation". It is also apparent that for these two enzymes, the selecti...
Naden J, Squires EL, Nett TM, Amann RP.The pituitary response to exogenous GnRH was studied in 8 colts of Quarter Horse phenotype from 32 to 96 weeks of age. Colts were from dams treated daily from Day 20 to 325 of gestation with (1) 2 ml neobee oil per 50 kg body weight (controls); or (2) 2 ml altrenogest per 50 kg body weight. GnRH challenges (5 micrograms/kg body weight) were administered every 8 weeks from 32 to 96 weeks of age to estimate pituitary content of LH. Blood samples were collected every 20 min for 4 h before GnRH and 15, 30, 45, 60, 90, 120, 180, 240 and 360 min after GnRH. Serum concentrations of LH and FSH were de...
Dice PF, Cooley PL.This report involves a retrospective study of five horses with an unusual form of progressive peripheral corneal ulcers. These ulcers were located at the perilimbal region of the cornea and spread both centripetally to mid periphery and circumferentially. Lipping of the epithelial edge was observed often. The depth ranged from superficial to mid stroma. Patients ranged from two and a half to eight years, both sexes, and were referred after a variety of antibacterial therapy. Histories were similar in that all ulcers were initially located adjacent to the limbus in one or more quadrants. No tra...
Smith HL, Rosenblatt AJ, Suen WW, Owen H, Ahern BJ.A 6-week-old Thoroughbred filly was presented for evaluation of an expansile mass overlying the right nasal passage and causing respiratory stertor. On skull radiographs, there was a loculated, soft tissue-opaque mass identified dorsal to the right upper premolars and effacing the right nasal cavity. Computed tomography (CT) revealed a locally extensive mass with relatively benign characteristics located centrally on the tooth root apices of the deciduous second premolar (506). The mass extended axially into the right nasal cavity, occluding the meatuses and causing displacement of the nasal s...
Sugita S, Oki H, Hasegawa T, Ishida N.Estimation formulas for the morbidity of horses infected with equine influenza virus by linear regression, logistic regression and probit transformation were developed, using data from the outbreak at the Sha Tin Racing Track in Hong Kong in 1992. Using these formulas, we estimated the equine influenza virus morbidity rates at training centers belonging to the Japan Racing Association (JRA) in October 1997 and in October 1998. In 1998 JRA started a new vaccination program, and every horse must now be vaccinated twice per year. At that time, the vaccine included two US lineage virus strains, th...
Marais J.The vascular architecture of the dermal laminae was studied by scanning electron microscopy of vascular corrosion casts. Ultrastructurally, the laminar vasculature consisted of arterioles, capillaries, venules and veins, arranged in a sheet-like network. Through the laminae, arterioles ran parallel to the solar surface and branched at two levels to form a continuous arteriolar arcade, parallel to the hoof wall. Capillaries originating from these arcades formed hairpin loops joining the marginal vein prior to forming an axially situated venous network. Additional capillaries were also given off...
Irvine CH.Isoelectric focussing of crude extracts of equine pituitaries was used to obtain fractions containing FSH and LH. By comparison with FSH, LH was distributed over a similar but wider pH range indicating more marked polymorphism as determined from their isoelectric point (pI). Molecules with more sialic acid showed lower pI consistent with the concept that sialic acid is the major factor in determining pI and polymorphism in FSH and LH. Appropriate fractions were labelled with 125I, purified further and used in kinetic studies. FSH and LH molecules of similar pI had similar kinetics; however, LH...
Derisoud E, Jouneau L, Margat A, Gourtay C, Dubois C, Archilla C, Jaszczyszyn Y, Dahirel M, Daniel N, Peynot N, Briot L, De Geoffroy F, Wimel L....No abstract available
ElWishy AB.The morphological changes which take place in the sperm during their passage
through the excurrent ducts have been studied in the bull (BRANTON and SALISBURY
1947; HANCOCK 1955; BAILY and SMITH 1958; AMANN and ALMQUIST 1962; GUSTAFSSON and CRABO 1971 ; RAO 1971) and boar (GUSTAFSSON, CRABO and EINARSSON 1970).
Such knowledge is of major importance in understanding the origin and significance
of the different sperm abnormalties as well as providing the basis for proper appraisal
of semen picture and devising useful spermiograms.
The aim of the present work is to study the morphological ch...
Leroux AJ, Schott HC, Hines MT.Ventricular tachycardia was diagnosed in a 12-year-old unconditioned Appaloosa gelding after a 3-day trail ride. Initial signs were those of abdominal discomfort, ileus, and dehydration. Medical treatment included IV administration of lactated Ringer's solution. During hospitalization, the horse developed ventricular tachycardia. Serum potassium concentrations were within reference limits; however, assessment of total body potassium stores was not performed. Resolution of the arrhythmia occurred with further fluid treatment and potassium supplementation. Cardiac arrhythmias should be considere...
Arroyo LG, Vengust M, Dobson H, Viel L.A 10-day-old quarter horse colt was presented for signs of disorientation and inability to nurse. Hydronephrosis/hydroureters, with concomitant pyelonephritis and a severe electrolytes disturbance, were diagnosed. The clinical findings closely resembled those described for a syndrome of transient pseudohypoaldosteronism in human neonates. Un poulain Quarter horse âgé de 10 jours a été présenté pour des signes de désorientation et d’incapacité à se nourrir. Une hydronéphrose/hydrouretères avec pyélonéphrite concomitante et débalancement électrolytique sévère ont été diagno...
Baran Ketencioğlu B, Yilmaz I, Tutar N, Gülmez I, Oymak FS.Sensitivity and symptoms related to animal proteins have been investigated in various occupational groups. However, data from horse farm workers are limited. We aimed to determine horse allergen sensitivity in the horse farm workers, and to evaluate its relationship with respiratory symptoms and functional parameters. A total of 110 subjects were enrolled in the study. The study group consisted of 80 horse farm workers. Face-to-face surveys, skin prick tests (SPT), and pulmonary function tests (PFT) were performed in the study group. Control group consisted of 30 healthy subjects. SPT and PFTs...
Bell K.Transferrin, albumin, 6-phosphogluconate dehydrogenase and vitamin D-binding protein polymorphisms were detected in 242 feral and domesticated Australian donkeys by polyacrylamide gel electrophoresis, starch gel electrophoresis, autoradiography, immunoblotting with specific antisera and activity staining. All four TF and two ALB variants were donkey specific while only one of the PGD variants was donkey specific. The two GC variants were electrophoretically identical to the Equus caballus F and S proteins. Available evidence suggested that the TF, ALB, PGD and GC systems are controlled by co-d...
Lucas JM, Ross MW, Richardson DW.A retrospective study of 176 Standardbred horses that had arthroscopic surgery for carpal chip fractures over a 7 year period was done in order to determine fracture location and post operative performance. Chip fractures of the proximal third carpal bone and the distal radiocarpal bone occurred with equal frequency (49.2 and 49.6% respectively), and chip fractures involving the antebrachiocarpal joint were rare. Trotters had significantly more third carpal bone lesions than radiocarpal bone lesions when compared to pacers (P = 0.0304). Seventy-four per cent of horses made at least one start f...