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Topic:Equine Diseases
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.
Genetic markers for stallion fertility–lessons from humans and mice. Our knowledge on the many aspects of mammalian reproduction in general and equine reproduction in particular has greatly increased during the last 15 years. Advances in the understanding of the physiology, cell biology, and biochemistry of reproduction have facilitated genetic analyses of fertility. Currently, there are more than 200 genes known that are involved in the production of fertile sperm cells. The completion of a number of mammalian genome projects will aid in the investigation of these genes in different species. Great progress has been made in the understanding of genetic aberrati...
[EIAV (equine infectious anemia virus): to better understand the lentiviral pathogenesis]. Equine infectious anemia virus (EIAV) is a lentivirus related to HIV (human immunodeficiency virus). EIAV causes a persistent infection characterized by recurring febrile episodes associating viremia, fever and thrombocytopenia. Despite a rapid virus replication and antigenic variation, most animals progress from a chronic stage characterized by recurring peaks of viremia and fever to an asymptomatic stage of infection. The understanding of the correlates of this immune control is of great interest in defining vaccine strategies. Research on EIAV over the last five decades has produced some in...
Neurologic disorders of neonatal foals. Neurologic examination of the neonatal foal is quite different from the process used to examine older foals and adult horses. Abnormal neurologic signs are best appreciated in the context of a detailed knowledge of general neonatal medicine and awareness of nor-mal foal behavior and milestones of development. A systematic approach to neurologic examination is provided. The results of such examination are used to localize a lesion or lesions in the nervous system. Descriptions and treatment strategies are given for most common and important neonatal neurologic diseases.
Immunologic disorders in neonatal foals. Foals live in an environment heavily populated by bacteria, many of which are capable of causing disease. Development of infection,however, is the exception rather than the rule. The ability of the foal to prevent infection by most pathogens is the result of a sophisticated set of defense mechanisms. These defense mechanisms can be divided into adaptive and innate immunity. Innate immunity encompasses defense mechanisms that pre-exist or are rapidly induced within hours of exposure to a pathogen. Conversely, adaptive or acquired immunity represents host defenses mediated by T and B lymphocytes...
Abdominal surgery in neonatal foals. Abdominal surgery in foals under 30 days old has become more common with improved neonatal care. Early recognition of a foal at risk and better nursing care have increased the survival rates of foals that require neonatal care. The success of improved neonatal care also has increased the need for accurate diagnosis and treatment of gastrointestinal, umbilical, and bladder disorders in these foals. This chapter focuses on the early and accurate diagnosis of specific disorders that require abdominal exploratory surgery and the specific treatment considerations and prognosis for these disorders.
Pharmacokinetics of imipenem-cilastatin following intravenous administration in healthy adult horses. In two studies, six healthy adult horses were given imipenem-cilastatin by slow intravenous (i.v.) infusion at an imipenem dosage of 10 mg/kg (study 1) and 20 mg/kg (study 2). The same horses were used in each dosage schedule, with a 2-week washout period between studies. In each dosage group, serial blood and synovial fluid samples were collected for 6 h after completion of the infusion. HPLC was used to determine the imipenem concentration in all samples. Imipenem was well tolerated by all horses at both dosages; no adverse effects were noted during the study period or during the 24-hour pos...
Orthopedic disorders in neonatal foals. The first month of life is a vulnerable time for foals. They must adjust to their environment while they are still compromised immunologically, and their musculoskeletal system is rapidly growing and adjusting to stresses from an increasing amount of exercise. Therefore, if a foal is born with or acquires an abnormality or disease related to the musculoskeletal system, rapid adjustments must be made to allow the foal to grow and respond so that future athletic performance will not be compromised. Problems must be identified early, which requires thorough examinations. This article summarizes t...
Nutritional support for neonatal foals. In recent years, equine neonatal medicine has made significant advances. The importance of nutritional support for the sick neonatal foal has been recognized, and methods of providing that sup-port have been developed. Today, the clinician has many options when designing a nutritional plan for the neonatal foal. When the foal's gut permits, enteral diets are an inexpensive source of nutrients. Under conditions where the gut requires rest, methods for delivering nutrients by the parenteral route have also been developed. In this article, the nutrition of the normal and sick foal is described. G...
Nondiarrheal disorders of the gastrointestinal tract in neonatal foals. Neonates can have a variety of gastrointestinal disorders, primary and secondary in nature. Important primary disorders include con-genital abnormalities and meconium retention. One of the most important secondary lesions is generalized ileus. Gastric ulceration can occur as a primary or secondary event. This article addresses the pathophysiology, diagnosis, and treatment of gastrointestinal problems commonly observed in neonatal foals.
Sudden death due to thoracic lymphoma in a standardbred racing horse. During training, a 6-year-old standardbred gelding collapsed, exhibiting severe epistaxis and agonal breathing and was euthanized. The horse had a recent history of poor performance, lethargy, and unilateral eyelid swelling with serous ocular discharge. Postmortem and histopathologic examination findings revealed thoracic lymphosarcoma and concurrent exercise-induced pulmonary hemorrhage. Résumé — Mort subite d’un cheval de course de race standardbred causée par un lymphome thoracique. En cours d’entraînement, un standardbred hongre âgé de 6 ans s’est effondré, présentant des s...
Immunoglobulins and immunoglobulin genes of the horse. Antibodies of the horse were studied intensively by many notable immunologists throughout the past century until the early 1970's. After a large gap of interest in horse immunology, additional basic studies on horse immunoglobulin genes performed during the past 10 years have resulted in new insights into the equine humoral immune system. These include the characterization of the immunoglobulin lambda and kappa light chain genes, the immunoglobulin heavy chain constant (IGHC) gene regions, and initial studies regarding the heavy chain variable genes. Horses express predominately lambda light c...
Establishment of cloned Anaplasma phagocytophilum and analysis of p44 gene conversion within an infected horse and infected SCID mice. Diverse p44 alleles at the p44 expression locus (p44Es) encoding surface-exposed major membrane proteins, P44s, of Anaplasma phagocytophilum were hypothesized to be garnered by recombination to enact antigenic variation. However, this hypothesis has not been proven so far, due to inability to clone this obligate intragranulocytic rickettsia. To define the p44E recombination, we developed a novel method to clone A. phagocytophilum. This isogenic cloned population containing a defined p44E was used to infect a naive horse and severe combined immunodeficiency (SCID) mice. During a 58-day infectio...
Heterogeneous clearance of antithymocyte globulin after CD34+-selected allogeneic hematopoietic progenitor cell transplantation. Antithymocyte globulins (ATG) are purified, concentrated preparations of polyclonal immunoglobulin G from hyperimmune serum of horses or rabbits immunized with human thymus lymphocytes. Both the horse and the rabbit products induce immunosuppression as a result of lymphocyte depletion and immune modulation. The exact mechanism of action is unknown but may include T-cell clearance from the circulation and modulation of T-cell activation, homing, and cytotoxic activities. Both horse and rabbit ATG include multiple antibodies against T-cell surface antigens and have been used extensively in allog...
Sequence analysis of canine and equine ferritin H and L subunit cDNAs. Canine and equine ferritin H and L subunit cDNA clones were obtained using reverse transcriptase-polymerase chain reaction (RT-PCR) and TA cloning from various tissues. Canine liver and spleen ferritin H subunit cDNA clones contained an open reading frame for the same 182-amino acid protein as that reported in canine brain ferritin H subunit cDNA although there were substitutions in the 3'-noncoding regions. Ferritin L subunit cDNA clones from canine liver, spleen, and kidney showed identical coding sequences encoding the 174-amino acid protein except for a single nucleotide substitution in ki...
Mast cells and IgE-bearing cells in lungs of RAO-affected horses. Recurrent airway obstruction (RAO) is a common condition in stabled horses characterised by small airway inflammation and obstruction following exposure of susceptible horses to mouldy hay and straw. The aim of the present study was to investigate whether lung tissue from horses with RAO contains higher numbers of IgE-protein positive (+) cells and mast cells compared to controls after mouldy hay challenge. Furthermore, mast cell subtypes in lung tissue were investigated. IgE+ cells were detected in most lung tissue samples but no significant differences between RAO-affected and control horses...
The equine larynx. A series of landmark studies on the function of the equine larynx was conducted by a group of researchers at Massey University between 1970 and 1987. These studies commenced with investigations on the normal laryngeal anatomy and physiology (Goulden et al 1976a; Anderson et al 1980; Quinlan et al 1982), and progressed to a clinical appraisal of laryngeal hemiplegia, the most important clinical disease affecting the horse's larynx (Goulden and Anderson 198 lab, 1982). The studies concluded with a series of in-depth cytological and pathological studies of the intrinsic laryngeal muscles and nerv...
Post operative neutrophilic inflammation in equine small intestine after manipulation and ischaemia. Post operative ileus (POI) remains an important cause of post operative morbidity and mortality in the horse. However, clinical progression of naturally occurring cases of POI in both horse and man does not entirely support the 'neurogenic' hypothesis as the sole mechanism of POI; and the hypothesis that inflammation plays a major role at 12-24 h after surgery requires validation. Objective: An inflammatory infiltrate in the muscularis externa and myenteric plexus of equine jejunum is present 18 h following a period of ischaemia. Methods: Samples of normal jejunum, jejunum from the proximal re...
Modelling long-term survival of horses following surgery for large intestinal disease. Large intestinal diseases are an important cause of equine colic that require surgical management, but there is little published information about long-term survival of such cases. Objective: To identify variables associated with post operative mortality and to develop a model for post operative survival following surgery for large intestinal disease. Methods: Clinical data and long-term follow-up information from 275 horses undergoing surgery for large intestinal disease were used. A multivariable, Cox proportional hazards model for post operative death was developed and the fit of the model ...
In vitro evaluation of the effect of the opioid antagonist N-methylnaltrexone on motility of the equine jejunum and pelvic flexure. Although potent analgesics, opioids decrease intestinal activity, leading to ileus in many species. N-methylnaltrexone (MNTX), an opioid antagonist which does not cross the blood-brain barrier and antagonises the morphine effect on the intestine, directly stimulates motility and restores function without affecting analgesic properties. While its use has been reported in human subjects, there is no information with regard to its usage in the horse. Objective: To determine whether MNTX has an effect on contractile activity of the equine jejunum and pelvic flexure. Methods: Using circular smooth ...
A retrospective analysis of left dorsal displacement of the large colon treated with phenylephrine hydrochloride and exercise in 12 horses (1996-98). To review the outcome of cases of left dorsal displacement of the large colon (LDDLC) treated with phenylephrine HCl and mild exercise. Methods: Physical parameters, laboratory data, ultrasonographic findings and outcome were analysed in a retrospective study of 12 horses with a confirmed diagnosis of LDDLC which were treated with phenylephrine HCl and mild exercise. Results: Administration of phenylephrine HCl and mild exercise resulted in the resolution of LDDLC in 11 of 12 treated horses. One horse failed to resolve the entrapment and required surgical correction. Conclusions: Administratio...
Evaluation of peritoneal fluid lactate as a marker of intestinal ischaemia in equine colic. The most common cause of death as a direct result of colic is acute circulatory failure secondary to intestinal ischaemia. Early and accurate recognition of ischaemic bowel is essential to decrease complications and increase survival. Blood to peritoneal lactate values have been evaluated as a prognostic indicator, but lactate values characterised by type of lesion have not been reported. Objective: Plasma and peritoneal lactate values are higher in horses with intestinal ischaemia secondary to a strangulating obstruction (ISSO). Methods: Venous blood and peritoneal fluid were collected sequen...
Equine respiratory viruses in foals in New Zealand. To identify the respiratory viruses that are present among foals in New Zealand and to establish the age at which foals first become infected with these viruses. Methods: Foals were recruited to the study in October/ November 1995 at the age of 1 month (Group A) or in March/ April 1996 at the age of 4-6 months (Groups B and C). Nasal swabs and blood samples were collected at monthly intervals. Nasal swabs and peripheral blood leucocytes (PBL) harvested from heparinised blood samples were used for virus isolation; serum harvested from whole-blood samples was used for serological testing for the...
Detection of differentially regulated genes in ischaemic equine intestinal mucosa. Colic is a serious disease syndrome in horses. Much of the mortality is associated with ischaemic-injured intestine during strangulating obstruction, yet there is limited understanding of the associated molecular events. Identification of differentially expressed genes during ischaemic injury should expand our understanding of colic and may lead to novel targeted therapeutic approaches in the future. Objective: To isolate and identify differentially expressed genes in equine jejunum following a 2 h ischaemic event compared to normally perfused jejunum. Methods: Suppressive subtractive hybridis...
