Equine diseases encompass a wide range of health conditions that can affect horses, including infectious diseases, metabolic disorders, and genetic conditions. These diseases can impact the overall health, performance, and well-being of horses. Common equine diseases include equine influenza, equine herpesvirus, laminitis, and equine metabolic syndrome. Diagnosis and management of these diseases often require a combination of clinical evaluation, laboratory testing, and appropriate treatment strategies. This page gathers peer-reviewed research studies and scholarly articles that explore the etiology, pathophysiology, diagnosis, and treatment options for various equine diseases, providing valuable insights for veterinarians and researchers in the field.
Stanley SM.The metabolism and urinary excretion of a 100 mg dose of the non-sedating anxiolytic drug buspirone was examined using high-performance liquid chromatography/electrospray ionization mass spectrometry in the positive ion mode. In addition to a significant proportion of unchanged buspirone we were able to detect three major metabolite classes. These were identified as monohydroxy, dihydroxy and dihydroxymethoxy products. Detection of the metabolites and the parent drug was possible in all the urine samples collected (1-12 h) post-administration.
Cohen ND, Berry SM, Peloso JG, Mundy GD, Howard IC.To determine the association between high-speed exercise and risk of injury while racing among Thoroughbreds in Kentucky. Methods: Matched case-control study. Methods: 206 Thoroughbreds that sustained a musculoskeletal injury while racing and 412 Thoroughbreds that were not injured during the same races. Methods: Data regarding official timed workouts and races and the Beyer's numbers for the 3 races before the race during which injury occurred were extracted from past performance charts and compared between injured horses and control horses. Results: For injured horses, cumulative distance of...
Kellam LL, Johnson PJ, Kramer J, Keegan KG.Signs of mild colic, intermittent lethargy, and weight loss of 6 weeks' duration in a 2-year-old Quarter Horse gelding were attributed to persimmon (Diospyros virginiana) phytobezoar formation. Diagnosis of the phytobezoar was facilitated by gastric endoscopy. Signs of gastrointestinal tract obstruction were associated with a large phytobezoar in the lumen of the stomach, gastric ulceration, and obstruction of the small intestine (as a consequence of fragmentation of the primary bezoar). Conservative treatment, using mineral oil and dioctyl sodium sulfosuccinate, was unsuccessful. A celiotomy ...
Douglas JE, Thomason JJ.Circumferential and proximodistal variations in the morphology of the primary epidermal laminae of six neonatal and five adult equine feet were documented. Three parameters were quantified: interlaminar spacing, the orientation of the laminae with respect to the overlying wall, and any angulation within the laminae themselves ('internal angle'). In adult feet, the laminae were most closely spaced at the dorsum, the spacing increasing gradually towards the heels. In foals there was a non-significant trend for the dorsal laminae to be more widely spaced than those in more caudal parts of the foo...
Bureau F, Bonizzi G, Kirschvink N, Delhalle S, Desmecht D, Merville MP, Bours V, Lekeux P.Asthma is a chronic inflammatory disease of the airways, in which many inflammatory genes are overexpressed. Transcription factor, nuclear factor-kappaB (NF-kappaB), which is thought to control the transcriptional initiation of inflammatory genes, has been poorly investigated in asthma. In the present report, bronchial cells (BCs), recovered by bronchial brushing in healthy and heaves-affected horses (i.e., an animal model of asthma), were assessed for NF-kappaB activity. Small amounts of active NF-kappaB were present in BCs of healthy horses, whereas high levels of NF-kappaB activity was foun...
Fleury C, Bérard F, Balme B, Thomas L.The clinical and pathological characteristics of cutaneous melanomas occurring in Camargue-type gray-skinned horses are reported. Examination of 83 tumor-bearing horses revealed that the tumors occurred most frequently underneath the tail (93.9%) and at high rates in the peri-anal region (43.0%), the lips (33.0%), and the eyelids (24.0%), but rarely in the vulva (3.8%). Tumorous lesions were characterized by the presence of either hemispheric nodules or large infiltrated plaques, or their combinations. Microscopic examination indicated that tumorous lesions were composed mostly of melanocytes ...
Bailey SR, Andrews MJ, Elliott J, Cunningham F.Platelets are thought to play a role in equine diseases such as acute laminitis and verminous arteritis and may be involved in allergic disease. Mediators implicated in the pathophysiology of these conditions activate platelets and responses may be enhanced by interactions between mediators. The present study compared platelet aggregation, thromboxane production and release of radiolabelled [(3)H]5- HT in response to 5- HT, histamine, ADP and PAF alone and in combination in vitro.PAF caused concentration-related aggregation, [(3)H]5- HT release and thromboxane production. In contrast, ADP caus...
Kästner SB, Marlin DJ, Roberts CA, Auer JA, Lekeux P.The performance of a Fleisch No. 5 pneumotachometer (F), and two commercial ultrasonic pneumotachometers, the BRDL (B) and the Spiroson (S) systems were compared in respect to their use for determination of ventilatory parameters at rest and during lobeline-induced hyperpnoea. Five clinically healthy Thoroughbred horses were tested with the three pneumotachometers in random order. Respiratory airflow, respired gas concentrations, oesophageal pressures, pressures within the mask systems and arterial blood gases were determined before and during lobeline-induced hyperpnoea. Because measured peak...
Gray AW, Davies ME, Jeffcott LB.We report on novel methods to isolate osteoclasts (OC s) and generate osteoclast-like cells (OCL s) from the bone and bone marrow of the equine femur. OC s were successfully isolated from bone scrapings taken from the endosteal surface of the femurs of three horses. OCL s were generated from bone marrow cells taken from the same animals. The validity of using the formation of OCL s as a method for studying OC differentiation and activity was confirmed by the similar characteristics of these two cells. In particular, they both were multinuclear, expressed the enzyme tartrate resistant acid phos...
Lunn DP, Townsend HG.Equine infectious disease remains a constant and important threat to the health of domesticated horses. Vaccination plays a critical role in protecting against such disease, but at the present time the efficacy of some equine vaccination strategies is in doubt. The best strategy for resolving these concerns is an improved knowledge of the immunologic basis of successful vaccination, combined with the appropriate integration of effective vaccines into well-designed disease control policies.
Rush BR, Flaminio MJ.Nonspecific immunomodulators are substances that induce non-antigen-specific enhancement of the body's native or acquired defense mechanisms. Immunomodulant preparations are most often used for treatment of chronic, viral, or bacterial infection with evidence of secondary immunosuppression. The proposed mechanism of action of these products is macrophage activation and subsequent release of cytokines that enhance humoral and cell-mediated immunity. In equine medicine, nonspecific immunostimulant products are used for prevention and treatment of infectious respiratory disease and treatment of s...
McClure JT.Leukoproliferative disorders reported in horses include lymphoma, lymphocytic leukemia, plasma cell myeloma, granulocytic leukemia, monocytic leukemia, myelomonocytic leukemia, and eosinophilic leukemia. Lymphoma affects horses of all ages, whereas leukemias often occur in younger horses. Clinical signs are often nonspecific including depression, anorexia, fever, and weight loss. Specialized diagnostic techniques such as cytochemistry and immunophenotyping better define the cellular origin of leukoproliferative disorders, which is essential for developing appropriate therapeutic protocols and ...
Klei TR.Helminths are among the most significant parasites of horses in developed countries. This article examines immune responses against helminth parasites and the implications that immunologic investigations have on vaccine development, improvement of diagnostic procedures, and disease eradication.
Young KM, Lunn DP.Technologic advances in immunodiagnostic testing have enhanced our understanding of the pathogenesis of a broad array of diseases, including infectious diseases, immunodeficiency disorders, and immune-mediated disorders. If applied rationally, with an understanding of the questions the tests answer as well as the limitations that constrain their use, these tests can serve as valuable aids in the diagnosis and management of equine diseases.
Horohov DW.The ultimate reason for better characterizing the immune response to infectious agents is the hope that this knowledge may lead to the development of better preventative or therapeutic measures. As more information becomes available, it becomes possible to incorporate these findings into the design of better vaccines and treatments. Likewise, attempts to either enhance or suppress specific helper T-cell responses may be required to control immunopathologic reactions. Although cytokine intervention in the clinical setting remains theoretic at this time, future manipulation based on the TH1/TH2 ...
Giguère S, Prescott JF.The remarkable ability of the horse and other animals to prevent infection by most bacterial pathogens encountered is the result of a complex set of distinct but overlapping defense mechanisms. This article summarizes the current state of knowledge on innate and adaptive immunity to bacterial pathogens and reviews various ways in which some bacteria have evolved in order to evade components of the host response.
Perryman LE.Primary immunodeficiency disorders are genetically determined failures of immune defense that increase susceptibility to infectious agents. This article reviews the salient features of equine primary immunodeficiency disorders, summarizes the molecular mechanisms of each disorder, and updates information that facilitates diagnosis and management of affected horses. The central theme is to encourage clinicians to ask, "I wonder if this horse has an underlying primary immunodeficiency disorder?" when caring for horses suffering from chronic and recurring infections and responding poorly to stand...
McClure JJ.Although relatively little is known about autoimmunity and autoimmune mechanisms specifically in horses, the similarities between clinical syndromes with identifiable effector mechanisms in horses and other species suggest that comparable mechanisms may be applicable. Our understanding of equine autoimmunity undoubtedly will benefit from the extensive study of autoimmunity in other species.
Swiderski CE.Hypersensitivity is an exaggerated immunologic response to a foreign agent that results in inflammation and organ dysfunction. Hypersensitivity disorders are broadly divided into antibody-mediated and T-cell-mediated reactions. The inflammatory pathways that result in disease are initiated in an antigen-specific manner through Fab portions of antibodies or the T-cell receptor, causing the up-regulation of effector mechanisms designed to clear the offending agent. Effector mechanisms include the generation of inflammatory chemicals such as cytokines and chemokines and the attraction of leukocyt...
MacKay RJ.After inflammation is initiated by detection of antigen, plasma components and activated leukocytes are concentrated at the inflammatory site. Cellular and chemical effectors of inflammation are focused on the offending antigen, usually resulting in its destruction and elimination. Activation of endogenous counter-regulatory systems damps down the inflammatory process and is the first stage of repair. In addition to local effects, the inflammatory focus may initiate a continuum of systemic acute phase responses ranging from the systemic inflammatory response syndrome (SIRS) to generalized immu...
Slater J, Hannant D.The identification of some of the adaptive immune responses to infection with equine viruses has been the first step toward rational immunoprophylactic design. Sufficient knowledge of infection-induced immunity and informed estimates of the requirements for long-term immunity for EIV have now been obtained. Thus, the future for inactivated EIV vaccines is promising now that new adjuvants have been applied to induce cellular immunity and safe methods have been designed to stimulate virus-neutralizing (VN) antibody at mucosal surfaces. Adenoviruses induce circulating VN antibody, the presence of...
Nixon AJ, Brower-Toland BD, Sandell LJ.This study cloned and sequenced equine transforming growth factor (TGF)-beta1, yielding a unique nucleotide structure which predicted amino acid substitutions not seen in other mammalian species. The nucleotide sequence homology was 89% to bovine, 91% to man, 90% to ovine, and 86% to rat. Derived amino acid sequence comparison showed that the equine protein was unique, differing by two residues from man, cow, sheep, pig, and dog, and by three residues in the rat. Subsequent use of the cDNA clones to examine the expression of the TGF-beta1 gene in various tissues indicated predominant expressio...
Corvilain B, Collyn L, van Sande J, Dumont JE.The regulation of thyroid metabolism by iodide involves numerous inhibitory effects. However, in unstimulated dog thyroid slices, a small inconstant stimulatory effect of iodide on H(2)O(2) generation is observed. The only other stimulatory effect reported with iodide is on [1-(14)C]glucose oxidation, i.e., on the pentose phosphate pathway. Because we have recently demonstrated that the pentose phosphate pathway is controlled by H(2)O(2) generation, we study here the effect of iodide on basal H(2)O(2) generation in thyroid slices from several species. Our data show that in sheep, pig, bovine, ...
Roy MF, Lavoie JP, Deschamps I, Laverty S.Primary splenic disease in the horse is rarely recognised as a
clinical entity. A few cases of splenic abscesses (Swan 1968),
splenic haematoma (Spier et al. 1986; McGorum et al. 1996),
and splenic rupture (Finocchio 1971; Steiner 1981; Dyke and
Friend 1988) have been reported. One case of primary
splenomegaly associated with recurrent colic has been
described in the veterinary literature and a splenectomy was
performed which corrected the problem (Varra and Nelson
1976). We are aware of only one report of splenomegaly
associated with splenic infarction in horses (Scott et al. 1978);
...
Meyer GA, Rashmir-Raven A, Helms RJ, Brashier M.This study was performed to determine the effect of administration of i.v. oxytocin on the contractility of the musculature associated with the equine oesophagus. Nine clinically normal horses were fitted with a nasogastric tube modified with inflatable latex cuffs. These cuffs were connected to piezoelectric pressure recording devices. Oxytocin in 3 different doses or saline controls were administered i.v. in a randomised block pattern. Systolic blood pressure, ECG, heart rate and nasogastric tube cuff pressures were then measured for 60 min. Administration of oxytocin i.v. at 0.11 and 0.22 i...
von Rechenberg B, McIlwraith CW, Akens MK, Frisbie DD, Leutenegger C, Auer JA.Nitric oxide (NO), prostaglandin E2 (PGE2), and the activity of neutral metalloproteinases (NMPs) were measured in conditioned media of equine synovial membrane and articular cartilage explant cultures from horses with normal joints (n = 7) and from horses affected with moderate (n = 7) or severe osteoarthritis (n = 14) as judged by macroscopic appearance. Normal articular cartilage appeared glossy and bluish-white, was of normal thickness and showed no evidence of discolouration, fibrillation or other cartilage discontinuity. Slight discolouration and fibrillation or minor clefts of the carti...
Epstein V, Hodge D.Multiple cutaneous lymphosarcomas were diagnosed in an 8-year-old Thoroughbred stallion presented for evaluation of lumps on its scrotum. Histological examination of skin biopsy samples showed a homogenous pattern of lymphoid tissue suggestive of a T-cell lymphosarcoma. Immuno-histochemical tests showed a positive reaction to Rabbit/Anti-Human T-Cell, CD3 antibodies confirming T-cell lymphosarcoma. The animal was not treated and was subsequently euthanased.
Castelijns HH.Domesticated horses need hoof care, because it is rare for wear and growth of the hooves to be in perfect equilibrium. During the shoeing interval, the hoof grows downwards and forward in the direction of the horn tubules, losing some degree of angle. Few horses have perfect limb conformation. The shape of a hoof of a limb with conformation defects adapts in a predictable way. If, for therapeutic or performance reasons, the hoof-shoe combination is modified, there is a not a lot of leeway in the trim of a particular foot, whereas the applied shoe type, placement, and adjustments provide endles...
Widders PR, Stokes CR, Bourne FJ.The antigenic cross reactivity between equine IgG and IgGT was investigated. On the basis of immunodiffusion and immunoelectrophoresis reactions using an antiserum raised against the Fc fraction of IgGT, this equine immunoglobulin can be unequivocally classified as a subclass of IgG.
Ousey JC, Rossdalet PD, Palmer L, Grainger L, Houghton E.The aims of this study were to ascertain 1) whether fetal maturation could be induced precociously by maternal administration with adrenocorticotrophic hormone (ACTH) and 2) whether maturation could be achieved without significant risk to mare or fetus. Twenty-two mares received either 1 mg (low dose, LD, n = 6) or 4 or 5 mg (higher dose, HD, n = 16) synthetic Depot ACTH(1-24) at 300, 301 and 302 days gestation. Because, during the course of the study, ACTH appeared to have a greater influence on mares mated during the later part of the breeding season, the HD group were divided retrospectivel...
van Bergen T, Wiemer P, Bosseler L, Ugahary F, Martens A.Epiploic foramen entrapment (EFE) is, based on the number of reports in the literature, a relatively important life-threatening cause of colic in horses that could be prevented by closing the epiploic foramen (EF) in horses at risk of developing EFE. Objective: To describe the laparoscopic foramen epiploicum mesh closure (FEMC) technique and its outcome. Methods: Descriptive experimental study. Methods: The EF of 6 horses was closed with the FEMC technique. A diabolo-shaped constructed mesh was introduced into the omental vestibule through the EF under laparoscopic visualisation in the standin...
Paquette B.Equine infectious anemia in Canada was reviewed for the period January 1976 to December 1981. The human and ecological factors prevailing in Canada are deemed instrumental with respect to the evolution of the disease. The natural spread of the disease on a large scale has not been influenced by the Federal program. Reactors with signs of the disease are important for it's propagation. The author underlines the necessity of cooperation with private practising veterinarians to control it.
Rodriguez M, Hooghuis H, Castaño M.African horse sickness (AHS) is an infectious, non-contagious, highly fatal viral disease of Equidae, transmitted by arthropod vectors of the genus Culicoides, and endemic in Africa south and east of the Sahara. The disease is caused by a virus of the Reoviridae family, genus Orbivirus, and 9 serotypes have been recognized. Recent outbreaks of AHS in the Iberian peninsula and Northern Africa emphasize the need for accurate diagnosis and rapid implementation of control measures. In this paper, the epizootiological factors, clinical signs and necropsy findings of AHS are discussed, and an update...
Walker JE, Lewis CW, MacLeay JM, Kawcak CE, Wheeler DL.Functional relationships between articular cartilage and underlying subchondral bone have been shown to be associated with the progression of osteoarthritis (OA). However, quantifiable factors substantiating this relationship do not exist. Therefore, the study objective involved quantifying subchondral bone mineral density (BMD) of the equine metacarpophalangeal (MCP) and stifle joints as a step in determining if regional subchondral BMD may be associated with OA changes. BMD was bilaterally quantified using dual energy xray absorptiometry (DEXA) for four subchondral regions: palmer and dorsal...
Power HT, McEvoy EO, Manning TO.A 4-month-old foal was examined because of generalized exfoliative dermatitis, with thick scales, extensive crusting, and oozing of serum. A diagnosis of pemphigus foliaceus was made by histologic and immunopathologic examinations of skin biopsy specimens. The foal was treated with a gold compound, aurothioglucose (1 mg/kg once weekly for 14 weeks). For the initial 5 weeks, high-dose glucocorticoid treatments also was used. The skin disorder resolved entirely after 12 weeks of treatment.
Lunn DP, Townsend HG.Equine infectious disease remains a constant and important threat to the health of domesticated horses. Vaccination plays a critical role in protecting against such disease, but at the present time the efficacy of some equine vaccination strategies is in doubt. The best strategy for resolving these concerns is an improved knowledge of the immunologic basis of successful vaccination, combined with the appropriate integration of effective vaccines into well-designed disease control policies.