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.
Testa M, Raffe MR, Robinson EP.Twenty-five percent, 50%, and 67% nitrous oxide was administered to 12 horses anesthetized with halothane and oxygen. Compared to halothane-oxygen alone, there was no significant difference in heart rate, systolic, diastolic, or mean blood pressure values, arterial pH, PaCO2, or plasma bicarbonate values when nitrous oxide was included. A significant linear reduction in PaO2 values could be correlated with N2O:O2 concentrations. The halothane level required to maintain surgical anesthesia was reduced when nitrous oxide was administered, but it was not affected by changing the nitrous oxide con...
Goetz TE, Manohar M.The effect of age on maximal heart rate induced by IV infusion of isoproterenol was studied in 19 healthy, sedentary, normothermic horses ranging in age from 0.25 to 9.90 years. Isoproterenol was administered IV (1.0 micrograms/kg of body weight/min) for 3 minutes, and the heart rate attained during the last 30 seconds of the infusion was determined. Linear regression of the maximal heart rate on age suggested that the rate decreased with age in a trend described by the equation: maximal heart rate (beats/min) = 209.63 - 3.28 x age (years). The regression coefficient (r) for this relation was ...
Harrison IW, Cartee RE.A nine-year-old gelding was presented to the Auburn University Large Animal Clinic with discharge of saliva and food material from both nostrils. A diagnosis of esophageal diverticulum was made; treatment is described.
Bertone AL, Stashak TS, Smith FW, Norrdin RW.In nine horses (18 forelimbs), a 3 cm section of superficial digital flexor tendon was removed and the tendons were repaired with immobilization for 6 weeks and (1) no suture (n = 6); (2) a double locking loop tenorrhaphy with carbon fiber (n = 6); or (3) a double locking loop tenorrhaphy with size 2 nylon suture (n = 6). Clinical assessment, gross evaluation, morphometry, histology, and mechanical testing were performed on two limbs from each treatment group at weeks 6, 12, and 24. At weeks 6 and 12, the unsutured tissue was less mature than the tissue sutured with nylon. By week 24, the carb...
Nunamaker DM, Butterweck DM, Provost MT.The North American Thoroughbred racehorse was chosen as a model to study the pathogenesis of fatigue failure of bone. This species has a high incidence of spontaneous fatigue failure of bone (bucked shins) during its early training. In vivo strain gauge studies of the third metacarpal bone of four young racehorses running at racing speeds showed high principal compressive strains [-4,841 +/- 572 (SD) microstrain] while two older horses had lower principal compressive strains (-3,317 microstrain measured at racing speed, -3,250 microstrain extrapolated from a slower speed run). Previously repor...
Watson ED, Zanecosky HG.Fluid was aspirated from the preovulatory follicles of mares before and 12, 24 and 36 h after intravenous administration of hCG. Follicular fluid significantly (P less than 0.001) reduced lymphocyte blastogenesis in vitro and, at a dilution of 1:100, fluid collected at 36 h after administration of hCG was significantly more suppressive (P less than 0.01) than fluid collected before 36 h. Suppression of blastogenesis was reduced by extracting the follicular fluid with ether or by charcoal treatment (P less than 0.01) or by heating at 56 degrees C for 30 min (P less than 0.05). Preincubation of ...
Nishita T, Matsushita H.A sensitive sandwich enzyme immunoassay (EIA) for measuring equine carbonic anhydrase III (CA-III) was established using a microplate as a solid-phase and peroxidase as a labelling enzyme. The assay can detect concentrations as low as 5 ng/ml using 20 microliters of sample sera. Within-run coefficients of variation obtained using standard equine CA-III were less than 5 per cent. CA-III levels in equine serum ranged from 5 to 50 ng/ml (n = 370), and apparently abnormal levels of CA-III from 100 to 1900 ng/ml (n = 27) were observed. The concentrations of immunoreactive CA-III in the extracts of ...
Schougaard H, Falk Ronne J, Phillipson J.This research study investigated the prevalence and potential genetic factors of tibiotarsal osteochondrosis, a joint condition, in trotting horses in Denmark through a radiographic survey. The study examined 325 yearlings, […]
Johnson L, Kattan-Said AF, Hardy VB, Scrutchfield WL.Stages of the spermatogenic cycle in the horse were determined by trans-illumination of enzymically isolated, seminiferous tubules and were verified by whole-mounted tubules observed by Nomarski optics and by conventional histology. Isolated tubules were obtained from young (less than 2 years) and adult (4-10 years) horses by enzymic digestion. Dispersed tubules were separated into three different groups based on the presence, size, and intensity of a dark region in the centre of the tubules: (1) pale--homogeneously light, (2) spotty--light on the periphery with a wide spotty region in the cen...
Rebhun WC.Corneal squamous cell carcinomas with surface areas of more than 2.0 cm were diagnosed in 26 eyes of 25 horses. The depth of the lesion into the corneal stroma and involvement of the ocular adnexa were important determinants for surgical treatment. Corneal tumors that extended into adjacent palpebral conjunctiva, eyelid, or orbit were not amenable to complete excision, while those that involved only cornea and bulbar conjunctiva were treated surgically by keratectomy and beta radiation. Initial treatment was keratectomy followed by beta radiation on 24 eyes and enucleation of two eyes. Twenty ...
Edwards DJ, Brownlow MA, Hutchins DR.A series of blood and urine samples was collected from each of eight normal foals between birth and eight weeks. Blood chemistry relating to renal function was evaluated as well as physical and chemical characteristics of urine. During the first 4d of life it was impractical to suggest meaningful normal values due to wide variation among foals and with time. Serum urea and plasma creatinine fell markedly to levels less than those previously reported for normal adult horses, while urine, mildly hypersthenuric at birth, rapidly became hyposthenuric. There was also a marked proteinuria during the...
Watson ED, Mair TS, Sweeney CR.Because of their capacity to produce prostanoids, alveolar macrophages may play a part in the pathogenesis of chronic obstructive pulmonary disease (COPD). Cultured equine alveolar macrophages and peripheral blood monocytes synthesised mainly prostaglandin (PG)F and PGE2. They also synthesised smaller quantities of PGI2, measured as the stable metabolite 6-keto-PGF1 alpha, and thromboxane B2. Concentrations of immunoreactive PGF and PGE2 were measured in bronchoalveolar lavage fluid collected from clinically normal horses (n = 3) and horses with COPD (n = 3). None of the normal horses had dete...
Kamerling SG, Hamra JG, Bagwell CA.Endogenous opioid peptides have been implicated in the regulation of pain perception, behaviour, gastrointestinal activity and other physiological responses. However, the functional role of these peptides in the horse has yet to be elucidated. The opioid antagonist, naloxone, is often administered to infer endogenous opioid effects. In the present study, naloxone (0.75 mg/kg bodyweight) was administered to eight Thoroughbred racehorses and a number of behavioural and autonomic responses were measured. Naloxone produced rapid onset diarrhoea, restlessness, abdominal checking, tachycardia, tachy...
Matthews NS, Dollar NS, Shawley RV.The halothane-sparing effect of 2 benzodiazepines, diazepam and temazepam, were investigated in ponies by measuring the minimum alveolar concentration (MAC) for halothane before and after drug administration. The MAC value for halothane decreased 29% and 16% when either 0.044 mg/kg of diazepam or 0.044 mg/kg of temazepam, respectively, was administered intravenously. Heart rate, respiratory rate, systolic and mean arterial blood pressure, and expired CO2 were also measured. No differences were present in these variables before and after drug administration nor were differences noted between th...
Anderson WI, De Lahunta A, Vesely KR, Tucker GW.Infarction of the pons and rostral medulla secondary to arteriolar thrombosis was documented histologically in a 17-year-old mixed-Arabian female horse. Clinically, the animal experienced a sudden onset of a head tilt and subsequent non-controllable seizures. There was no historical, clinical or histological evidence to suggest the presence of infection of Equine Herpesvirus-1 or the feeding of corn contaminated by Fusarium moniliforme.
Fadok VA, Greiner EC.Forty-four seasonally pruritic horses and 21 asymptomatic horses in Florida, USA, were tested for insect, grass and mould hypersensitivity by intradermal injection of allergenic extracts. The affected horses ranged in age from 10 months to over 30 years and included a variety of breeds. Affected horses reacted to varying dilutions of extracts made from Culicoides, mosquitoes, horse flies and black flies. Reactions to Culicoides were more intense than those caused by injection of antigens from other arthropods. Mild pruritus existed from the end of February until the end of June when the condit...
Jain NC, Vegad JL, Kono CS.Equine neutrophil antibody was raised in rabbits inoculated with equine neutrophils isolated to purity greater than 99.0%, using Percoll density-gradient sedimentation. Neutrophil antibody was detected by use of agar gel diffusion, leukoagglutination, indirect immunofluorescence, staphylococcal protein A and streptococcal protein G binding, and phagocytic inhibition techniques. Precipitin lines and leukoagglutination were seen in antiserum dilutions of 1:4 and 1:64, respectively. The specific nature of leukoagglutination was characterized by the formation of rosette-like clumps of neutrophils....
Alwan WH, Carter SD, Bennett D, May SA, Edwards GB.Degradation of cartilage in osteoarthritis of man results in the release of sulphated glycosaminoglycans, particularly keratan sulphate, into tissue fluids. A study was made to evaluate these markers for osteoarthritis in the horse. Synovial fluid and serum levels of keratan sulphate, measured by an ELISA-inhibition technique, and sulphated glycosaminoglycans measured by specific dye binding assay, were found to be significantly increased (P less than 0.001) in joints from horses with osteoarthritis, compared with normal joints. Synovial fluids from joints with infective arthritis also showed ...
Haywood PE, Teale P, Moss MS.Thoroughbred geldings were fed racehorse cubes containing a predetermined concentration of theobromine in the form of cocoa husk. They were offered 7 kg of cubes per day, divided between morning and evening feed, and food consumption was monitored. Urinary concentrations of theobromine were determined following the consumption of cubes containing 11.5, 6.6, 2.0 and 1.2 mg per kg of theobromine, to verify whether or not such concentrations would produce positive urine tests. Pre-dose urine samples were collected to verify the absence of theobromine before each experiment. It became apparent fro...
Schmall LM, Muir WW, Robertson JT.The effects of treatment with small volume hypertonic (2400 mOsm/litre) and isotonic (300 mOsm/litre) saline on serum electrolyte and biochemical concentrations, haemograms and blood gases were evaluated in 12 horses using a haemorrhagic shock model. Intravascular catheters were placed surgically for sample collection prior to anaesthesia. Controlled haemorrhage was initiated and continued until mean systemic pressure reached 50 to 60 mmHg. Hypertonic or isotonic saline (2 litres) was administered by intravenous infusion and data collected for 2 h. Following haemorrhage, packed cell volume (PC...
Andrews FM, Hamlin RL, Stalnaker PS.Whole blood viscosity (WBV) was measured on six healthy horses and ten horses presented for colic surgery. A Wells-Brookfield cone-and-plate microviscometer at 6 rpm was used to determine WBV and WBV was adjusted for packed cell volume (PCV). The ten colic horses were divided into two groups: five horses that died or were euthanatized (group 1) and five horses that were discharged after surgery and medical therapy (group 2). The mean WBV for each group was compared using analysis of variance followed by Duncan multiple-range tests. Mean WBV of group 2 (5.81 +/- 1.48 centipoise [cp]) and normal...
Lees P, May SA, Hooke RE, Silley P.The administration of a single dose of the antibacterial agent cephalexin intramuscularly to six ponies at a dose rate of 7 mg/kg was well tolerated. No reactions at the injection site were apparent. It was absorbed rapidly and reached a mean peak plasma concentration of 6.77 micrograms/ml after a mean of 1.41 hours; plasma concentrations above 2.0 and 0.5 micrograms/ml were maintained for 3.8 and 9.8 hours, respectively.
Evans SV, Brayer GD.The three-dimensional structure of horse heart metmyoglobin has been refined to a final R-factor of 15.5% for all observed data in the 6.0 to 1.9 A resolution range. The final model consists of 1242 non-hydrogen protein atoms, 154 water molecules and one sulfate ion. This structure has nearly ideal bonding and bond angle geometry. A Luzzati plot of the variation in R-factor with resolution yields an estimated mean co-ordinate error of 0.18 A. An extensive analysis of the pattern of hydrogen bonds formed in horse heart metmyoglobin has been completed. Over 80% of the polypeptide chain is involv...
Tulleners EP.Fifty-seven Standardbred and 44 Thoroughbred racehorses and 1 Thoroughbred polo mare with primary clinical signs of exercise intolerance or respiratory tract noise or combined exercise intolerance and respiratory tract noise were referred for laser correction of epiglottic entrapment. Significantly (P less than 0.001) more Standardbred than Thoroughbred racehorses were affected, compared with the observed hospital population during the same period. At referral, 14 horses did not have evident epiglottic entrapment and were returned to exercise without development of entrapment after treatment, ...
Bristol F.A 6-year-old stallion was placed in a pasture for 9 days with 20 mares in which oestrus was synchronized with two treatments of PGF-2 alpha given 15 days apart. Breeding and observation began 3 days after the second treatment. Observations were carried out during the daylight hours (05:00 to 21:30 h). Eighteen mares showed oestrus and mated an average of 4.56 times each (range 1-12). There were 1.74 mounts per mating. The maximum number of matings by the stallion during 1 day was 16 on Day 2. The overall mean interval between matings was 72.8 min, ranging from 34.5 min on Day 1 to 128.7 on Day...
The research paper involves a study targeting lesions in the foot joints of Warmblood horses, which was found to be common. However, the authors acknowledge that the initial paper contained […]
Plumlee KH, Tor ER.The research evaluates cholinesterase activity across different brain regions in horses to better understand its role in neuromuscular function and how it can be affected by certain toxic exposures. Cholinesterase […]
Merkens HW, Rutgers LJ.To gain an insight into the procedures adopted in castrating stallions in the Netherlands, a questionnaire was sent to 670 Dutch veterinary practitioners. The 176 veterinary practitioners who replied performed 1850 castrations. Castration of the recumbent horse was preferred by 88 per cent of the veterinary surgeons. Fifty per cent preferred the open method of castration and 44 per cent the half-closed technique. A local anaesthetic was given by 65 per cent of the practitioners; 84 per cent administered antibiotics in an attempt to prevent wound infection. Postoperative complications were obse...
Hong CB.Three cases of congenital polyalveolar lobe (pulmonary hamartoma) were diagnosed in female Thoroughbred foals. Foal 1 was born at full term but died shortly afterwards. Foal 2 was aborted at the seventh month of gestation. Parturition was induced at the tenth month of gestation in foal 3 because it developed hydrops of the amnion and ascites. In all three foals, the polyalveolar lobe occurred on the right side and affected the entire right lung. In each case, the right lung formed a tumour-like mass, and expanded into the left chest cavity. The lung masses were pink to dark red and spongy to r...
Mama KR, Wagner AE, Steffey EP, Kollias-Baker C, Hellyer PW, Golden AE, Brevard LF.Eight horses [5.6 ± 3.6 years, 489 ± 48.6 kg (mean ± SD)] were anesthetized four times under laboratory conditions to characterize physiologic and behavioral (reported elsewhere) responses associated with a 1-hours period of total intravenous anesthesia (TIA). Each horse was premedicated with xylazine (X, 0.75 mg kg−1) and anesthesia induced 5 minutes later with 5% guaifenesin (75 mg kg−1) and ketamine (K, 2 mg kg−1), all given IV After anesthetic induction, horses were intubated and received one of six treatments [X 35, K 90, O2; X 35, K 120, O2; X 35, K 120, air; X 35, K150, O2; X 7...
Parkes RD, Blackmore DJ.Equine placental extracts show phosphatase activity with a pH optimum between 4.5 and 6. The enzyme shows heat stability to 45 degrees C and electrophoresis on cellulose acetate demonstrates the presence of two bands of activity. Histochemistry confirms the presence of phosphatase activity in the placental villi. Assay of plasma samples from pregnant mares showed no increase in phosphatase activity through pregnancy under conditions of test.
Hauspie S, Vanderperren K, Gielen I, Pardon B, Kromhout K, Martens A, Saunders JH.A synovial plica is present at the dorsoproximal aspect of the fetlock joint. The objective of this study was to describe the location of the synovial plica during induced hyperextension using Magnetic Resonance Imaging. For this study 20 cadaver limbs from five Warmblood horses were used. Measurements were made of the dorsal; palmar/plantar length and the thickness of the plica with the joint in a normal position. During induced hyperextension of the joint, the position of the plica was described; the dorsal angle of extension and angle of contact between the proximal phalanx (P1) and the con...
Stepanov VM, Lavrenova GI, Rudenskaia GN, Gonchar MV, Lebareva LS.6 forms of pepsin are found in horse gastric juice. Amino acid sequence is determined of N-terminal (most variable) part of polypeptide chain of main pepsin components. Equine pepsines, which have pI 2.1 and 2.3, are found to have identical amino acid sequence at least for 31 amino acid residues. The same sequence is observed in the component with pI 2.6 for 10 first residues. The sequence of equine pepsin with pI 3.2 has 3 substitutions for 33 amino acids, when compared with pepsines having pI 2.1 and 2.3. The forms of equine pepsin studied are more similar than the other isoenzyme pair, huma...
Guillot J, Collobert C, Gueho E, Mialot M, Lagarde E.A case is reported in a 9-year-old Anglo-Arab horse with guttural pouch mycosis caused by Emericella nidulans. Acute death occurred by exsanguination following erosion of the external carotid artery. Histopathological examination of the mycotic plaque demonstrated septate hyphae, conidial heads, hülle cells and mature cleistothecia containing characteristic ascospores. Specific identification was confirmed by culture. In accordance with previous reports, Emericella nidulans should be considered as the major agent of guttural pouch mycosis in Equidae.
Sabiniewicz A, Białek M, Tarnowska K, Świątek R, Dobrowolska M, Sorokowski P.Whereas several recent studies demonstrated that some animal species are able to recognize human emotions based on information from body odor [...].
Leikola E, Nieminen E, Teppo AM.Human epidermis, hair, nails, and kidney as well as bovine and horses' hooves were found to contain a lipid fraction, which on thin-layer chromatography migrated slightly ahead of the cerebroside sulfate esters and gave the color reaction specific for sialic acid. This fraction was isolated from horse hoof, in which it constituted nearly half of the total lipids. The purified fraction contained sulfur, but no phosphorus. The IR spectrum revealed the presence of a sulfate group, which was also determined by the benzidine method. Thin-layer and gas-liquid chromatography of the products of acid h...
Gibson K, O'Hara A, Huxtable C.Focal intramural nodules were palpated in the rectal wall of a 12-year-old pony mare presented for rectal prolapse. Eosinophilic proctitis was diagnosed by examination of fine needle aspirates and biopsy of the largest rectal nodule. After treatment with a course of corticosteroids, the rectal nodule and accompanying peripheral eosinophilia resolved. There was no recurrence of the condition during the follow-up period of 20 months. Focal eosinophilic proctitis appeared to be an unusual cause of tenesmus and rectal prolapse in this case.
Magnuson NS, Perryman LE, Grant B, Estergreen VL.Plasma corticosteroid concentrations of seven Arabian foals with combined immunodeficiency (CID) and five non-CID Arabian foals were measured. Plasma corticosteroid concentrations were quantitated throughout gestation for ten mares heterozygous for the CID trait and pregnant with CID foals, as well as for 20 mares heterozygous for the CID trait and pregnant with non-CID foals. Five nonpregnant mares heterozygous for the CID trait also were tested during the same period. Concentrations of plasma corticosteroids in foals with CID (34.4 +/- 5.2 ng/ml) were not different from those of non-CID foal...
Kondo T, Sato F, Tsuzuki N, Watanabe K, Horiuchi N, Kobayashi Y, Yamada K.The purpose of this observational study was to determine the characteristic computed tomographic (CT) myelography findings of cervical vertebral stenotic myelopathy (CVSM) lesions in Thoroughbred horses. A total of 23 Thoroughbred horses (age range, 155-717 days on CT examination; mean, 410.9 days) were analyzed. All 23 Thoroughbred horses underwent unenhanced radiography, radiographic myelography, and CT myelography. Unenhanced radiographs were observed the presence of cervical vertebral malalignment and osseous lesions. Radiographic myelograms were observed for signs of cervical spinal cord ...
Kalsow CM, Albrecht TR, Steinberg NP, Lunn DP.Immunohistochemical evaluation of equine tissue necessitates the use of antibodies reactive with cells from a heterogeneous population. Lymphoid tissues from 12 horses were fixed in Bouin's fluid, ethanol or formalin and examined for immunohistochemical reactivity with anti-equine and anti-human monoclonal antibodies (MAbs) specific for MHC Class II antigens, T and B lymphocytes, and macrophages. Only a few of the anti-equine MAbs tested were reactive with fixed, paraffin wax-embedded tissue. Anti-human MAbs expanded the desired range of reactivity and increased the consistency in different an...
Zgórniak-Nowosielska I, Kosiniak K, Slagowska A.Eleven mycoplasma strains were isolated from the semen of 24 stallions. Eight of these strains were identified as Mycoplasma equigenitalium. Three strains which hydrolized arginine could not be identified. The growth inhibition test with immune sera against M. arginini and M. equirhinis was negative. Antibiotic sensitivity test showed that all strains were sensitive to four antibiotic of tetracycline group (oxytetracyclin, minocycline, transcycline and vibramycin). Lincomycin and gentamycin appeared to be the most active against all the strains. Comparative analysis of routine semen examinatio...
Boles C.Adequate post-operative management of equine abdominal patients is as necessary to patient survival as the most heroic corrective surgery. Post-operative management must begin during the anaesthesia recovery phase to insure adequate oxygen supply, ventilation, and minimize any abdominal discomfort. The animal's physiological status must be constantly monitored to detect and determine the degree of abnormalities concerning serum electrolytes, fluid balance, and acid-base abnormalities. The most commonly observed serum electrolyte imbalance is hypokalaemia. Replacement potassium is usually suppl...
Pugliesi G, Fürst R, Carvalho GR.The effects of freezing technique and thawing protocol on thawed semen viability and fertility were studied. Ejaculates from 5 stallions (n = 25) were frozen by conventional or a fast-freezing technique. Frozen semen was thawed by two thawing protocols (37 °C 30 s(-1) or 75 °C 7 s(-1) ). Thawed semen was evaluated by progressive motility, vigour, morphology and plasma membrane integrity. Mares (n = 25) were inseminated with 300 (n = 11) or 150 (n = 14) million spermatozoa. A greater (P < 0.05) vigour and progressively motile spermatozoa were detected, respectively, at thawing a...
Vaughan LC, Edwards GB, Gerring EL.Implants of carbon fibre, made by plaiting a tow of 10,000 filaments of Grafil type HT-S, were used to treat strains and ruptures of digital flexor tendons in 46 horses. The relevant clinical data, the techniques employed and an analysis of the results are described. Apart from two horses in which the implant was extruded and had to be removed, there were minimal untoward consequences of the surgery. Of the 34 horses with acute or chronic tendinitis, 14 returned to racing, seven were used as hunters and seven as hacks. Among the former group, seven suffered a further strain while racing but th...