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.
Southwood LL, Evans DL, Bryden WL, Rose RJ.Twenty-five Thoroughbred (TB) and 25 Standardbred (SB) stables were visited to determine their feeding practices. The ingredients of the main feed of the day for a mature gelding of average size in full training were weighted at each stable. Nutrient content of diets was calculated using published data for the individual ingredients. Results are expressed as mean +/- sd. The estimated body weight of TB horses was 493 +/- 34 kg and 437 +/- 32 kg for SB horses. There was considerable variation in diet composition and nutrient intake between stables. The TB trainers fed 11.0 +/- 2.4 kg and SB tra...
Edwards DF, Parker JW, Wilkinson JE, Helman RG.Plasma cell myelomas in horses have been reported infrequently. Data from 10 cases, 9 from the literature and 1 new case, are used to characterize the disease in the horse. Hot-blooded horses (7/10), specifically Quarter Horses (4/10), were most often affected. Median age at diagnosis was 11 years (range, 3 mo-22 yr) and both male (5) and female horses (5) were represented equally. Clinical findings included weight loss (6/8), anorexia (4/8), fever (4/8), limb edema (4/8), pneumonia (3/8), rear leg paresis/ataxia (3/8), epistaxis (3/8), palpable lymphadenopathy (2/8), and bone pain (2/8). Anem...
Scepek S, Lindau M.We have investigated the granule fusion events during exocytosis in horse eosinophils by time-resolved patch-clamp capacitance measurements. Stimulation with intracellular GTP gamma S leads to a stepwise capacitance increase by 4.0 +/- 0.9 pF. At GTP gamma S concentrations < 20 microM the step size distribution is in agreement with the granule size distribution in resting cells. Above 80 microM the number of steps is reduced and very large steps occur. The total capacitance increase, however, is unaffected. These results show that at high GTP gamma S concentrations granule--granule fusion o...
Threadgill DS, Steagall WK, Flaherty MT, Fuller FJ, Perry ST, Rushlow KE, Le Grice SF, Payne SL.The putative dUTPase domain was deleted from the polymerase (pol) gene of equine infectious anemia virus (EIAV) to produce a recombinant delta DUpol Escherichia coli expression cassette and a delta DU proviral clone. Expression of the recombinant delta DUpol polyprotein yielded a properly processed and enzymatically active reverse transcriptase, as determined by immunoblot analysis and DNA polymerase activity gels. Transfection of delta DU provirus into feline (FEA) cells resulted in production of virus that replicated to wild-type levels in both FEA cells and fetal equine kidney cells. In con...
Sellon DC, Cullen JM, Whetter LE, Gebhard DH, Coggins L, Fuller FJ.An IgG1 mouse monoclonal antibody, designated 1.646, is described which recognizes a cytoplasmic antigen of equine mononuclear phagocytes. Indirect fluorescent antibody staining of peripheral blood leukocytes reveals a granular cytoplasmic staining, predominantly in adherent blood mononuclear cells. Indirect fluorescent antibody staining is positive for alveolar and peritoneal macrophages. In some horses, a few neutrophils are also stained. In equine tissue samples stained by immunohistochemistry, the distribution of positive cells is consistent with the distribution of tissue macrophages. The...
Goff AK, Sirois J, Pontbriand D.The objective of this study was to clarify the role of oestradiol in luteal function by examining its effect on the oxytocin stimulation of 15-keto-13,14-dihydro-prostaglandin F2 alpha (PGFM) concentrations in cyclic mares. In the first experiment, three groups of mares (4 per group) were given a bolus injection of 17 alpha-oestradiol (1 mg), oestradiol (1 mg) or vehicle on days 7, 9, 11, 13 and 15 of the cycle. Six hours later the mares were challenged with 10 iu oxytocin intravenously and frequent blood samples were taken from 15 min before to 15 min after for measurement of PGFM. Results sh...
Piller K, Portmann P.Four new basic proteins were isolated from horse eosinophils and purified. The eosinophils release these proteins after permeabilization with saponin and degranulation stimulized by guanosine 5'-O-thiotriphosphate. The proteins were separated and purified on a Superose P12- and a Mono S-column by fast protein liquid chromatography. The amino acid composition, the relative molecular mass, the isoelectric point and the partial N-terminal sequence of the four proteins were determined. Papain-activation and ribonuclease activity of the four proteins were tested for comparison with the human eosino...
de Haas GH, Dijkman R, Lugtigheid RB, Dekker N, Van den Berg L, Egmond MR, Verheij HM.The inhibitory power (Z) of a number of (R)-1-alkyl-2-acylamino phospholipid analogues was determined for three mammalian phospholipases A2 from pig, ox and horse pancreas. All three enzymes display a clear preference for anionic (phosphoglycol) inhibitors over the zwitterionic (phosphocholine) derivatives; this effect is most pronounced for the bovine enzyme. Upon variation of the 1-alkyl chain length, the bovine and equine phospholipases, like the porcine enzyme in previous studies, show an optimum in Z for a six-carbon alkyl group. The introduction of a double bond in the 2-acylamino group ...
Stanley SM, Wilhelmi BS, Rodgers JP, Bertschinger H.Immunoaffinity chromatography using a synthesised immunosorbent was used to extract tritiated dexamethasone (with dexamethasone carrier) from equine urine at a recovery of 81.7 +/- 8.4% (mean +/- S.D.). A method utilising this procedure coupled to cool on-column injection gas chromatography-negative ion chemical ionisation mass spectrometry is also described for the confirmation of low levels of flumethasone in equine urine samples.
Hanson PD, Frisbie DD, Dubielzig RR, Markel MD.A 5-year-old Quarter Horse mare was examined because of a 6-month history of quidding and nasal discharge that contained feed material. Physical examination revealed weight loss and dorsal displacement of the soft palate, caused by a soft tissue mass located at the dorsal aspect of the base of the tongue. Surgical resection of the mass was successfully performed through an oral approach. The histopathologic diagnosis was rhabdomyosarcoma.
Bernard WV, Bolin C, Riddle T, Durando M, Smith BJ, Tramontin RR.Leptospirosis was documented as the cause of abortion in a 5-year-old mare. Leptospires were detected in tissue specimens from fetal kidneys and from placenta by histologic evaluation of silver-stained sections. Antibodies against Leptospira interrogans serovar pomona were detected in fetal serum at a titer of 1,600 by use of a microscopic agglutination test. The mare had serum titers of 6,400; 0; 400; 800; 3,200; and 6,400 to L interrogans serovars bratislava, canicola, grippotyphosa, hardjo, icterohaemorrhagiae, and pomona, respectively. A serologic survey identified titers of at least 6,400...
Parente EJ, Richardson DW, Spencer P.Medical records of 57 horses admitted between 1980 and 1991 because of basal sesamoidean fractures were evaluated. Radiographic measurements of fragment size and fracture characteristics were recorded to determine their relationship to outcome. A successful outcome was assessed on the basis of the ability to return to racing, ability to race more than one time, and ability to finish first, second, or third. Any change in racing class also was assessed. There was a significant (P < 0.001) overrepresentation of Thoroughbreds, compared with other breeds in the hospital population. Fractures of...
Handy LH, Peyton LC, Calderwood-Mays MB, Ackerman N.A diagnosis of gingival hyperplasia in a 22-year-old Quarter Horse gelding was confirmed by histologic examination. Clinical signs included difficulty eating hay, and a large, intraoral soft tissue mass measuring 13 x 8 x 4.5 cm. The mass was located in the mucosa on the lingual aspect of the caudal left portion of the mandible, ventral to the base of the tongue, and covered the second and third lower molars, extending rostrally along the buccal mucosa to the premolars. The left maxillary second and third molars were overgrown with sharp edges. Lateral radiography of the mandible revealed abse...
Tözsér J, Friedman D, Weber IT, Bláha I, Oroszlan S.The proteinase of the equine infectious anemia virus (EIAV), a lentivirus closely related to human immunodeficiency virus (HIV), was purified from concentrated virus. The specificity of the enzyme was characterized using oligopeptides representing naturally occurring cleavage sites in the Gag and Gag-Pol polyproteins. The length of the substrate binding pocket was found to be 1-2 residues longer than that of HIV proteinases. Although the EIAV and HIV proteinases cleaved most of the peptides at the same bond, some were hydrolyzed by only the EIAV enzyme. Oligopeptides representing cleavage site...
Collins MH.The placenta provides many critical services to the developing foetus. Proper placental implantation, growth and function are necessary for normal foetal growth and development. Placental structure varies widely among species but all mammalian placentas have a convoluted materno-foetal interface that may be quite simple or highly complex; the more complicated interdigitations tend to characterise smaller placentas that have limited areas of contact between the placenta and the endometrium. The intimacy of the contact between maternal and foetal tissue varies from apposition only, as in the equ...
Nickels FA.Conditions of this portion of the respiratory tract are relatively uncommon. This article reviews these conditions and discusses the different modes of therapy. The conditions covered are redundant alar folds, diseases of the nasal septum, fungal infections, neoplasms, nasal polyps, and ethmoid hematomas. The different surgical approaches to the nasal cavity are reviewed, and surgery of removal of the nasal septum and the alar fold are described.
Carvalho M, Derse D.Equine infectious anemia virus (EIAV) is a lentivirus that causes a chronic disease of horses characterized by cyclic episodes of fever, anemia, and viremia. Although the genome and promoter of EIAV are much less complex than those of its relatives the primate immunodeficiency viruses, the cellular proteins that activate and regulate transcription of EIAV have not yet been identified. In this report, we show by electrophoretic mobility shift assays and DNase I footprinting that the EIAV promoter contains multiple binding sites for ubiquitous, cell type-specific, and inducible cellular proteins...
Cohen ND.Neurologic evaluation should be performed in horses with diseases of the head. Although neurologic examination should focus on assessing behavior, mental status, and cranial nerve evaluation, evaluation of neurologic function of other body regions should be performed. Neurologic evaluation of the head can be performed expediently by practitioners to provide useful diagnostic and prognostic information. The numerous causes of dysphagia can be classified as obstructive, painful, or neurogenic. Common causes of neurogenic dysphagia are summarized, and methods for initial diagnosis and management ...
Chopineau M, Maurel MC, Combarnous Y, Durand P.In order to localize the epitopes of equine chorionic gonadotropin (eCG) involved in interaction with luteinizing hormone (LH) and follicle-stimulating hormone (FSH) receptors, we used 14 monoclonal anti-eCG antibodies (mAbs). Different effects of these mAbs on the bioactivities of eCG were observed in in vitro bioassays, but the effects of each mAb on the two bioactivities were similar for all but four mAbs. All mAbs were found to inhibit the binding of eCG to LH receptors except 3A3 mAb, in radioreceptor assay. Six mAbs, which were strong inhibitors of eCG binding to LH receptors and of both...
Hanson PD, Bartz TA, Stone WC, Darien BJ, Markel MD.A modification of the Roux-en-Y anastomosis procedure was used to bypass a pyloroduodenal mass in a 12-year-old Arabian stallion. Clinical signs had consisted of a 4-week progression of ventral and hind limb edema, hypoproteinemia, fecal occult blood, intermittent abdominal pain, weight loss, and gastric reflux. On exploratory celiotomy, an obstructive mass was found in the pylorus and proximal portion of the duodenum. Gastrojejunostomy and duodenojejunostomy were performed by use of stapled side-to-side anastomosis techniques. Inaccessibility of the obstructed pyloric region prevented resecti...
Rimstad E, Evensen O.Paraffin-embedded organ samples from 28 aborted fetuses and three foals, partly archival and partly sampled in 1991, were examined by polymerase chain reaction (PCR) and immunohistochemistry for the presence of DNA and antigens, respectively, specific for equine herpesvirus 1 (EHV-1). Virologic examination had been performed on 23 of the aborted fetuses. DNA fragments specific for EHV-1 were identified by PCR, and EHV-1 antigens were identified in situ by immunohistochemistry, with an agreement between the methods of 94% (kappa = 0.85). Compared with virus isolation, PCR agreement was 87% (kap...
Haga HA, Ytrehus B, Rudshaug IJ, Ottesen N.Neoplasia may cause hypoglycemia in different species including the horse, but hypoglycemia has not previously been reported in the horse associated with gastrointestinal stromal tumours. Methods: A case of a gastrointestinal stromal tumour in a Fjord pony with severe recurrent hypoglycemia is presented. The mechanism causing the hypoglycemia was not established. Conclusions: This case indicates that a gastrointestinal stromal tumour may cause hypoglycemia also in the horse.
Patterson SD, Bell K.The carbohydrate side chains of the major plasma serpins of the horse and wallaby have been characterized by lectin analyses of protein blots from two-dimensional gels using the major human plasma serpin, alpha 1-protease inhibitor, as a control. Eight lectins were used in the characterization in conjunction with enzymatic deglycosylation of complex and high mannose side chains, chemical desialylation and defucosylation, and one round of 'Smith degradation', all being performed on the nitrocellulose blots. Assuming a standard complex side chain structure, the results of the 21 lectin/treatment...
Socha W, Larska M, Rola J.Susceptibility to long-term persistent infection with Equine Arteritis Virus (EAV) in stallions is related with EqCXCL16 gene alleles of the host. In our study EqCXCL16 gene alleles were determined for 63 EAV shedders and 126 non-shedders of various horse breeds. In total, 60 (31.7%) out of 189 tested stallions were identified as carriers of susceptible variants of EqCXCL16 by real time PCR and Sanger sequencing. The presence of susceptible genotype was related to horse breed with the highest percentage in Wielkopolska breed, Polish coldblood and Silesian breed horses. Strong correlation betwe...
Kamm JL, Bramlage LR, Schnabel LV, Ruggles AJ, Embertson RM, Hopper SA.Analysis was performed to examine a method for refining the preoperative prognosis for horses that had surgery to remove apical fractures of the proximal sesamoid bones (PSBs). Objective: To determine if: 1) there was a difference in size or configuration of apical fractures between the different anatomical locations of the PSBs, which have been shown to affect the prognosis; and 2) the size or configuration could predict the prognosis for racehorses with these fractures. Methods: The study included 110 weanlings and yearlings and 56 training racehorses that underwent surgery to remove apical ...
Hempstead JE, Clode AB, Borst LB, Gilger BC.To evaluate corneal changes associated with chronic, nonhealing, superficial, corneal ulcers in horses via common histopathological stains. Methods: Retrospective study. Methods: Twenty-four horses diagnosed with chronic, nonhealing, superficial, corneal ulceration. Methods: The medical records of horses evaluated at North Carolina State University's Veterinary Teaching Hospital (NCSU-VTH) from 2005 to 2011, diagnosed with a chronic, nonhealing, superficial, corneal ulcer and treated with superficial keratectomy (SK) were reviewed. Inclusion criteria were superficial corneal ulceration, no cel...
Weaver BM, Webb AI.The halothane muscle/gas partition coefficients at 37 degrees C for 26 samples of eight different muscles from four horses were found to depend significantly on the fat content of the muscle sample with a regression coefficient of 1.913 (SEM 0.109) per per cent ether-extractable fat content. The blood/gas partition coefficients in 24 horses showed a significant dependence on plasma triglyceride concentration (regression coefficient 0.00084 (SEM 0.00033) per mg dl-1), an insignificant positive dependence on plasma free and total cholesterol concentration and, in a multiple regression analysis, ...
Steinmetz A, Gittel C, Böttcher D, Lapko L, Offhaus J.A melanoma of the upper eyelid was resected in a gray warmblood gelding. A full functional eyelid could be obtained by completion a sliding skin graft with a free labial mucocutaneous graft transplantation to restore the mucocutaneous junction and to decrease the risk of postoperative trichiasis.
Galey FD, Beasley VR, Schaeffer D, Davis LE.An aqueous extract was made from black walnut (Juglans nigra) heartwood obtained in the fall of the year. Ten hours after nasogastric administration of 5 L of the extract, a 550-kg, 13-yr-old Quarter Horse gelding experienced Obel grade-3 laminitis. The effect of aqueous extract of black walnut on vascular contractility was then tested, using isolated equine digital arteries and veins. The vessels were maintained in Krebs bicarbonate buffer with 95% oxygen at 37 C. The extract did not induce a direct contractile effect. It did, however, reversibly enhance the vasoconstriction induced in the is...
Hussein HA, Ibrahim A, Ali MF.This study aimed to establish normal ultrasonographic reference values of kidney dimensions in donkeys (Equus asinus) and to describe and evaluate the clinicopathological variations associated with ultrasound-guided renal biopsy. The ultrasonographic dimensions of the right and left kidneys were conducted on 16 donkeys, which were then divided into two groups; eight each for biopsy of the right kidney (RK) and left kidney (LK). Three ultrasonographic cineloops were obtained at 17th intercostal space daily for 3 consecutive days. Renal length, width, and dimensions of the cortex, medulla, and p...
Perryman LE.Primary immunodeficiency disorders are genetically determined failures of immune defense that increase susceptibility to infectious agents. This article reviews the salient features of equine primary immunodeficiency disorders, summarizes the molecular mechanisms of each disorder, and updates information that facilitates diagnosis and management of affected horses. The central theme is to encourage clinicians to ask, "I wonder if this horse has an underlying primary immunodeficiency disorder?" when caring for horses suffering from chronic and recurring infections and responding poorly to stand...
Winter MD, Berry CR, Reese DJ.Nuclear scintigraphy has been used successfully for various applications in horses in the past 30 years. Many private practices and most veterinary schools have gamma cameras, which are used to image an injected radionuclide in an equine patient. Unique exercise-related demands place specific physiologic stressors on the musculoskeletal system of horses. Horses are often pushed beyond normal physiologic limits because of specific performance stresses; therefore, injury to their musculoskeletal system is common. Skeletal scintigraphy is exceedingly sensitive but relatively nonspecific for deter...
Tetens J, Venugopal CS, Holmes EP, Koch CE, Hosgood G, Moore RM.To evaluate the in vitro effects of adenosine tryphosphate (ATP) on vasomotor tone of equine colonic vasculature. Methods: Arteries and veins from the left ventral colon of 14 mixed-breed horses euthanatized for reasons unrelated to cardiovascular or gastrointestinal tract disease. Methods: Endothelium-intact and -denuded arterial and venous rings were precontracted with 10(-7) and 1.8 x 10(-8) M endothelin-1, respectively. In 1 trial, endothelium-intact rings were also incubated with 10(-4) M N omega-nitro-L-arginine methyl ester (L-NAME) to inhibit nitric oxide (NO) production. Adenosine tri...
Sigel CW, Byars TD, Divers TJ, Murch O, DeAngelis D.Two fasted and 2 fed horses were dosed orally with a combined trimethoprim and sulfadiazine paste formulation at a dose of 35 mg (1:5 combined active ingredients)/kg. Serum concentrations of each drug were determined periodically for 3 consecutive days for the 4 horses. The extent and rate of absorption for trimethoprim were variable, but peak serum concentrations occurred generally within 3 hours; sulfadiazine absorption was slower, reaching peak concentrations by 6 hours. Fasting did not have a consistent effect on the serum concentration profiles for either drug. Both drugs achieved serum c...
Carpenter TE, McBride MD, Hird DW.We examined the risk of importing and mistakenly releasing equine infectious anemia virus (EIAV)-infected horses into California. A computer simulation model was constructed to evaluate current and alternative quarantine station procedures; 150,000 iterations were performed to simulate 15 different scenarios of 10,000 horses imported into the state over a 14-year period. Simulation results showed that under current conditions of low EIAV prevalence in exporting countries, increasing the quarantine period would not decrease the number of EIAV-infected horses mistakenly released from quarantine....
Bertero A, Ritrovato F, Evangelista F, Stabile V, Fortina R, Ricci A, Revelli A, Vincenti L, Nervo T.The purpose of this study was to observe -matured equine oocytes with an objective computerized technique that involves the use of a polarized light microscope (PLM) in addition to the subjective morphological evaluation obtained using a classic light microscope (LM). Equine cumulus-oocyte complexes (COCs, = 922) were subjected to different maturation times (24, 36 or 45 h), however, only 36-h matured oocytes were analyzed using CLM. The 36-h matured oocytes that reached maturity were parthenogenetically activated to evaluate the quality and meiotic competence. Average maturation perce...
Rankins EM, Manso Filho HC, Malinowski K, McKeever KH.Horses' muscular tension during acute stress remains unexplored. Our aim was to assess muscular, behavioral, cortisol, and hematocrit responses to social isolation (ISO), novel object exposure (NOV), and sham clipping (CLIP). Altered stress responses were expected. Eight mature Standardbred horses (four mares and four geldings) were exposed to acute stressors and a control period (CON) in a balanced, replicated 4×4 Latin Square experimental design with 3 min treatment periods and 10 min washout periods. Surface electromyography collected from the masseter, brachiocephalas, cervical trapeziu...
Ewert M, Böröcz J, Uphaus H, Oldenhof H, Distl O, Sieme H.The aim of this study was to evaluate factors affecting pregnancy rates in the German Thoroughbred Breed with particular emphasis on optimisation of fertility rates for breeding stallions of older ages. Methods: Data from the studbooks of the German Thoroughbred Breeding Association from 1996 to 2009 analysed. This analysis included the records of 319 stallions and 6622 brood mares, resulting in 21,372 pregnancies at the end of the season. Results: Pregnancy rates were significantly affected by the age of the stallion and mare as well as the season (month in the breeding season in which coveri...