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.
Harris RC, Marlin DJ, Snow DH.To define the metabolic response to maximal exercise in the thoroughbred horse under field conditions, muscle biopsies and venous blood samples were taken from five horses after a single 800-m gallop and from four horses after a single 2,000-m gallop. Muscle and blood samples were also collected during 60 min of recovery. After exercise muscle ATP contents were decreased by 30 +/- 7 (SD) and 47 +/- 3% after the 800- and 2,000-m gallops, respectively. As indicators of purine catabolism, ammonia and uric acid increased in plasma, the accumulation being greater after the 2,000-m gallop. Blood amm...
Sedgwick AD, Dawson J, Lees P.Subpopulations of equine leucocytes, polymorphonuclear and mononuclear cells, were separated from whole blood on a discontinuous Percoll gradient and used in studies of chemokinesis and chemotaxis. Polymorphonuclear cells responded to the chemo-attractant properties of zymosan-activated plasma in Boyden chamber and agarose microdroplet assays but they responded only slightly (Boyden chamber) or not at all (agarose microdroplet) to the peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP). Equine mononuclear cell movement was increased by FMLP in both assay systems and these cells also respond...
Ward DS, Fessler JF, Bottoms GD.Electromagnetic flow transducers were implanted via left thoracotomy in 8 ponies (122.7 to 263.6 kg) around the main pulmonary and left main coronary arteries for continuous measurement of mean and pulsatile blood flow. Flow transducers were calibrated in vitro with a gravity flow system. The mean +/- SE pulmonary flow was 73.1 +/- 5.1 ml/kg of body weight/min. Left coronary flow was 0.95 +/- 0.07 ml/kg/min (1.3% of cardiac output) and was not believed to be an accurate measurement. This was caused by the inability to implant a zero-flow occluder, requiring the use of minimum flow during systo...
Brunson DB, Majors LJ.Xylazine, morphine, butorphanol, and nalbuphine were evaluated in 5 adult male horses, using dental dolorimetry. Comparisons were made at 30, 60, and 100 minutes after IV drug administration. Peak analgesia and the time to develop peak analgesia also were compared. Xylazine induced a marked increase in the tooth pulp pain threshold measurements as did the xylazine/narcotic combinations. Statistical differences were not detectable between these treatments. Xylazine and xylazine/butorphanol were better analgesics than was butorphanol alone at 30 and 60 minutes. Xylazine resulted in peak analgesi...
Jang SS, Biberstein EL, Hirsh DC.Actinobacillus suis-like organisms have been recognized in equine specimens at the University of California Veterinary Medical Teaching Hospital since 1975. The most common source (65%) of the organism was transtracheal washings. The organism was gram-negative, produced hemolysis on blood agar, and gave a positive reaction for oxidase, urease, o-nitrophenyl-beta-D-galactopyranoside, and esculin. Carbohydrate reactions were variable, consisting of 4 main patterns. Actinobacillus suis-like organisms were (90%) sensitive to therapeutic concentrations of amikacin, cephalothin, chloramphenicol, gen...
Robertson SA.Three different anaesthetic techniques were studied in normal, healthy Thoroughbred or Thoroughbred type horses. These were (a) acepromazine, thiopentone and suxamethonium; (b) acepromazine, glyceryl guaiacolate and a 'half-dose' of thiopentone; and (c) xylazine and ketamine. Anaesthesia was maintained with halothane vaporized in oxygen and nitrous oxide. All horses underwent either laryngeal or body surface surgery. Heart rate, packed cell volume, blood glucose and lactate, plasma non-esterified fatty acids, insulin and cortisol were measured before, during and after surgery. The greatest met...
Ross MW, Orsini JA, Ehnen SJ.A 5-year-old Thoroughbred gelding with recurrent cecal impaction refractory to medical management was treated with a side-to-side jejunocolic anastomosis. Cecal impaction did not recur after surgery. The horse gained weight and performed successfully for 14 months, but experienced three episodes of mild abdominal pain between 14 and 20 months after surgery. Mild cecal gas distention and firm ingesta in the colon were detected on rectal examination. The horse's feces remained soft after surgery, except during the colic episodes when dry, firm feces were passed.
Timoney PJ, McCollum WH, Roberts AW, McDonald MJ.Clinical cases of equine arteritis virus infection have not been diagnosed in Kentucky since 1984, and there has been no indication that any of the horses involved in the 1984 epizootic have since been responsible for spread of the disease to horses in other states or other countries. Cases of abortion caused by naturally acquired infection with this virus have not been confirmed in 1984 or 1985. Neither field nor vaccine strains of equine arteritis virus have been shown to induce teratologic abnormalities or the carrier state in foals born to infected or vaccinated mares. The carrier stallion...
Skarda RT, Muir WW, Couri D.Arterial and/or central venous plasma concentrations of lidocaine were determined in 12 nonmedicated adult horses (422 +/- 59 kg of body weight, mean +/- SD) after injecting a 1% lidocaine HCl solution into the cervicothoracic ganglion (CTG). A mean dosage of 2.9 +/- 0.5 mg of lidocaine/kg of body weight was used to induce unilateral CTG blockade in 8 horses and 4.8 +/- 0.8 mg was used to induce bilateral CTG blockade in 4 horses. Blood samples were collected before and at 5, 15, 30, 45, 60, 75, 90, 105, and 120 minutes after injection. The plasma lidocaine concentrations were determined by us...
Jones RL, Adney WS, Shideler RK.Clostridium difficile was isolated from the feces of 27 of 43 diarrheic foals (63%), and cytotoxin was detected in feces from 28 diarrheic foals (65%). The foals had not received any antimicrobial treatment before the onset of diarrhea. C. difficile was not isolated from feces of 18 normal foals without diarrhea and 62 adult horses (P less than 0.005). This finding of C. difficile and its toxins in association with diarrhea in foals adds another possible cause to the list of infectious agents which may cause diarrhea in foals.
Fischer AT, Stover SM.Third carpal sagittal fractures were found to be related to racing injuries in 10 of 12 horses. These fractures occurred most commonly on the medial aspect of the bone. A dorsoproximal-dorsodistal view of the carpus was required to visualize the fracture in all cases. Healing of the fracture required periods of rest of up to one year. Conservative management of these fractures resulted in return to function in 7 of 12 horses.
Bertone AL, McIlwraith CW.Arthroscopic approaches to the scapulohumeral joint were developed in four clinically normal, live horses (5 limbs) to determine their usefulness for evaluation and potential surgical treatment of intraarticular lesions. The articular surface of the entire glenoid, cranial humeral head (medial and lateral) and caudolateral humeral head, as well as the synovial membrane, could be closely examined from an arthroscopic portal cranial to the infraspinatus tendon. The caudomedial humeral head could be examined partially. Cranial and caudal instrument portals allowed good surgical access to the enti...
McLean RG, Calisher CH, Parham GL.Blood samples collected in September and November 1980 from 87 horses in southwestern Michigan were examined for virus isolation and for plaque-reduction neutralizing antibody against selected arboviruses. Cache Valley virus was isolated from the blood of a clinically normal horse in St Joseph County in September. The age-specific antibody prevalence for Cache Valley virus indicated enzootic transmission in the study area. The high antibody prevalence and the lack of age-specific antibody prevalence indicated sporadic, but intense, exposure to Jamestown Canyon virus. Low prevalences of antibod...
Sullins KE, McIlwraith CW.Transverse or oblique midshaft tibial osteotomies were created in 11 foals. The osteotomies were repaired during the same procedure using external skeletal fixation in either full splint or 3-dimensional (3-D) tent configurations. Four of the six foals receiving the full splint fixator recovered to full soundness; two were euthanized because of complications. The foals receiving the 3-D tent configuration would not bear weight on the limbs and consequently suffered significant secondary fracture disease. These foals were euthanized for humane reasons before the scheduled termination of the pro...
Lane JG, Mair TS.The clinical records of 100 cases of headshaking in horses were reviewed. Possible causes of the abnormal behaviour were identified in 11 animals; these included ear mite infestation, otitis interna, cranial nerve dysfunction, cervical injury, ocular disease, guttural pouch mycosis, dental periapical osteitis and suspected vasomotor rhinitis. However, in only two of these could it be shown that correction of the abnormality led to elimination of the headshaking. The additional clinical signs exhibited by the other idiopathic cases of headshaking included evidence of nasal irritation, sneezing ...
Smith HJ, Snowdon KE.Light Trichinella infections were established in three ponies given 1000, 5000 and 25000 T. spiralis spiralis infective larvae respectively by stomach tube. A predilection site of infection in all ponies was the tongue. Anti-Trichinella antibodies were detected in all ponies by the enzyme-linked immunosorbent assay using a T. spiralis spiralis excretory-secretory antigen. The ponies given 5000 and 25000 infective larvae reacted positively on days 26 and 24 postinfection, respectively, using a criterion of greater than or equal to 5 X mean optical density readings of preinfection sera as positi...
Wiest JJ, Thompson DL, McNeill-Weist DR, Garza F.Twenty ovariectomized pony mares were used to determine if dihydrotestosterone propionate (DHTP) administration, with or without estradiol benzoate (EB) pretreatment, would have the same effects on follicle stimulating hormone (FSH) and luteinizing hormone (LH) secretion as testosterone propionate (TP) administration. All mares were given an initial injection of gonadotropin releasing hormone (GnRH) to characterize their LH and FSH response, and then two groups of mares (n = 4/group) were administered EB (22 micrograms/kg of body weight), two groups were administered vehicle (safflower oil) an...
Edwards JF, Yedloutschnig RJ, Dardiri AH, Callis JJ.Virus isolation was attempted from 262 field samples of vesicular material collected during the outbreaks of vesicular exanthema of swine in the U.S.A. from 1952-54. Using primary swine kidney culture, viral cytopathogenic agents were isolated from 76.3% of the samples. However, an overall recovery rate of 82.1% was obtained after samples negative in tissue culture were inoculated intradermally in susceptible swine. All vesicular exanthema of swine virus isolates were identified as serotype B51 using complement fixation and serum neutralization tests. Two isolates did not react with antisera t...
Ward DS, Fessler JF, Bottoms GD, Turek J.Ponies with electromagnetic blood flow transducers implanted around the main pulmonary and left main coronary arteries, were used to evaluate effects of chronic sublethal endotoxin on cardiac output (CO), stroke volume, and left coronary blood flow (LCBF). Plasma thromboxane (TX), as indicated by TXB2, prostacyclin as indicated by 6-keto-prostaglandin (PG) F1 alpha, and hematologic and blood chemical values also were evaluated. Over 24 hours, 2 groups of ponies were given progressively increasing IV and intraperitoneal doses of Escherichia coli lipopolysaccharide (LPS) at 0, 6, 12, and 18 hour...
Franci P, Bertamini A, Bertamini O, Pilla T, Busetto R.A new volatile anaesthetic agent delivery system was tested in 15 horses undergoing scheduled surgical procedures. The delivery system consisted of a laptop computer (with dedicated software), a computer-controlled syringe driver (loaded with liquid isoflurane) connected to the inspiratory arm of a large-animal circle breathing system and a respiratory gas monitor, providing isoflurane end-tidal concentrations (ET(measured)) every 20 s to the computer. Following induction and connection to the breathing system, mechanical ventilation was started. The bodyweight (BW), fresh gas flow, breathing ...
Schuberth HJ, Hadam M, Leibold W.The determination of differentiation and transplantation antigens will be of growing importance in immune diagnosis for individual animals as well as for breeding purposes in populations. Differentiation antigens characterize subsets of cell populations and indicate their functional capacity while transplantation antigens represent markers of individuals of a species. Occurrence and significance of these antigenic systems are briefly reviewed.
Asperio RM, Marzola P, Sbarbati A, Osculati F, Addis F.To analyze the tendon of the deep digital flexor (TDDF) muscle of the forelimb in horses by use of a contrast radiographic agent (gadopentate dimeglumine [Gd-DTPA/Dimeg]) and magnetic resonance imaging (MRI) and to determine the concentration of water protons in the tendons by use of MRI. Methods: 8 TDDF harvested from the forelimbs of 6 horse cadavers. Methods: Examinations were performed on the same portion of each tendon. Tendons were examined by use of two techniques: MRI before and after treatment with Gd-DTPA/Dimeg as well as scanning electron microscopy. Results: Tendons did not have de...
Held JP, Blackford JT.Three cases of vaginal perforation after coitus are discussed. The most consistent clinical sign is a small amount of blood escaping from the vulvar lips immediately after breeding. Secondary infection and posttraumatic swelling may cause abdominal pain due to rectal impaction. Treatment with high levels of an appropriate antibiotic is important to reduce the risk of a severe infectious peritonitis. The use of artificial insemination or a breeding roll to prevent full intromission is recommended.
Dzierzecka M, Czerwinski E.On the basis of a digital analysis of radiograms it was checked if, and to what extent, the extended loading of one of the sides of the body of racehorses leads to differences in the microstructure of the spongy bone of the bilateral pastern bones of the thoracic limbs. The research material consisted of radiograms of the pastern bones of the right and left thoracic limbs of racehorses. On the basis of computer image radiological analysis with the use of the "Trabecula,, programme, a quantative evaluation of the structure of the spongy bone of the pastern bones was conducted. It was noted that...
Mama KR.Many new or modified injectable anesthetic techniques are available for use in horses. This increased availability allows the clinician to select the technique most appropriate for the patient and clinical circumstance. The use of sedative and anesthetic drugs in managing a variety of anesthesia-related and unrelated aspects of patient care is also increasing. As we begin to use these techniques in the clinical management of our patients, it is important to remember that, while there are more options, no single anesthetic agent or combination of agents is devoid of undesirable effects. Knowled...
Lean NE, Zedler ST, Van Eps AW, Engiles JB, Ford M, Stefanovski D, Walsh DM, Pollitt CC.Surgical stabilisation of the distal phalanx (DP) is a potential therapeutic strategy for severe acute laminitis. Objective: To evaluate the effects of locking compression plate (LCP) fixation of the DP to the dorsal hoof wall. Methods: Ex vivo and in vivo experiments. Methods: A T-shaped LCP was applied to one limb per pair in six pairs of cadaver forelimbs subjected to a combination of thermally induced lamellar failure and vertical load to simulate severe acute laminitis. Standard radiographic measurements were used to compare DP displacement. The LCP was then applied to one forefoot in 12 ...
Valpotić I, Kastelan M, Rudolf M, Gerencer M, Jukić B, Basić I.The percentage of T and B lymphocytes in the peripheral blood of horses chronically infected with equine infectious anaemia (EIA) virus was determined and the results were compared with the percentage of these cells in healthy uninfected horses. Cells with membrane receptors for sheep erythrocytes (T and active T lymphocytes) were determined by E and A rosette techniques, while cells with receptors for the C3b component of complement and those with receptors for mouse erythrocytes (B lymphocytes), were determined by the EAC rosette method. The percentage of Fe positive cells was assayed by the...
Colborn DR, Thompson DL, Rahmanian MS, Roth TL.Ten lighthorse stallions were used to determine 1) whether prolactin (PRL) and cortisol responses previously observed after acute exercise in summer would occur in winter when PRL secretion is normally low, 2) whether subsequent treatment with a dopamine receptor antagonist, sulpiride, for 14 d would increase PRL secretion and response to thyrotropin-releasing hormone (TRH) and exercise, and 3) whether secretion of LH, FSH, and cortisol would be affected by sulpiride treatment. On January 11, blood samples were drawn from all stallions before and after a 5-min period of strenuous running. On J...
Zachar EK, Burgess HJ, Wobeser BK.Fine-needle aspiration (FNA) is commonly used to diagnose skin disease in companion animals, but its use in horses appears to be infrequent. Equine veterinarians in western Canada were surveyed to determine their opinions about FNA and 15 years of diagnostic submissions were used to compare the perceived to actual value of FNA in the diagnosis of skin disease in horses. Practitioners viewed FNA as quick, easy, economical, and minimally invasive. However, most veterinarians rarely chose to use FNA due to a perception that sample quality and diagnostic yield were poor and there was a narrow rang...
Allen WE, Clarke AR.Plasma concentrations of sodium benzylpenicillin following intrauterine infusion were increased by reducing the volume of solution and expelling air from the vagina after infusion. Instillation of 10 per cent Lugol's iodine solution into the uterus before penicillin infusion further increased the absorption rate, although peak plasma levels of penicillin were less than half those which resulted from intramuscular injection of the same dose.
White NA, Moore JN, Douglas M.This paper describes the histological and scanning electron microscopical examinations of the right colic artery of eight ponies. Lesions all had large thrombi surrounding a larva or larvae, with arterial wall thickening. Endothelial shape change, degeneration and loss were present. Fibrin-platelet red blood cell aggregates were present on endothelial surfaces as well as on the surface of thrombi. Damage to the intima appeared to produce the conditions for progressive thrombus formation.
Barr AR, Sridhar B, Denny HR.Five horses with long incomplete longitudinal fractures of the third metacarpal bone and three horses with similar fractures of the third metatarsal bone were examined. In three of the metacarpal fractures a long incomplete fissure extended proximomedially, in association with the more common lateral condylar fracture of the third metacarpal bone, and in the other two cases the fracture originated from the medial aspect of the distal articular surface. In the three horses with fractures of the third metatarsal bone the fractures had a consistent spiral configuration.
Capik I, Ledecky V, Mihály M.Abnormalities of dental development such as hypoplasia of cementum, oligodontia, polydontia, enamel hypoplasia, brachygnathia, and prognathia are quite common in the horse. Abnormalities of eruption are less common and often associated with trauma. This case report describes the diagnosis and therapy for pre-eruption displacement of the maxillary left third and fourth premolar teeth resulting from previous facial trauma in a 1.5-year-old filly.
de Oliveira AC, Rosenbruch M, Schulz LC.The morphology of asteroid bodies in equine arteries is demonstrated by light microscopy as well as by scanning and transmission electron microscopy combined with chemical analysis. Asteroid bodies first occur in horses at four weeks of age in all investigated tissues except the esophagus and always are located in the subendothelial space. The number, shape, ultrastructure and chemical composition of asteroid bodies differ markedly--depending on the age of the horse. Asteroid bodies are round and smooth in foals, but are shaped irregularly and have several projections and marked stratified cal...
Courtot D, Roux L, Mouthon G, Jeanin E.Doping with tranquilizers has appeared recently in horse-back riding sports. In this paper we study the effects of acepromazine, one of the main tranquilizers used, on various physiological and biochemical aspects of muscular activity (cardiac and respiratory rhythms, seric rates of glucose, urea, protein, creatine phosphokinase, glutamate oxalacetate transaminase, alkaline phosphatase). A low dose (0.02 mg/kg) of acepromazine is injected; the evolution of the variables is studied before and after a standardized effort. After the effort and during recuperation, acepromazine administration caus...
Pongratz MC, Junge HK, Riond B, Schwarzwald CC.To assess the accuracy and reliability of a point-of-care (POC) triglyceride analyzer and to establish reference intervals for blood ([TRIG]POC/WB ) and plasma triglyceride concentrations ([TRIG]POC/PL ) in horses, ponies, and donkeys. Methods: Prospective study. Methods: University teaching hospital. Methods: 120 adult healthy equids (78 horses and ponies, 42 donkeys) and 79 equids suffering from hypertriglyceridemia (73 horses and ponies, 6 donkeys). Methods: None. Results: [TRIG]POC/WB and [TRIG]POC/PL were measured using a POC analyzer and plasma triglyceride concentrations were measured u...
Vagnoni KE, Ginther OJ, Lunn DP.Chorionic girdle cells are a highly invasive subpopulation of trophoblastic cells of the horse conceptus that adhere to the uterine epithelium and begin to invade the endometrium on Days 34-36 (Day 0 = day of ovulation). Just prior to and during invasion (Days 32-36), chorionic girdle cells express high levels of major histocompatibility complex (MHC) I, but expression of this antigen decreases by Days 40-45 and is lost by Day 55. The mechanisms involved in the control of chorionic girdle cell invasion and altered MHCI expression over time are not known. The objective of this study, therefore,...
