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.
Gasthuys F, de Moor A, Parmentier D.Haemodynamic and respiratory responses to halothane were investigated in dorsally recumbent, ventilated ponies during 2 hours. Normocapnia was maintained using intermittent positive pressure ventilation. Compared to the base line values at 30 minutes of constant dose halothane, no significant changes in heart rate, systemic blood pressure, cardiac output, cardiac index, stroke volume and left ventricle work were observed during a 2 hours anaesthesia. Arterial oxygenation increased initially (greater than 300 mm Hg) but tended to decrease non-significantly during the rest of the anaesthesia. Bl...
Hintz HF.Interest in mycotoxins and mycotoxicosis in humans and animals has greatly increased in recent years. Horses have long been considered very susceptible to molds. The signs, treatment, and prevention of several conditions, such as leukoencephalomalacia, aflatoxicosis, ergotism, fescue toxicity, slobbering disease, ryegrass staggers, and moldy sweet clover disease, are discussed.
Seethanathan P, Bottoms GD, Schafer K.Direct effects of endotoxin (lipopolysaccharide [LPS]) on equine WBC are known to stimulate the release of a variety of mediators including thromboxane, prostacyclin, and leukotrienes. In this study, 0.1 microgram of LPS/ml stimulated an early increase in tumor necrosis factor, succeeded by an increase in interleukin-1, but concentrations of LPS up to 5.0 micrograms/ml caused no significant increase in superoxide anion release. The concentration of LPS (0.1 microgram/ml) used in this experiment was in the range of concentrations measured in plasma of some horses with gastrointestinal problems....
Shires GM, Adair HS, Patton CS.In an attempt to ablate the laryngeal saccule as an alternative method of sacculectomy (conventially done through a laryngotomy incision for laryngeal hemiplegia) a neodymium:yttrium aluminum garnet laser was used transendoscopically in noncontact fashion in 6 horses. The procedure was easy, quick, and labor-saving, with few complications. Endoscopically, the lased sacculectomy site appeared healed at postsurgical day 42. On postsurgical day 42, microscopic examination revealed mucosal remnants under the granulation bed. Laser energy caused thermal damage to tissues adjacent to the lased saccu...
Mfitilodze MW, Hutchinson GW.A postmortem survey of 57 horses in tropical northern Queensland revealed 41 (89%) infected with intestinal strongyles. Thirty-five strongyle species (8 large strongyles and 27 small strongyles [Cyathostominae]) were recorded of which 9 species are reported from Australia for the first time. The 14 most prevalent small strongyles were Cyathostomum catinatum (in 76% of horses), Cyathostomum coronatum (65%), Cyathostomum pateratum (33%), Cyathostomum labiatum (30%), Cylicostephanus calicatus (70%), Cylicostephanus longibursatus (67%), Cylicostephanus goldi (43%), Cylicostephanus minutus (26%), C...
Houpt KA, Zahorik DM, Swartzman-Andert JA.The ability of ponies to learn to avoid a relatively novel food associated with illness was tested in three situations: when illness occurred immediately after consuming a feed; when illness occurred 30 min after consuming a feed; and when illness was contingent upon eating one of three feeds offered simultaneously. Apomorphine was used to produce illness. The feeds associated with illness were corn, alfalfa pellets, sweet feed and a complete pelleted feed. The ponies learned to avoid all the fees except the complete feed when apomorphine injection immediately followed consumption of the feed....
Whitlock RH.The equine practitioner often encounters serious diagnostic and therapeutic challenges regarding the specific origin of a disease. Such challenges may occur when horses become unaccountably ill after consuming what was thought to be acceptable feed but which in fact was contaminated or contained additives intended for other species. Examples of such additives and contaminants are monensin, lasalocid, salinomycin, blister beetles, and such antimicrobics as lincomycin and clindamycin.
Zhang JJ, Muzs LZ, Boyle MS.In vitro fertilizing ability of stallion spermatozoa was assessed using horse follicular oocytes matured in vitro. After collection, stallion spermatozoa were either: 1) washed and incubated in TALP medium with 3 mg/ml bovine serum albumin (BSA) and 10 micrograms/ml heparin for 4h, 2) washed and incubated in TALP with 3 mg/ml BSA for 3 h and cultured for a further 1 h with 1 mM caffeine and 5 mM dbcAMP, 3) washed and incubated in TALP medium with 3 mg/ml BSA at pH 7.9-8.2 for 2-4 h, or 4) diluted and incubated in TALP medium with 10 mg/ml BSA and 7.14 microM calcium ionophore A 23187 for 5-10 ...
Dill SG, Correa MT, Erb HN, deLahunta A, Kallfelz FA, Waldron C.A case-control study was done to identify factors associated with the development of equine degenerative myeloencephalopathy (EDM). Questionnaires were mailed to the owners of 146 horses admitted to the New York State College of Veterinary Medicine between November 1978 and June 1987 and diagnosed as having EDM by histologic examination. Questionnaires also were sent to owners of 402 clinically normal horses admitted to the college during the same period. Data were compared between the EDM-affected and control groups (56 and 179 questionnaires returned, respectively). Risk factors identified i...
Kohn CW, Brooks CL.Blood, serum, and plasma total calcium concentrations and plasma and serum ionized calcium concentrations were anaerobically determined by use of a calcium-specific electrode for samples obtained from 39 healthy horses. Mean (+/- SD) serum ionized calcium concentration was 6.6 +/- 0.3 mg/dl (1.6 +/- 0.1 mmol/L) and the mean serum ionized calcium percentage was 58.2 +/- 3.4%. Serum ionized calcium percentage was not significantly correlated with serum pH. Plasma ionized calcium percentage was weakly correlated with plasma pH (r = -0.480; P less than or equal to 0.05). Ionized calcium concentrat...
Cymbaluk NF, Christison GI.Horses are reared in all types of weather. Temperatures as diverse as -40 degrees C to 40 degrees C are tolerated by horses. The nutrient requirement most influenced by cold weather is energy. In cold weather, feeding good quality hays free-choice is usually sufficient for mature horses in good body condition. Grain may have to be fed when poor quality hays are used. Hot weather (greater than 30 degrees C) necessitates heat loss to maintain body core temperature. Horses sweat to reduce body heat. Heat stress can be minimized by feeding diets that reduce the heat increment. Use of grain and fat...
Hohenhaus MU.A rapid progesterone assay for cow's milk was checked as to whether it was applicable to mares' blood plasma. The "Hygia Progesterone-Test" is an on-farm test which serves for qualitative analysis. It is generally unusable for mares' plasma but sufficiently precise only in cases of larger or smaller progesterone levels. In cases of moderate amounts of progesterone the test is imprecise. The test can be carried out quickly and easily, but the preparation of blood samples takes more time than preparation of milk samples. The test can be recommended for usage in veterinary practice only, but not ...
Specht TE, Miller GJ, Colahan PT.The breaking strength (stress at failure) of equine third metacarpal bones, with and without clustered drill holes, was determined in vitro. Paired ossa metacarpalia II-IV of 39 horses (n = 39) between 2 and 7 years old were tested in palmarodorsal 3-point bending. Four treatments were compared. Clustered 2.7- or 3.5-mm drill holes, in a 4- or 7-hole pattern, were made in the dorsal cortex of the distal diaphysis of the left third metacarpal bone. Undrilled right third metacarpi were used as controls. Bones with clustered drill holes failed by an oblique fracture through 1 or more drill holes,...
Maylin GA, Bache CA, Lisk DJ.Effluents from a number of industries which are typically treated in municipal sewage plants result in cadmium-containing sludge. Disposal of such sewage sludge by application to agricultural land can result in uptake of cadmium by crops. In this study, oats were grown on soils which had been amended with sewage sludge from Syracuse, New York. The cadmium concentration in the sludge-grown oats was 1.79 ppm dry weight. Horses were fed the sludge-grown oats for 6 weeks during which time blood samples were taken for the determination of cadmium. No significant differences (p greater than 0.05) we...
Roth TL, White KL, Thompson DL, Barry BE, Capehart JS, Colborn DR, Rabb MH.In this experiment we have identified and partially characterized the immunosuppressive activity of preimplantation horse conceptus-conditioned medium (HCCM). Horse conceptuses were nonsurgically flushed from mares at Days 9-10 (n = 6), 15-16 (n = 3), and 25-26 (n = 3). After incubating the conceptuses for 24 h in RPMI-1640 supplemented with 15% fetal calf serum (FCS) and 1% penicillin/streptomycin, HCCM was obtained from cultures and tested for immunosuppressive activity in lymphocyte proliferation assays. Peripheral blood lymphocytes obtained from randomly selected mares were stimulated with...
Langton CM, Ali AV, Riggs CM, Evans GP, Bonfield W.A portable system using a direct contact for the measurement of ultrasonic velocity and broadband attenuation in bone is described (contact ultrasonic bone analyser, CUBA). Soft-tissue compensation is performed using an ultrasonic pulse-echo technique. CUBA has been successfully validated using reference materials, the precision of velocity and broadband attenuation measurements being typically 0.2% and 0.5% respectively. The clinical reproducibility has been assessed on the equine third metacarpal bone. The reproducibility of velocity measurement is typically 0.5% for cortical bone and 1% for...
Ono K, Inui K, Hasegawa T, Matsuki N, Watanabe H, Takagi S, Hasegawa A, Tomoda I.The change in activities of 3 major antioxidative enzymes in equine erythrocytes, superoxide dismutase (SOD), glutathione peroxidase (GSHpx), and catalase, was investigated in order to evaluate the effect of exercise. Blood samples were obtained from 11 thoroughbred horses before and immediately after vigorous exercise which induced the increase of plasma lipid peroxide (Lpx) concentration from 1.16 +/- 0.40 nmol/ml to 1.29 +/- 0.34 nmol/ml. Following the exercise, the GSHpx activity in erythrocytes was significantly reduced from 69 +/- 10 IU/gHb to 65 +/- 8 IU/gHb, whereas SOD and catalase ac...
Bauer JE, Brooks TP.Immunoturbidimetric determination of serum IgG concentration in foals was compared with the reference methods of single radial immunodiffusion and serum protein electrophoresis. High positive correlations were discovered when the technique was compared with either of these reference methods. The zinc sulfate turbidity test for serum IgG estimation was also evaluated. Although a positive correlation was discovered when the latter method was compared with reference methods, it was not as strong as the correlation between reference methods and the immunoturbidimetric method. The immunoturbidimetr...
Rose RJ.Many factors can influence electrolytes in the horse. With the major electrolytes (sodium and potassium), alterations in serum or plasma values do not reflect changes in total body status. However, estimates of electrolyte alterations may be made by combining assessments of body weight changes with plasma sodium values by using the formula of Edelman et al. In planning electrolyte therapy, it has to be remembered that access to green feed or hay is important in correcting any total body potassium depletion and that diets marginal in sodium may interfere with exercise capacity by limiting sweat...
Harrison LA, Squires EL, Nett TM, McKinnon AO.We hypothesized that the LH response to GnRH would be greater as the interval from foaling increases, whereas the FSH response would decrease, and that corpus luteum function after the first ovulation would be similar to that after the second ovulation. At parturition, mares were assigned to receive GnRH (2 micrograms/kg) intravenously on 1) d 3 postpartum (n = 6); 2) d 6 postpartum (n = 6); 3) d 1 of first postpartum estrus (foal estrus) and again on d 1 of second postpartum estrus (n = 8). Blood was collected through an indwelling cannula at -2, -1 and 0 h relative to GnRH stimulation (basal...
Takiguchi M, Fujinaga T, Naiki M, Mizuno S, Otomo K.C-reactive protein (CRP) was isolated from equine serum by use of calcium-dependent affinity chromatography conjugated pneumococcal C-polysaccharide, anion exchange chromatography, and gel filtration. It was identified as genuine CRP by its immunochemical cross-reactivity with anti-human CRP, its homology with human CRP in amino acid composition, and its pentameric structure as revealed by electron microscopy. Purified equine CRP had a molecular weight of approximately 118,000 and was composed of 5 identical, nonglycosylated and noncovalently associated subunits with molecular weight of approx...
Stephens RM, Derse D, Rice NR.We isolated and characterized six cDNA clones from an equine infectious anemia virus-infected cell line that displays a Rev-defective phenotype. With the exception of one splice site in one of the clones, all six cDNAs exhibited the same splicing pattern and consisted of four exons. Exon 1 contained the 5' end of the genome; exon 2 contained the tat gene from mid-genome; exon 3 consisted of a small section of env, near the 5' end of the env gene; and exon 4 contained the putative rev open reading frame from the 3' end of the genome. The structures of the cDNAs predict a bicistronic message in ...
Ehnen SJ, Divers TJ, Gillette D, Reef VB.Eight adult horses with obstructive nephrolithiasis and/or ureterolithiasis were examined between 1981 and 1987. One horse had bilateral ureteral obstruction at hospital admission; the others had unilateral ureteral obstruction. All horses had similar bilateral renal pathologic findings that were compatible with chronic intermittent or complete obstruction. Horses were referred for evaluation of weight loss, poor performance, and/or decreased appetite. Clinical findings, laboratory results, and/or postmortem findings in all horses supported the diagnosis of chronic renal failure. Age of the 8 ...
Furr MO, Tyler RD.The CSF creatine kinase (CK) activity was determined in 70 CSF samples from 69 horses with CNS disease. Abnormal values (greater than or equal to 1 IU/L) were determined from 32 CSF samples, and normal values (less than 1 IU/L) were found in 38 samples. Increased CK activity was most frequently associated with a diagnosis of equine protozoal myelitis; CK activity was not increased in 11 horses with cervical compressive myelopathy. Other diagnoses, in which CSF CK activity was increased included trauma (n = 1), idiopathic epilepsy (n = 2), botulism (n = 2), articular facet fracture (n = 1), int...
Darien BJ, Potempa J, Moore JN, Travis J.Two synthetic substrate assays (fluorometric and chromogenic) were used to measure antithrombin-III (AT-III) activity (residual thrombin activity) in non-medicated and heparin (sodium) treated horses. In 18 non-medicated horses the fluorometric substrate assay (FSA) values were similar to previous reports but they reflected inconsistent trends and larger deviations in the heparin-treated groups (Group 2: 40 and 100 U/kg IV, n = 6; Group 3: 240 U/kg IV, n = 5; Group 4: 80 U/kg IV followed by 160 U/kg SC, n = 8) when compared to the chromogenic substrate assay (CSA) values. The CSA values for th...
Bistner S.This article outlines various conditions affecting the fundus of horses, their symptoms, and associations. The conditions discussed include retinal hemorrhages in newborns, retinal detachments, inflammation, optic neuritis, and congenital stationary […]
Booth TM, Hainisch EK, Knottenbelt DC, Edwards GB, Clegg PD, Kelly DF.An 11-year-old, eight-months pregnant mare suddenly developed severe respiratory distress. Endoscopic examination identified intralaryngeal granulation tissue obstructing the airway. In order to avoid general anaesthesia and the problems associated with a permanent tracheostomy, the mass was resected electrosurgically while the mare was standing. Patency was restored to the airway and the mare foaled without complication.
Glass K, Watts AE.Many long bone fractures that are not considered repairable in the adult horse are repairable in the foal. This is largely because of reduced patient size and more rapid healing in the foal. When there is no articular communication, the long-term prognosis for athletic function can be very good. Emergency care and transport of the foal with a long bone fracture is different than the adult.
van Weeren PR.Kinematic gait analysis is a rapidly growing field of veterinary research promising to become even more important in coming years. All modern analytical techniques are based on the use of skin markers and are therefore prone to suffering from a biological error caused by the sliding of the skin over the underlying skeletal structures. To investigate this error skin displacement was quantified at 18 relevant sites using techniques designed to ensure simultaneous visualization of skin and underlying bone. Mathematical models for correction of skin displacement were formulated. Application of the...
Harasawa R, Konishi S, Ogata M.This research study focuses on detecting the presence of antibodies against adenovirus in horses imported into Japan and it demonstrates that the majority of horses imported into Japan have displayed […]
Klem ME, Kreider JL, Pruitt JB, Potter GD.Inclusion of either 1 or 3% (w/v) bovine serum albumin (BSA) in 8.6, 10, or 12% sucrose enhanced the maintenance of equine sperm motility in vitro at 38 degrees C for 8 h. There was a trend toward higher percent motile spermatozoa (PMS) at 16 and 24 h of incubation in semen samples containing BSA than in those that did not. The highest concentration of sucrose (12%) was slightly less effective in supporting PMS than either of the lower concentrations. However, sucrose concentrations had no apparent effect on rate of forward movement (RFM) of spermatozoa. Pregnancy and foaling rates were simila...
Girard C, Macieira S.A 6-year-old Haflinger mare was presented with a history of recurrent hemoabdomen. On necropsy, a firm infiltrative multinodular yellow mass was observed in the wall of the posterior abdomen. Histopathologic examination revealed a proliferation of fibroblastic cells, which were positive for α-smooth muscle actin and vimentin.
Ginther OJ.Uterine filling by the conceptus and uterine constrictions and allantoic-fluid shifts after filling were studied by daily ultrasound examinations on Days 40 to 74 in 10 mares. Allantoic fluid was first detected at the extremities of the uterus on the following days: 1) tip of umbilical-cord horn, Day 60.0 +/-1.9 (mean +/-SEM); 2) tip of noncord horn, Day 64.8 +/-1.3; and 3) near cervix, Day 48.5 +/-1.3. Transient uterine constrictions with expulsion of allantoic fluid were detected in 37% of 271 examinations. Other end points were studied by weekly ultrasound examinations from Day 40 to term. ...
Hodson N, Hunt J, Causon RC.The research article discusses an investigation into how exploratory diagnostic laparotomy affects the circulating histamine levels in acute, subacute, and chronic suspected equine grass sickness cases. The study utilized a […]
Hansen S, Stephansen MG, Fjeldborg J, van Galen G.Blood glucose concentrations fluctuate with stress, but little is known on how it is influenced by clinical procedures. The objective was to investigate the effect of clinical procedures on blood glucose concentration in healthy horses. Methods: Prospective, experimental study. Seven hospital-owned research horses were included in the study. A total of 4 horses were sampled either during a control sedation trial or during 3 different student workshops (prepurchase, oral, and rectal examination-the latter 2 with sedation). Blood samples were taken every 15 minutes and glucose concentration in w...
Bertone JJ.Antimicrobial treatment is an important component of infectious respiratory disease management. However, across all systems in horses there is substantial deficit in definitive information concerning the efficacy of antimicrobials. This disassociation between laboratory data and antimicrobial efficacy and the obstacles to effective antimicrobial treatment should be understood.
Hornof WJ, Koblik PD, O'Brien TR.A 2-month-old thoroughbred colt with noisy and difficult respiration was diagnosed as having an intrathoracic mass, using conventional radiographic techniques. Nuclear scintigraphy was then used to characterize the mass, leading to successful surgical removal.
Rantanen NW.Because the abdomen of the adult horse is too thick to obtain good-quality radiographs, diagnostic ultrasound is a particularly valuable imaging modality in the diagnosis of abdominal disease. The size, shape, position, and texture of the liver, spleen, kidneys, urinary bladder, gravid uterus, and gut wall can be determined by scanning the abdominal surface. The presence or absence of abdominal fluid can be determined efficiently. Gut motility as well as ileus secondary to peritonitis or obstruction can be assessed. Suspected adhesions of the bowel can often be documented, and primary or secon...
Welland LM.A 6-year-old, primiparous standardbred mare was presented with a history of intestinal protrusion from the rectum shortly after parturition. A subacute grade IV rectal tear was diagnosed. The unusual nature of the tear led to speculation of a possible owner palpation accident. A grave prognosis was given and the mare was euthanized.
Hurtgen JP, Whitmore HL.Luteolysis, estrus, and ovulation were induced by endometrial biopsy during three periods of prolonged diestrus in two mares. Serum progesterone concentrations decreased to less than 1 ng/ml within 48 hours after biopsy. Mares were in estrus within 3 days after endometrial biopsy. It was concluded that endometrial biopsy may induce regression of the persistent corpus luteum by stimulating the release of an endogenous uterine luteolysin (prostaglandin).
Katila T, Combes GB, Varner DD, Blanchard TL.Three containers commonly used to transport cooled equine semen (Equitainer, ExpectaFoal and a Swedish-designed semen-transport container, previously called the Salsbro Box and now called Equine Express) were compared, using four ejaculates from each of three stallions. Each ejaculate was diluted to a spermatozoal concentration of 25 x 10(6)/ml with a nonfat dry milk-glucose extender containing amikacin sulfate (1 mg/ml) and potassium penicillin G (1000 units/ml). Extended semen was divided into three 40-ml aliquots for placement in each of the three semen-transport containers. The extended se...
Barnabé A, Moulard Y, Trevisiol S, Boyer S, Caroff M, Taleb W, Tendon S, Drif L, Delcourt V, Popot MA, Bailly-Chouriberry L.The study focuses on the discovery of kavain, a natural-occurring compound of the plant Piper methysticum, in a post-race urine sample of a horse. The researchers traced the potential source […]
Thomas HL, Zaruby JF, Smith CL, Livesey MA.Castration of horses is considered a common and routine surgical procedure, but the potential for complications is high. By far the most serious of these is eventration. The objectives of this study were to determine the long-term survival of horses undergoing surgical treatment of indirect (1) inguinal eventration of the small intestine following castration, and to identify prognostic indicators for survival. The case records of 18 horses undergoing surgical treatment of postcastration eventration (PCE) between 1985 and 1995 were reviewed. Follow-up information was obtained by telephone inter...