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.
Edington N, Bridges CG.Two groups each of six sibling ponies were exposed to sequential infections with equid herpesvirus 1 or 4 (EHV-1 or EHV-4) at four or five month intervals. Two exposures to EHV-4 did not significantly reduce virus shedding or pyrexia when the ponies were subsequently exposed to EHV-1. However, two sequential infections with EHV-1 completely protected against challenge with EHV-4. Virus neutralising antibody in each group did not increase until 21 days after primary exposure and was subtype specific. However, complement fixing antibody rose within seven days after inoculation with EHV-1, and 14...
Pollitt CC, Molyneux GS.The microcirculation of the dermal laminae and papillae of the equine foot from seven clinically normal Australian ponies was studied using an improved microvascular casting corrosion technique and scanning electron microscopy. Casts of veins, arteries, capillaries and arteriovenous anastomoses (AVAs) were readily identified by their characteristic surface morphology. Arteries entered the laminar circulation axially, between pairs of axial veins, and were connected to each other by smaller calibre interconnecting arteries. Short abaxial branches of the axial interconnecting arteries gave rise ...
Katila T, Lock TF, Hoffmann WE, Smith AR.A study was conducted to 1) determine differences in the inflammatory response following bacterial challenge between normal mares and mares with chronic endometritis and 2) to determine if enzyme activity in uterine fluid can be used to evaluate degree of inflammation in the equine uterus. Six normal mares (Group 1) and four mares with chronic endometritis (Group 2) received an intrauterine infusion of beta-hemolytic streptococci on the second day of estrus. Neutrophil concentration as well as lysozyme and alkaline phosphatase activity were determined in uterine secretions obtained by placing ...
Stevenson AJ, Weber MP, Todi F, Mendonca M, Fenwick JD, Kwong E, Young L, Leavitt R, Nespolo R, Beaumier P.A study of the effects of intravenous administration of either 150 mg or 250 mg of furosemide to standardbred mares pre-treated with other drugs was undertaken to determine whether a unique pattern of drug elimination into urine and from plasma for each compound occurred. Furosemide significantly reduced the plasma concentrations of codeine compared to control 2-6 h after furosemide administration. In contrast, the plasma concentrations of theophylline, phenylbutazone, pentazocine, guaifenesin and flunixin were not markedly altered by furosemide. In the case of acepromazine, clenbuterol and fe...
Kotze SH, Van Aswegen G.The ileocaecal junctions of 5 horses and 2 donkeys were examined by using antisera to the following peptides: somatostatin, glucagon, gastrin, neurotensin, vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI), calcitonin gene-related peptide (CGRP), substance P (SP) and neuropeptide Y (NPY). Antisera to somatostatin, neurotensin and NPY demonstrated endocrine cells in the ileal- and caecal parts of the ileocaecal junction, while immunoreactivity for glucagon was demonstrated in endocrine cells of the ileal part only. Nerve cell bodies showing immunoreactivity to SP, VIP, CGR...
Milne EM, Doxey DL, Gilmour JS.Serum total lipids, lipoprotein fractions, triglycerides, cholesterol, phospholipids and free fatty acids were measured in horses with acute, subacute and chronic grass sickness (equine dysautonomia) and in colic cases. The values were compared with those of normal grazing and stabled horses. A marked individual variation occurred, but total lipids, triglycerides and free fatty acids were significantly higher than normal in grass sickness and colic cases with cholesterol was significantly higher than normal in grass sickness cases only. Pre-beta lipoprotein was significantly increased in colic...
Campbell GL, Reeves WC, Hardy JL, Eldridge BF.Neutralization tests were done on sera from 141 horses from high elevation regions of California. Antibody prevalences to Jamestown Canyon, snowshoe hare, and California encephalitis viruses in the California serogroup and Northway virus in the Bunyamwera serogroup were 55%, 43%, 18%, and 46%, respectively. In 51 horses from rural low elevation regions, seroprevalences were 31%, 35%, 35%, and 37%, respectively. Twenty-four horses from a suburban lowland area were seronegative, except for a single horse with a low titer to snowshoe hare virus. Seroprevalence to Jamestown Canyon and snowshoe har...
Mumford JA, Hannant D, Jessett DM.Infection of seronegative Welsh mountain ponies was established by intranasal instillation or exposure to nebulised aerosol of egg grown H3N8 viruses. Pyrexia and coughing were noted following intranasal instillation and high titres of virus were recovered from the nasopharynx. Exposure to aerosol resulted in more severe clinical signs characterised by high temperatures, dyspnoea, anorexia and coughing; lower levels of virus were recovered from the nasopharynx. The severity of clinical signs and the kinetics of virus shedding were dose-related with the minimal infectious dose being 10(2)EID50/...
Attenburrow DP, Flack FC, Portergill MJ.The technique of impedance plethysmography is described and its application to observation of lung volume changes in the horse at exercise is discussed. The results from horse at rest show that there is a close relationship between rate of lung volume change (flow rate) and the associated impedance changes during both inspiration and expiration. Impedance changes during exercise were related to inspiration and expiration by observation of associated respiratory sounds. Artefacts related to technical difficulties are also indicated.
Pyörälä S, Kotilainen T, Silvennoinen P, Hänninen U, Mero M, Kaartinen L.Serum tinidazole concentrations were monitored in five clinically healthy adult horses after intravenous (i.v.) and oral administration of the drug (15 mg/kg and 25 mg/kg, respectively). After i.v. administration, the mean residence time was 7.0 h, the elimination half-life 5.2 h and the body clearance rate 1.6 ml/min/kg. The distribution volume was found to be 660 ml/kg. After oral administration, the mean residence time was 8.5 h, the absorption half-life 1.1 h and the bioavailability essentially 100%. In view of the in-vitro sensitivities of various anaerobic bacteria, a dosage of 10-15 mg/...
Irvine CH, Sutton P, Turner JE, Mennick PE.Plasma progesterone concentrations were measured in 179 mares bled on alternate days commencing with a positive pregnancy diagnosis on Days 17 to 18 after ovulation and concluding on Days 42 to 45. During this period 17 mares (10 per cent) lost their pregnancies, 11 before Day 25. In 15 mares the timing of the pregnancy loss could be determined with adequate accuracy; in only one did a decline in progesterone precede the loss. Thus pregnancy loss between Days 17 and 42 was rarely caused by a fall in plasma progesterone.
Freeman DE, Orsini PG, Ross MW, Madison JB.A large frontonasal bone flap was created to treat diseases of the paranasal sinuses in 14 horses. The bone flap was made as wide as possible within the confines of the nasolacrimal duct so the floor of the frontal sinus and the dorsal and ventral conchae could be opened. These openings exposed the nasal passages, maxillary sinuses, and ventral conchal sinus thereby facilitating removal of diffuse and localized lesions from these sites. Diseases treated were ethmoid hematomas (4 horses), sinus cysts (5 horses), cryptococcal granuloma, osteoma, hemangiosarcoma, pus in the ventral conchal sinus,...
McMiken DF.Archaeological evidence of horse domestication dates from 4000 BC in the Eurasian Steppes of the Ukraine. There, Indo-Europeans rode horses and herded them for meat. This had profound social and economic consequences which led to the development of nomadic equestrian cultures. The earliest direct evidence of riding is from Mesopotamian plaques, and correspondence of the Kings of Mari (2000 BC). Indo-Europeans brought the horse to the Near East and there, outside its natural habitat, used specialised knowledge to raise and train horses on a large scale for military use. Hittite instructions on ...
Lawrence L, Kline K, Miller-Graber P, Siegel A, Kurcz E, Fisher M, Bump K.Twenty-two Standardbred horses in race training were used in a crossover experiment to determine the effect of oral sodium bicarbonate (NaHCO3) administration on performance and metabolic responses to a 1.6-km (1-mile) race. Horses were paired and one horse in each pair was treated with either NaHCO3 (300 mg/kg BW) or a placebo, 2.5 h before they raced against each other. Each horse was scheduled to compete in two races, approximately 1 wk apart, one on each treatment. Horses always raced in the same pairs. Fourteen horses successfully completed both races. Jugular blood samples were obtained ...
Hinrichs K, Riera FL.Ten mares were used to investigate the effect of administration of prostaglandin F2 alpha on uterine tubal motility, as reflected by embryo recovery from the uterus 5 days after ovulation (day 0). Mares were assigned to 3 groups: group A, uterine flush for embryo recovery on day 7; group B, uterine flush for embryo recovery on day 5; and group C, uterine flush for embryo recovery on day 5, after treatment with prostaglandin F2 alpha (10 mg, IM) on day 3. Each mare was assigned to each group once. Embryo recovery rates for the 3 groups were: A, 6 of 10; B, 2 of 8; and C, 0 of 10. The embryo rec...
Gaughan EM, Wallace RJ, Kallfelz FA.The effects of two local anesthetic agents on the diagnostic quality of nuclear medical bone images (NMBIs) of distal parts of the equine fore limb were investigated. Local effects on bone uptake of technetium 99m methylene diphosphonate (99mTc-MDP) 4 and 24 hours after perineural and intraarticular injection of mepivacaine hydrochloride and bupivacaine hydrochloride were evaluated in the carpal and metacarpophalangeal regions of 12 horses and ponies. Neither mepivacaine hydrochloride nor bupivacaine hydrochloride significantly altered the diagnostic quality of the NMBIs. The injection and sub...
Reeves MJ, Vansteenhouse J, Stashak TS, Yovich JV, Cockerell G.A study was undertaken to evaluate the significance and mechanism of reperfusion injury in the equine large colon following 1 h of haemorrhagic strangulation obstruction (HSO) or ischaemic strangulation obstruction (ISO) and to assess the effect of treatment with dimethyl sulphoxide (DMSO). ISO or HSO were created 40 cm from the pelvic flexure and maintained for 60 mins under general anaesthesia. Normal saline or 20 per cent DMSO (1 g/kg bodyweight) was administered intravenously 10 mins prior to the end of the ischaemic period. Four groups of four horses in a 2 x 2 factorial design were used....
Wood T, Weckman TJ, Henry PA, Chang SL, Blake JW, Tobin T.Our investigation of the urine of grazing horses at the University of Kentucky shows that the mean pH level is about 7.9, and if their diet is supplemented with grain, it is about 7.4. There appears to be no significant effect of time of day or year on urine pH levels in horses. However, horses taken from pasture and supplemented with grain in a stalled environment show a slight decrease in urine pH. Additionally, we investigated the effects of storage on pH levels. Equine urine samples appear to be quite stable with regard to pH for 48h, but then show a marked increase. Urine pH can have a gr...
Boy MG, Galligan DT, Divers TJ.Medical records of 82 horses with clinical signs of neurologic disease and histologic lesions suggestive of protozoal encephalomyelitis were reviewed. The presence of a protozoan parasite in the CNS was not influenced by prior treatment of the horse with corticosteroids. Prior treatment of horses with trimethoprim-sulfonamide alone or in combination with pyrimethamine resulted in a decreased number of horses in which a protozoan parasite was detected in the CNS at necropsy. The mean age of affected horses was 3.62 +/- 2.78 years, with male and Standardbred horses being overrepresented, compare...
Riggs C, Whitley RD.Intraocular silicone prostheses were implanted in the eyes of a horse and a dog with traumatic corneal lacerations and protrusion of intraocular contents. Several months after surgery, the horse and dog were tolerating the intraocular prostheses, and the appearance was cosmetically acceptable. This contradicts earlier reports that have cited corneal disease as a contraindication for implantation of intraocular silicone prostheses.
Asmis R, Jörg A.Horse eosinophils preincubated with 3H-labelled acetate and stimulated with the Ca2+ ionophores ionomycin or A23187 form a radioactive compound, which we have shown to be 1-O-alkyl-2-[3H]acetyl-sn-glycero-3-phosphocholine (platelet-activating factor). We could detect no 1-O-acyl-2-[3H]acetyl-glycero-3-phosphocholine in the radioactive fraction. The formation of platelet-activating factor was strongly correlated to the generation of leukotriene C4, the main arachidonate metabolite in horse eosinophils, suggesting that platelet-activating factor and leukotriene C4 have a common precursor pool (1...
Mair TS, Taylor FG, Harbour DA, Pearson GR.Combined immunodeficiency syndrome is an inherited disorder of the Arabian breed of horses. Affected foals usually die of infectious disease within the first few months of life, and the respiratory tract is the commonest site of infection. This report describes the clinical and pathological features of a case which showed signs of alimentary and respiratory infections. Intestinal infection by coronavirus (not previously recorded in cases of the syndrome) and cryptosporidia was identified. Histopathological evidence also suggested the presence of an adenovirus infection.
Allison N, Gillis JP.Enteric pythiosis was diagnosed in a 2-year-old Quarter Horse gelding. The horse had signs of colic, which appeared to be alleviated by administration of mineral oil and analgesics, but only temporarily. Intestinal distention developed after initial examination. At surgery, a thick stenotic area was observed in the middle portion of the jejunum. The thick intestine and associated mesentery contained multiple firm nodules of gritty caseous material. Histopathologic findings included sclerosing eosinophilic granulomatous enteritis and peritonitis. Although the lesion resembled a response to migr...
Beard WL, Robertson JT, Leeth B.Congenital frontal sinus cysts were found bilaterally in the frontal sinuses of a one-year-old miniature horse. Diagnosis was based on radiography of the head and cytologic examination of tissue aspirated from the frontal sinuses. The cysts were surgically removed, using a hinged bone flap technique bilaterally over the frontal sinuses.
Grint NJ, Lorena SE, Johnson CB, Luna SP, Whay HR, Murrell JC.To report the severe metabolic acidosis identified in a group of 11 healthy mules anaesthetized with halothane for castration. Methods: Data generated from a prospective study. Methods: Eleven mules aged 2.5-8 years, weighing 230-315 kg and 11 horses aged 1.5-3.5 years, weighing 315-480 kg. Methods: Animals were anaesthetized for castration as part of an electroencephalographic study. Preanaesthetic medication was acepromazine (0.03 mg kg(-1) ) administered through a preplaced jugular venous catheter. Anaesthesia was induced 30-90 minutes later with intravenous thiopental (10 mg kg(-1) ). ...
Möller R, Graglia F, Pizzigatti D, van Lier E.Horses went through functional differentiation during their evolutionary and reproductive development, however, some body parts continued to improve their specificity for speed. Regarding this, we evaluated by morphometric analysis the relationship between limb section (LS) differences in the appendicular structures of horses. Two hundred and seven (n = 207) adult horses of different breeds and sex were selected. The limb section was measured by identification of topographic palpable skeleton landmarks with a measurement tape (centimetres). Quantitative variables (limb section) were analysed...
Rumpler MJ, Colahan P, Sams RA.The disposition of plasma glycopyrrolate (GLY) is characterized by a three-compartment pharmacokinetic model after a 1-mg bolus intravenous dose to Standardbred horses. The median (range) plasma clearance (Clp), volume of distribution of the central compartment (V1 ), volume of distribution at steady-state (Vss), and area under the plasma concentration-time curve (AUC0-inf ) were 16.7 (13.6-21.7)Â mL/min/kg, 0.167 (0.103-0.215)Â L/kg, 3.69 (0.640-38.73)Â L/kg, and 2.58 (2.28-2.88)Â ng*h/mL, respectively. Renal clearance of GLY was characterized by a median (range) of 2.65 (1.92-3.59)Â mL/min/k...
Apolinário ECF, Oliveira LLDS, Rocha RHF, Silva FVE, Santos IS, Alves CA, Dias Júnior JA, Mendes LJ, Lima WDS.The intensive use of anthelmintics has resulted in resistant parasite populations in horses. The objective of this trial was to evaluate the anthelmintic efficacies of the anthelmintics fenbendazole, ivermectin and abamectin in 24 horse farms in Northern Minas Gerais. Egg counts per gram of faeces (EPG) were performed individually in 619 animals. Animals presenting EPG counts greater than or equal to 150 were used in the tests on faecal egg count reduction (FECR), totalling 436 equines. These animals received the anthelmintics, fenbendazole, ivermectin, and abamectin. Faeces were collected 14Â...
Pollmann U.The conditions under which horses are kept and the performance of acts in the circus ring may give rise to animal protection-relevant aspects for circus and show horses. A number of intolerable conditions under which horses are kept and procedures adopted for the work with circus and show horses are described. In addition, attention is drawn to monitoring methods capable of exposing the deplorable shortcomings of these businesses.
Katila T, Oijala M, Kotilainen T, Väisänen K.Four subfertile mares (at least 2 barren years) were used as donors in an embryo transfer program. The embryo recovery rate was 50%, varying between 0-100. The transfer of 9 embryos resulted in the pregnancy rate of 44%. The efficiency of embryo transfer using subfertile mares is low. In this material 20% of flushings resulted in a pregnancy. Fyra subfertila ston (gatt galla i minst 2 är) användes som donatorer i ett program för embryot rans fer. Femtio procent av embryon tillvaratogs (varians 0–100%). Transfer av 9 embryon gav en dräktighetsresultat på 44%. Embryotransfer från subfert...
Magnus RP.The take-home message in marketing your equine practice is simple: understand your position in the target market and the buying behavior of your current and prospective customers. Time well spent on analysis and evaluation of options can maximize customer value in the services and products you offer. This allows you to capture profit and to attain your personal and professional goals as an equine practitioner.
Willette J, Gerras A, Sledge D, Koch D.A 13-year-old multiparous Quarter Horse mare was presented to the Michigan State University's, Large Animal Emergency service for dystocia. Clinical evaluation revealed a minimally dilated cervix on vaginal examination, with a palpable deceased fetus. Postmortem evaluation following owner-elected humane euthanasia revealed a circumferential, tan, fibrous band at the base of the uterine body that constricted the uterus and was adhered to the left and right ovaries. A routine histologic section of the incarcerating cord attached to the ovary consisted predominately of dense fibrous connective ti...
Uhlhorn H, Eksell P, Sandgren B, Carlsten J.To assess the significance of radiographic signs of sclerosis of the third carpal bone (C3) in young Standardbred trotters in relation to performance, lameness and bone turnover both carpi in 14 Standardbred trotters were radiographically and scintigraphically examined 6 times, from the beginning of speed training until the beginning of racing, between the mean ages of 20 and 42 months. At the end of the study 8 horses had raced in official qualifying races and 14 limbs in 11 horses had been diagnosed with carpal lameness. All horses but 2 developed sclerosis and all but one had increased bone...
Lopp CT, McCoy AM, Boothe D, Schaeffer DJ, Lascola K.To characterize the pharmacokinetics of a clinically relevant dose of misoprostol administered PO or per rectum (PR) to horses. Methods: 8 healthy adult horses. Methods: In a randomized 3-way crossover design, horses received a single dose of misoprostol (5 μg/kg) administered PO (with horses fed and unfed) and PR, with a minimum 3-week washout period separating the experimental conditions. Blood samples were obtained before and at various points after drug administration (total, 24 hours), and plasma concentrations of misoprostol free acid were measured. Results: Mean maximum plasma concentr...
Marti E, Szalai G, Bucher K, Dobbelaere D, Gerber H, Lazary S.In order to isolate a part of the immunoglobulin E (IgE) heavy chain cDNA of the horse, primers have been designed based upon well conserved sequences in humans, sheep and rats. The PCR resulted in a 500 bp fragment which hybridised with a human IgE constant region probe. The fragment was cloned and sequenced and its derived protein sequence compared with the corresponding sequences in humans, sheep and mice. Most amino acids common to these three species are also shared by the horse.
Troedsson M, Concha C, Einarsson S, Holmberg O.From 6 mares with chronic uterine infection, polymorphonuclear neutrophils (PMNs) were obtained from the uterus. In order to recover an adequate number of viable PMNs, 0.1% oyster glycogen was infused into the uterus as a mild irritant 12 h prior to the uterine flushing. Phagocytosis and chemotaxis of the uterine derived PMNs were determined. The supernatant from the uterine flushing was compared with autologous serum for its capacity as an opsonin and chemoattractant. There was a significant increase of both phagocytosis and chemotaxis when autologous serum was used compared with the supernat...
Ginther OJ.Recent findings on the luteolytic process in mares are reviewed and differences from other farm species are noted. It is well known that the luteolysin, PGF2α (PGF), is secreted from the endometrium in the absence of pregnancy in farm animal species. But PGF is a potent chemical and safeguards have evolved so that only the corpus luteum (CL) is affected. The safeguards include a short PGF half-life and secretion in two or three pulses per day. In mares, endogenous PGF travels from the uterus to the CL through the systemic circulation, but the luteal-cell membranes are highly efficient in capt...
Lavoie JP, Pascoe JR, Kupershoek CJ.The partitioning of total pulmonary resistance (RL) into upper airway resistance and lower airway resistance (RI) was studied in 8 Thoroughbred geldings. In addition, the phase shift and amplitude distortion of 3 catheters used for pressure measurements in this study were evaluated under static and dynamic conditions. Flow rate was obtained from a heated pneumotachograph attached to a tight-fitting mask placed over the nose. Electronic integration of the flow signal gave tidal volume. Transpulmonary pressure (PL) was obtained from calculation of the difference between the esophageal balloon ca...
Asbury AC.Medical examination of the reproductive system of mares or stallions relevant to purchase is complex, imprecise, and potentially hazardous legally. In these ways it does not differ from other examinations of animals in which purchase is the objective. It is the responsibility of the veterinary profession to undertake these assignments and complete them as conscientiously as possible. After the examination is completed, communication with the principals and documentation of the procedures are essential to success and to the satisfaction of all involved.
Sanders EA, Gleed RD, Hackett RP, Dobson A.In the quietly standing horse I.V. administration of adrenaline decreased, and of dobutamine increased, bronchial artery flow. These changes paralleled changes in arterial pressure. With phenylephrine and noradrenaline bronchial artery flow decreased while arterial pressure increased, indicating active vasoconstriction in the bronchial circulation. With clenbuterol an increase in bronchial artery flow was accompanied by a decrease in systemic blood pressure, indicating bronchial arterial vasodilatation. We conclude that alpha-constrictor and beta 2-dilator receptors are present in the bronchia...
Courtot D, Mouthon G, Roux L, Jeanin E.The practise of repeated doping of the sport horse led us to examine its effects on the health of the animal, and particularly on muscular activity. The main doping agent used at present (acepromazine) has already been studied (COURTOT et al., 1974). In this paper, we study the secondary effects of diazepam, a derivative of the benzodiazepine series, which is being used more and more frequently on horses. In treated animals as compared to controls, we observe: -- a slight respiratory depression related solely to effort, -- an increase in seric creatine phosphokinase rate with no apparent relat...
Trommershausen-Smith A, Suzuki Y.A family study of an index case in the Arabian breed of horses demonstrated the presence of a new allele in the prealbumin (Pr) system of electrophoretically determined markers in horse serum which, when homozygous, results in the absence of any recognizable zones in the Pr region. The symbol PrO is proposed for this allele which has an estimated frequency in Arabian horses of 0.09.