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.
Woods WE, Weckman T, Wood T, Chang SL, Blake JW, Tobin T.A commercially available radioimmunoassay kit was used to screen for the presence of etorphine in post-race urines from horses racing in Kentucky. Most horse urines contained small amounts of materials which reacted positively in this immunoassay. These materials are apparently endogenous to the horse and were called apparent etorphine equivalents. The levels of these apparent etorphine equivalents in post-race urines from 70 horses were estimated. Their modal level averaged 0.1 ng/ml, the population distribution was log normal, and individual horses showed levels of up to 0.8 ng/ml.
Dyson SJ, Greet TR.ALTHOUGH diaphyseal and distal metaphyseal fractures of
the equine humerus have been discussed in the literature
(Johnson, Lowe, Fessler and Amstutz 1974; Vaughan and
Mason 1975; Turner 1984), reports of humeral fractures of
other configurations are rare. Allen and White (1984) described
the successful surgical treatment of a chip fracture of the greater
tubercle of the humerus. This report describes the clinical
features and treatment of a fracture of the deltoid tuberosity.
MacGregor CM.Radiographic examination of the navicular bones of 258 horses was carried out. Of these 258 horses, 83 were sound (Group A), 151 had been diagnosed clinically as having navicular disease (Group B), and 24 had a forefoot lameness of unknown aetiology (Group C). Seven basic shapes of distal nutrient foramina were identified from these radiographs. A scoring system was then developed based on these different types of distal nutrient foramina. When this scoring system was applied to the radiographs of the 258 horses examined significant differences were found between the mean navicular scores of t...
Amin TM, Sirs JA, Allen BV, Colles CM.A preliminary investigation has been undertaken of blood rheology in horses and ponies, its variation in navicular disease and the changes following treatment with warfarin. Erythrocyte flexibility, measured by a centrifuge packing technique, is higher in horses (30 per cent min-1) than in ponies (23.8 per cent min-1). There are corresponding differences in blood viscosity. The high erythrocyte flexibility in horses is caused by an unknown factor present in plasma. The erythrocyte flexibility in horses with navicular disease is even higher, at 38.5 per cent min-1. Treatment with warfarin reduc...
Mendoza L, Kaufman L, Standard PG.A practical, sensitive, and specific immunodiffusion test was developed for diagnosing and monitoring pythiosis in horses. Culture filtrates, a soluble cell mass, and trypsinized Pythium sp. antigens were evaluated against prepared rabbit anti-Pythium sp. serum and pythiosis horse case sera. The culture filtrate antigens demonstrated the greatest capacity for detecting precipitins and the greatest stability during storage. In contrast, the trypsinized antigens had the weakest capability for detecting multiple precipitins and the poorest stability. The 13 sera from horses with proven active pyt...
Hodgson DS, Steffey EP, Grandy JL, Woliner MJ.Cardiopulmonary effects of spontaneous, assisted, and controlled ventilatory modes were determined with 6 young, healthy geldings anesthetized with halothane at a constant dose (1.3 minimum alveolar concentration). All horses were in lateral recumbency, and all modes of ventilation were studied at least once during each anesthetic exposure. Cardiac output did not differ between spontaneous and assisted ventilation modes, but both modes were associated with significantly (P less than 0.05) higher cardiac output than that with controlled ventilation. The PaCO2 differed significantly (P less than...
Mair TS, Taylor FG, Gibbs C, Lucke VM.THE horse appears to possess a strong innate resistance to
tuberculosis because the disease is infrequently recognised even
in countries where the condition is common in other species
(Luke 1958). Reports of the disease are now scarce and earlier
records of infections in horses usually implicated the bovine
strain of Mycobacterium tuberculosis, although avian and
human strains have been isolated. Of 55 equine cases reviewed
by Griffith (1937), 53 were caused by the bovine strain and two
were independently infected with avian and human strains.
Since the implementation of the bovine tu...
Walker M, Geiser D.Heart rate, blood velocity, volumetric blood flow, and arterial diameter for 10 horses given acetylpromazine were determined from measurements of the dorsal metatarsal artery 3 (the great metatarsal artery), using 2-dimensional real-time and gated pulsed Doppler ultrasonography. Acetylpromazine induced significant increases in arterial diameter (P less than 0.01) and volumetric flow rate (P less than 0.05)--all compatible with adrenergic blockade. There was a trend indicating that there was increased blood velocity. Heart rate was unchanged.
Pollitt CC, Holdsworth PA, Kelly WR, Meacham CS, Sheahan B.A single oral dose of ivermectin paste was administered to 12 horses with dermatitis and clinical signs typical of onchocerciasis. Two of the horses also had lesions of Queensland itch. Microfilarias of Onchocerca cervicalis were identified in fresh, macerated, skin biopsies from the neck, brisket or umbilical regions of all horses and microfilarias of O. gutturosa from the neck of 2. Eight of the horses developed skin reactions 4 to 24 h after the administration of the ivermectin, notably weals over the neck, shoulders and flanks and pitting oedema of the ventral midline and intermandibular s...
Takai S, Kawazu S, Tsubaki S.Humoral immune response to intestinal Rhodococcus (Corynebacterium) equi in horses was studied by enzyme-linked immunosorbent assay. Anti-R. equi immunoglobulin M (IgM), IgG, and IgA antibodies were demonstrated in the healthy horse population. Adult horse levels of anti-R. equi IgM and IgG antibodies were reached by 5 to 9 weeks of age in two healthy newborn foals. R. equi was recovered from the foals in the range of 10(3) to 10(4) per g of intestinal contents. A 1-week-old foal was infected with R. equi by mouth daily for 9 weeks. The foal did not show any clinical signs of illness. Anti-R. ...
Cymbaluk NF, Christensen DA.Five groups of horses were fed different diets of known trace mineral concentration for a minimum of six months. Copper (Cu), zinc (Zn) and manganese (Mn) concentrations were measured in livers of 125 yearling horses and kidneys of 81 yearling horses as an assessment of trace mineral status. Plasma Cu and Zn determinations were made for all horses.Mean hepatic Cu concentrations of horses fed diets containing 6.9 to 15.2 mg Cu/kg dry matter (DM) feed were 0.27 to 0.33 mumol/g DM tissue. Plasma Cu concentrations ranged between 22.8 to 28.3 mumol/L. There was no simple mathematical relationship b...
Stadler P, Deegen E.Dynamic compliance, airway resistance, viscous work and respiratory frequency were measured at intervals in horses over 12 h periods. Variation, daily averages and circadian patterns were recorded. Examinations were performed on 24 horses. They were divided into three groups: Normal horses, horses with chronic latent bronchitis and horses with manifest chronic obstructive pulmonary disease (COPD). Significant differences were found between the daily averages and the fluctuations when the normal group and the COPD group were compared. In most cases differences between all three groups were sign...
Watson AG, Mayhew IG.Familial occipitalization of the atlas with atlantalization of the axis was defined as a single congenital disease in Arabian horses following a clinical, radiologic, and morphologic study of 16 horses with congenital malformations of the occiput, atlas, and axis, and from a study of three reported cases. The constant morphologic features were interpreted as congenital atlantooccipital fusion, hypoplasia of the atlas and dens, malformation of the axis, and modification of the atlantoaxial joint. Atlantoaxial subluxation was also a frequent finding. The clinical syndromes shown by these horses ...
Zink MC, Yager JA, Smart NL.Of 131 cases of Corynebacterium equi infection in horses submitted for necropsy to the Ontario Veterinary College or Veterinary Laboratory Services, OMAF, Guelph, Ontario from 1958 to 1984, 115 were diagnosed as suppurative pneumonia, and of these 55 had associated ulcerative enterocolitis. Only five animals had intestinal involvement without pulmonary lesions. The remaining 11 cases included arthritis/cellulitis, skin abscesses and submandibular lymphadenitis. While the lung, intestine and associated lymph nodes yielded C. equi most frequently, in 21% of cases C. equi was also cultured from p...
Gordon BJ, Latimer KS, Murray CM, Moore JN.Continuous-flow centrifugation leukapheresis techniques were used to collect 300-ml volumes of leukocyte-rich plasma from 5 nonmedicated horses and from 5 corticosteroid-stimulated horses. White blood cell counts and differential counts were performed on the horses before (base line) and up to 48 hours after leukapheresis. Systemic administration of hydrocortisone increased numbers of total WBC and neutrophils and improved harvest of these cells. Nonmedicated horses had a mean yield of 3.38 X 10(10) leukocytes in the 300-ml volume. Stimulated horses yielded a mean of 6.88 X 10(10) leukocytes. ...
Dumasia MC, Houghton E, Sinkins S.A gas chromatographic-mass spectrometric (GC-MS) method using three analytes to detect and confirm the administration to equine male castrates of veterinary pro-drugs based upon esters of testosterone is described. The method involves extraction of steroid conjugates from horse urine by C18-bonded cartridges and fractionation into glucuronic acid and sulpho-conjugates by Sephadex LH-20 column chromatography. After deconjugation, the free neutral steroids were partially purified by thin-layer chromatography and following derivatization (methyloxime-trimethylsilyl ether) were analysed by capilla...
Bondesson U, Johansson IM.This study demonstrates the development of a method using gas chromatography-mass spectrometry for determining nefopam, a non-narcotic pain reliever that is sometimes abused in horse doping, in equine plasma. Background […]
Al-Mashat RR, Taylor DJ.Thirty-three species of bacteria were isolated from the gastrointestinal mucosa of 23 adult horses and two foals. The bacteria isolated could be related to gross and microscopical lesions in some cases. Clostridium perfringens type A, Actinobacillus equuli, Salmonella typhimurium and Campylobacter coli biotype 1 could all be associated with gastrointestinal lesions. C jejuni biotype 1 and Aeromonas hydrophila were both recovered in this study and have been identified as causes of enteritis in horses or in other species. The case of C coli enteritis appears to be the first such report. The diff...
Greene HJ, O'Connor JP.A 16-year old thoroughbred mare was presented with dysphagia and food being ejected from the mouth and nostrils. Clinical signs were exhibited for three weeks before it was euthanased on humanitarian grounds. Post mortem examination revealed a soft haemangioma measuring 7 cm X 5 cm suspended from the roof of the medial compartment of the left guttural pouch.
Campbell-Thompson ML, Brown MP, Slone DE, Merritt AM, Moll HD, Levy M.Gastroenterostomy was performed in 14 foals to treat gastric outflow obstruction caused by advanced gastroduodenal ulcer disease. The onset of excessive salivation and teeth grinding, without response to medical treatment, combined with endoscopic and radiographic evidence of gastric outflow obstruction, were indications for surgical intervention. Successful outcome in 5 foals was attributed to early diagnosis, patient stabilization, early surgical correction, and postoperative management including antibiotics and antiulcer medication.
Giordano A, Castagnetti C, Panzani S, Paltrinieri S, Freccero F, Veronesi MC.In newborn babies, endothelin 1 (ET-1), a potent vasoconstrictor, increases during septicemia and severe respiratory syndromes. Because equine neonatal sepsis (ENS) and perinatal asphyxia syndrome (PAS) are major causes of morbidity and mortality in newborn foals and because no information on the concentration of ET-1 in healthy and sick foals has been reported yet, the aims of this study were (1) to define the serum concentration of Big ET-1 in healthy neonatal foals during the first week of age; (2) to preliminarily explore the diagnostic and prognostic role of Big ET-1 during ENS and PAS. S...
Specht TE, Colahan PT.Eleven horses with acute or chronic incomplete cortical fractures of the left or right third metacarpal bone (McIII) were treated with surgical puncture (osteostixis). The fractures were diagnosed by physical examination and radiography. Four to eight holes, 2.7 or 3.5 mm in diameter, were drilled in the fractured bone. Radiographically, the fractures were healed by month 3, and the drill holes were inapparent by month 7. Nine horses (82%) returned to race competition, and two horses were retired, one the result of a surgical complication. The mean time between surgery and the first race was 9...
François L, Hoskens H, Velie BD, Stinckens A, Tinel S, Lamberigts C, Peeters L, Savelkoul HFJ, Tijhaar E, Lindgren G, Janssens S, Ducro BJ, Buys N....Insect bite hypersensitivity (IBH), which is a cutaneous allergic reaction to antigens from Culicoides spp., is the most prevalent skin disorder in horses. Misdiagnosis is possible, as IBH is usually diagnosed based on clinical signs. Our study is the first to employ IgE levels against several recombinant Culicoides spp. allergens as an objective, independent, and quantitative phenotype to improve the power to detect genetic variants that underlie IBH. Genotypes of 200 Shetland ponies, 127 Icelandic horses, and 223 Belgian Warmblood horses were analyzed while using a mixed model approach. No s...
Henderson WM.An attempt is made to review the validity of the claim that more equine research is required with the conclusion that the problems in the equine field that would respond to research must be listed and each assigned a degree of priority according to suggested criteria. Future action will then depend upon identifying or stimulating scientific initiative and seeking the required financial support noting that self help from the equine industry has not been adequately utilised.
Cavallero S, Pombi M, Perrone V, Milardi GL, D'Amelio S, Giuliani C, Gabrielli S.Larval forms of the bot-fly Gasterophilus are obligate parasites commonly found in the gastrointestinal tract of equids, causing intestinal myiasis. Five species are reported so far in Italy, mostly observed during necroscopy, located in different portion of gastrointestinal tract of equids: G. intestinalis, G. nasalis, G. inermis, G. pecorum and G. haemorrhoidalis. An unusual finding of larval Gasterophilus intestinalis deeply inserted into the diaphragmatic muscle is here reported. Due to the uncommon localization, to the absence of clinical signs related to myiasis and subsequent uncertaint...
Blue BJ, Pickett BW, Squires EL, McKinnon AO, Nett TM, Amann RP, Shiner KA.Gonadotrophin-releasing hormone (GnRH) was administered subcutaneously to reproductively normal stallions, either in a pulsatile manner (10 micrograms GnRH/2 h; n = 6) or as a continuous infusion (10 micrograms GnRH/2 h; n = 6), and in a pulsatile manner to 9 reproductively abnormal stallions, from February to July, 1988. Hormonal secretion patterns, testicular parameters and semen characteristics were monitored before and during treatment. In general, pulsatile GnRH caused a significant increase (P less than 0.05) in luteinizing hormone (LH) concentrations in the peripheral blood of normal st...
Peter AT, Colenbrander B, Gadella BM.The present study was designed to test the hypothesis that addition of anticaspase cocktails (inhibiting caspases and thus blocking apoptosis) to the extenders increases the post-thaw viability of equine spermatozoa. The addition of caspase inhibitors failed to improve the acrosome and plasma membrane integrity of spermatozoa, suggesting that in equine sperm cryopreservation protocols, the addition of these caspase inhibitors to cryopreservation medium may not be beneficial in protecting the sperm from the stress of cryopreservation.
Kraft W.Neurological examination in equine practice, physiological findings and pathological disturbances are described. Because of the sizes of the horse the neurological examination is more difficult than in small animals. The examination of cerebrospinal fluid is a worthful completion and is able to refer to the etiology of a certain disease. The technique of the puncture of cerebrospinal fluid is described.
Marquardt J, Heymer J, Heinz H, Deegen E, Adolf GR, Leibold W.Interferon is known to induce antiviral mechanisms and to exert immunoregulatory capacities on various cell types. The antiviral capacity of recombinant equine interferon-beta 1 (rEqIFN-beta 1) is most sensitively monitored by indirect quantitation of multiplication of vesicular stomatitis virus (VSV) in blood cells of horses. As few as 0.5 pg rEqIFN-beta 1/ml can be assessed by means of 90% reduction of VSV-replication in whole blood (w.b.) as well as in isolated mononuclear blood cells (MNC) in spite of individual variations. The immunoregulatory influence of 20-50 pg rEqIFN-beta 1/ml is suf...
Vivrette SL, Irvine CH.Acyclic mare given oestradiol for 3 days to simulate the preovulatory plasma oestradiol surge showed a non-significant 37% decrease in plasma LH during treatment. When GnRH analogue injections were given with oestradiol on Days 1--3, oestradiol had no effect on each GnRH-induced LH increase, but LH increases were more prolonged following subsequent GnRH injections on Days 4--7 when oestradiol was no longer being given. A much greater prolongation of LH release occurred when the course of GnRH injections was commenced after oestradiol treatment ceased; the LH response was almost identical to th...
Rasbech NO, Koefoed-Johnsen HH, Holm G.On the basis of progesterone determination on plasma or blood after RIA and the kit method respectively and consecutive scanning performed on a total number of 31 mares the following features were demonstrated: The overall material shows that in 20 mares (64.5%) embryonic vesicles were demonstrated. Of these mares 16 have conceived after service in the 1st estrous cycle and 3 mares in the 2nd estrous cycle. 18 mares were scanned in the time interval 13th-26th day after the latest service, while 2 mares were scanned on day 46 and 41 respectively. A total of 14 scanning positive mares were exami...
Coignoul FL, Bertram TA, Cheville NF.Three pony mares and 4 pony foals were inoculated with a subtype 2 strain of equine herpesvirus 1. Foals had periods of fever 12 h and 2.5 days after inoculation and leukopenia, involving both neutrophils and lymphocytes, followed by leukocytosis. Mares had transient fever and leukopenia 24 hours after inoculation that were less severe than in foals. An increase in circulating virus-neutralizing antibody was seen in 2 of 3 inoculated mares, but not in foals. Attempts to isolate virus from blood were unsuccessful. These studies show that equine herpesvirus 1 subtype 2 is a mild pathogen for pon...
Długołęcka E, Tobolski D, Janowski T.Early embryonic death (EED) is one of the causes of infertility in the mare. We compared endometrial environment in 9 mares with EED and 13 mares in diestrus phase. Cotton swab (CS), cytobrush (CB) and uterine biopsy (B) samples were obtained for the cytological, bacteriological and histopathological examinations. In the first step we compared CS and CB methods to biopsy as a reference method, as B revealed the highest number of positive results in cytological and bacteriological examinations in both groups. In turn, we also compared cytological, bacteriological and histopathological findings ...
Booth AD, Hidalgo FL, Bellezzo F, Young JM, Bianco AW, Hughes LE, Maher M, Trumble TN, Ernst N.To describe outcomes of horses with temporohyoid osteoarthropathy (THO) treated with partial ceratohyoidectomy. 10 client-owned horses. Medical records from 2 institutions were examined for records of horses with THO treated with partial ceratohyoidectomy between 2010 and 2021. History, signalment, clinical signs, diagnostics, medications, and surgery-related details were recorded. Horses with a minimum of 6 months follow-up were recruited for neurologic and imaging examinations in the hospital or field where radiography of the basihyoid-ceratohyoid articulation were performed along with CT, w...
Romano MC, Francis KA, Janes JG, Poppenga RH, Filigenzi MS, Stefanovski D, Gaskill CL.Poisoning of nontarget species is a major concern with the use of anticoagulant rodenticides (ARs). At postmortem examination, differentiating toxicosis from incidental exposure is sometimes difficult. Clotting profiles cannot be performed on postmortem samples, and clinically significant serum, blood, and liver AR concentrations are not well-established in most species. We chose diphacinone for our study because, at the time, it was the publicly available AR most commonly detected in samples analyzed at the University of Kentucky Veterinary Diagnostic Laboratory. We determined an approximate ...
Dyer DC, Hsu WH, Lloyd WE.Twenty healthy ponies were given i.v. 1.1 mg/kg of xylazine from 2 manufacturers and the pharmacokinetic parameters calculated from the disposition curves. The disposition curves for the 2 commercial preparations were not different. Yohimbine, an antagonist of the pharmacologic effects produced by xylazine, did not alter the disposition of xylazine in the plasma. A single i.v. bolus of xylazine was completely described in 17 of 20 animals by the biexponential equation: Cp = 1.30e(-0.3955t) + 0.58e(-0.033t) where Cp represents the concentration of xylazine in the plasma at time t (min). The t1/...