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.
Reef VB.A 10-year-old Quarter Horse mare was referred for evaluation and treatment of a large pectoral skin slough and hemoglobinuria. The skin slough was secondary to Clostridium perfringens cellulitis and associated gas gangrene. Cold hemagglutinin disease was diagnosed and was suspected to be secondary to C perfringens septicemia. The autoimmune hemolytic anemia, severe intravascular hemolysis, and hemoglobinuria were treated with dexamethasone and hydrocortisone. The infection was treated with 20 X 10(6) units of sodium penicillin, IV, 4 times daily, and the wound was debrided. When the mare relap...
Slone DE, Purohit RC, Ganjam VK, Lowe JL.Three ponies and 1 horse were bilaterally adrenalectomized (BADX). The initial hypoadrenal episode after BADX was reversed with 20 mg of dexamethasone (DXM) IM (n = 2) or 20 mg of triamcinolone (TMC) IM (n = 2). Nine hypoadrenal crises were reversed with 20 mg of DXM given IM (n = 4) or 20 mg of TMC given IM (n = 5). Sodium and chloride retention and potassium excretion were documented based on changes in serum electrolytes and urinary excretion. Eight intact adult horses were randomly assigned to 2 groups to study the effects of a single IM injection of DXM (0.044 mg/kg of body weight) or TMC...
Guerrero J, Michael BF, Rohovsky MW, Campbell BP.Eighteen pony foals were experimentally infected with 500 third stage larvae of Strongylus vulgaris at 2 weeks, and at 2, 4, 6 and 8 months after birth. For the duration of the study, all foals were kept in the same pasture with their mothers to allow natural infection with other parasites by exposure to a contaminated environment. Twelve of the foals were utilized in groups of 3 and treated orally five times at two month intervals starting at one month of age with closantel at doses of 5, 10, 20 or 40 mg kg-1. Ten months after birth the foals were necropsied to determine the parasitic burdens...
Turk MA, Breeze RG, Gallina AM.The pathologic features of bronchiolitis were studied in horses and ponies from 30 minutes to 27 days after an oral dose of 3-methylindole (3MI). From 30 minutes to 3 hours, lesions were limited to nonciliated bronchiolar epithelial (Clara) cells, which lost apical caps and cytoplasmic granules and had dilated smooth endoplasmic reticulum (SER). At 12 hours, necrotic Clara cells were exfoliated; degeneration and necrosis were evident, in bronchiolar ciliated cells. Rare epithelial cells with hyperplastic SER appeared on the denuded basal lamina at 24 hours. Inflammatory cells, epithelia, fibro...
Nilsson O, Klingborn B.The effect of oxfendazole (Synanthic vet. Syntex) on the strongyle egg output of naturally infected horses was evaluated. It was demonstrated that the compound, administered orally as an 18,5% paste or as 6,48% pellets mixed in feed (46.3 grams per 300 kg bodyweight) at a dose-rate of 10 mg per kg bodyweight, markedly reduced the strongyle egg output over a 10 week period. As this period to egg reappearance is considerably longer than for most other anthelmintics at recommended dose levels, oxfendazole may be considered a valuable compound for the control of strongylosis in horses.
Camp CJ, Leid HW.Extracts of Onchocerca cervicalis, an equine parasite, were incubated with radiolabeled equine neutrophils and neutrophil migration was assessed for factors derived from the parasite itself or for host-derived factors after incubation of these same parasite extracts with equine serum. No stimulus for cell migration was observed in saline extracts of adult worms, uterine microfilariae, or skin microfilariae at any dosage tested. However, after incubation of saline extracts with fresh normal equine sera a marked stimulus for neutrophil migration was observed. Ablation of this biologic activity w...
McLaughlin SA, Brightman AH, Helper LC, Manning JP, Tomes JE.In 123 cases of external ocular disease in the horse, pathogenic microorganisms isolated with greatest frequency were Streptococcus sp (43.9%), Staphylococcus sp (24.2%), and Pseudomonas sp (13.8%). Fungi were isolated in 4.8% of the cases. In vitro testing showed that most of the Streptococcus sp isolants were sensitive to ampicillin, cephalothin, and carbenicillin. Most of the Staphylococcus sp isolants were sensitive to gentamicin, cephalothin, and bacitracin. Most of the Pseudomonas sp isolants were sensitive to polymyxin B and gentamicin.
Wiebe ME, Scherer WF, Peick WJ.Ninety-four strains of Venezuelan encephalitis (VE) virus isolated from sentinel hamsters exposed in the Middle American countries of Mexico, Guatemala, Belize, and Honduras were examined for the presence of virions with marker characteristics of strains that cause large epidemics and equine epizootics. Thirty-four strains came from before and 60 strains came from after the Middle American epidemics and equine epizootics of 1966 and 1969-1972. Twenty-three virion clones that resembled epizootic strains by hydroxylapatite chromatography and Vero monkey kidney cell plaque size determinations wer...
Miller RI.Although 'phycomycosis' is a common disease of horses in northern Australia little is known about the causative fungi. In this paper the laboratory methods for diagnosis are described. These revealed 38 cases caused by Pythium sp. (Hyphomyces destruens), 6 cases caused by Basidiobolus haptosporus and 2 caused by Conidiobolus coronatus. Laboratory studies on the chemotatic behaviour of zoospores of Pythium sp. showed that they were strongly attracted to both animal hairs and plant tissue. Because of this behaviour a simple baiting method using human hair was used to trap the fungus from water s...
van Wuijckhuise-Sjouke LA.Report on the case of a pony with colic submitted a to the department of internal medicine. However, the animal was found to be affected with dilatation of the oesophagus which had given rise to acute pleurisy resulting from rupture of the wall of the oesophagus. The diagnosis was established after death.
Montelaro RC, West M, Ivey M.Representative glycoproteins including fetuin, protein A, ovalbumin, alpha 1 acid glycoprotein, and the major glycoprotein of equine infectious anemia virus were labelled with 125I by the chloramine-T or Bolton-Hunter procedure and their binding to immobilized Con A or lentil lectin compared to untreated samples of each glycoprotein. Glycoprotein modification was no greater than one substituted residue per protein molecule. Yet the radioiodinated glycoproteins typically displayed only 0-50% of the lectin binding observed with untreated samples. These results indicate that lectin glycoprotein b...
van den Hoven R, Franken P.This paper describes the clinical and laboratory findings in 16 horses suffering from lymphosarcoma and the autopsy results in 13 of these cases which were examined at the Large Animal Medicine Clinic, State University of Utrecht, from 1969 to 1981. The cases were classified into four groups, designated multicentric, alimentary, thymic and cutaneous forms, according to the situation of the tumours.
Mishra PC, Leach DH.The venous organisation of the dermal lamellae of the equine hoof wall of 18 pairs of forelimb hooves from clinically healthy horses was studied using plastic vascular corrosion casts, and scanning electron microscopic and histological techniques. A consistent pattern of venous organisation was observed in the dermal lamella of the toe, quarter and heel regions. The lamellar corium had an extensive interconnecting capillary network which drained into axially located veins of the primary dermal lamella. Many of the capillaries had a proximodistal orientation and most of those located at the int...
Li CH, Chung D.Isolation of prolactin from equine pituitary glands has been described. It has a potency of 42 IU/mg in the pigeon crop-sac test and consists of 199 amino acids. The hormone has only four half-cystine residues in contrast to other mammalian prolactins which have six residues. From NH2-terminal sequence analysis and amino acid composition of cyanogen bromide fragments, the NH2-terminal disulfide loop is missing in the equine prolactin molecule. Circular dichroism spectra indicate that the alpha-helical content of equine prolactin appears to be lower (50%) than that found in the ovine hormone (6...
Heyneman RA.The subcellular distribution of the superoxide-forming enzyme in horse polymorphonuclear leukocytes was investigated. After activation of the cells with sodium oleate, a relatively stable and NAD(P)H-dependent oxygen consumption and superoxide production was found in association with the plasma membranes. The pH dependence displayed an optimum near neutrality. The apparent Km values were 38 x 10(-6) mol/l for NADPH and 1,560 x 10(-6) mol/l for NADH, suggesting that NADPH is the physiological donor. The rates of oxygen uptake, O2- production, and NADP consumption were consistent with the stoich...
Hinshaw VS, Naeve CW, Webster RG, Douglas A, Skehel JJ, Bryans J.Influenza outbreaks involving viruses of the H3N8 subtype (equine 2) often occur in vaccinated horses. For this reason, a series of influenza viruses of the H3N8 subtype were examined to determine if antigenic variation could be detected in isolates during the period 1963-81. Antigenic analyses with post-infection ferret sera and monoclonal antibodies showed that the haemagglutinins of recent isolates were antigenically distinguishable from the prototype A/eq/Miami/1/63 and that antigenically distinguishable groups of equine 2 viruses co-circulate in the horse population. Based on these studie...
Andersson L, Juneja RK, Sandberg K.Genetic linkage between the equine loci for phosphohexose isomerase (PHI) and serum Xk protein was demonstrated by means of segregation data from three sire families. The recombination frequency was estimated from pooled data to be 0.23 +/- 0.02; a significant heterogeneity between sires for estimates of the recombination frequency was observed. No indication of linkage was detected between Xk and 14 other blood marker loci. Linkage between the Xk locus and the locus for soluble malic enzyme (ME1) has recently been reported in horses. An equine linkage group designated LG IV comprising the thr...
Svalastoga E, Smith M.The subchondral bone pressure in the navicular bone of horses with navicular disease is compared with corresponding pressures in normal horses. An increased intraosseous pressure and a lengthened pressure drop time was demonstrated in patients with navicular disease, which indicates the existence of a venous stasis. Compared with similar investigations in humans with arthrosis it is concluded that navicular disease is a condition resembling arthrosis. The classical clinical symptoms are explained as an expression of resting pains. Treatments are suggested which theoretically can render the pat...
Raz T, Amorim MD, Stover BC, Card CE.The objective of this study was to compare the efficacy of purified equine- and porcine-FSH treatment regimes in mares in early vernal transition. Mares (n = 22) kept under ambient light were examined ultrasonographically per-rectum, starting January 30th. They were assigned to one of two treatment groups using a sequential alternating treatment design when a follicle >or= 25 mm was detected. In the eFSH group, mares were treated twice daily with equine-FSH, and in the pFSH group mares were treated twice daily with porcine-FSH; treatments were continued until follicle(s) >or= 35 mm, and 24 h l...
Caudron I, Grulke S, Farnir F, Vanschepdael P, Serteyn D.Adaptation of an in-foot shoe force sensor and the gait analysis system 'Fscan' makes it possible to monitor the distribution of the vertical forces under the equine foot in motion. The aim of this study is to investigate the effects of two different trimmings on forces under the foot during the trot. The first one increased the height of the lateral hoof wall and the second one restored the mediolateral balance of the foot. These two trimmings were examined by using a radiographical method that quantifies the interphalangeal articular asymmetries due to asymmetrical bearing. The location of t...
Hay WP, Tulleners EP, Ducharme NG.An extralaryngeal approach to partial arytenoidectomy in the horse was developed by in vitro experiments on isolated larynges and then on intact equine cadavers. The goals of the approach were to preserve the laryngeal mucosa, eliminate the need for a laryngotomy or tracheotomy, and minimize postoperative complications. The new approach was evaluated in seven horses with normal upper respiratory tracts. Left laryngeal hemiplegia was surgically created, and, after a 30-day convalescence, left partial arytenoidectomy was performed using an extralaryngeal approach. The left-to-right hemilaryngeal...
Rogers CW, Davies AS, Pfeiffer DU, Davie PS.To quantify the linear and temporal characteristics of the trot of 3-day event horses during the preliminary horse inspection of an advanced grade CCI*** 3-day event. Methods: A cross sectional study was made of the kinematics of 24 3-day-event horses during the first horse inspection at a CCI*** level S-day event. Video footage was digitised and linear and temporal measurements were made. Results: The horses trotted for an average of 10.44+/-1.55 strides. Spatial measurements were made on an average of 5.66+/-0.92 consecutive strides when the horses were within the calibration zone. The horse...
Henninger RW, Bramlage LR, Schneider RK, Gabel AA.Case records of 25 horses with transverse fractures of the proximal sesamoid bone were reviewed to evaluate the success of treatment. All fractures were repaired by use of lag screw fixation and an autogenous cancellous bone graft because the fracture fragments were considered too large for surgical removal and reconstruction of the suspensory apparatus was necessary. Radiography was performed in all cases, and the fractures were classified into 3 types: (1) proximal midbody fractures, which included all fractures in the proximal aspect of the sesamoid bone that resulted in fragments involving...
Pollock PJ, Kelly PG, Reardon RJ, Kelly GM.The objectives of this report were to describe the occurrence and features of dynamic ventrorostral displacement of the dorsal laryngeal mucosa (VRDDLM) in a group of Thoroughbred horses presented for investigation of poor performance and/or abnormal respiratory noise. Records from 600, dynamic, endoscopic examinations of the upper respiratory tract of horses were reviewed. Horses with VRDDLM were identified as those in which the dorsal laryngeal mucosa progressively obscured the interarytenoid notch and dorsoaxial portion of the corniculate processes of the arytenoid cartilages during high-sp...
Guerri G, Palozzo A, Straticò P, Varasano V, Celani G, Di Francesco P, Vignoli M, Petrizzi L.(1) Two-dimensional shear wave elastography (2D-SWE) employs an ultrasound impulse to produce transversely oriented shear waves, which travel through the surrounding tissue according to the stiffness of the tissue itself. The study aimed to assess the reliability of 2D-SWE for evaluating the elastosonographic appearance of the distal attachment of the fetlock joint capsule (DJC) in sound horses and in horses with osteoarthritis (OA) (2). According to a thorough evaluation of metacarpophalangeal joint (MCPJ), adult horses were divided in a sound Group (H) and in OA Group (P). Thereafter, a 2D-S...
Blikslager AT, Tate LP, Tudor R.To document the use and clinical outcome of transendoscopic laser techniques for treatment of rostral displacement of the palatopharyngeal arch (RDPA) in horses. Background: Rostral displacement of the palatopharyngeal arch is a rare cause of upper respiratory noise and exercise intolerance in horses, and may be associated with abnormal laryngeal anatomy. There are few reports of successful treatment of this condition, and no reports of the treatment of RDPA using laser techniques. Methods: The diagnosis of RDPA was based on the presence of palatal tissue covering the dorsal aspect of the aryt...
Francqueville M, Sabbah A.Chronic urticaria in otherwise healthy sport horses, generally has an origin in a food allergy, accompanied by a facultative latent enteritis. Etiological diagnosis may be made by skin tests that permit a following targeted avoidance.
Hondalus MK, Lofstedt J.A 16-year-old pony with signs of intermittent abdominal pain was treated with phenylbutazone in excess of the recommended dosage. Endoscopy revealed ulceration of the esophagus, stomach, and proximal portion of small intestine. The pony developed diarrhea. Salmonella typhimurium was isolated from the blood and feces. Treatment included fluids, trimethoprim-sulfadiazine, sucralfate, and ranitidine hydrochloride. The diarrhea resolved, as did the gastrointestinal ulceration. This case was unusual because septicemia with salmonellosis is an uncommon finding in adult equids. Also, complications co...
Louie EW, Streeter R, Story M, Scrivani PV, Barrett M, Mullen KR.A neonatal Dutch Warmblood colt was evaluated for inability to stand, incoordination and intention tremor. Despite partial improvement in clinical signs during the first 4 days of hospitalization, neurological deficits remained. Magnetic resonance imaging identified a unilateral infratentorial arachnoid cyst-like lesion with ipsilateral compression and displacement of the cerebellar hemisphere, absent corpus collosum, polymicrogyria, suspect leukoencephalopathy, and noncompressive occipitoatlantal malformation. Improvement in clinical signs during the first 6 months of life suggests that ho...
Berryhill EH, Knych H, Edman JM, Magdesian KG.The neurokinin-1 (NK) receptor antagonist, maropitant citrate, mitigates nausea and vomiting in dogs and cats. Nausea is poorly understood and likely under-recognized in horses. Use of NK-1 receptor antagonists in horses has not been reported. The purpose of this study was to determine the pharmacokinetic profile of maropitant in seven adult horses after single intravenous (IV; 1 mg/kg) and intragastric (IG; 2 mg/kg) doses. A randomized, crossover design was performed. Serial blood samples were collected after dosing; maropitant concentrations were measured using LC-MS/MS. Pharmacokinetic pa...
Williams GL, Amstalden M, Blodgett GP, Ward JE, Unnerstall DA, Quirk KS.Three experiments were conducted during the operational breeding season to confirm that continuous, subcutaneous infusion of low-dose GnRH would not disrupt established estrous cycles (Experiment 1), and test the hypotheses that a similar treatment would stimulate secretion of LH and induce development of ovulatory follicles in persistently anovulatory mares (Experiments 2 and 3). Treatment with GnRH (5 microg/h) increased (P<0.001) serum P4 during the luteal phase (7.7+/-0.5 versus 6.4+/-0.5 ng/mL), tended to increase serum LH (2.6+/-0.27 versus 1.9+/-0.25 ng/mL), and did not modify intero...
Smith P, Stubley D, Blackmore DJ.Methods were developed for the measurement of superoxide dismutase (SOD), diamine oxidase (DAO) and caeruloplasmin oxidase in the blood of thoroughbred horses. These enzymes were measured in 178 normal thoroughbreds stabled throughout the United Kingdom. The relationships between the activities of SOD, DAO and caeruloplasmin oxidase and the blood concentrations of their associated trace metals (copper, zinc and manganese) were studied in 52 of the thoroughbreds. Trace metals were measured by electrothermal atomic absorption spectrophotometry. No relationships were found between the activities ...
Wang Y, Zhang XY, Wei LL, Wu DL, Wang XJ, Xiang WH, Shen RX, Shao YM.To evaluate the relationship between the transcriptional level of IFN-gamma mRNA in peripheral blood mononuclear cells (PBMC) and immune protective response driven by inoculated horses with donkey leukocyte attenuated vaccine of EIAV(DLV), and to elucidate the immune mechanism of DLV. Methods: A real-time PCR method was established for quantitative detection of IFN-gamma mRNA level from horse PBMCs. Twelve horses were divided into vaccination group, healthy control group, challenging control group and EIAV natural infection group. The transcriptional level and distribution of IFN-gamma mRNA in...