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.
Kawaoka Y, Webster RG.A severe influenza outbreak occurred in horses in South Africa in 1986. The causative agent was identified as an influenza virus [A/Equine/Johannesburg/86 (H3N8)]. Antigenic analyses of the hemagglutinin (HA) with ferret antisera and monoclonal antibodies showed that the Eq/Johannesburg/86 virus is similar to recent equine H3 viruses. The nucleotide sequence analysis on the HA genes of Eq/Johannesburg/86 and other equine H3 influenza viruses, together with the epidemiological data, clearly demonstrated that the Eq/Johannesburg/86 virus was derived from a virus that had been circulating in hors...
Ginther OJ.Ultrasonography was used to determine whether there is embryo reduction in mares with unilaterally fixed twins when a major portion of the vascularized area of the wall of one of the embryonic vesicles is in apposition with the wall of the adjacent vesicle, rather than with the endometrium (deprivation hypothesis). In addition, the effect of ovulatory pattern (synchronous and asynchronous) on the incidence of embryo reduction was studied. Twin vesicles were ultrasonically detected on days 11 to 15 (ovulation = day 0) and were examined daily until there was embryo reduction or until day 40. In ...
Jedruch J, Gajewski Z, Kuussaari J.The effect of detomidine on the electrical activity of the uterus was studied during the last trimester of pregnancy in 6 mares. The effect was observed in 3-5 min after the i.m. injection and it lasted for 50-70 min. 20 and 40 micrograms/kg b.w. doses of detomidine decreased the myometrial electrical activity, whereas 60 micrograms/kg dose did not have any effect on the activity. The results suggested that 20, 40 and 60 micrograms/kg b.w. doses of detomidine can be administered to mares during the last trimester of pregnancy without the risk of abortion induced by increased uterine electrical...
Browning GF, Studdert MJ.The BamHI, EcoRI, and HindIII physical maps of the genomes of 14 isolates of equine herpesvirus 2 (EHV 2) were determined by Southern blot analysis using DNA fragments of a previously mapped EHV 2 strain 86/67. No two isolates had identical maps for all 3 enzymes, the number of differing cleavage sites between pairs of isolates varying from 3 to 21. Overall 75 cleavage sites were mapped, of which 40 were variable. Cleavage sites occurred throughout the genome, including within the terminal repeat regions. Additionally, fragment length polymorphisms, independent of cleavage site loss or gain, w...
Verschooten F, Roels J, Lampo P, Desmet P, De Moor A, Picavet T.Radiographic measurements from the lateromedial projection of the equine foot were compared in three groups of horses. Group 1 consisted of 143 normal horses, group 2 were 60 horses with clinical navicular disease and group 3 were 161 horses with clinical and radiographic navicular disease. Several measurements tended to be larger in group 3 than group 1. An enlargement of the navicular bone was observed in proximodistal and dorsopalmar directions. Partial enlargement of the pedal bone was observed in groups 2 and 3. Few differences were observed between age classes. All horses aged four years...
van Schie HT.The ultrasonic examination of tendons and ligaments of the distal limb of the horse improves the diagnostic possibilities of these frequently injured structures. The successful application is based upon a reliable knowledge of the normal sonographic anatomy and upon a standardized, flawless technic of the examination. Practice and experience allow the recognition of minor alterations which enables a more precise diagnosis, a more reliable prognosis, and in follow-up examinations also more specific information about the further use of the horse.
Colles CM.A study was carried out on five horses and four ponies to assess the effect of altering frog pressure on hoof expansion. Measurements of hoof expansion were made using strain gauges. It was concluded that whereas frog pressure affects hoof expansion, it is only one of several factors. Increasing frog pressure may result in increased expansion, or contraction, or may have virtually no affect. The variable results of changing frog pressure should be taken into account when considering therapeutic shoeing.
López ML, Grez P, Gribbel I, Bustos-Obregón E.The epididymis of stallion castrated during the breeding and non breeding seasons were subdivided into six regions and their ultrastructural and cytochemical characteristics were studied in order to provide a better understanding of the structure-function relationship of this androgen target organ. Even when the stallion has been postulated to be a seasonal breeder, our results do not show significant ultrastructural or cytochemical differences in both seasons. The pseudostratified epithelium is composed mainly of principal and basal cells and intraepithelial lymphocytes. The principal cells s...
Morgan SJ, Storts RW, Stromberg PC, Sowa BA, Lay JC.Factors involved in the proliferation of equine vascular smooth muscle cells were studied in vitro. The most prominent proliferative responses in cultured vascular smooth muscle cells were induced by Strongylus vulgaris larval antigen extract (LAE) and platelet-derived factors. Less significant proliferative responses were obtained with conditioned media from S. vulgaris LAE stimulated and from unstimulated equine mononuclear leukocytes. Additionally, vascular smooth muscle cells exposed to S. vulgaris LAE developed numerous perinuclear vacuoles and were more spindle-shaped than control or smo...
Cecio A, Vittoria A.Amines and/or peptide-producing cells, deserving to be called paraneurons, were demonstrated in the urethro-prostatic complex of the man, rabbit, buffalo and sheep and in the uterine horns of the pig, horse and mouse, by means of histochemical, immunohistochemical, immunofluorescent and double labeling immunofluorescent techniques. In particular, the urethro-prostatic complex of the sheep contains cells producing serotonin, chromogranin A and somatostatin. Often the amine and the "marker"-protein were colocalized in the same cells. Chromogranin A- and somatostatin-containing cells were found i...
Weiss DJ, Kraemer R, Schmit K.A simple discontinuous Percoll density-gradient technique was adapted for isolation of granulocytes and mononuclear cells from cats, dogs, horses and cattle. Separation was accomplished at low speeds using a standard tabletop centrifuge. Cell purity was 100% for both granulocytes and mononuclear cells and cell viability exceeded 95%. Percent recovery of leukocytes ranged from 69 to 83%.
Jolly RD, Dalefield RR.The lipopigments are a heterogenous group of pigments whose pathogenesis and terminology is confused. Whereas there is epidemiological and observational evidence that ceroid is derived from degeneration and peroxidation of unsaturated lipid, the assumption that all so-called lipopigments are similarly formed, is questioned. In particular, recent studies have distanced the pathogenesis of the pigment found in the ceroid-lipofuscinoses from that perceived for ceroid. The importance of protein rather than lipid in the pathogenesis of the pigment of ceroid-lipofuscinosis and of age pigment from th...
Kobluk CN, Schnurr D, Horney FD, Sumner-Smith G, Willoughby RA, Dekleer V, Hearn TC.High-speed cinematography with computer aided analysis was used to study equine hindlimb kinematics. Eight horses were filmed at the trot or the pace. Filming was done from the side (lateral) and the back (caudal). Parameters measured from the lateral filming included the heights of the tuber coxae and tailhead, protraction and retraction of the hoof and angular changes of the tarsus and stifle. Abduction and adduction of the limb and tarsal height changes were measured from the caudal filming. The maximum and minimum values plus the standard deviations and coefficients of variations are prese...
Fischer A, Lechner J, Kraft W, Hirschberger J.The QBC is a centrifugal haematology system. Modified haematocrit capillaries are measured optically. The parameters haematocrit, total leukocyte count, relative and absolute values of granulocyte and lympho-/monocyte fractions, and total thrombocyte count are stated. The microhaematocrit method, the counting chamber, and the differential blood count are reference methods. Blood samples of the dog, cat and horse were used for the study. As a screening method the QBC analysis meets all requirements for the veterinary practice.
Tobin T, Kwiatkowski S, Watt DS, Tai HH, Tai CL, Woods WE, Goodman JP, Taylor DG, Weckman TJ, Yang JM.We have developed and evaluated a one step enzyme-linked immunosorbent assay (ELISA) test for sufentanil and a 125I radioimmunoassay test for alfentanil as part of a panel of pre- and post-race tests for narcotic analgesics in racing horses. Our sufentanil ELISA test detects sufentanil with an I-50 of about 0.5 ng/ml. The test is rapid and economical in that it can be read with an inexpensive spectrophotometer, or even by eye. The test readily detects the presence of sufentanil or its metabolites in equine blood and urine from 1 to 24 hours respectively after administration of therapeutic or s...
Ball BA, Little TV, Weber JA, Woods GL.The estimated embryonic loss rate between Days 4 and 14 after ovulation for young, normal mares (9%) was significantly lower (P less than 0.01) than the estimated embryonic loss rate for aged subfertile mares (62%). Fertilization rates, which were based on the recovery of embryos at Day 4 after ovulation, were 96% and 81% (P less than 0.1) for normal and subfertile mares, respectively. Day-4 embryos were collected from the oviducts of normal and subfertile donors mares. These embryos were transferred to the uteri of synchronized, normal recipient mares to test the hypothesis that the high inci...
Dill SG, Kallfelz FA, deLahunta A, Waldron CH.Serum vitamin E and blood glutathione peroxidase values were determined in 40 horses with a histologically confirmed diagnosis of degenerative myeloencephalopathy and in 49 age-matched control horses with normal neurologic function. Significant differences were not detected in serum vitamin E or blood glutathione peroxidase values between horses affected with degenerative myeloencephalopathy and control horses. These findings fail to support a reported role of vitamin E deficiency as a cause of equine degenerative myeloencephalopathy.
Montesissa C, Stracciari JM, Fadini L, Beretta C.A comparison has been made of the in vitro metabolism of febantel (FBT) with that of one of its pharmacologically active metabolites fenbendazole (FBZ) using microsomal preparations from liver of sheep, calf, horse, pig, rat, chicken and trout. The oxidation of FBT to the corresponding sulphoxide appeared to be far more rapid with the exception of the trout, than a similar reaction with FBZ. Indeed FBT was further metabolized in several species by cyclization and further oxidation. This observation could have toxicological significance in view of the greater tetratogenic effects of the metabol...
May SA, Hooke RE, Lees P.Although an E-series prostaglandin has previously been identified in equine inflammatory exudate, the identity of this eicosanoid as PGE2 has not been confirmed. The objective of this study was the specific characterisation of the prostaglandin produced by equine cells in the presence of an inflammatory stimulus. By using two radioimmunoassays, a relatively non-specific PGE2 assay and a more specific PGE1 assay, it has been possible to identify the E-series prostaglandin produced by equine chondrocytes and synovial cells, in response to a variety of stimuli, as PGE2.
Specht TE, Colahan PT.Medical records of 48 equids (47 horses, 1 pony) with surgical sand colic were reviewed. The diagnosis of sand colic was made if a sand impaction(s) was palpated during exploratory abdominal surgery or if a large quantity of sand was found during colotomy. Most equids did not experience a previous episode of sand diarrhea or sand colic. Clinical findings and results of clinicopathologic determinations were not diagnostic. Rectal palpation findings in 40 of 46 horses were compatible with large-colon and/or cecal distention. Impactions were palpable per rectum in only 7 horses, but emergency abd...
Robertson GR, Whalley JM.We have identified the equine herpesvirus 1 (EHV-1) thymidine kinase gene (TK) by DNA-mediated transformation and by DNA sequencing. Alignment of the amino acid sequence of the EHV-1 TK with the TKs from 3 other herpesviruses revealed regions of homology, some of which correspond to the previously identified substrate binding sites, while others have as yet, no assigned function. In particular, the strict conservation of an aspartate within the proposed nucleoside binding site suggests a role in ATP binding for this residue. Comparison of 5 herpes TKs with the thymidylate kinase of yeast revea...
Weidolf LO, Chichila TM, Henion JD.Methods for screening by thin-layer chromatography, quantification by high-performance liquid chromatography with ultraviolet detection and confirmation by gas chromatography-mass spectrometry of boldenone sulfate in equine urine after administration of boldenone undecylenate (Equipoise) are presented. Sample work-up was done with C18 liquid-solid extraction followed by solvolytic cleavage of the sulfate ester. Confirmatory evidence of boldenone sulfate in equine urine was obtained from 2 h to 42 days following a therapeutic intramuscular dose of Equipoise. The use of 19-nortestosterone sulfat...
LeBlanc PH, Caron JP, Patterson JS, Brown M, Matta MA.Local anesthetics given in the epidural space of a horse may cause hind limb weakness in addition to analgesia. Because alpha 2 agonists given by epidural injection cause sensory blockade without motor effects in human beings and other species, their use in veterinary anesthesia is appealing. This study was designed to examine the effectiveness of xylazine HCl, an alpha 2 agonist commonly used in horses. Xylazine, 0.9% NaCl, and lidocaine were given by epidural injection to horses subjected to perineal electrical stimulation. Administration of xylazine (0.17 mg/kg of body weight, diluted to a ...
Pascoe JR, Pascoe RR.Although they are pivotal events in the continued production of new generations of horses, breeding and foaling are not without risk to the mare. This article reviews the accidents that can occur and result in injury, displacement, and malpositions of the urogenital tract of the mare.
Licka TF.The differentiation of ataxia and orthopedic disease can be facilitated by the use of several additional tests, not commonly part of either neurologic or orthopedic examination protocols. However, a full neurologic and orthopedic examination and suitable diagnostic imaging will of course also be necessary in such cases. The common association of orthopedic and neurologic disease makes it even more necessary to correctly attribute movement or posture abnormalities to potentially treatable structures.
Pozor MA, Benson SM, Macpherson ML, Kelleman AA.Transplantation of stem cells into dysfunctional testes is currently being investigated as a therapeutic option for men and stallions with advanced testicular degeneration. This series of "proof of concept" studies aimed to identify a safe and efficient method of inducing severe testicular degeneration to create an optimal equine recipient model for intratesticular stem cell transplantation (SCT). Two ex vivo and two in vivo experiments were conducted. At first, forty testes obtained from castrations were used to identify an effective therapeutic ultrasound (TUS) device and the protocol for ...
Hanson RR, Nixon AJ, Gronwall R, Meyer D, Pendergast J.Postoperative abdominal fluid changes were compared in 2 groups of horses; those undergoing double small-colon resection and anastomosis (n = 10) and those undergoing exploratory celiotomy alone (n = 5). Peritoneal fluid was collected before surgery and on postoperative days 1, 3, 5, and 7. Total and differential nucleated cell counts, RBC numbers, and total protein and fibrinogen concentrations were evaluated. In both groups, all values were significantly higher than normal on the first postoperative day (after small-colon resection and anastomoses, WBC = 130,350 +/- 23,310 cells/microliters,...
Davis JL, Kruger K, LaFevers DH, Barlow BM, Schirmer JM, Breuhaus BA.Angiotensin converting enzyme (ACE) inhibitors improve survival and quality of life in human patients and small animals with cardiovascular and renal disease. There is limited information regarding their effects in horses. Objective: The purpose of this study was to determine the pharmacokinetics of quinapril and its effects on ACE and renin in horses. Methods: Experimental study using healthy mature horses. Methods: Six healthy horses were administered quinapril at 120 mg i.v., 120 mg per os and 240 mg per os in a 3-way crossover design. Blood was collected for measurement of quinapril ...
Williams PF, Brooks SP, Cooper DR.Sir, — We wish to report the death of a foal due to a parasitic lesion caused by Parascaris equorum..P equorum is reported to cause periodic colic, enterilis, obstructive colic with occasional rupture of the small intestine. However, personal communications with other veterinarians and our experience indicate fatal cases are not as common as indictaed in the literature.
Rahmani Shahraki A, Raisi A.One of the reasons of weight loss and poor performance in horses is decrease in food intake. Oral cavity problems can cause malfunctions in prehension and deglutition resulting in dysphagia. There are few published reports about a metallic foreign body disorders in the oral cavity of horses due to an important role of their flexible lip and incisor teeth in food selection and prehension. This report describes the history, clinical, hematological and radiographic findings and surgical management of a left oral wall fistula formation due to a piece of wire penetration in a pregnant mare. The wir...
Gysens L, Depuydt E, Patruno M, Haspeslagh M, Spaas JH, Martens A.Sarcoids are the most common equine skin tumours Although they do not metastasize, they can be locally aggressive and cause significant clinical symptoms in affected horses. Despite being common, very little is known about the host immune response and the biological mechanisms underlying persistence and recurrence of equine sarcoids. The latter reflects the need for further research in this field. This in-vitro study used sarcoid explants from horses with naturally occurring sarcoids (n = 12) to evaluate the induction of a humoral immune response directed against equine sarcoid-derived bovin...
Poppie MJ, McGuire TC.Foals with combined immunodeficiency (CID), a fatal genetic defect in the production of both B and T lymphocytes, are born without immunoglobulins and are unable to synthesise them. CID foals receiving immunoglobulins via the dam's colostrum may live up to four months of age. Those CID foals with failure of passive transfer (FPT) die at a much earlier age. The occurrence of CID is of value in studying passive transfer of immunoglobulins, as no confusion exists as to when passive transfer ends and active synthesis of immunoglobulins begins. A high correlation has been found between early foal d...
Van Hoogmoed LM, Snyder JR, Nieto J, Harmon FA.To determine whether a customized solution could attenuate the effects of low-flow ischemia and reperfusion injury of the equine jejunum. Methods: A segment of jejunum obtained from 21 healthy adult horses. Methods: A segment of jejunum was maintained in an isolated extracorporeal circuit, and arterial flow was reduced to 20% of baseline for 40 minutes (ischemia) followed by 60 minutes of reperfusion. In 1 group, a customized solution was infused at a rate of 1 ml/min during low-flow ischemia and 3 ml/min during reperfusion. In a second group, the solution was infused at the same rate during l...
Akinboade OA, Awani O, Best O, Cole T.Summary Twelve (12) heavy horses of the Shire breed imported into Nigeria in 1974 died within two months after importation. This was because of inclement weather and non-availability of AHS vaccine.
Spoormakers TJ, Donker SH, Ensink JM.The anaesthetic potency, onset of action, duration of action, and side effects of lidocaine and lidocaine plus epinephrine for proximal metacarpal block of the lateral and medial palmar nerves were determined. Ten horses were used and legs were injected using a cross-over model with three test solutions: 1) solvent and lidocaine (2%) plus epinephrine (SLE); 2) solvent and lidocaine (2%) without epinephrine (SL); and 3) solvent only (S). The contra-lateral leg was injected with saline (placebo; P). In both the SL and SLE groups, the onset of anaesthesia occurred between 5 and 15 minutes after i...
van Zadelhoff C, Ehrle A, Merle R, Jahn W, Lischer C.Scintigraphy is a standard diagnostic method for evaluating horses with back pain due to suspected thoracic processus spinosus pathology. Lesion detection is based on subjective or semi-quantitative assessments of increased uptake. This retrospective, analytical study is aimed to compare semi-quantitative and subjective methods in the evaluation of scintigraphic images of the processi spinosi in the equine thoracic spine. Scintigraphic images of 20 Warmblood horses, presented for assessment of orthopedic conditions between 2014 and 2016, were included in the study. Randomized, blinded image ev...
Schamhardt HC, Merkens HW.A method was developed to quantify the ground reaction force pattern of the horse. A number of selected force amplitudes and peak-time positions in the normalized stance phase of left and right contralateral limbs were used to calculate symmetry indices. Data from each limb were compared with those of a 'standard horse' resulting in limb indices. The combination of amplitude and peak-time symmetry and limb indices yielded one H(orse)INDEX. These indices were useful for comparison of different horses and for the evaluation of lameness and treatment.
Foreman JH, Waldsmith JK, Lalum RB.Three-day event horses are subject to various external environmental stresses including changes in ambient temperature, humidity, altitude, and test severity. Considerable research on the adverse effects of increased heat and humidity preceded the 1996 Olympic Summer Games in Atlanta, Georgia USA, but no research has been done previously on the effects of altitude on 3-day eventing. Physical and venous blood gas data were collected on horses (n = 24) competing in the High Prairie Preliminary (CCN*) and Intermediate (CCN**) 3-day events and Preliminary Horse Trials in Parker, Colorado (1900 m a...
The Veterinary recordSeptember 9, 2017
Volume 181, Issue 10 ii doi: 10.1136/vr.j4128
Carslake H.Harry Carslake, equine medicine specialist at the Philip Leverhulme Equine Hospital, Liverpool, reviews a fiveday course on advanced cardiac ultrasound scanning that he completed recently.
Folz SD, Hanson BJ, Griffin AK, Dinvald LL, Swerczek TW, Walker RD, Foreman JH.Ceftiofur sodium was evaluated as a therapy for respiratory infections in horses. This cephalosporin antimicrobial was administered intramuscularly every 24 h and at a dose of 2.2 mg/kg (1.0 mg/lb) of body weight. The efficacy of ceftiofur sodium was compared with that of a positive control drug, ampicillin sodium (recommended dose of 6.6 mg/kg [3 mg/lb], given every 12 h). Both treatments were continued for 48 h after clinical symptoms were no longer evident (maximum of 10 days). Fifty-five (55) horses with naturally acquired respiratory infections were included in the study; 28 were treated ...
Houpt KA, Northrup N, Wheatley T, Houpt TR.When a preliminary experiment in sodium-replete ponies revealed an increase, but not a significant increase, in salt consumption after furosemide treatment, the experiment was repeated using sodium-deficient horses in which aldosterone levels might be expected to be elevated to test the hypothesis that a background of aldosterone is necessary for salt appetite. Ten Standardbred mares were injected intravenously with furosemide or an equivalent volume of 0.9% sodium chloride as a control to test the effect of furosemide on their salt appetite and blood constituents. Sodium intake and sodium los...
Gomez-Villamandos R, Santisteban J, Ruiz I, Avila I.Two horses with fibrotic myopathy of the semitendinosus muscle are described. The report deals with the aetiology, clinical signs and diagnosis of the condition, and discusses the different surgical techniques described in the literature. Tenotomies were performed on both horses. Excellent results were obtained in the horse in which only the semitendinosus muscle was affected, but in the horse in which the semimembranosus and gracilis muscles were also involved the results were less satisfactory.
Jones MB, Gonzalez-Ochoa A, Marx MB, Furcolow ML.In a 3-month period, 2,221 Mexican horses were skin tested for sensitivity to Histoplasma capsulatum antigen. The prevalence of reactivity was 7.9%. There was little evidence of a difference in geographic distribution of sensitivity. The prevalence of reactivity increased with age of the horse. This increment with age is thought to be a function of time exposure to the organism and possibly of selective survival of the horses.
Magnuson NS, Decker DM, Perryman LE.1. Activities of S-adenosylhomocysteine (AdoHcy) hydrolase were measured in tissues of horses with severe combined immunodeficiency. No decrease in activity of the enzyme was detected.
2. The activity in erythrocytes was 14.2 ± 9.2 nmol AdoHcy formed/min/g hemoglobin and in fibroblasts it was 28.0 ± 7.9 nmol AdoHcy formed/min/108 cells.
3. Km values were obtained for hemolysates (0.77 μM) and for fibroblast lysates (0.59 μM).
4. Effects of 2′-deoxyadenosine on enzyme inactivation were studied.