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.
Esser AF, Tarnuzzer RW, Tomlinson S, Tatar LD, Stanley KK.Lack of hemolytic activity of horse serum is an inherent property of horse C9. To understand the molecular reasons for this deficiency we have cloned C9 cDNA from a horse liver cDNA library and have sequenced the cDNA yielding the complete coding sequence for horse C9. Purification of C9 from horse plasma and microsequencing established the N-terminus of the mature protein and verified that the correct horse C9 cDNA clone had been isolated. The deduced amino acid sequence corresponds to a mature protein of 526 amino acids that is 77% identical to human C9. It has the same domain structure as h...
de Verdier Klingenberg K, Esfandiari J.An immunochromatographic test for the detection of group A rotavirus was evaluated against a reference group A rotavirus ELISA, by using a panel of 161 bovine, porcine and equine faecal samples submitted for routine examination. The sensitivity of the test was 89 per cent and the specificity 99 per cent compared with the ELISA. Its reproducibility was 100 per cent. The simplicity and rapidity of the test procedure make it suitable for use in practice.
Daels PF, Chang GC, Hansen B, Mohammed HO.We have characterized the testosterone secretion pattern during the first 80 d of pregnancy in mares and determined the sources that contribute to circulating testosterone levels during this period. Ten untreated, pregnant mares (Group 1), 10 altrenogest-treated, pregnant mares (Group 2), and 10 altrenogest-treated, pregnant mares in which the CL was eliminated by administration of PGF-2alpha on Day 16 (Group 3) were used in this study. Complete luteolysis occurred following PGF-2alpha administration in all mares in Group 3. Six of the 10 mares in Group 3 did not have an active CL until after ...
The Journal of physiologyApril 15, 1996
Volume 492 ( Pt 2), Issue Pt 2 587-596 doi: 10.1113/jphysiol.1996.sp021331
Lafortuna CL, Reinach E, Saibene F.1. To investigate the effect of locomotor activity on the pattern of breathing in quadrupeds, ventilatory response was studied in four healthy horses during horizontal and inclined (7%) treadmill exercise at different velocities (1.4-6.9 m s(-1)) and during chemical stimulation with a rebreathing method. Stride frequency (f(s)) and locomotor-respiratory coupling (LRC) were also simultaneously determined by means of video recordings synchronized with respiratory events. 2. Tidal volume (V(T)) was positively correlated with pulmonary ventilation (V(E)) but significantly different linear regressi...
The Journal of physiologyApril 15, 1996
Volume 492 ( Pt 2), Issue Pt 2 347-358 doi: 10.1113/jphysiol.1996.sp021313
Fleischmann BK, Wang YX, Pring M, Kotlikoff MI.1. The relationship between voltage-dependent calcium channel current (I(Ca)) and cytosolic free calcium concentration ([Ca2+]i) was studied in fura-2 AM-loaded equine tracheal myocytes at 35 degrees C and 1.8 mM Ca2+ using the nystatin patch clamp method. The average cytosolic calcium buffering constant was 77 +/- 3 (n = 14), and the endogenous calcium buffering constant component is likely to be between 15 and 50. 2. I(Ca) did not evoke significant calcium-induced calcium release (CICR) since (i)[Ca2+]i scaled with the integrated I(Ca) over the full voltage range of evoked calcium currents, ...
Atwill ER, Mohammed HO.To determine whether horses in New York should be vaccinated against equine monocytic ehrlichiosis (EME). Methods: Decision-tree analyses of data from a cross-sectional study and a case-control study. Methods: Horses in New York. Methods: Annual expected monetary loss per horse attributable to EME was calculated for vaccinated and nonvaccinated horses in New York. Because risk of being seropositive was dependent on county in which the horse was located, farm elevation, and use of each horse, decision-tree analyses were stratified by these factors. Results: Annual expected monetary loss per hor...
Atwill ER, Mohammed HO.To determine whether preferentially vaccinated horses were at risk for exposure to Ehrlichia risticii, whether horses with equine monocytic ehrlichiosis (EME) were likely to have been nonvaccinated, and whether clinical severity and financial costs associated with care and treatment of EME were less for vaccinated horses with EME than for nonvaccinated horses with EME. Methods: Cross-sectional and case-control studies. Methods: Information on usage of E risticii bacterins to control EME was collected for 2,587 horses located on 511 farms throughout New York. Each horse was tested for serum ant...
Seltzer KL, Byars TD.To determine the percentage of Thoroughbred racehorses that would be capable of racing performance after recovery from infectious pleuropneumonia. Methods: Retrospective case series. Methods: 70 Thoroughbred horses that had recovered from pleuropneumonia. Only horses 5 years old known to be in race training at the time of illness were included in the study. Results: Forty-three of the 70 (61%) horses raced after recovery, and 24 of the 43 (56%) won at least 1 race. Horses that required placement of an indwelling thoracic drain apparently did not have a worse prognosis than did horses that did...
Christensen P, Whitfield CH, Parkinson TJ.The ability of the glycosaminoglycan, heparin, and the calcium ionophore, A23187, to induce acrosome reaction in equine spermatozoa was assessed using semen from 3 warmblood stallions of known high fertility. After collection of semen, the spermatozoa were washed and incubated in vitro with heparin or A23187. Incubation periods were 0, 4, 6 or 8 h with 0, 1, 10 or 100 microg/ml heparin or 0, 10, 30 or 60 min with 0, 0.01, 0.1, 1 or 10 microM A23187, respectively. Acrosome reactions were determined by staining the spermatozoa with naphthol yellow S plus erythrosin B, and sperm viability was ass...
Neto LM, Andraus MH, Salvadori MC.A method is described for the qualitative and quantitative determination of phenylbutazone and oxyphenbutazone in horse urine and plasma samples viewing antidoping control. A horse was administered intravenously with 3 g of phenylbutazone. For the qualitative determination, a screening by HPLC was performed after acidic extraction of the urine samples and the confirmation process was realized by GC-MS. Using the proposed method it was possible to detect phenylbutazone and oxyphenbutazone in urine for up to 48 and 120 h, respectively. For the quantitation of these drugs the plasma was deprotein...
Adeyefa CA, Tomori O, Akpavie SO, Awoseyi OA.Thirteen cases of a disease with a low morbidity and very high mortality in horses in Nigeria are described; the disease is characterised by fever (rectal temperature > or = 40 degrees C), generalised muscle spasms, ataxia, increased respiratory and heart rates and terminal lateral recumbency. The illness generally lasts three to five days but durations of 12 to 30 hours have been observed. Laboratory investigations, including histopathology and serology suggest a viral aetiology, possibly an alphavirus of the equine encephalitis group.
Pycock JF, Newcombe JR.The effects on pregnancy rate of three different treatments to remove intrauterine fluid were assessed in 1267 mares. The mares were mated and allocated, in strict rotation, to four treatment groups: 1) untreated controls, 2) intrauterine infusion of broad spectrum antibiotics, 3) intravenous injection of oxytocin, 4) intravenous injection of oxytocin followed by intrauterine antibiotics. The pregnancy status of the mares was determined 13 to 15 days and 27 to 30 days after ovulation by transrectal ultrasonography. The pregnancy rate of group 4 (72 per cent) was higher than that of group 2 (64...
Coté N, Trout DR, Hayes AM.The electrophoretic position and behavior of the native and activated forms of equine plasma alpha-2-macroglobulin (alpha 2M) were characterized and compared to human alpha 2M by nondenaturing polyacrylamide-gel electrophoresis (PAGE). Plasma alpha 2M was also compared between 6 normal horses and 6 horses with clinical signs of colic and endotoxemia due to volvulus or enteritis. Native and activated forms of alpha 2M were quantified by PAGE and densitometry. Binding of radio-labeled recombinant human tumour necrosis factor-alpha (125I-rhTNF-alpha) to native and activated forms of equine alpha ...
Raulo SM, Hyyppa S, Räsänen LA, Pösö AR.The activities of lysosomal enzymes, such as beta-glucuronidase and N-acetyl-beta-D-glucosaminidase, have been shown to increase in muscle after endurance exercise. We examined whether measurable activities of lysosomal enzymes are present in equine plasma and whether the exercise-induced changes in the muscle are reflected in plasma. Six trained Standardbred trotters performed three exercise bouts with 1 h intervals and the same procedure was repeated 3 days later. Venous blood samples and muscle biopsies from the middle gluteal muscle were taken before and after exercise. The activities of b...
Loredo GA, MacDonald MH, Benton HP.To investigate whether recombinant human bone morphogenetic protein-2 (rhBMP-2) regulates glycosaminoglycan (GAG) synthesis and release from equine articular cartilage explant cultures. Methods: Equine articular cartilage explants were maintained in vitro for 7 days in the presence of 0 (control), 1, 10, or 100 ng of rhBMP-2/ml. Synthesis and release of GAG were assessed as measures of production and degradation of the extracellular matrix, respectively. Methods: 6 horses (age range, 2 to 25 years old) without clinically detectable musculoskeletal abnormalities. Methods: Rate of synthesis of G...
Dobrinski I, Suarez SS, Ball BA.Interaction of spermatozoa with oviductal epithelial cells (OEC) in the oviductal isthmus prolongs the life span of spermatozoa. The hypothesis that the interaction of equine spermatozoa with OEC affects their intracellular calcium concentration ([Ca2+]i) was tested in a sperm-OEC coculture model. Changes in [Ca2+]i in spermatozoa loaded with the fluorescent calcium indicator indo-1 acetoxymethylester (AM) were determined for spermatozoa attached to OEC or to Matrigel, as well as for free-swimming spermatozoa incubated without oviductal epithelium. [Ca2+]i was determined before incubation and ...
Veeramachaneni DN, Sawyer HR.Conventional light microscopic evaluation does not fully utilize potential indicators in seminal ejaculates for diagnosis of disorders of the reproductive tract. The technique of evaluation of all cellular components of semen, as described in this article, utilizing both light and transmission electron microscopy is a valuable diagnostic tool. Compare with other common biopsy procedures, use of semen as biopsy material is noninvasive, more representative than excisional biopsy, less expensive, and helps in the longitudinal evaluation after a therapeutic regimen.
Smith KC, Mumford JA, Lakhani K.Four Welsh Mountain pony mares at 3 months of gestation and one mare at 5 months were inoculated intranasally with equid herpesvirus-1 (EHV-1: Ab4 isolate) at doses of 10(5) to 10(6.6) TCID50. All five mares became infected, but no cases of paresis or abortion occurred. On days 8, 9, 11, 12 (3-month-pregnant mares) and 13 (5-month-pregnant mare) after infection, a detailed examination of the pregnant uterus was made. Small numbers of vascular lesions with EHV-1 antigen expression in endothelial cells were present in the uteri of the early gestational mares; thrombi were rare and foci of thromb...
Maddison JE.Seventy-seven reports of suspected adverse drug reactions (ADRs) were received by the Adverse Drug Reaction Subcommittee (ADRSc) of the Australian Veterinary Association from April 1993 to December 1994 inclusive. The number of reports received/number of animals involved per species were: dogs (32/44), cats (18/31), horses (17/48), and cattle (10/21). Of these, 49 (64%) were classified as definite ADRs and 9 (12%) as probable ADRs. In 11 (14%) reports an ADR could not be substantiated or there was insufficient information available to make a decision. Eight reports were not classified because ...
Gamble HR, Gajadhar AA, Solomon MB.Twelve horses were infected with various doses of Trichinella spiralis and then tested for infection using direct (artificial digestion) and indirect (enzyme immunoassay) methods. Horses became infected in a dose-dependent manner. Larvae accumulated preferentially in the tongue, followed by the masseter, neck, supraspinatus, trapezius, and diaphragm. At lower infection levels, the tongue harbored several times more parasites than were found in other tissues. The sensitivity of artificial digestion methods for detecting infections was directly related to sample size. One-gram samples were not r...
Zierz J, Wintzer HJ.To judge acute processes of pain objectively the results are told of a determination of adrenaline and noradrenaline in the plasma of 30 horses suffering from pain. Besides a scheme basing on an awarding of points is developed to ascertain changes of physiological and ethological parameters caused by pain. These results in changes of behaviour are compared to results determined by laboratory experiments. Concerning pain of medium and high level a relation to the concentration of catecholamines is noticed. Therefore the total of certain clinical observations is suitable for graduating acute pai...
Asari M, Sasaki K, Miura K, Ichihara N, Nishita T.To elucidate locations of cytosolic carbonic anhydrase isoenzyme (CA-I, CA-II, and CA-III)-positive epithelial cells in equine male reproductive organs. Methods: Descriptive and immunohistochemical study. Methods: 4 clinically normal male horses. Methods: The testis (seminiferous tubules, rete tubules), epididymis (initial, middle, and terminal segments), proximal and distal portions of the ductus deferens, ampulla ductus deferentis, seminal vesicle, prostate, and bulbourethral gland were excised from euthanatized horses after administration of an overdose of pentobarbital. The tissue specimen...
Squires EL.Equine oocytes obtained either by transvaginal ultrasound-guided follicular aspiration or from slaughterhouse ovaries can be matured in vitro. This generally requires culture in TCM-199 containing serum and hormones for 30 to 36 hours. With this protocol, approximately 50% to 60% of the oocytes are at metaphase-II at the end of the culture period. At least some of these oocytes appear viable based on production of fertilized eggs either through in vitro fertilization or fertilization in vivo of a recipient mare. The success of producing equine embryos in vitro is still extremely low. More than...
Keegan KG, Wilson DA, Kreeger JM, Ellersieck MR, Kuo KC, Li Z.To evaluate the distribution of mepivacaine hydrochloride after distal interphalangeal (DIP) joint injection in horses. Methods: Prospective, uncontrolled study. Methods: 10 adult horses. Methods: 30 minutes before euthanasia, 8 ml of 2% mepivacaine hydrochloride was injected into the dorsal pouch of a forelimb DIP joint. Synovial tissue from the DIP joint and podotrochlear (navicular) bursa and bone tissue from the medullary cavity of the distal sesamoid (navicular) bone were taken from both forelimbs immediately after death. All synovial and bone specimens were analyzed for tissue concentrat...
Santangelo B, Robin A, Simpson K, Potier J, Guichardant M, Portier K.Xenon, due to its interesting anesthetic properties, could improve the quality of anesthesia protocols in horses despite its high price. This study aimed to modify and test an anesthesia machine capable of delivering xenon to a horse. Methods: An equine anesthesia machine (Tafonius, Vetronic Services Ltd., UK) was modified by including a T-connector in the valve block to introduce xenon, so that the xenon was pushed into the machine cylinder by the expired gases. A xenon analyzer was connected to the expiratory limb of the patient circuit. The operation of the machine was modeled and experimen...
Lyman CC, Baldrighi JM, Anderson CO, Germaine SS, Kane AJ, Holyoak GR.A significant welfare concern for those within the horse industry is that of the overpopulation in free-roaming horses in the western US. The goal of the present study was to identify a humane and inexpensive means of providing contraception and reducing pregnancy rates in a way that could be applied to free-roaming horses on the western U.S. open range lands. A series of studies was conducted utilizing the previously-described silastic O-ring intrauterine devices (IUDs). Throughout these studies pregnancy was successfully prevented in mares with an O-ring IUD, but collective retention rates f...
Easton-Jones CA, Estell KE, Magdesian KG.Information concerning clinical presentation, conditions associated with immune-mediated haemolytic anaemia (IMHA) and thrombocytopenia (IMTP) and outcome in equids is lacking. Previous case reports suggest that immune-mediated disease and neoplasia are associated. Objective: Characterise the clinical presentation, clinicopathologic data, underlying conditions, treatment and outcome of IMHA and IMTP cases in equids. We hypothesise that IMHA with concurrent thrombocytopenia occurs more often than IMHA or IMTP alone, and that neoplasia is commonly associated with these immune diseases and cases ...
Yu M, Robinson NE, Wang Z, Derksen FJ.The effects of epithelial removal and cyclooxygenase inhibition on contractions induced by exogenous acetylcholine (ACh) and electrical field stimulation (EFS) were evaluated in horse tracheal strips and bronchial rings. Epithelial removal potentiated the response to ACh but had no influence on the response to EFS. The effect of epithelial removal was not altered by pretreating the tissues with meclofenamate, a cyclooxygenase inhibitor. In trachealis strips, meclofenamate augmented contractions induced by EFS but not by ACh. In bronchial rings, meclofenamate augmented EFS-induced contraction t...
Adeyefa CA.The precipitin response of the mitogen produced by Strongylus vulgaris arterial larvae was investigated. IgG (T) from the sera of horses naturally infected with S. vulgaris adults and arterial larvae recognised the presence of two antigenic components of the mitogenic fractions. The results obtained seem to confirm that these antigens are immunogenic in stimulating the production of increased levels of IgG(T) in infected animals, and showed that the procedures could be used as immunological tools in the diagnosis of S. vulgaris infection.
Lustgarten M, Redding WR, Schnabel LV, Prange T, Seiler GS.Navigational ultrasound imaging, also known as fusion imaging, is a novel technology that allows real-time ultrasound imaging to be correlated with a previously acquired computed tomography (CT) or magnetic resonance imaging (MRI) study. It has been used in man to aid interventional therapies and has been shown to be valuable for sampling and assessing lesions diagnosed with MRI or CT that are equivocal on ultrasonography. To date, there are no reports of the use of this modality in veterinary medicine. Objective: To assess whether navigational ultrasound imaging can be used to assist commonly...
Canada NC, Beard WL, Guyan ME, White BJ.Clinicians frequently place post operative abdominal bandages on horses undergoing laparotomies. Presently, no information exists on the amount of incisional support provided by these bandages. Determination of sub-bandage pressure provides a means of comparing the ability of different bandages to support incisions. Objective: Determination of sub-bandage pressure over a 24 h period using 3 bandaging techniques. Methods: A randomised, crossover design using 9 healthy horses. Methods: Horses were randomly assigned to a treatment regimen consisting of placement of 3 abdominal bandage types, name...
Lee CG, Ross AD.Klossiella equi in the kidney of a horse is described. Gametocytic and sporogonic stages were observed in the epithelium of the collecting tubules in association with schizonts in the glomeruli and proximal convoluted tubules. The condition was asymptomatic and caused only minor renal damage and inflammation.
Bramlage LR, Hanes GE.A 3-year-old Thoroughbred mare was examined because of hindlimb lameness from incomplete fracture of the tibia, which became a complete diaphyseal fracture during the examination. The fracture was repaired by open reduction and internal fixation with lag screws and 2 neutralization plates. A cranial approach was used and the plates were placed craniolateral and medial on the tibia. At 18 months after surgery, there was no evidence of complications resulting from the fracture or its repair. It was concluded that a cranial approach with craniolateral and medial plate placement allows easier inse...
Smith R, Chaffin MK, Cohen ND, Martens RJ.To characterize changes in lymphocyte subsets over time in foals from birth to 18 weeks of age, accounting for differences among individuals, and to determine the effect of overnight storage of blood samples on foal lymphocyte subset concentrations. Methods: 8 healthy Quarter Horse foals from birth to 18 weeks of age. Methods: Blood samples were collected longitudinally from birth to 18 weeks of age and a CBC performed on each sample. The samples were stained for lymphocyte markers, either immediately or after overnight storage and analyzed by flow cytometry. Results: Total leukocytes, total l...
Weiss N, Mardo E, Avidan G.A major question in the domain of face perception is whether faces comprise a distinct visual category that is processed by specialized mechanisms, or whether face processing merely represents an extreme case of visual expertise. Here, we examined O.H, a 22 years old woman with congenital prosopagnosia (CP), who despite her severe deficits in face processing, acquired superior recognition skills for horses. To compare the nature of face and horse processing, we utilised the inversion manipulation, known to disproportionally affect faces compared to other objects, with both faces and horses. O....
Verkade ME, Suthers J, Wiemer P, Martens A, De Clercq E, Burford J.To determine the variability in length, width, and thickness of the equine linea alba (LA) and the effect of a standing vs dorsal recumbent position on these measurements. Methods: Descriptive anatomical comparative study. Methods: Standing horses (N = 75; in 30 horses, measurements were obtained in dorsal recumbency first and repeated after horses were standing). Methods: Linea alba length was measured in standing position from xiphoid to umbilicus, and transverse ultrasonographic images were obtained at five reference points to measure LA width and thickness. In 30 horses, measurements were ...
O'Rielly JL, Bertone AL, Genovese RL.A four-year-old Standardbred gelding was examined because of vague right hind limb lameness of 3 to 4 months' duration. Results of physical examination, radiography, and scintigraphy were indicative of a chronic comminuted fracture of the proximal portion of the right fibula. A cancellous bone graft was placed in the fracture site, and 3 months later, the fracture appeared to be healed radiographically. Fractures of the fibula are rare in horses and should not be confused with normal anatomic discontinuities that result in a bi- or tripartite appearance of the fibula on radiographs. Because th...
Meyer H.Colics are often initiated by mistakes in feeding inadequate feed quality or quantity or poor feeding technique. The consequences are obstruction, impaction or dysbiosis with increased production of organic acids, gas or toxins. Nutritional anamnesis in patients with colic may give information on the pathogenesis of the disease.
Seahorn TL, Brumbaugh GW, Carter GK, Wood RL.Erysipelothrix rhusiopathiae serotype 5 was isolated from blood obtained antemortem from a horse with presenting problems of laminitis, uveitis, acute blindness, localized ventral edema and depression. The patient failed to respond to therapy and died 96 hours after the onset of clinical signs. Cultures of the lung postmortem yielded Erysipelothrix rhusiopathiae serotype 5, Beta-hemolytic Streptococcus sp., Escherichia coli, Proteus sp., and Klebsiella sp.
Freire R, Clegg HA, Buckley P, Friend MA, McGreevy PD.The effects of dietary supplements of virginiamycin on the behaviour and physiology of 17 thoroughbred geldings (five cribbers, six weavers and six control horses) were compared with the effects of a placebo over a period of 16 weeks. Virginiamycin had no effect on the horses' stereotypic behaviour, but it reduced their explorative behaviour, possibly owing to a reduction in feeding motivation. Virginiamycin increased the water intake of the cribbers and decreased the water intake of the control horses, but it was not possible to eliminate possible confounding factors for this effect. Virginia...
Treiber KH, Geor RJ, Boston RC, Hess TM, Harris PA, Kronfeld DS.Advances in modeling and tracer techniques provide new perspective into glucose utilization and potential consequences to health or exercise performance. This study used stable isotope and compartmental modeling to evaluate how adaptation to a feed high in sugar and starch (SS) compared with a feed high in fat and fiber (FF) affects glucose kinetics at rest and during exercise in horses. Six trained Arabians adapted to each feed underwent similar tests at rest and while running approximately 4 m/s on a treadmill. For both tests, horses received 100 micromol/kg body weight [6,6-(2)H]glucose thr...
Ingvast-Larsson C, Paalzow G, Paalzow L, Ottosson T, Lindholm A, Appelgren LE.The pharmacokinetics of theophylline were determined in Standardbred trotters after single intravenous and oral administration. A bi-exponential equation was fitted to the intravenous data and a tri-exponential equation to the oral data. The biological half-life of theophylline was found to be 14.8 h, the volume of distribution 1.02 l/kg and the total plasma clearance 0.86 ml/kg/min. The oral absorption of the drug was complete (bioavailability 108%) and rapid (absorption half-life 0.4 h).
Patel J, Lofstedt RM.This report involves uterine rupture in a mare, which was unique because it was not associated with assisted or difficult foaling. We describe an alternative to surgical correction of the condition and illustrate the need for luminal uterine palpation, so that uterine rupture does not go undiagnosed.
Satué K, Felipe M, Mota J, Muñoz A.The length of gestation in Carthusian broodmares was calculated on the basis of 339 spontaneous full-term deliveries taking place in the 8-year period 1998-2005 from 158 broodmares and 29 stallions in a major farm of Spanish horses of Carthusian strain in southern Spain. Ultrasonography was used to determine follicular dehiscence, 1st day of pregnancy and to confirm conception in mares. Mean GL was 332.4 +/- 12.1 days, and a normal interval of 297-358 days was established for this breed. GL records were grouped on the basis of foal sex (colts or fillies), mating month (between November and Jan...