Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Disease Etiology
Disease etiology in horses refers to the study of the causes and development of diseases within equine populations. It encompasses various factors, including genetic predisposition, environmental influences, infectious agents, and nutritional imbalances, that contribute to the onset and progression of diseases in horses. Understanding disease etiology is essential for identifying risk factors and implementing preventative measures in equine health management. This topic includes research on pathogen-host interactions, the impact of management practices on disease incidence, and the role of genetic and environmental factors in disease susceptibility. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, contributing factors, and implications of disease etiology in horses.
Regional and zonal variations in the sulfation patterns of chondroitin sulfate in normal equine corneal stroma. To determine regional and zonal variation in sulfation patterns of chondroitin sulfate in normal equine corneal stroma. Methods: 22 normal eyes from 11 horses. Methods: Corneas were collected within 24 hours of death from equine necropsy specimens. After papain-chondroitinase digestion of corneal tissue, disaccharides deltaDi4S and deltaDi6S were quantified by use of capillary zone electrophoresis in the superficial, middle, and deep zones of central and peripheral regions of the cornea. Results: For the 2 regions combined, deltaDi6S/deltaDi4S values were significantly lower in the deep and mi...
Effect of acute airway inflammation on the pulmonary antioxidant status. Effects of acute airway inflammation induced by organic dust inhalation on pulmonary antioxidant status were investigated in healthy horses and horses affected by recurrent airway obstruction. Exposure to organic dust induced acute airway neutrophilia, which was associated with increases in elastase and decreases in ascorbic acid concentrations in bronchoalveolar lavage fluid. However, markers of oxidative stress were unaffected, as was hydrogen peroxide in breath condensate. Decreases in ascorbic acid correlated with increased respiratory resistance (P = .001) when both groups were combined. ...
Specific localisation of gap junction protein connexin 32 in the gastric mucosa of horses. In the glandular stomach, gap junctional intercellular communication (GJIC) plays an important role in the gastric mucosal defense system, and loss of GJIC is associated with ulcer formation. In spite of the high incidence of gastric ulcers in horses, particularly at pars nonglandularis, the presence of gap junctions in the equine stomach has not yet been studied. The objective was to obtain basic data on the distribution of gap junction protein connexin 32 (Cx32) in the different regions of normal equine gastric mucosa. Samples of mucosa were taken from seven horses at cardiac, fundic, and py...
[Equine strongyles. I. Development of anthelmintic resistance]. Small strongyles (cyathostomes) that are resistant against anthelmintics have become a major problem in equine medicine in the recent years. In many European countries benzimidazole-resistant cyathostomes are widespread and are now present in well over 50% of equine populations investigated. In contrast, resistance against ivermectin has not been reported despite its widespread use in the recent years. Optimising the frequency of treatments based on quantitative faecal monitoring is of great importance to preserve remaining anthelmintic efficacy.
Changes in structure of lymphatic organs in foals died due to Rhodococcus equi infection. The aim of this study was to investigate the structure of lymphatic organs in foals which died due to Rhodococcus equi infection. The material for this study consisted of 9 foals, of both genders, various breeds, 6-14 weeks old. The routine histopathological examination and immunocytochemical reaction for cytokeratine-3 receptors revealed the disturbances in the thymus epithelial cells development. This was manifested by a complete lack of cells expressing cytokeratine-3 receptors, as well as absence of normal thymocytes differentiation. The supposed thymus epithelial cells were very few, expr...
Equine amniotic membrane transplantation for corneal ulceration and keratomalacia in three horses. Amniotic membrane has antifibrotic, anti-angiogenic and antiprotease properties. This retrospective study was designed to investigate the use of equine amniotic membrane transplants (AMT) at preserving vision, maintaining the structural integrity of the globe and maximizing cosmesis in equine eyes with corneal ulceration and severe keratomalacia. Methods: Equine amnion had previously been aseptically harvested from a 12-year-old Thoroughbred mare during an elective Cesarean section. Sections of amnion were stored at -80 degrees C and thawed as needed. Records of equine cases at the University ...
Gastric ulcer development in horses in a simulated show or training environment. To determine whether conditions representing activities that are typical in the recreational use of horses, including transport to and from show grounds, stall confinement in unfamiliar surroundings, and light exercise, are associated with increased incidence of gastric ulcers in horses. Methods: Randomized controlled study. Methods: 20 client-owned horses. Methods: Horses had no gastric ulcers as determined by endoscopic examination on study day -1. Ten control horses were maintained on-site with no changes in management variables. Ten horses were transported via trailer for 4 hours on day 0 ...
Factors associated with adverse reactions induced by caprylic acid-fractionated whole IgG preparations: comparison between horse, sheep and camel IgGs. Caprylic acid purification of IgG, currently used in the manufacture of horse-derived antivenoms, was successfully adapted for the preparation of sheep and camel IgG. Sheep IgG had a molecular mass of approximately 150 kDa, whereas camel IgG presented two bands of molecular masses of approximately 160 and 100 kDa, the latter corresponding to heavy-chain IgG, which is devoid of light chains. Horse, sheep and camel IgGs were compared by several parameters aiming at predicting their potential for induction of early and late adverse reactions. Horse and sheep IgGs showed a higher anticomplementary...
Comparison of results for intradermal testing between clinically normal horses and horses affected with recurrent airway obstruction. To evaluate differences in response to ID injection of histamine, phytohemagglutinin (PHA), and Aspergillus organisms between clinically normal horses and horses with recurrent airway obstruction (RAO). Methods: 5 healthy adult horses and 5 adult horses with RAO. Methods: Intradermal testing (IDT) was performed on the neck with 2 positive control substances (histamine and PHA) and a mixture comprising 5 Aspergillus species. Four concentrations of each test substance plus a negative control substance were used. Equal volumes (0.1 mL) of each test substance were prepared to yield 15 syringes ([4...
Comparative linkage mapping of the Grey coat colour gene in horses. Grey horses are born coloured, turn progressively grey and often develop melanomas late in life. Grey shows an autosomal dominant inheritance and the locus has previously been mapped to horse chromosome 25 (ECA25), around the TXN gene. We have now developed eight new single nucleotide polymorphisms (SNPs) associated with genes on ECA25 using information on the linear order of genes on human chromosome 9q, as well as the human and mouse coding sequences. These SNPs were mapped in relation to the Grey locus using more than 300 progeny from matings between two Swedish Warmblood grey stallions and...
Leukocyte emigration in the early stages of laminitis. The mechanisms that initiate the pathophysiologic changes in the digital laminae in equine laminitis are poorly understood. Due to the fact that (1) the horse at risk of laminitis has many similarities clinically to the human sepsis patient and (2) our recent finding of marked laminar proinflammatory cytokine expression at the developmental time point of the black walnut extract (BWE) model of laminitis, we tested the possibility that, similar to organ damage in human sepsis, leukocyte emigration is an early event in laminitis. Using immunoperoxidase methods with an anti-equine CD13 monoclonal...
Acute lung injury/acute respiratory distress syndrome in 15 foals. Few reports exist in the veterinary medical literature describing clinical and pathological findings resembling conditions described as (ALI) and acute respiratory distress syndrome (ARDS) in man. Objective: To document history, clinical, laboratory and diagnostic findings, treatment and outcome of foals age 1-12 months diagnosed with ALI/ARDS at a referral hospital. Methods: Medical records, including radiographic, cytological, microbiological, serological and post mortem findings, were reviewed in a retrospective manner to identify foals with acute onset of respiratory distress, a partial pr...
Functional consequences of cartilage degeneration in the equine metacarpophalangeal joint: quantitative assessment of cartilage stiffness. No quantitative data currently exist on the relationship of the occurrence of cartilage degeneration and changes in site-specific biomechanical properties in the metacarpophalangeal (MCP) joint in the horse. Objective: To gain insight into the biomechanical consequences of cartilage deterioration at 2 differently loaded sites on the proximal articular surface of the proximal phalanx (P1). Objective: Static and dynamic stiffness of articular cartilage decreases significantly in degenerated cartilage. Methods: Cartilage degeneration index (CDI) values were measured at the lateral dorsal margin (...
Is there a characteristic distal tarsal subchondral bone plate thickness pattern in horses with no history of hindlimb lameness? Osteoarthritis (OA) is a common cause of distal tarsal pain, but disease development is poorly understood. Awareness of normal tarsal structure and function is important in order to understand the pathogenesis of OA. Thickening of the subchondral bone (SCB) plate has been related to the development of OA, but SCB plate patterns in the equine tarsus have not been documented. Objective: There is a repeatable pattern of SCB thickness across the distal tarsal joints, and specifically that thickness would be greatest dorsally and laterally. Methods: Twenty cadaver tarsi were collected from mature h...
Transarterial coil embolisation in 31 horses (1999-2002) with guttural pouch mycosis: a 2-year follow-up. There have been no previously published large case series describing short- and long-term outcome of transarterial coil embolisation (TCE) in horses with guttural pouch mycosis (GPM). Objective: To describe the clinical and surgical features of horses with GPM presented at the Veterinary School of Lyon during a 28 month period; and to evaluate immediate to long-term results of TCE as a treatment. Methods: Medical records of all horses with GPM treated with TCE between February 1999 and July 2002 were analysed. To be included in the study, no other surgical or medical treatment for the mycosis ...
Effect of composition and different fractions of hay dust suspension on inflammation in lungs of heaves-affected horses: MMP-9 and MMP-2 as indicators of tissue destruction. Airway matrix metalloproteinases (MMPs) increase following inhalation of organic dust. The relative contribution of dust components to this elevation is unknown. Objective: To identify components of organic dust responsible for elevated MMP levels in equine airways. Methods: Bronchoalveolar lavage (BALF) from 7 heaves-susceptible horses, collected 6 h following inhalation challenges with saline, 2 different hay dust suspensions (HDS-1 and -2) and soluble and particulate fractions of HDS-1, were analysed for MMP-2 and -9 using SDS-page gelatin zymography. Results: HDS-1 challenge increased BALF...
Funisitis associated with leptospiral abortion in an equine placenta. Funisitis, inflammation of the umbilical cord, is well recognized in human placentas. This report describes a case of funisitis associated with leptospiral infection in the placenta of a Thoroughbred foal born prematurely. The umbilical cord had diffuse superficial yellow discoloration along its entire length. Microscopic evaluation showed an exudate of neutrophils admixed with fibrin on the surface. Warthin-Starry staining showed spirochetes in the Wharton's jelly of the umbilical cord. A locally extensive, severe placentitis not involving the star and allantoic cystic hyperplasia were the ot...
Application of the 51Cr-EDTA urinary recovery test for assessment of intestinal permeability in the horse. Altered intestinal permeability is implicated in the pathogenesis of diverse equine medical conditions including alimentary laminitis and protein-losing enteropathies associated with parasitic infection. The aims of this study were to assess the feasibility of applying the 51Cr-EDTA absorption test for the assessment of intestinal permeability in the horse, and to apply this test in horses with experimentally induced alterations in gastrointestinal function. Four healthy ponies were administered 36 MBq of 51Cr-EDTA via naso-gastric tube, and urine samples were collected into polythene bags str...
Matrix metalloproteinase 2 (MMP-2) and tissue transglutaminase (TG 2) are expressed in periglandular fibrosis in horse mares with endometrosis. Periglandular arrangement of myofibroblasts, associated with the deposition of extracellular matrix (ECM), is a cardinal feature of endometrosis in mares. We hypothesized that a disturbance in the expression of matrix degrading enzymes such as matrix metalloproteinases (MMP's) and matrix cross-linking proteins might lead to an imbalance in deposition and degradation of extracellular matrix components and thereby accentuate degeneration. Therefore, distributions of MMP-2, capable of collagen IV and laminin degradation, and tissue transglutaminase (TG2), a cross-linker of extracellular matrix pr...
Natural infection of a horse with Fascioloides magna. A 25-year-old Quarterhorse mare was euthanized for a variety of medical reasons. At necropsy, 7 liver flukes, identified as Fascioloides magna, were recovered from the liver. This is the first report of F. magna in a horse.
[Verrucous pastern dermatitis syndrome in heavy draught horses. Part II: Clinical findings]. In the present field study the skin of the feet of 37 heavy draught horses of different breeds showing verrucous pastern dermatitis was examined clinically. Included were the degree of severity of the disease and the prevalence of anatomically normal structures associated with the skin: fetlock tufts of hair ("feathering"), ergots, chestnuts, bulges in the pastern region, cannon circumference. Each horse was examined for Chorioptes sp. skin mites. Information was also collected on the development of the skin alterations and housing conditions and feeding. These individual data were correlated ...
Respiratory mechanics in Standardbred horses with sub-clinical inflammatory airway disease and poor athletic performance. The aim of this study was to investigate and quantify respiratory mechanical dysfunctions in Standardbred horses with both poor performance and bronchoalveolar lavage fluid cytology characteristic of inflammatory airway disease (IAD). A control group of healthy Standardbred horses was compared. Respiratory mechanics and breathing pattern were examined at rest and during hyperventilation induced using a rebreathing method. At rest, respiratory mechanics and breathing pattern were superimposable in both groups. In IAD horses, rebreathing increased ventilation, with larger tidal volumes and lower...
Preliminary trial on the reproducibility of epizootic lymphangitis through experimental infection of two horses. Epizootic lymphangitis (EL) was experimentally reproduced in four horses that had been purchased from an EL-free district. Two horses were injected with either 0.2 mL of the yeast form of Histoplasma capsulatum var. farciminosum (HCF) in pus (Horse 1), or 0.2 mL (ca. 20 mg) of a suspension in saline of the mycelial form (Horse 2), both into the pre-scapular and pre-femoral lymph nodes, with scarification of the skin of the left hind limb, conjunctiva of the right eye and the nasal membrane of the right nostril. The two other horses served as controls. Nodular lesions of EL appeared during the ...
First observation of an Hashimoto thyroiditis-like disease in horses from Eastern Europe: histopathological and immunological findings. Among 622 slaughtered horses from eastern Europe, 156 thyroid glands were selected on the basis of macroscopic alterations (e.g., determination of volume and weight). In the 80% of these thyroids, microscopic alterations consistent with a diagnosis of Hashimoto thyroiditis-like disease were found. In particular, a subverted architecture of the thyroid gland with colloid rarefaction, lymphocytic infiltration, and fibrosis was noted. The confirmation of the histopathological diagnosis of an equine Hashimoto thyroiditis-like disease was provided by the increased serum concentration of thyroglobul...
Epidemic West Nile virus encephalomyelitis: a temperature-dependent, spatial model of disease dynamics. Since first being detected in New York in 1999, West Nile virus (WNV) has spread throughout the United States and more than 20,000 cases of equine WNV encephalomyelitis have been reported. A spatial model of disease occurrence was developed, using data from an outbreak of serologically confirmed disease in an unvaccinated population of horses at 108 locations in northern Indiana between 3 August and 17 October 2002. Daily maximum temperature data were recorded at meteorological stations surrounding the study area. The distribution of the total number of degree-days elapsing between July 4 and ...
Datura contamination of hay as the suspected cause of an extensive outbreak of impaction colic in horses. Datura poisoning of horses is extensively reviewed. An outbreak of intractable impaction colic affecting 18 of 83 horses was stopped by withdrawing dried tef hay contaminated with young Datura plants. The dried, botanically identified Datura stramonium and D. ferox contained respectively 0.15% mass/mass (m/m) hyoscyamine as well as 0.16% m/m hyoscine (scopolamine) and only hyoscine at a concentration of 0.11% m/m. Immature, unidentifiable plants resembling D. stramonium, contained 0.14% m/m and 0.12% m/m of the 2 respective tropane alkaloids. The outbreak was characterised by protracted and re...
Temporal regulation of cytokine mRNA expression in equine recurrent airway obstruction. Acute and chronic inflammation of the airway remains an important health problem for equids. "Heaves" or recurrent airway obstruction (RAO) remains one of the most commonly diagnosed conditions affecting the lung of older horses in Europe and the United States. The typical clinical signs of RAO include non-productive coughing, serous nasal discharge, labored expiratory effort, and flaring of the nostrils. Auscultation of the lungs of the affected horse often reveals abnormal respiratory sounds, described as crackles and wheezes, throughout the area of the lung field. These clinical signs occur...
