Topic:Animal Models
Animal models in equine research refer to the use of horses or other species to study biological and disease processes relevant to equine health. These models facilitate the investigation of various physiological and pathological conditions, allowing researchers to explore disease mechanisms, test therapeutic interventions, and understand genetic influences on health outcomes. Horses themselves are often studied as models for human diseases due to certain physiological similarities. Additionally, other species may be used to model equine-specific conditions when direct study in horses is impractical. This page compiles peer-reviewed research studies and scholarly articles that explore the application, development, and findings of animal models in equine research.
Genetics of racing performance in the Japanese Thoroughbred horse:: I. Description of the data. The Japan Racing Association (JRA) operates 10 national racecourses with both turf and dirt tracks. JRA formulates the rules for horseracing; registers owners, colors, and horses using foal registration; and licenses all JRA trainers and jockeys. In 1990, at the 10 racecourses there were 288 racing days, 3,353 races, and some 38,397 horses. Horse breeding is concentrated in 7 locations with 93% of the Thoroughbreds foaled each year coming from Hokkaido. Thoroughbred flat racing comprise 92% of all races held. Two year olds race together and nearly 40% of their races are run at 1200 m. Some 39%...
Animal models of Cushing’s disease. Cushing's disease, defined as hyperadrenocorticism resulting from excessive secretion of pituitary ACTH, occurs spontaneously and quite commonly in dogs and horses. In dogs, as in humans, the disease is usually associated with a small tumor of the pituitary pars distalis. However, the disease may arise occasionally (dogs) or exclusively (horses) from tumors or hyperplasia of the pituitary pars intermedia. In dogs, pars intermedia tumors may arise from one of two proopiomelanocortin-containing cell types that are present in normal tissue.
The frequent occurrence of thyroid tumours in aged horses. Thyroid tumours have been described as "moderately common" in horses, but diseases associated with them are rare and the actual incidence has not been reported. A survey of thyroids from 29 horses aged 12 to 32 years revealed gross lesions in 11 animals, all older than 17. Most lesions were microfollicular adenomas. There was no evidence that the horses suffered from long-standing iodine deficiency or diffuse hyperplasia. Adenomas were more common than hyperplastic nodules and it is unlikely that the former arose from the latter. One thyroid adenocarcinoma was discovered. Progression from thyr...
Equine herpesviruses 2 and 5: comparisons with other members of the subfamily gammaherpesvirinae. This chapter describes the molecular and biological properties of equine herpesviruses (EHV)2 and EHV5. It highlights advances in the study of EHV2 and EHV5. The reclassification of EHV2 and EHV5 as gammaherpesviruses rather than betaherpesviruses has profound implications for future approaches to the study of the two equine herpesviruses. The chapter places emphasis on a comparison between the properties of EHV2 and EHV5 and those of other gammaherpesviruses, especially Epstein-Barr virus (EBV), which is the causative agent of infectious mononucleosis/glandular fever in humans. Studies of the...
[The immunogenic properties of a recombinant vaccinia virus with an incorporated DNA copy of the 26S RNA of the Venezuelan equine encephalomyelitis virus]. A recombinant strain of vaccinia virus (VR26) containing a DNA-copy of the subgenomic 26S RNA of Venezuelan equine encephalomyelitis virus (VEE) inserted into the coding region of thymidine kinase (TK) gene was produced. This subgenomic RNA contained the genes for all structural proteins of the VEE virus, the strain Trinidad donkey (TRD). VR26 effectively expressed VEE virus glycoproteins on the membranes of the infected cells. Blood sera of VR26-immunized animals were found to contain VEE virus-specific antibodies. VR26-immunized mice and rabbits showed a high level of resistance to subcutane...
Technical note: equine skeletal preservation techniques to enhance teaching effectiveness. When the decision was made to euthanatize an acutely laminitic Thoroughbred broodmare, graduate students from the Department of Animal Sciences and Industry reconstructed the skeleton for use as a teaching tool. The reproductive and gastrointestinal tracts were removed and preserved in formalin. The hide, muscle, tendons, ligaments, and organs were removed, and the bones were boiled in water for > or = 48 h to remove all remaining tissue. After boiling, the bones were soaked in gasoline to remove fat from the marrow cavities and then soaked in a bleach/detergent mixture as a final cleaning ...
Effects of gestation, lactation, and maternal calcium intake on mechanical strength of equine bone. Skeletal homeostasis during late gestation, lactation, and the post-lactational recovery period is poorly understood. In an experiment using an animal model (the horse), metacarpal breaking strengths (MBS) estimated via transmission ultrasonics were examined during the last 12 weeks of gestation and for 40 weeks after parturition. MBS increased during the last 6-10 weeks of gestation in mares fed amounts of calcium (Ca) recommended by the National Research Council; maximum MBS coincided with the week of parturition. In contrast, MBS in mares fed 20% less Ca remained relatively constant during ...
Development of a competitive enzyme-linked immunosorbent assay for detection of bovine, ovine, porcine, and equine antibodies to vesicular stomatitis virus. Two competitive (C) enzyme-linked immunosorbent assays (ELISAs) were developed for the detection of antibodies to vesicular stomatitis virus (VSV) in animal sera. The assays are based upon the availability of polyclonal antibodies (PAbs) from mouse ascitic fluids prepared against the New Jersey (NJ) and the Indiana (IN) VSV serotypes. The assays were performed by the immobilization of VSV-NJ and VSV-IN antigens on a solid phase (microtiter plate). Appropriately diluted test serum mixed with an equal volume of serotype-specific PAb was allowed to incubate in the presence of the relevant VSV ant...
Pathogenicity of a thymidine kinase-deficient mutant of equine herpesvirus 1 in mice and specific pathogen-free foals. Both intranasal (i.n.) and intracerebral (i.c.) inoculation of mice with wild-type equine herpesvirus type 1 (wt EHV-1) caused clinical signs and mortality. Virus could be recovered from target organs (turbinates, lungs and blood) for several days. By contrast, the thymidine kinase (TK)-deficient deletion mutant PR1 produced markedly less clinical disease following both i.n. and i.c. inoculation, and, in particular, no mortality occurred. PR1 did, however, establish productive infections following either route of inoculation. High titres of virus were recovered from target organs although viru...
Maturation of the central nervous system: comparison of equine and other species. This review covers the development and maturation of the cerebellum of the horse and compares this developmental sequence with that of man, mouse and chicken. These comparisons attempt to correlate morphological and neurochemical features, developmental time and functional performance necessary for survival at birth. Although there is great disparity between these 3 species, the basic anatomical structures of the cerebellum are present as are specific cellular groups, synapses and neurochemical markers. In addition to this structural homogeneity, other attributes of the cerebellum are its easi...
Multi-body modelling and simulation of animal locomotion. Multi-body models of musculoskeletal systems can be used to determine internal forces from measured external forces and movements ('inverse dynamics') and to perform simulations of movements using muscle forces or activations as input ('direct dynamics'). Examples of 'direct' simulations of movements in the horse are presented. With a model of the equine hindlimb, the function of the 'passive stay apparatus' could be explained. A model of the forelimb was used to determine force distributions in the digital flexor tendons, and to experiment with various methods to change the force distribution...
Pinealitis accompanying equine recurrent uveitis. There is no direct verification of pineal gland involvement in human uveitis. Specimens of pineal tissue are not available during active uveitis in human patients. Naturally occurring uveitis in horses gives us an opportunity to examine tissues during active ocular inflammation. We examined the pineal gland of a horse that was killed because it had become blind during an episode of uveitis. The clinical history and histopathology of the eyes were consistent with post-leptospiral equine recurrent uveitis. The pineal gland of this horse had significant inflammatory infiltration consisting mainly...
Effects of holmium:YAG laser on equine articular cartilage and subchondral bone adjacent to traumatic lesions: a histopathological assessment. This study was performed to investigate the effects of holmium:yttrium-aluminum-garnet (Ho:YAG) laser energy on articular cartilage and subchondral bone adjacent to traumatically created cartilage lesions in a continuous weight-bearing model. The 2.1-microns wavelength was delivered efficiently and precisely in hand-controlled contact and near-contact hard tissue arthroscopic surgery in a saline medium. Bilateral arthroscopy was performed on normal antebrachiocarpal and intercarpal joints of four adult horses. One hundred twenty traumatic lesions were created on three weight-bearing articular ...
Ocular trauma. Horses with ocular trauma frequently present as emergency cases. This article provides a succinct review of various adnexal and globe injury issues. Accurate case assessment, management, prognosis, and follow-up considerations are presented.
Cross-species comparison of 5-lipoxygenase-activating protein. To identify regions of 5-lipoxygenase-activating protein (FLAP) important for the function of the protein and the binding of leukotriene biosynthesis inhibitors, we performed a cross-species analysis of FLAP. FLAP from all 10 mammalian species analyzed (human, monkey, horse, pig, cow, sheep, rabbit, dog, rat, and mouse) were immunologically cross-reactive and specifically bound leukotriene biosynthesis inhibitors with high affinity. Using the polymerase chain reaction, cDNA clones for FLAP from six species (monkey, horse, pig, sheep, rabbit, and mouse) were isolated and sequenced. The deduced ...
Visual acuity in the horse. We assessed the ease with which horses could learn visual discriminations and measured their resolution acuity. We trained three horses to press their noses against one of two large wooden panels to receive a small food reward. Following training on a series of two-choice discrimination tasks, resolution acuity was measured. Although there was some variability between animals, the best acuity obtained was 23.3 c deg-1. Within the margin of error imposed by limited anatomical data, the obtained values are consistent with predictions based on retinal ganglion cell density estimates and posterior...
Animal immunodeficiency viruses. Feline immunodeficiency virus (FIV) has morphological, physical and biochemical characteristics similar to human immunodeficiency virus (HIV), the cause of AIDS in man. However, it is antigenically and genetically distinct from HIV; an antigenic relatedness with equine infectious anaemia virus has been demonstrated. FIV has been molecularly cloned and sequenced. Diagnostic tests are commercially available and attempts at preparing inactivated, subunit and molecularly engineered vaccines are being made in different laboratories. During FIV infection a transient primary illness can be recognized...
Detection of group C rotavirus antigens and antibodies in animals and humans by enzyme-linked immunosorbent assays. Enzyme-linked immunosorbent assays (ELISAs) were developed to detect group (gp) C rotavirus antigens and antibodies. Both assays were confirmed to be specific for gp C rotavirus by using serogroup A, B, and C rotaviruses; hyperimmune antisera to these serogroups of rotaviruses; and paired serum specimens from animals infected with gp C rotaviruses. The ELISA for antigen detection reacted not only with porcine gp C rotaviruses but also with human and bovine gp C rotaviruses. Following experimental challenge of gnotobiotic pigs with porcine gp C rotavirus, the virus was found by ELISA in all dia...
Evaluation of intra-articularly administered sodium monoiodoacetate-induced chemical injury to articular cartilage of horses. Three doses of sodium monoiodoacetate (MIA) were used to induce degenerative changes in articular cartilage in middle carpal joints of horses. Twelve young (2- to 5-year-old) horses, free of lameness, were randomly allotted to 3 groups. One middle carpal joint of each horse was injected with 0.9% NaCl solution (control joint). The contralateral middle carpal joint was injected with 0.09 mg of MIA/kg of body weight (group 1); 0.12 mg/kg (group 2); or 0.16 mg/kg (group 3). After MIA administration, horses were allowed ad libitum exercise in a 2-acre paddock for 12 weeks. At the end of the study,...
Increased pulmonary production of immunoreactive 15-hydroxyeicosatetraenoic acid in an animal model of asthma. Airway obstruction and hyperreactivity are characteristics of human asthma and of "heaves," a naturally occurring respiratory disorder of horses and ponies. We measured pulmonary function and plasma immunoreactive 15-hydroxyeicosatetraenoic acid (i15-HETE) concentrations in simultaneously collected carotid artery and right ventricle blood samples in five affected ponies and their age- and gender-matched control ponies. Measurements and sampling were performed before (Period A), during (Period B), and following recovery from (Period C) acute airway obstruction precipitated by housing ponies in ...
Brachygnathia in horses: 20 cases (1979-1989). The medical records of 20 horses admitted to the veterinary medical center with a diagnosis of brachygnathia over a 10-year period (1979 to 1989) were reviewed. The study included 18 foals and 2 adult horses. Males were affected 5.7 times more frequently than females. The amount of disparity between the mandible and premaxilla varied between 0.75 and 3 cm. Sixteen foals were treated surgically with the temporary application of premaxillary tension band devices. Thirteen of the 16 surgical cases were available for follow-up evaluation. All of the surgically treated animals had improved incisive...
Pinealitis coincident with recurrent uveitis: immunohistochemical studies. Although experimental models of autoimmune uveitis predict pinealitis coincident with uveitis, there is no direct evidence of pineal pathology accompanying a human uveitis. Horses with naturally occurring uveitis are a potential source of eye and pineal tissues that are not available from human patients with active uveitis. We have observed pinealitis in a mare with equine recurrent uveitis. By immunohistochemistry we demonstrated immunoglobulin and MHC Class II antigen on infiltrating and resident cells of eye and pineal gland. These results support the relevance of the animal models and sugg...
Domestic animal models of severe combined immunodeficiency: canine X-linked severe combined immunodeficiency and severe combined immunodeficiency in horses. This review describes the clinical, immunologic and pathologic features of two naturally-occurring models of severe combined immunodeficiency (SCID) in domestic animals that represent different forms of human SCID. Canine X-linked SCID (XSCID) has an X-linked recessive mode of inheritance and, as such, represents a model for the most common form of human SCID in the United States. Affected dogs have normal percentages of circulating B cells and low to normal percentages of phenotypically mature, but nonfunctional T cells. Severe combined immunodeficiency in the horse is an autosomal recessive ...
[Teratogenic effect of the Venezuelan equine encephalitis virus: a review of the problem]. Clinical findings on Venezuelan Equine Encephalitis virus infection and the teratogenic effects of several Togaviruses are described. Similarities between the intrauterine alterations induced by Venezuelan Equine Encephalitis virus and rubella virus are pointed out. Findings described by Wenger in 1967 were those of massive cerebral necrosis in fetuses of women presumably suffering of encephalitis and they are commented along with the development of an animal experimental model at the end of 1970-1980. Pathogenesis of the intrauterine infection seemed to be related to changes in the placental ...
Immunotherapy of cryptosporidiosis in immunodeficient animal models. Immunotherapy for persistent infection caused by Cryptosporidium parvum was attempted in two immunodeficient animal models. BALB/c Athymic (nude) mice were infected with two oral doses of 2 x 10(7) C. parvum oocysts, and subsequently treated with monoclonal antibody (MAb) 17.41 that neutralizes sporozoites and merozoites. Persistent infection was established in all exposed mice. Daily oral treatment with MAb 17.41 for 10 days significantly reduced (p less than 0.005) the number of C. parvum organisms observed by microscopic study of intestinal tracts of infected mice. Young horses with severe ...
Chronic cervical compressive myelopathy in horses: patterns of astrocytosis in the spinal cord. The distribution and morphology of fibrous astrocytes in the cervical spinal cord of normal horses and horses with chronic compressive myelopathy were demonstrated using immunohistochemical staining for glial fibrillary acidic protein. In the spinal cord from normal horses, astrocytes with stellate cell bodies and short processes were irregularly distributed in grey matter. In the white matter, their cell bodies were small and angular in areas adjacent to grey matter and larger and more stellate-shaped in the subpial area. Astrocyte processes were fine, and evenly distributed in a predominantl...
Comparative growth of different rotavirus strains in differentiated cells (MA104, HepG2, and CaCo-2). The production of viral antigen after infection of MA104, HepG2 (derived from human liver), and CaCo-2 (derived from human colon) cells with various cultivatable human and animal rotavirus strains was compared using immunofluorescence tests. All rotavirus strains examined expressed antigen in CaCo-2 cells and MA104 cells, but only some virus strains, namely, SA11-Cl3 (simian), RRV (simian), CU-1 (canine), and Ty1 (turkey), produced antigen in numbers of infected HepG2 cells comparable to infections in MA104 and CaCo-2 cells. Fl-14 (equine), OSU (porcine), NCDV (bovine), and Ch2 (chicken) strai...