Topic:Animal Study
Animal studies involving horses encompass a wide range of research activities aimed at understanding various aspects of equine biology, behavior, health, and management. These studies can include investigations into equine physiology, nutrition, reproduction, and disease processes. Research often involves controlled experiments or observational studies to gather data on how horses respond to different interventions, environments, or management practices. This topic includes peer-reviewed research studies and scholarly articles that explore methodologies, findings, and implications of animal studies in equine science, contributing to the broader understanding of horse welfare and management.
Evidence for a retroviral insertion in TRPM1 as the cause of congenital stationary night blindness and leopard complex spotting in the horse. Leopard complex spotting is a group of white spotting patterns in horses caused by an incompletely dominant gene (LP) where homozygotes (LP/LP) are also affected with congenital stationary night blindness. Previous studies implicated Transient Receptor Potential Cation Channel, Subfamily M, Member 1 (TRPM1) as the best candidate gene for both CSNB and LP. RNA-Seq data pinpointed a 1378 bp insertion in intron 1 of TRPM1 as the potential cause. This insertion, a long terminal repeat (LTR) of an endogenous retrovirus, was completely associated with LP, testing 511 horses (χ(2)=1022.00, p<<...
Detection and elimination profile of cathinone in equine after norephedrine (Propalin®) administration using a validated liquid chromatography-tandem mass spectrometry method. Cathinone is the principal psychostimulant present in the leaves of khat shrub, which are widely used in East Africa and the Arab peninsula as an amphetamine-like stimulant. Cathinone readily undergoes metabolism in vivo to form less potent cathine and norephedrine as the metabolites. However, the presence of cathine and norephedrine in biological fluids cannot be used as an indicator of cathinone administration. The metabolism of pseudoephedrine and ephedrine, commonly used in cold and allergy medications, also produces cathine and norephedrine, respectively, as the metabolites. Besides, cath...
Conditioned medium from horse amniotic membrane-derived multipotent progenitor cells: immunomodulatory activity in vitro and first clinical application in tendon and ligament injuries in vivo. We have recently demonstrated that heterologous transplantation of horse amniotic membrane-derived mesenchymal cells (AMCs) can be useful for cell therapy applications in tendon diseases, and hypothesized that these cells may promote tendon repair via paracrine-acting molecules targeting inflammatory processes. To test this hypothesis, here we examined the immunomodulatory characteristics of AMCs and of their conditioned medium (AMC-CM) in vitro, and studied the potential therapeutic effect of AMC-CM in thirteen different spontaneous horse tendon and ligament injuries in vivo. Our results demo...
Multiple glucagon-producing pancreatic neuroendocrine tumors in a horse (Equus caballus). Pancreatic neuroendocrine tumors of glucagon-producing cells are extremely rare in domestic animals. In this report, we describe for the first time, to our knowledge, the incidental finding of multiple glucagon-producing neuroendocrine tumors of the pancreas of a horse. The animal was euthanized due to severe local infection after tooth extraction. On postmortem examination, multiple white nodules of up to 4 cm in diameter were observed in the pancreas. Histologically, pancreatic nodules had the appearance of neuroendocrine neoplasms with positive immunoreactivity for glucagon, synaptophysin, ...
Detection of Neorickettsia risticii from various freshwater snail species collected from a district irrigation canal in Nevada County, California. This study investigated the role of a district irrigation canal in Nevada County, California, USA, as the point source of infection for Neorickettsia risticii, causative agent of equine neorickettsiosis (EN). A total of 568 freshwater snails comprising Juga spp., Planorbella subcrenata (Carpenter, 1857) (Rough Rams-horn), Physella virgata (Gould, 1855) (Protean Physa) and feces from three horses with EN were collected and tested for N. risticii by real-time PCR. A total of four freshwater snails tested PCR positive for N. risticii. Phylogenetic analysis showed 99.8-100% homology between the di...
Non-terminal animal model of post-traumatic osteoarthritis induced by acute joint injury. Develop a non-terminal animal model of acute joint injury that demonstrates clinical and morphological evidence of early post-traumatic osteoarthritis (PTOA). Methods: An osteochondral (OC) fragment was created arthroscopically in one metacarpophalangeal (MCP) joint of 11 horses and the contralateral joint was sham operated. Eleven additional horses served as unoperated controls. Every 2 weeks, force plate analysis, flexion response, joint circumference, and synovial effusion scores were recorded. At weeks 0 and 16, radiographs (all horses) and arthroscopic videos (OC injured and sham joints) ...
Effects of compressive abdominal bandaging and transrectal palpation on intra-abdominal pressures in horses. To determine the effect of an abdominal support wrap and transrectal abdominal palpation on intra-abdominal pressures (IAPs) measured directly from the peritoneal space. Methods: Prospective, experimental study. Methods: A university-based equine research facility. Methods: Ten healthy adult horses, 5 males and 5 females. Methods: IAPs were measured through an intraperitoneal cannula zeroed at a height midway between the height of the tuber ishii and point of the shoulder. Triplicate measurements were obtained at rest, during transrectal palpation, after placement of an abdominal support wrap,...
True blue: S-opsin is widely expressed in different animal species. Colour vision in animals is an interesting, fascinating subject. In this study, we examined a wide variety of species for expression of S-opsin (blue sensitive) and M-/L-opsin (green-red sensitive) in retinal cones using two novel monoclonal antibodies specific for peptides from human opsins. Mouse, rat and hare did not express one of the investigated epitopes, but we could clearly prove existence of cones through peanut agglutinin labelling. Retinas of guinea pig, dog, wolf, marten, cat, roe deer, pig and horse were positive for S-opsin, but not for M-/L-opsin. Nevertheless all these species ...
Seasonal pasture myopathy/atypical myopathy in North America associated with ingestion of hypoglycin A within seeds of the box elder tree. We hypothesised that seasonal pasture myopathy (SPM), which closely resembles atypical myopathy (AM), was caused by ingestion of a seed-bearing plant abundant in autumn pastures. Objective: To identify a common seed-bearing plant among autumn pastures of horses with SPM, and to determine whether the toxic amino acid hypoglycin A was present in the seeds and whether hypoglycin metabolites were present in SPM horse serum or urine. Methods: Twelve SPM cases, 11 SPM pastures and 23 control farms were visited to identify a plant common to all SPM farms in autumn. A common seed was analysed for amin...
Extensive myenteric ganglionitis in a case of equine chronic intestinal pseudo-obstruction associated with EHV-1 infection. A 7-year-old male trotter horse with a history of recurrent colic displayed clinical findings consistent with chronic intestinal pseudo-obstruction (CIP). At laparotomy, an impaction of the descending colon associated with marked atrophy of the right dorsal colon was found. The horse was humanely destroyed and tissues collected at necropsy examination revealed diffuse enteric ganglionitis comprising an infiltrate of CD3(+) T lymphocytes and plasma cells. At all levels of the intestinal tract the number of myenteric ganglia and of normal ganglion cells was decreased significantly. There were ch...
Distribution and processing of a disintegrin and metalloproteinase with thrombospondin motifs-4, aggrecan, versican, and hyaluronan in equine digital laminae. To determine the expression and distribution of a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4), its substrates aggrecan and versican, and their binding partner hyaluronan in laminae of healthy horses. Methods: Laminae from the forelimb hooves of 8 healthy horses. Methods: Real-time quantitative PCR assay was used for gene expression analysis. Hyaluronidase, chondroitinase, and keratanase digestion of lamina extracts combined with SDS-PAGE and western blotting were used for protein and proteoglycan analysis. Immunofluorescent and immunohistochemical staining of tiss...
Effect of intraperitoneal PERIDAN™ concentrate adhesion reduction device on clinical findings, infection, and tissue healing in an adult horse jejunojejunostomy model. To evaluate the effect of PERIDAN™ Concentrate on clinical findings, infection, and tissue healing in adult horses undergoing celiotomy and jejunojejunostomy. Methods: Block randomized blinded experimental in vivo study. Methods: Adult horses (n = 12). Methods: Horses had jejunojejunostomy at 2 sites and were administered 5 L of diluted PERIDAN™ Concentrate (6 horses) or Lactated Ringer's Injection (LRS) control intraperitoneally (6 horses) before body wall closure. Postoperative monitoring comprised physical examinations, serial hematology, coagulation and chemistry panels, and ultrasonog...
Agreement between arterial partial pressure of carbon dioxide and saturation of hemoglobin with oxygen values obtained by direct arterial blood measurements versus noninvasive methods in conscious healthy and ill foals. To determine agreement between indirect measurements of end-tidal partial pressure of carbon dioxide (PetCO(2)) and saturation of hemoglobin with oxygen as measured by pulse oximetry (SpO(2)) with direct measurements of PaCO(2) and calculated saturation of hemoglobin with oxygen in arterial blood (SaO(2)) in conscious healthy and ill foals. Methods: Validation study. Methods: 10 healthy and 21 ill neonatal foals. Methods: Arterial blood gas analysis was performed on healthy and ill foals examined at a veterinary teaching hospital to determine direct measurements of PaCO(2) and PaO(2) along wit...
Network simulation modeling of equine infectious anemia in the non-racehorse population in Japan. An equine infectious anemia (EIA) transmission model was developed by constructing a network structure of horse movement patterns in a non-racehorse population. This model was then used to evaluate the effectiveness and efficiency of several EIA surveillance strategies. Because EIA had not been detected in Japan since 1993, it was appropriate to review the current surveillance strategy, which aims to eradicate EIA by intensive testing, and to consider alternative strategies suitable for the current EIA status in Japan. The non-racehorse population was divided into four sectors based on horse u...
Serum amyloid A is expressed in histologically normal tissues from horses and cattle. mRNA expression of the acute phase protein serum amyloid A (SAA) in histologically normal tissues derived from horses (n=13) and cattle (n=4) was investigated by quantitative reverse-transcriptase real-time polymerase-chain reaction. As expected, high constitutive SAA mRNA expression was demonstrated in hepatic tissue in both species. In horses, moderate (>1% of the hepatic expression) SAA mRNA expression was detected in the lung, mammary gland, pancreas, synovial membrane, thymus, thyroid gland and uterus. Other equine tissues and organs sampled included adipose tissue, adrenal gland, aort...
Dynamic mobilisations in cervical flexion: Effects on intervertebral angulations. Based upon human data, it is probable that many conditions associated with neck pain in horses may benefit from performing mobilisation exercises as part of the rehabilitation protocol. Objective: To compare sagittal plane intervertebral angulations in a neutral standing position with the angulations at end range of motion in 3 dynamic mobility exercises performed in cervical flexion. Methods: Sagittal plane motion of the head, neck and back were measured in 8 sound horses standing in a neutral position and in 3 end-of-range neck flexion positions: chin-to-chest, chin-between-carpi, and chin-b...
Adaptive molecular evolution of the Major Histocompatibility Complex genes, DRA and DQA, in the genus Equus. Major Histocompatibility Complex (MHC) genes are central to vertebrate immune response and are believed to be under balancing selection by pathogens. This hypothesis has been supported by observations of extremely high polymorphism, elevated nonsynonymous to synonymous base pair substitution rates and trans-species polymorphisms at these loci. In equids, the organization and variability of this gene family has been described, however the full extent of diversity and selection is unknown. As selection is not expected to act uniformly on a functional gene, maximum likelihood codon-based models o...
Effects of equine grass sickness on sympathetic neurons in prevertebral and paravertebral ganglia. Acute equine grass sickness (EGS) is a fatal disease of horses that is thought to be due to ingestion of a neurotoxic agent causing extensive damage to autonomic neurons. The aim of this study was to compare the effects of EGS on neurons in two sympathetic ganglia, the paravertebral cranial cervical ganglion (CCG) and the prevertebral coeliac/cranial mesenteric ganglion (CG/CMG). Specimens from horses with EGS and controls were obtained post mortem and processed using single and double immunofluorescence labelling for PGP 9.5 and HuC/HuD (pan-neuronal markers), TUNEL and caspase 3 (markers for...
Periodontal regeneration capacity of equine particulate bone in canine alveolar bone defects. This study was performed to evaluate the periodontal wound healing effect of particulate equine bone mineral on canine alveolar bone defects. Methods: Twelve adult male beagle dogs were used as study subjects. The mandibular second and fourth premolars were extracted prior to the experimental surgery, and the extraction sites were allowed to heal for 8 weeks. After periodontal probing, two-walled defects were created at the mesial and distal sides of the mandibular third premolars bilaterally, and the defects were filled with equine particulate bone with collagen membrane or bovine particulate...
Analysis of multiyear studies in horses in Kentucky to ascertain whether counts of eggs and larvae per gram of feces are reliable indicators of numbers of strongyles and ascarids present. Increasing levels of anthelmintic resistance in equine nematodes have led to recommendations of more sustainable anthelmintic treatment protocols with emphasis on parasite surveillance and diagnosis, rather than prophylactic calendar-based treatments. This requires knowledge of the diagnostic test performance of techniques for counts of eggs per gram of feces (EPG) as well as methods for culturing, counting and identifying third stage (L(3)) strongyle larvae per gram of feces (LPG). For horses, such information does not exist in the published literature. The aim of this study was to examine th...
Critical tests evaluating efficacy of moxidectin against small strongyles in horses from a herd for which reduced activity had been found in field tests in Central Kentucky. Critical tests were performed in 2009 and 2010 in four 2-year-old horses naturally infected with internal parasites. The horses were from a herd (Farm MC) where reduced activity of ivermectin and moxidectin on small strongyles was demonstrated previously from EPG (eggs/gram of feces) data in field tests. Also, in critical tests in horses from the same herd, ivermectin was less effective on immature small strongyles in the lumen of the large intestine than when the drug was first marketed. The main interest in the present critical tests was to determine the efficacy of moxidectin (400 μg/kg) o...
Osteogenic comparison of expanded and uncultured adipose stromal cells. Adipose stromal cells (ASC) are a promising alternative to progenitor cells from other tissue compartments because of their multipotential and capacity to retrieve significantly more progenitor cells. Initial cell samples are heterogeneous, containing a collection of cells that may contribute to tissue repair, but the sample becomes more homogeneous with each passage. Therefore, we hypothesized that the osteogenic potential of culture-expanded ASC would differ from uncultured ASC. Methods: Adipose tissue was collected from a yearling colt, and ASC were isolated and expanded using standard prot...
Clinical aspects of multinodular pulmonary fibrosis in two warmblood horses. Two warmblood horses with a history of chronic weight loss and inappetence were referred to the Faculty of Veterinary Medicine, Ludwig-Maximilians University of Munich, Germany, for further examination. The clinical signs in horse 1 were fever, tachycardia and tachypnoea, and chronic ulcerative keratopathy of both eyes. Horse 2 had severe oral ulcerations and was coughing during feeding. In both horses, increased bronchovesicular sounds were heard during auscultation of the lungs. Laboratory findings included mild anaemia, lymphopenia and hypoalbuminaemia. Radiographic examination of the thora...
Spatial niche competition among helminth parasites in horse’s large intestine. The spatial distribution of large intestinal helminth parasites of 50 horses was studied. Both adult and mucosal larval stages were examined and counted within the ventral colon, dorsal colon and caecum. Thirty-three species of adult parasites were identified and their distribution in the three large intestinal regions reported, together with the localization of cyathostome encysted larvae and of empty mucosal cysts. In order to highlight interspecific interactions, both Spearman pairwise correlation (among all parasites) and multivariable negative binomial regression (among the most abundant ...
Collection of equine cord blood and placental tissues in 40 thoroughbred mares. Stem cells derived from umbilical cord tissue (UCT) and umbilical cord blood (UCB) in human subjects and horses can be obtained in a minimally invasive fashion with successful propagation of mesenchymal stem cells (MSCs). Currently there are no detailed protocols documenting a procedure to harvest UCB and UCT safely for equine stem cell propagation. Objective: UCB and UCT could be collected without harm to mare or foal. Objective: To develop a standard and safe method for UCB and UCT collection, and prospectively to compare foal and mare health between groups of animals where tissue was and wa...
In vivo evaluation of autologous cartilage fragment-loaded scaffolds implanted into equine articular defects and compared with autologous chondrocyte implantation. Current autologous chondrocyte implantation (ACI) techniques require 2 surgical procedures: 1 for cell harvest and 1 for reimplantation of cultured cells. A 1-step procedure is more desirable. Objective: A 1-step surgical procedure using autologous cartilage fragments on a polydioxanone scaffold, or CAIS (cartilage autograft implantation system), in a clinically relevant defect (15-mm diameter) within equine femoral trochlea was compared with a 2-step ACI technique as well as with empty defects and defects with polydioxanone foam scaffolds alone. Methods: Controlled laboratory study. Methods: ...
Imidocarb dipropionate clears persistent Babesia caballi infection with elimination of transmission potential. Antimicrobial treatment of persistent infection to eliminate transmission risk represents a specific challenge requiring compelling evidence of complete pathogen clearance. The limited repertoire of antimicrobial agents targeted at protozoal parasites magnifies this challenge. Using Babesia caballi as both a model and a specific apicomplexan pathogen for which evidence of the elimination of transmission risk is required for international animal movement, we tested whether a high-dose regimen of imidocarb dipropionate cleared infection from persistently infected asymptomatic horses and/or elimi...
Evaluation of autologous chondrocyte transplantation via a collagen membrane in equine articular defects: results at 12 and 18 months. To evaluate a technique of autologous chondrocyte implantation (ACI) similar to the other techniques using cell-seeded resorbable collagen membranes in large articular defects. Methods: Autologous cartilage was harvested arthroscopically from the lateral trochlear ridge of the femur in fifteen 3-year-old horses. After culture and expansion of chondrocytes the newly created ACI construct (autologous chondrocytes cultured expanded, seeded on a collagen membrane, porcine small intestine submucosa) was implanted into 15mm defects on the medial trochlear ridge of the femur in the opposite femoropat...