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.
Thompson NE, Bergdoll MS, Pattee PA.The factor in normal sera primarily responsible for the enhancement of transfection (and transformation) of Staphylococcus aureus was identified as fibronectin. Serum samples which were depleted of fibronectin by affinity chromatography showed a marked decrease in enhancing activity. Fibronectin isolated from sera of several animal species demonstrated enhancing activity.
Trenfield K, Spradbrow PB, Vanselow B.DNA was extracted from 14 equine sarcoids, electrophoresed and hybridised with a radioactively labelled probe of bovine papillomavirus type I (BPV 1) DNA under conditions of low stringency. Twelve sarcoids contained sequences of DNA that hybridised with the probe and that comigrated with BPV 2 DNA. The viral DNAs in four of these sarcoids differed from BPV 1 and BPV 2 DNA on restriction endonuclease analysis. One of four cell lines derived from sarcoids also contained BPV 1 related DNA. The results confirm the frequent presence in equine sarcoids of unintegrated papillomaviral DNA and suggest ...
Trim CM, Colbern GT, Martin CL.Intraocular pressure was measured with a MacKay-Marg tonometer in eight horses following auriculopalpebral nerve block and topical application of lignocaine. Measurements were recorded before and after xylazine, 1.1 mg/kg intravenously, every two minutes for 16 minutes after administration of ketamine, 2.2 mg/kg intravenously, and after recovery from anaesthesia. Before xylazine, intraocular pressure was 17.1 +/- 3.9 and 18.4 +/- 2.2 mm Hg in the left and right eyes, respectively. Intraocular pressure tended to decrease after administration of xylazine and ketamine, with a significant decrease...
Pipers FS, Reef V, Wilson J.Ventricular septal defects in a foal, a 2-year-old filly, and 2 calves were demonstrated with M-mode and two-dimensional real-time echocardiography. The studies were performed with the animals unsedated, either standing or in lateral recumbency. Cardiac windows were located between the 4th and 7th intercostal spaces, approximately at the level of the olecranon. In each case, the septal defect was visualized high in the membranous portion of the interventricular septum. Defects were visualized by use of sector scanning or linear-array ultrasonic equipment, with transducer frequencies of 2.25 to...
Watney GC, Watkins SB, Hall LW.The pressure flow characteristics of a demand valve which has been suggested to be suitable for use in anaesthetised horses were determined at a range of flow rates commonly encountered in equine anaesthesia. The resistance of the valve was found to be very much greater than the resistance of normal large animal anaesthetic apparatus or the equine lower respiratory tract. The effects of the valve on pulmonary ventilation were investigated in seven anaesthetised, intubated horses. Respiratory rate and dynamic compliance were unaffected by connection of the valve but mean tidal and minute volume...
Halliwell RE, Hines MT.A radioimmunoassay was developed for detection of immunoglobulin in the aqueous of normal horses and horses with intraocular diseases. Levels of albumin were detected by radial immunodiffusion. Results of assays on samples from normal eyes from which aqueous was obtained by paracentesis under anesthesia were 32.10 +/- 21.50 microgram/ml for IgG, 0.05 +/- 0.01 microgram/ml for IgM, 0.04 +/- 0.02 microgram/ml for IgA and 34.0 +/- 38.0 microgram/ml for albumin. Results in 138 normal eyes sampled post mortem were 41.56 +/- 38.65 microgram/ml for IgG, 0.18 +/- 0.43 microgram/ml for IgM, 0.46 +/- 1....
Cremers HJ.The feet of horses, sheep, and goats of different breeds and from many different localities were examined for Chorioptes bovis. In horses, mites were mainly found in the Belgian and Frisian breeds (40% and 62% infected, respectively). In sheep and goats, respectively 63% and 86% were infected. In horses as well as in sheep and goats, mange-lesions were rarely seen. A number of sheep and goats were examined for mites and lesions quantitatively. In sheep all mites were restricted to the region close to the accessory digits and the claws. In goats the average number of mites was higher than in sh...
Liu IK, Pascoe DR, Chang LW, Zee YC.Serum antibody concentrations against influenza A-equi-1 virus and A-equi-2 virus were measured in a group of 18 foals from birth to 4 months of age. More than 50% of the foals were seronegative to A-equi-1 virus infection by 4 weeks of age, with titers of less than or equal to 1:16. For A-equi-2 virus, more than 50% of the foals were seronegative by 2 weeks of age, with titers of less than or equal to 1:8. Passively derived antibodies against influenza A-equi-1 virus and A-equi-2 virus in foals obtained from recently vaccinated mares and from mares not vaccinated within 6 months before foalin...
Tablin F, Weiss L.The equine bone marrow responds to blood loss by increased erythropoiesis, only releasing reticulocytes into the peripheral circulation in severe chronic anemia. We have used morphometric analysis based on electron microscopy of the equine marrow to examine the maturation and release of reticulocytes. Developing red cells in the bone marrows of normal and chronically anemic horses were divided into four stages: early, intermediate, late-stage erythroblasts, and reticulocytes. Morphometric analysis of each stage included volume density of mitochondria per micron3 of cytoplasm, surface area of t...
Muir WW, Robertson JT.The visceral analgesic, cardiorespiratory, and behavioral effects induced by xylazine, butorphanol, meperidine, and pentazocine were determined in 9 adult horses with colic. Colic was produced by inflating a balloon in the horses' cecum. Heart rate, respiratory rate, mean arterial blood pressure, and cardiac output increased after cecal balloon inflation. Xylazine and butorphanol decreased the hemodynamic response to cecal balloon inflation. Meperidine and pentazocine had minimal effects on the cardiorespiratory changes induced by cecal balloon inflation. Xylazine produced the most pronounced ...
McCraw BM, Slocombe JO.The development and pathological effects of Strongylus equinus were studied in 17 pony foals and one horse foal raised in isolation and examined at necropsy from seven days to 40 wk postinfection (PI). Following inoculation of 15000 +/- 6% or 16000 +/- 6% infective larvae by stomach tube foals were monitored for clinical signs and selected blood changes. Larvae penetrated the wall of the ileum, cecum and colon. The molt to the fourth stage occurred mostly in the wall of the ventral colon before 2 wk PI and larvae attained the liver mainly via the peritoneal cavity as early as eight days PI and...
Dean PW, Robertson JT, Jacobs RM.In 7 horses, 4 anastomoses were done in the small intestine in each, using the combinations of synthetic absorbable monofilament and multifilament suture materials with continuous- and interrupted-suture patterns in the serosubmucosal layer of a 2-layer inverting-suture technique. Horses were evaluated 30 days after the operation for adhesion formation, lumen diameter, evidence of chronic obstruction, and suture tract inflammation at the anastomosis. Postoperative obstruction occurred in 5 of the 7 horses, and 6 horses survived. One horse was euthanatized on postoperative day 6 after 48 hours ...
Tithof PK, Rebhun WC, Dietze AE.A linear array 5 mHz ultrasonic scanner was used to diagnose aorto-iliac thrombosis in a 3 year old Standardbred gelding. There are no reports in the literature of utilization of ultrasonography for visualization of an aortic thrombus. The technique is fairly non-invasive, requiring only a rectal examination with a linear array probe. Arteriography is the only other method described for actual visualization of a thrombus. This procedure is technically difficult and highly invasive.
Rebhun WC, Shin SJ, King JM, Baum KH, Patten V.Malignant edema (clostridial myositis) was diagnosed in 9 horses with signs of illness that included fever, depression, painful muscular swellings, and toxemia. The infection followed intramuscular injections in 8 horses and developed in a puncture wound in 1 horse. Treatment consisted of surgical fenestration of the involved muscle, high doses of penicillin, nonsteroidal anti-inflammatory agents and analgesics, and supportive fluid therapy. Five horses recovered and 4 died. Those that died had advanced signs of the disease at admission.
Vernon SD, Webb PA.We developed an enzyme-linked immunosorbent assay (ELISA) that was capable of detecting immunoglobulin M (IgM) antibody to vesicular stomatitis virus (VSV) in the sera of experimentally and naturally infected cattle and horses. The detection of IgM in the sera of these animals permitted an estimate of the recency of infection by VSV serotype New Jersey. A VSV serotype New Jersey epizootic strain isolated from a horse and passed once in an Aedes albopictus cell line was used to infect a horse and a calf. Sera from these animals were used to standardize the ELISA. This assay was used to test ser...
McKibbin LS, Paraschak DM.Bone spavin, splint, and fractured splint bone injuries have been treated with varying methodologies at Wheatley Hall Farm Equine Clinic. Cryosurgery is the most successful. With cryosurgery the small, pain-producing afferent C fibers are destroyed, and painful neuromas do not return. Injured sites were cryosurgically treated with liquid nitrogen for a double freeze-thaw period of 45 sec. 5 sec, 45 sec. Before and after treatment comparisons were conducted on study standardbreds. In all three injury groups, results showed that the standardbreds tended to race as well or with improved times and...
Kaneps AJ, Shires GM, Watrous BJ.The use of real-time ultrasound for examination of the bladder was a useful diagnostic aid in 2 cases of cystic calculi. The ultrasound procedure revealed that a firm mass palpated per rectum in the bladder of one horse was a calculus. In the other horse, ultrasound revealed additional small uroliths. To remove the uroliths in both horses, laparocystidotomy via a ventral paramedian approach was chosen because it provided the best access to the bladder lumen. The calculi were analyzed by qualitative chemical analysis and quantitative crystallography. Results differed between analysis methods. C...
Hayes KE, Pierson RA, Scraba ST, Ginther OJ.The morphological changes in ultrasound images of the uterus at various times of the year were characterized in nonbred mares, using a linear-array scanner. The uterus was recorded as having an ultrasonic morphology characteristic of diestrus (uterine score 1, endometrial folds not visible), estrus (score 3, distinct endometrial folds), or an intermediate stage (score 2). In Experiment I, uterine scores for the first ovulatory period of the year were compared to scores for the second period in 23 pony mares. More mares (P<0.05) showed endometrial folding prior to the second ovulation of the...
Halliwell RE, Brim TA, Hines MT, Wolf D, White FH.An enzyme linked immunosorbent assay was developed for the detection of immunoglobulin class specific antibodies to Leptospira interrogans serovar pomona in the serum and aqueous humor of horses. Serum antibody was also assayed by microscopic agglutination tests. Although higher levels of antibody were found in sera from horses with signs of uveitis, the association was not statistically significant. Antibodies to pomona were detected in the aqueous of 12 eyes from the 101 horses sampled at a slaughterhouse, and in most instances, a comparison of the aqueous/serum antibody level with that of t...
Gerken DF, Sams RA.The effects of i.v. chloramphenicol sodium succinate on the pharmacokinetics of i.v. phenylbutazone in six healthy adult horses were investigated. Administration of chloramphenicol sodium succinate to mares reduced mean (+/- SD) phenylbutazone clearance from 0.600 +/- 0.222 to 0.339 +/- 0.123 ml/min per kg and increased mean (+/- SD) half life from 244 +/- 59.8 to 371 +/- 80.8 min and mean residence time from 333 +/- 86.2 to 533 +/- 124 min. The mean steady-state volume of distribution of phenylbutazone was unchanged, with mean (+/- SD) values of 187 +/- 28.9 ml/kg in control animals and 170 +...
Seal US, Siniff DB, Tester JR, Williams TD.Combinations of etorphine hydrochloride and xylazine hydrochloride in different dosages were tested for their efficacy as immobilizing agents on 16 recently captured feral mares in corrals. The results of these trials led to the utilization of a standard combination of 5.5 mg of etorphine hydrochloride, 150 mg of xylazine hydrochloride, and 3 mg of atropine sulfate in a 7-ml dart syringe for field capture. This combination was used, administered by dart gun from helicopters, to capture 87 free-ranging feral horses from about 80 bands. Five mares died at the time of capture and the remains of t...
Juzwiak JS, Milton JL.A 4-day-old foal underwent repair of a proximal metaphyseal fracture of the tibia. After closed reduction, fixation was achieved by use of blind cross-pinning. Thirty-five days after surgery, radiography demonstrated complete healing. The foal was mildly lame 4 months after repair of the fracture. Blind cross-pinning may be considered as a method of repair for certain long bone fractures in small foals.
Schumacher J, Bratton GR, Williams JW.The pudendal and caudal rectal nerves in four male and five female adult crossbred horses were anesthetized with a local solution. The injection site was located at the foramen for the caudal gluteal artery and vein in the sacrosciatic ligament. Twenty milliliters of local anesthetic solution were injected via a 15-cm, 18-gauge needle. Quantitative data on anesthesia were determined from these injections. Dye was injected with the anesthetic in four additional horses so that accurate placement of the solution could be determined at postmortem examination. Satisfactory anesthesia of the anus, p...
Engelking LR, Mariner JC.The effect of large-dose heparin therapy on erythrocyte mass depletion in ponies was investigated to determine whether stimulation of reticuloendothelial cell activity and catabolic function would be evidenced by enhanced catabolism of heme to bilirubin. Ponies with chronic external biliary fistula were used to examine biliary excretion of bilirubin both before and after heparin loading (107 U/kg, IV, plus 320 U/kg, subcutaneously) and at maintenance dosages of 320 U/kg given (subcutaneously) at 12 and 24 hours after initial loading with heparin. Results indicated that by 48 hours after ponies...
Watkins JP, Auer JA, Morgan SJ, Gay S.The effect of pulsing electromagnetic field (PEMF) therapy on the healing of surgically created defects in equine superficial digital flexor tendons was evaluated. Defects were created in both front superficial digital flexor tendons of 20 horses. The defect in 1 limb was exposed to a PEMF for 2 hours daily. The other limb served as a control. Histologic and immunofluorescent evaluations were done in horse killed at postsurgical weeks 2, 4, 8, 12, and 24. Therapy with the PEMF significantly (P less than 0.05) delayed the maturation of the tissue formed within the defect at postsurgical weeks 8...
Martens RJ, Malone PS, Brust DM.Oral lactose tolerance tests were evaluated in 25 healthy foals (principals) assigned to 4 groups of approximately 1 week, 4 weeks, 8 weeks, and 12 weeks of age. Lactose monohydrate (1 g/kg of body weight [in a 20% water solution]) was administered via nasogastric tube after a 4-hour fast. Plasma glucose concentrations were monitored before dosing (0 minutes) and sequentially for 300 minutes. Six control foals were given a volume of water equivalent to the volume of lactose monohydrate administered to principal foals. After oral lactose loading, mean plasma glucose concentrations of all princi...
Watkins JP, Auer JA, Gay S, Morgan SJ.Full-thickness defects were surgically created in the superficial digital flexor tendons of the front limbs of 20 horses. Tissues formed within the defect were evaluated histologically, and the collagen composition of the tissue was determined by immunofluorescence. Transformation occurred from loose fibrillar areas of types I and III collagen and pericellular types IV and V collagen to dense bundles of type I collagen fibers. Loose fibrillar areas of types I and III collagen were present after 24 weeks. Histologically, in horses killed after 2 weeks, the tissue within the defect was a randoml...
Douglas RH, Ginther OJ.Nine groups of pony mares (3/group) were used in a 3 times 3 factorial experiment. The factors were dose of PGF-2 alpha (0, 0.25 of 1.25 mg and route of administration (im, iu or il). Mares were laparotomized and treated on day 7 postovulation. Jugular blood was collected for progesterone RIA at 0 (pretreatment) and 1,6,12,24,48, and 72 hr posttreatment. In mares given either 0.25 mg or 1.25 mg PGF-2alpha, progesterone concentrations were not significantly different among the three routes at any of the posttreatment times studied except at 6 hr posttreatment. In mares given 0.25 mg, progestero...
Odenkirchen S, Huskamp B.Casuistics of 200 patients with acute diarrhea (72 horses with salmonellosis, 55 horses with typhlocolitis, 73 horses with unspecific diarrhea) have been analyzed. It was shown, that horses with salmonellosis have been fallen ill with a primary disease for a longer period of time before the beginning of diarrhea than those with typhlocolitis and that in cases of salmonellosis antibiotics very often were used during the preliminary treatment. Frequently a primary illness of the colon was seen with typhlocolitis. Besides the frequent use of butylscopolamin during the pretreatment was noticed. Th...
Kofler J, Kübber-Heiss A, Schilcher F.Clinical, ultrasonographic and pathological findings of a cutaneous, multilocular T-cell lymphosarcoma (malignant lymphoma) in a 13-year-old, brown Austrian warmblood mare are reported. The horse was under clinical observation, and the tumours were sonographically monitored over an 8 month period, revealing worsening of body condition, weight loss, lameness of the left hindlimb and a slight increase in the tumours size. Most of the tumours were covered by normal skin, one showed ulceration. Ultrasonography of the tumours allowed accurate anatomical localization in relation to the adjoining tis...
May-Davis S, Vermeulen Z, Hunter R, Brown W.For over 200 years, equine anatomic literature has chiefly portrayed the attachment points of the nuchal ligament lamellae (NLL) from the second to the seventh cervical vertebrae (C2-C7). However, recent studies have shown that the modern domestic horse, Equus caballus, primarily exhibits the attachments points from C2-C5. Here we present the rare finding of a complete NLL attached from C2-C7 in one Australian Stock Horse (ASH) and discuss the potential implications of these findings. Previously, this trait has only been confirmed among close descendants of Equus ferus ferus; namely the primi...
Gehlen H, Bubeck K, Rohn K, Stadler P.The aim of this study was to investigate the potential haemodynamic effects of valvular insufficiency and recurrent airway obstruction (RAO) in horses with atrial fibrillation (AF). Therefore in ten healthy horses (group 1) and 40 horses with AF a clinical examination, a lung examination, echocardiography and right heart catheterization for measurement of intracardic and pulmonary pressures were performed. According to the clinical findings the horses with AF were subdivided into 4 groups (group 2: AF; group 3: AF/valvular insufficiency; group 4: AF/RAO; group 5: AF/valvular insufficiency/RAO)...
Rinnovati R, Xenos S, Beltrame A, Marigo A, Forni G, Morini M.A neurofibroma was excised from the subcutis on the medial side of the left thigh of a 15-year-old Warmblood gelding, which had shown lameness of the left hind limb. No other source of lameness was found. Two weeks after surgery, the horse was sound at a lameness examination.
Lloyd KC, Wheat JD, Ryan AM, Matthews M.Sudden onset of hematuria was associated with mucosal ulceration of the proximal portion of the urethra in 1 stallion and 3 geldings. Hematuria was observed characteristically and consistently at the end of urination. Mucosal ulceration was identified endoscopically in the proximal portion of the urethra at the level of the ischial arch. Biopsy of an ulcerated area of the proximal urethra in one gelding revealed transitional cell carcinoma. Treatment regimens varied from systemic antimicrobial and/or vasoactive therapy to diversion of urinary flow via a temporary perineal urethrostomy. Hematur...
Ebrahimi M, Hamidinejat H, Tanabandeh MR, Razi Jalali MH, Rasouli A.Diversity among the pathogenic strains of Theileria equi (T. equi), a major agent of equine piroplasmosis, can affect the appropriate detection of parasite and host immunization. Production of recombinant surface proteins from an infected horse in natural endemic area provides a reliable tool for immunodiagnosis of parasite. Regarding this, the present study was targeted toward the cloning, expression, and purification of the immunogenic regions of equine merozoite antigen 1 (EMA-1 gene), as one of the most important immunodominant surface proteins in T. equi, from naturally infected horses in...
López ML, Fuentes P, Retamal C, De Souza W.The occurrence, localization and ultrastructural characteristics of a blood-tissue barrier throughout the stallion proximal seminal excurrent duct system were studied by the exclusion of electron-dense tracers and freeze-fracture techniques. Striking differences were observed in the distribution of lanthanum tracer and in the geometrical organization of the zonulae occludentes along the ductus efferentes, epididymides and vas deferens. The zonulae occludentes domain, the principal structural component of the blood-epididymis barrier, differed in permeability, width and strand numbers along the...
Maney JK, Dzikiti BT, Escobar A, Knych HK, Bennett RC.Morphine is the prototypical μ-opioid receptor agonist used to provide analgesia in veterinary species. Its effects are well-described in horses but not donkeys. Objective: To determine the antinociceptive effects of two doses of morphine in donkeys. To describe preliminary pharmacokinetic parameters of morphine in donkeys. Methods: In vivo experiment. Methods: Eight adult castrated male donkeys were given intravenous (IV) 0.9% saline, morphine 0.1 mg/kg bwt (LDM), or morphine 0.5 mg/kg bwt (HDM) in a randomised order with a minimum 1-week washout period. Mechanical nociceptive thresholds (...
Spier SJ, Meagher DM.Rational perioperative management improves the success rate of abdominal surgery. Important aspects of management are discussed, including principles of fluid therapy, nutrition, intravenous catheterization, antimicrobial prophylaxis, and the use of nonsteroidal anti-inflammatory medication. Current advances in the area of immunotherapy are mentioned.
Wintzer HJ.A long-term treatment with biotin (vitamin H) in 5 warm-blooded horses and 10 trotter horses is reported. The dose of 0.031-0.037 mg/kg body weight was well tolerated, and with a therapy period up to 10 months an improvement of the horn quality of the growing hoof could be attained as it had not been possible before with other measures. Biotin (Gabiotan) is recommendable as a therapeutic in all cases of hoof problems which are based on disturbed horn elasticity.
Vallance SA, Lumsden JM, Begg AP, O'Sullivan CB.To review eight horses diagnosed with idiopathic haemarthrosis and to describe the intra-articular use of yttrium-90 ((90) Y) and methylprednisolone acetate (MPA) in recurrent haemarthrosis cases. Methods: Retrospective case series. Methods: The medical records, diagnostic images, histopathology and outcome of all horses diagnosed with idiopathic haemarthrosis between 1998 and 2010 were reviewed. Results: Four Thoroughbred racehorses with haemarthrosis of the antebrachiocarpal joint had severe acute lameness (median, grade 4) and marked joint effusion after high-speed exercise. Another four ho...
Acutt EV, Zhou T, Mama K, Nelson BB, Selberg KT, Barrett MF.Delivery of mesenchymal stem cells (MSC) via intravascular techniques to treat diffuse and/or inaccessible soft tissue injuries has grown in popularity. The purpose of the current prospective, analytical pilot study was to utilize CT to validate this novel technique and provide additional evidence to support its use for injectate delivery to specific soft tissue structures. Of particular interest was the proximal suspensory ligament, which presents a challenging injection target. Six adult horses without lameness underwent CT of the distal hindlimbs. Scans were obtained prior to ultrasound-gui...
Allen WE.The ovaries of twenty pregnant mares were examined daily, per rectum, for the first 4 months of gestation and note was made of their estimated size and follicular content. Serial blood samples from sixteen of the mares were assayed for PMSG. A marked seasonal effect was noted on ovarian size, follicular content and ovulation rate during pregnancy but there was no such effect on PMSG production. It is concluded that PMSG is synergistic with gonadotrophins of pituitary origin and that the latter hormone are the primary stimulus on the ovary of the pregnant horse.