Veterinary medicine for horses encompasses the study and application of medical practices to diagnose, treat, and prevent diseases in equine species. This field involves a comprehensive understanding of equine anatomy, physiology, pathology, and pharmacology. Veterinary practitioners employ a range of diagnostic tools and therapeutic interventions to address health issues in horses, including lameness, gastrointestinal disorders, respiratory conditions, and infectious diseases. Preventative care, such as vaccination and deworming programs, is also a significant aspect of equine veterinary medicine. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of veterinary medicine as it pertains to horses, including advancements in diagnostic techniques, treatment protocols, and preventive health strategies.
Cervantes CC, Brown MP, Gronwall R, Merritt K.Each of 5 healthy mares was given 5 consecutive IM injections of ceftiofur sodium (2 mg/kg of body weight; 50 mg/ml) at 12-hour intervals. Ceftiofur concentrations were measured serially in serum, synovial fluid, peritoneal fluid, and urine, and were measured in CSF and endometrial tissue after the fifth dose. Mean elimination rate constant was 0.354 +/- 0.101 h-1 and elimination half-life was 2.49 +/- 0.49 hour. Mean serum ceftiofur concentrations peaked approximately 1 hour after each injection. The highest mean ceftiofur concentration was 5.09 micrograms/ml at 1 hour after the fifth dose fo...
Troedsson MH, deMoraes MJ, Liu IK.The relationship between histologic lesions in endometrial biopsy specimens and susceptibility to chronic uterine infection (CUI) in mares was investigated. Mares were allotted to 4 groups on the basis of degree of endometrial lesions. Mares in group 1 (n = 6) had no pathologic changes, mares in group 2 (n = 5) had only mild pathologic changes, group-3 mares (n = 7) had moderate changes, and group-4 mares (n = 7) had severe inflammatory and fibrotic endometrial changes. Susceptibility to CUI was determined by the inflammatory response to intrauterine inoculation of 5 x 10(6) Streptococcus zooe...
Sweeney CR, Freeman DE, Sweeney RW, Rubin JL, Maxson AD.Three horses were determined to have hemorrhage into a guttural pouch unassociated with mycosis, empyema, neoplasia, or foreign body. The source of the hemorrhage appeared to be the rupture of the longus capitis muscle and its associated vascular supply.
Small AC, Kelly WR, Seawright AA, Mattocks AR, Jukes R.A foal, small and jaundiced from birth, succumbed after two months to chronic hepatic damage which was characterised by fibrosis, biliary ductular hyperplasia and the presence of pleomorphic hepatocytes containing either a single large nucleus or multiple nuclei. The fixed liver contained sulfur-bound pyrroles, which are derived from pyrrolizidine alkaloids. During pregnancy the pasture was heavily infested with the pyrrolizidine alkaloid-containing plant, Senecio madagascariensis. The hepatic disease affecting the foal appears to have been initiated by consumption of the alkaloids by the mare...
Driesang I, Böhm D.Both hock joints were examined clinically, radiologically and scintigraphically in 80 horses with special regard to bone spavin. The positive x-ray and bone scan results corresponded in most cases. It was evident that there was no correlation between degree of lameness and/or extent of radiological findings and increased radioactive uptake in the joint. Scintigraphic evaluation may demonstrate early changes at the onset of bone spavin as well as the frequent bilateral nature of the condition.
McGorum BC, Dixon PM, Halliwell RE.A commercial radioimmunoassay kit was used to quantify histamine concentrations of plasma, bronchoalveolar lavage fluid (BALF) and pulmonary epithelial lining fluid (PELF) of normal horses and horses with chronic obstructive pulmonary disease (COPD), before and after 'natural (hay and straw) challenge' (NC). There were no significant changes in the concentrations of histamine in plasma or BALF at 0.5 or 5 h after NC, but the PELF histamine concentration of COPD affected horses was significantly increased at 5 h, but not at 0.5 h, following NC. As the histamine concentrations of whole BALF lysa...
Nicoll RG, Wood AK, Martin IC.Observations were made in dorsal and sagittal planes of the ultrasonographic mean gray scale of the flexor tendons and ligaments of the metacarpal regions of 5 Thoroughbred geldings, during weight bearing and nonweight bearing. In images made when the horses were nonweight bearing, the mean gray scale of the superficial and deep digital flexor tendons and accessory ligament was significantly reduced, but that of the interosseous medius muscle (suspensory ligament) was not. When relaxed, collagen fiber bundles in the tendons and ligaments acted as diffuse, rather than specular, reflectors of ul...
Trotter GW.Numerous conditions, including trauma, infection, neoplasia, and developmental problems, can affect the paranasal sinuses. Successful resolution of these problems is predicated upon a thorough diagnostic workup to ensure the most accurate presumptive diagnosis. Surgical intervention is enhanced by using approaches that allow wide access to sinus compartments. Rigorous postoperative management is also important to a successful outcome.
Yvorchuk-St Jean KE, Debowes RM, Gift LJ, Kraft SL, Sinha AK, Kennedy GA.A 5-week-old belgian colt was examined for colic of 12 hours duration after several episodes of diarrhea. Physical examination revealed signs of abdominal pain, mild dehydration and normal auscultable borborygmi in all abdominal quadrants. Distention of the cecum, large colon and small intestinal was evident on abdominal radiographs. The foal was treated medically as the owners declined surgery. The colt was euthanized because of continued deterioration and failure to respond to medical therapy. Post-mortem exam revealed the presence of a trichophytobezoar obstructing the distal part of the tr...
Jaeschke G, Lange W.In this paper three outbreaks of equine influenza in Berlin (Germany) in the years of 1988, 1989 and 1991 are discussed, reporting mainly clinical, hematological, virological and some epizootiological aspects. We have detected variations from the traditional pattern of equine influenza, whereby the main clinical symptoms like cough or fever were absent in several cases. If cough was found, it was moist. Furthermore a mucous nasal discharge was present in a number of cases for a period of 4-5 days. Extreme neutropenia, lymphocytosis and predominantly an unchanged level of monocytes were observe...
Freestone JF, Seahorn TL.Nutritional secondary hyperparathyroidism is associated with horses that are fed diets with an imbalance of calcium and phosphorus or diets containing oxalates. Clinical signs include a shifting lameness, with tenderness of the joints, reluctance to move, or a stiff, stilted gait. Some horses may have broadening of the nasal bones, enlargement of the maxilla and/or the mandible, or a ridge over the nasal bones. Diagnosis may include physical examination findings; analysis of feed; and clinical pathologic data, which may include normocalcemia, normal to increased serum phosphorus, and increased...
Park RD.Radiographic examinations of the equine head can be performed with portable x-ray machines. The views comprising the examination depend on the area of the head being examined. With a knowledge of radiographic anatomy and radiographic signs of disease, valuable diagnostic information can be obtained from the radiographic examination. In addition, the radiographic information can also be used to develop a prognosis and determine the most appropriate therapy.
Kainer RA.This topical presentation emphasizes the structures most likely to be encountered in the diagnosis and treatment of diseases of the equine head. Most of the approaches are from superficial to deep. Anatomic variations associated with aging are described. The larynx and guttural pouches are not included in this article.
Sonea IM, Bowker RM, Robinson NE, Broadstone RV.Immunohistochemical methods were used to determine the distribution of pulmonary nerves containing either an enzymatic marker of adrenergic nerves, dopamine beta hydroxylase, or the putative neurotransmitter neuropeptide Y in 7 equids with healthy lungs. Nerves immunoreactive for these substances were found on airway smooth muscle in nearly all the samples of healthy equine lung examined. These nerves were generally more numerous in the larger airways but could be detected even in noncartilaginous bronchioles. Pulmonary and bronchial vessels also contained numerous immunoreactive nerves. On th...
Howard RD, Stashak TS.Traumatic injuries to the head region of the horse are a common presenting complaint. Because of a copious blood supply, these wounds typically exhibit a tremendous capability for healing. By following the basic principles of wound management and employing a few techniques unique for specific injuries, the healing of these wounds can result in a satisfactory outcome.
Sasaki K, Igarashi S, Amasaki T, Amasaki H, Nishita T, Kano Y, Asari M.Immunohistochemical localizations of carbonic anhydrase isozymes (CA-I, CA-II and CA-III) in equine and bovine digestive tracts were studied. In the horse, epithelial cells in both the oesophagus and non-glandular part of the stomach lacked all three isozymes. In contrast, surface epithelial and parietal cells in the glandular region of the stomach showed reactivity for CA-II. In the small intestine, absorptive columnar cells covering the villi in the duodenum were positive for CA-II. The epithelium of the jejunum and ileum lacked all three isozymes. In the large intestine, CA-II was detected ...
Gardner SY, Sweeney RW, Divers TJ.Serum concentrations of cefotaxime and desacetylcefotaxime were measured in 1-week-old pony foals after IV administration of a single dose of cefotaxime. The cefotaxime disposition data conformed to a two-compartment model with elimination half-life of 0.60 hour. The combined cefotaxime and desacetylcefotaxime data was best described by a four-compartment model. The apparent half-life describing the disappearance of desacetylcefotaxime was 1.69 hours. Dosage of 40 mg/kg of body weight given IV every 4 to 6 hours for neonatal foals with gram-negative septicemia and every 2 hours for foals with ...
Smyth GB, Young DW, Duran SH.Postprandial insulin and glucose concentrations were measured in 3 Arabian and 3 Thoroughbred foals at 1 day, 1 week, 1 month and 3 months of age. Prefeeding serum insulin concentrations were similar in foals at 1 day (25.9 +/- 5.1 pmol/L), 1 week (32.4 +/- 5.8 pmol/L), and 1 month (38.2 +/- 7.9 pmol/L), but had increased significantly to 131.0 +/- 20.2 pmol/L at 3 months of age (P < 0.05). There was significantly increased serum insulin secretion after a feed in foals at 3 months of age (P < 0.05) when compared with that at younger ages. Prefeeding serum glucose concentrations ranged fr...
Sisken BF, Zwick M, Hyde JF, Cottrill CM.This review covers the development and maturation of the cerebellum of the horse and compares this developmental sequence with that of man, mouse and chicken. These comparisons attempt to correlate morphological and neurochemical features, developmental time and functional performance necessary for survival at birth. Although there is great disparity between these 3 species, the basic anatomical structures of the cerebellum are present as are specific cellular groups, synapses and neurochemical markers. In addition to this structural homogeneity, other attributes of the cerebellum are its easi...
Bertone JJ, Biller DS, Ruggles A.Physical examination of the paranasal sinuses is often insufficient to confidently reach a conclusion concerning suspected pathology in these cavities. Often, other evaluation techniques are necessary. This article describes physical examination, rhinoscopy, sinus centesis, radiology, and sinus endoscopy of the equine paranasal sinuses. These techniques can be used to diagnosis and determine the cause of most sinus disorders.
Rossdale PD.This review summarises comparative aspects of equine pregnancy and birth. The allantochorion covers the entire endometrial surface of the mare's uterus and the placenta is microcotyledonary and epitheliochorial in structure. The foetus has, therefore, to pass through the allantochorion at birth. The umbilical cord has amniotic and allantoic portions and remains intact after delivery, enabling an arterial venous circulation to be maintained for several minutes. Maternal IgG does not cross the placental barrier and passive transfer post-natally is essential for immune status. Gestation in Thorou...
Abdalla MA, Taleb ZA, Ebid MH.An outbreak of infectious influenza was recognized in Menofeia governorate in October 1989. Eight naturally influenza infected as well as 8 healthy control horses, mules and donkeys were selected for collection of blood and sera separation to estimate four lysosomal enzymatic activities and to describe the clinical findings, which were fever, congested nasal, conjunctival membranes and cough. Bronchopneumonia followed later with bilateral purulent nasal discharge as a complication in 2 donkeys. Thereafter laboured breathing occurred. Therefore a therapeutic penicillin-streptomycin dose was inj...
Schumacher J, Honnas CM.Anatomy, physiology, and diseases of the teeth are presented. Signs of dental disease and techniques for oral and radiographic examination of the teeth are discussed. Surgical procedures described include extraction, repulsion, and endodontic therapy.
Eades SC, Moore JN.Stimulation of alpha 2 adrenergic receptors inhibits colonic motility and may constrict some peripheral vascular beds. Endotoxemia elicits release of sympathetic neurotransmitters and increases sympathetic nerve activity, which may result in stimulation of alpha 2 adrenergic receptors. The objective of this study was to determine whether blockade of alpha 2 adrenergic receptors would restore cecal motility and blood flow during endotoxemia in horses. Strain-gauge force transducers and ultrasonic flow probes were used to measure cecal and colonic mechanical activity and lateral cecal arterial b...
McCann ME, Hunt RJ.Femoral fractures in young horses can occur as a result of severe trauma and generally have a poor prognosis despite treatment. Four young horses with femoral diaphyseal fractures were managed with conservative treatment consisting of prolonged rest, analgesics, hind limb support, and corrective farriery. A favorable outcome in the form of pasture soundness with potential for limited athletic usefulness was obtained in 3 out of the 4 cases. This report supports the use of conservative treatment of selected diaphyseal femoral fractures in young horses.
Watney GC, Norman WM, Schumacher JP, Beck E.The accuracy of a reflectance pulse oximeter was determined in 22 anesthetized horses. Oximetric blood oxygen saturation was measured with the pulse oximeter probe attached to the mucosa of the mandible. Arterial blood oxygen saturation (SaO2) was calculated from arterial blood gas values and the equine blood oxygen dissociation curve. The mean +/- SD difference between oximetric blood oxygen saturation and SaO2 was -1.3 +/- 3.1% for values of SaO2 ranging from 80 to 100%. The difference between oximetric blood oxygen saturation and SaO2 was influenced by SaO2, the mean arterial blood pressure...
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.
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...
Murase H, Matsui A, Endo Y, Sato F, Hada T.The lying behavior of Thoroughbred foals on breeding farms was continuously measured using triaxial accelerometers. Accelerometers were attached on the side of the hind limb cannon and under the halter of six foals to record triaxial angle data every 10 sec for a period of 24 hr. Lying behavior was divided into sternal lying and lateral lying based on head angle. Sampling was performed for two consecutive days each week until weaning. Sampling periods were divided into two periods on the basis of pasturing time: daytime pasturing (period A: 7-hr pasturing period, 2-60 days of age) and overnigh...