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.
Baba AI, Gaboreanu M, Rotaru O, Kwieczinsky R.Malignant melanomas in 5 horses, 1 calf, 1 cow and 2 pigs were described. The disease, in white or gray horses, was tegumentally located and generalized in the organs of the abdominal cavity. Microscopically, dendritic and fusiform pigment cells and multinucleated cells were identified. In the hypophysis there microcysts and in one case a hypophyseal adenoma were encountered. Electronmicroscopically, differentiated melanophores and melanophages were also found. The mature melanosomes were intensely black and the elementary granules concentrically and lamellarly arranged. In cattle, the general...
Giles CJ.Five out of 20 horses (25 per cent) on one farm died from an acute hepatic encephalopathy typical of ragwort toxicosis. Circumstantial evidence implicated pasture rather than hay as the principal source of the toxic alkaloids. Plasma levels of gamma glutamyl transferase (GGT) were determined on three occasions in all surviving ragwort-exposed horses. Elevated GGT levels were a useful early indicator of hepatic damage although not all horses with this biochemical sign developed clinical disease.
van Leeuwen W, Noden PA, Dieleman SJ.Three experiments were conducted to test the abortifacient effects of PGF2 alpha analogues on mares during midgestation (average gestation length 141.5 days). The progesterone concentration was measured by radioimmunoassay. In experiment 1. five mares received an injection of PGF2 alpha analogue (fluprostenol: 500 micrograms intramuscularly) and a second injection either at 24, 48, of 72 h. Although the progesterone concentration decreased (P less than 0.05) an average of 44 per cent in 24 h, none of the pregnancies were terminated. In experiment 2, beginning at least 10 days after experiment ...
Parry BW, Anderson GA, Gay CC.The present retrospective study compared objectively the prognostic value of many variables routinely used in the assessment of equine colic cases. The best prognostic variables were those which assessed the integrity of cardiovascular function. Ranked in order of decreasing merit the following variables were able to discriminate between horses which lived and those which died: systolic pressure, blood lactate concentration, oral mucous membrane capillary refill time, diastolic pressure, arterial pulse amplitude, degree of mental depression, blood urea concentration, haematocrit, heart rate, h...
Weiser G, Kohn C, Vachon A.Immune-mediated hemolytic anemia was diagnosed in two horses on the basis of regenerative anemia, increased erythrocyte fragility in hypotonic saline, autoagglutination, and a positive direct antiglobulin (Coomb's) test. During steroid therapy partial resolution of the anemia was indicated by rising packed cell volume, macrocytosis, and bone marrow erythroid hyperplasia. Using erythrocyte volume distribution histograms (erythrograms), the regenerative response was characterized by analysis of macrocytic and normocytic erythrocyte subpopulations. In both horses, a gradual net increase of about ...
Conner ME, Gillespie JH, Schiff EI, Frey MS.A total of 142 equine fecal samples (93 field fecal and 49 experimental fecal specimens) were examined for rotavirus using direct electron microscopy (EM) and the Rotazyme test. Eighty-six stool specimens were diarrhea samples. The Rotazyme test sensitivity and accuracy as compared to EM was determined by the visual (color reaction) and spectrophotometric methods. The overall agreement was 94.8% and 92.3% between EM and Rotazyme visual and spectrophotometric methods, respectively when suspect reactions (1 + color reaction or net absorbance between 0.05 and 0.1) were not included. The Rotazyme ...
Johnson JA, Prescott JF, Markham RJ.Six foals were inoculated intrabronchially with a suspension of Corynebacterium equi. Six weeks before this challenge, three foals were vaccinated with a C. equi bacterin. Three foals were unvaccinated controls. All foals developed a severe bronchopneumonia in the inoculated lung, indicating that vaccination was not protective. Three foals (two vaccinated, one control) were killed eight to nine days after infection. One control died on day 9 with lesions of disseminated intravascular coagulation. The remaining two foals (one vaccinated, one control) were killed on day 17. C. equi was cultured ...
Manley SV, Kelly AB, Hodgson D.Problems encountered during halothane anesthesia in 3 horses included increasing rectal temperature, muscle rigidity or movement during anesthesia, irregular breathing patterns, and difficulty in stabilizing blood pressure. One horse had prolonged muscle fasciculations and failure to relax after administration of succinylcholine in addition to halothane. That horse developed severe, bilateral myositis of the triceps, lumbar, and gluteal muscles. Problems encountered were similar to those caused by the disease known as malignant hyperthermia.
Carson K, Wood-Gush DG.Thoroughbred foals were found to nurse in bouts of nursing activity delimited by intervals of non-nursing activity lasting 27 secs or longer. Nursing activity included nosing, sucking and interval behaviour. During the first week after birth, foals nursed, on average, seven times an hour with a mean bout duration of 147 secs but were not successful at sucking during all nursing bouts. Time spent nursing decreased as the foals grew older until before weaning, at 24 weeks of age, the foals were nursing once an hour with a mean bout duration of 74 secs. The dams hindered their foals' nursing acti...
Ottley ML, Dallemagne C, Moorhouse DE.Investigations were conducted on the taxonomy, distribution in the carcase, pathology and transmission of Onchocerca spp. in equids from Queensland and the Northern Territory. Examination of small groups of horses and ponies revealed high infection rates with O. cervicalis, while lesser numbers were infected with O. gutturosa. O. reticulata was not found. Neither of the Australian species is likely to be of economic importance to the horsemeat industry. The findings support the belief that O. cervicalis is a pre-disposing factor in the aetiology of equine nuchal disease, most commonly seen cli...
Keay G, Doxey DL.Serum albumin concentrations were measured by the immediate reacting bromocresol green (BCG) method and by agarose gel electrophoresis in healthy cattle, sheep and horses. No statistically significant differences were found between the values obtained by the two methods. The immediate reacting BCG method is quicker and cheaper when used under the conditions described.
Morris DD, Whitlock RH, Palmer JE.Fecal samples from 74 horses with diarrhea were examined microscopically for leukocytes and epithelial cells. The diarrhea was categorized as either acute (less than two weeks) or chronic, Salmonella positive or negative, and mild or severe (based on the fecal consistency). A large number of fecal leukocytes was strongly suggestive of salmonellosis; however, approximately 1/3 of the horses with Salmonella-negative diarrhea also shed fecal leukocytes. Fecal leukocytes were more common in horses with acute and/or severe diarrhea regardless of cause. Numbers of fecal colonic mucosal epithelial ce...
Asmundsson T, Gunnarsson E, Johannesson T.Blood samples were taken from 18 healthy horses (Group A), 15 horses clinically diagnosed to have "haysickness" ("farmer's lung") (Group B), 10 closely related horses (Group C) and 14 inbred horses (Group D). Precipitins in sera were measured by double gel diffusion test against Micropolyspora faeni, Thermoactinomyces vulgaris, Aspergillus fumigatus, Alternaria, Penicillium and Rhizopus species. In Group A, all the horses were precipitin negative except one with a faint reaction to Rhizopus species. In Group B all had precipitin against M faeni. One horse also had precipitins against Rhizopus ...
Makawiti DW, Allen WE, Kilpatrick MJ.A simple and rapid (less than 2 h) immunoassay method has been developed based upon a novel separation technique called LIDIA (Ligand Differentiation Immunoassay), enabling direct estimation of the concentration of oestrone sulphate in ethanolic extracts of blood plasma. An antiserum raised against oestrone-3-glucuronyl-BSA was used which showed a higher cross-reaction with the sulphate than the glucuronide metabolite. The assay had a sensitivity of 5.2 pg/tube and acceptable inter-(less than 18%) and intra-(less than 8.5%) assay precision. Analysis of samples of peripheral venous plasma obtai...
McBeath DG, Wells PW, Eyre P, Hanna CJ.This paper attempts to relate the practicalities of vaccine development to the ideals which should be aimed for in a new vaccine. The type of immune response induced is dependent upon the nature of the antigen in the vaccine and the site and timing of its presentation to the immune system. In this respect the influence of age, maternal immunity and antigenic competition are discussed. The possible side effects associated with vaccination are defined and vaccines which are currently available for horses are reviewed. These vaccines are mostly for the prevention of respiratory disease. Finally, ...
Biedrzycki AH, Grant BG, Nemke B, Morello SL, Markel MD.OBJECTIVE To evaluate the biomechanical properties of 4 methods for fusion of the centrodistal and tarsometatarsal joints in horses and compare them among each other and with control tarsi. SAMPLE 24 sets of paired tarsi without substantial signs of osteoarthritis harvested from equine cadavers. PROCEDURES Test constructs (n = 6/type) were prepared from 1 tarsus from each pair to represent surgical drilling; 2 medially to laterally placed kerf-cut cylinders (MLKCs); a single large, dorsally applied kerf-cut cylinder (DKC); and a dorsomedially applied locking compression plate (DMLCP). Construc...
Duncan JL, McBeath DG, Best JM, Preston NK.The efficacy of fenbendazole against immature stages of Trichonema spp., Strongylus vulgaris and Strongylus edentatus was evaluated. Naturally infected 6 to 12 month old ponies were given single, oral doses of 0, 15, 30 and 60 mg/kg of body weight. A dose response relationship was noted between increasing dose levels and efficiency against larval trichonemes and migrating stages of S. vulgaris and S. edentatus. Dose levels of 30 mg/kg and higher removed 93 per cent of mucosal stages of Trichonema spp., while doses of 60 mg/kg removed 83 per cent and 89 per cent of the migrating larvae of S. vu...
Ullrich E, Selbitz HJ, Schieck R, Friedrich U, Schulz J.Clinical, bacteriological and serological examinations on a 6 years old pony mare were performed. Cytological alterations in the genital tract were also recorded. A cellular reaction was seen after infection with T. equigenitalis. This reaction is an evidence for infection but it is not specific for this organism. Cytological studies should be performed on mares especially in cases of latent infections to complete bacteriological examination and to prevent false positive or negative results.
Page AE, Partridge E, Erol E, Scoggin KE, Fedorka CE, Ruby RE, Ball BA, Horohov DW, Adam E.Cases of nocardioform placentitis are characterized by focal, mucoid placentitis resulting in late-term abortion, premature birth, or small, full-term foals, occur sporadically, and are most commonly associated with Crossiella equi and Amycolatopsis spp. infection. The goal of this project was to develop an enzyme-linked immunosorbent assay (ELISA) for quantifying antibodies against Crossiella equi and Amycolatopsis spp. and utilize the ELISA to determine when exposure occurs. Serum samples collected during the 2020 foaling season from Crossiella equi (n = 8) and Amycolatopsis spp. (n = 32...
Cornelissen BP, Rijkenhuizen AB, Barneveld A.The sesamoidean nerve branches from the palmar nerve and runs towards the proximal sesamoid bone. To study the structures innervated by this nerve, a technique for blocking it was developed. The effect of this nerve block was determined in ponies with an induced lameness located in the lateral proximal sesamoid bone (5 ponies) or in the distal part of the lateral branch of the suspensory ligament (5 ponies), and in 10 horses with clinical sesamoidosis. A lameness provoked by the implantation of an expansion plug in the proximal sesamoid bone could, to a large extent, be anaesthetized by a sesa...
Gehlen H, Groner U, Rohn K, Stadler P.In 18 horses, the pulmonary artery wedge pressure and the heart rate were measured during pharmacological stress load. 12 horses were healthy (4 trained, 8 untrained) and 6 horses had a heart disease (3 trained, 3 untrained). Pharmacological stress induction was carried out with the sympathomimetic drug dobutamine at a dosage rate of 7.5 microg/kg/min over 10 minutes of infusion. At the fourth minute, the parasympatholytic drug atropine was administered (5 microg/kg bw), and the heart rate and the pulmonary artery wedge pressure were continuously measured over 26 minutes. During sole dobutamin...
Kegler K, Mundle K, Walliser U, Wohlsein P.Schwannomas arising in the parotid gland are rare in man and are not documented in domestic animals. This report describes the clinical, morphological and immunohistochemical findings of a benign schwannoma in the parotid gland of a 12-year-old warmblood gelding. A slow-growing mass was surgically excised from the parotid gland and did not recur within the following 6 months. The tumour was well circumscribed and was composed of densely packed spindle cells partly arranged in an Antoni A pattern and intermixed with hypocellular areas resembling the Antoni B pattern. Tumour cells expressed vime...
Paweska JT.Eight sexually mature horse stallions were inoculated intranasally with a South African asinine strain of EAV, a strain that was isolated from the semen of a donkey carrier. All horses developed fever, with maximum rectal temperatures of 38.9-39.9 degrees C recorded 3-6 d post challenge. Six horses showed very mild clinical signs of equine viral arteritis and two were asymptomatic. The virus was recovered from the nasopharynxes of six horses 2-7 d after inoculation, and from buffy-coat samples of all horses, 2-11 d after inoculation. Seroconversion to EAV was detected on days 8 and 10 and peak...
Tsujita H, Brennan AB, Plummer CE, Nakajima N, Hyon SH, Barrie KP, Sapp B, Jackson D, Brooks DE.Chemically defined bioadhesives (CDB) are "two-component reactive adhesives" made from antibiotic food additives. They contain no animal-derived ingredients and are characterized by a high level of self-degradability, low toxicity, and strong bonding properties. Amniotic membrane (AM) transplantation is used to repair severe ocular surface disease in humans and horses. AM requires meticulous suturing to the injured cornea. The purpose of this study is to determine whether CDB can facilitate the suture-less placement and adherence of equine AM to porcine cadaver cornea. Methods: Prospective stu...
Le NPK, Gerdts V, Singh B.Integrin alpha-v/beta3 (αvβ3) recognizes arginine-glycine-aspartic acid (RGD) sequences and has important functions in cell adhesion, signaling, and survival. However, the expression of integrin αvβ3 in the equine lungs and jejunum is not well understood. The objective of this study was to explore the hitherto unknown expression of integrin αvβ3 in the lungs and jejuna of the horse using light and electron immunocytochemistry. Immunohistochemistry showed integrin αvβ3 on the epithelium, the immune cells in Peyer's patches, the smooth muscle, and the endothelium of equine jejuna. In equ...
Steven DH, Jeffcott LB, Mallon KA, Ricketts SW, Rossdale PD, Samuel CA.Post-partum placentae and uterine biopsy samples from mares after normal and abnormal foalings are described. After normal delivery there is little damage to fetal or maternal tissues. The villous epitheliochorial palcenta separates cleanly at the maternal-fetal interface and the afterbirth consists almost exclusively of fetal tissue. Uterine involution is well advanced by the 3rd and 4th days post partum and the changes are usually complete by the oestrus 7--10 days after parturition. Placental separation and involution of the uterus appear to proceed normally in malpresented foals and in oth...
Laskoski LM, Locatelli-Dittrich R, Valadão CA, Deconto I, Gonçalves KA, Montiani-Ferreira F, Brum JS, de Brito HF, de Sousa RS.The present study was aimed at identifying laminar lesions and leukocyte infiltration in hoof laminar tissue of horses with colic syndrome and its correlation with the total leukocyte count before death. Six healthy horses were used as control group (CG), and eighteen horses with lethal gastrointestinal disease were divided into two groups: leukopenic group (LG) with seven leukopenic horses, and non-leukopenic group (NLG) with 11 horses with total leukocyte count within reference range for the species. Leukocyte infiltration was examined by immunohistochemistry. Laminar lesions were observed i...
Stock KF, Hoeschele I, Distl O.Simulated horse data were used to compare multivariate estimation of genetic parameters and prediction of breeding values (BV) for categorical, continuous and molecular genetic data using linear animal models via residual maximum likelihood (REML) and best linear unbiased prediction (BLUP) and mixed linear-threshold animal models via Gibbs sampling (GS). Simulation included additive genetic values, residuals and fixed effects for one continuous trait, liabilities of four binary traits, and quantitative trait locus (QTL) effects and genetic markers with different recombination rates and polymor...
Nitschelm D, Van der Horst CJ.The hormonal pattern in the blood of eight mares was studied during the first 5 to 6 weeks of pregnancy; in two of the eight animals early embryonic death was established on D-28 and on D-40, respectively. Progesterone peaks were found in the blood around D-5, D-12 to D-10, and D-17 to D-18. It is suggested that the decrease of the progesterone concentrations in the blood during the intermediate periods is due to the action of oestrogens. During the period from D-18 to about D-34 the concentrations both of progesterone and of pregnenolone were low in the pregnant mares. Thereafter a small incr...
