Topic:Blood Vessels
Blood vessels in horses are integral components of the circulatory system, responsible for the transportation of blood throughout the body. They consist of arteries, veins, and capillaries, each serving distinct functions in maintaining circulatory efficiency. Arteries carry oxygen-rich blood away from the heart to various tissues, while veins return deoxygenated blood back to the heart. Capillaries facilitate the exchange of nutrients, gases, and waste products between blood and tissues. The structure and function of equine blood vessels are subjects of study due to their role in health and disease, including conditions such as laminitis and equine metabolic syndrome. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, and pathophysiology of blood vessels in horses.
Endothelial glycocalyx degradation in critically ill foals. Endothelial glycocalyx (EG) degradation occurs in septic humans and EG products can be used as biomarkers of endothelial injury. Information about EG biomarkers and their association with disease severity is lacking in hospitalized foals. Objective: Measure serum syndecan-1 (SDC-1), heparan sulfate (HS), angiopoietin-2 (ANG-2), aldosterone (ALD), and plasma atrial natriuretic peptide (ANP) concentrations and to determine their association with disease severity and death in hospitalized foals. Methods: Ninety foals ≤3 days old. Methods: Prospective, multicenter, longitudinal study. Foals we...
Biomechanical and histological variables differ by site but not by lameness in equine digital cushion samples from forelimbs. The equine digital cushion (DC) has been a poorly understood structure regarding its mechanical properties and composition. The objective of this study was to develop a sampling technique and to compare the biomechanical and histologic properties of DC between lame and non-lame forelimbs. Both forefeet from horses with induced carpal lameness were radiographed prior to humane euthanasia. Radiographs were used to guide sample collection of two, post-mortem, midline DC samples, palmar and dorsal, via an 8mm biopsy punch. Samples were subjected to compressive testing to determine elastic modulus....
Real-time in vivo confocal laser endomicroscopic imaging of equine endometrium: Preliminary observations and feasibility study. Endometrial health is vital for the reproductive efficiency of broodmares and accurate diagnostic testing is crucial for directing the best treatment options and outcomes. Confocal laser endomicroscopy (CLE) is an endoscopic technique for obtaining in-vivo, real-time microscopic imaging of tissues using a fiber optic probe. CLE relies on induced tissue fluorescence and fluorescein sodium, given intravenously, is the contrast agent most used in human medicine. This study aimed to determine the feasibility of CLE for imaging equine endometrium and determine a standard dose of fluorescein sodium ...
Emergency Standing Laparoscopic Treatment of Uncontrolled Post-Castration Hemorrhage in Two Geldings. Persistent hemorrhage of testicular vessels is a potentially life-threatening complication of equine castration. Frequently, general anesthesia is required to retrieve and ligate the bleeding vasculature when standing wound packing and retrieval of the spermatic cord are unsuccessful. We propose standing laparoscopic ligation of the testicular arteries via the paralumbar fossa as a rapid, effective means of halting hemorrhage while avoiding castration site trauma as well as the cardiovascular and recovery risks of general anesthesia. Methods: Two geldings, 6 and 9 months old, presented for eme...
Quantitative microCT imaging of a whole equine placenta and its blood vessel network. Placental structure is linked to function across morphological scales. In the placenta, changes to gross anatomy, such as surface area, volume, or blood vessel arrangement, are associated with suboptimal physiological outcomes. However, quantifying each of these metrics requires different laborious semi-quantitative methods. Here, we demonstrate how, with minimal sample preparation, whole-organ computed microtomography (microCT) can be used to calculate gross morphometry of the equine placenta and a range of additional metrics, including branching morphometry of placental vasculature, non-dest...
Flowmetry and spectrophotometry for the assessment of intestinal viability in horses with naturally occurring strangulating small intestinal lesions. Ancillary diagnostic methods to enhance the accuracy of viability assessment have not been established for use in clinical practice. Objective: To assess intestinal microperfusion measured by Laser Doppler Flowmetry and Spectrophotometry (LDFS) in naturally occurring small intestinal strangulations of different origins and to compare this between viable and non-viable segments. Methods: Prospective clinical trial. Methods: Forty horses undergoing colic surgery for naturally occurring small intestinal strangulations were included. Tissue oxygen saturation (tSO), haemoglobin (tHB) and blood flow...
An endothelial regulatory module links blood pressure regulation with elite athletic performance. The control of transcription is crucial for homeostasis in mammals. A previous selective sweep analysis of horse racing performance revealed a 19.6 kb candidate regulatory region 50 kb downstream of the Endothelin3 (EDN3) gene. Here, the region was narrowed to a 5.5 kb span of 14 SNVs, with elite and sub-elite haplotypes analyzed for association to racing performance, blood pressure and plasma levels of EDN3 in Coldblooded trotters and Standardbreds. Comparative analysis of human HiCap data identified the span as an enhancer cluster active in endothelial cells, interacting with genes relevant ...
Jugular venous thrombosis as a risk factor for exercise-induced pulmonary hemorrhage in thoroughbred racehorses. Exercise-induced pulmonary hemorrhage (EIPH) is one of the most commonly diagnosed disorders in racehorses. Many EIPH risk factors such as breed, age, high or low environmental temperature, and distance of the race have been studied in racehorses. Unassigned: The aim of this study was to study the relationship between EIPH and the presence of jugular vein thrombose in racehorses. Unassigned: Forty-eight thoroughbred racehorses randomly selected from animals with exercise intolerance due to respiratory disorders were enrolled in the present study. Clinical and tracheobronchoscopy examinations w...
Vascularity evaluation of the equine tarsocrural and proximal intertarsal joint septum, and comparative analysis of two arthroscopic transection techniques. To evaluate vascularity of the synovial membrane covered septum (SMS) separating the tarsocrural (TC) and proximal intertarsal (PIT) joints (Part 1) and compare two methods of transection, electrosurgical or Ferris Smith rongeur (FS rongeur) (Part 2). Methods: Experimental study. Methods: Part 1, 10 SMS (n = 5 horses). Part 2, six horses (n = 12 tarsi). Methods: In part 1, SMS harvested postmortem were each divided into eight regions of interest (ROIs), processed for histology, and immunostained with anti-α-actin antibody for blood vessel identification. Vascular density was calculate...
Immune-mediated Equine Vasculopathies. Immune-mediated vasculopathies occur secondary to infection or another noninfectious stimulus. Potential triggers include heterologous antigens including viruses, injected proteins and drugs; or auto-antigens including immunoglobulins or other endogenous proteins. Although these conditions are rare in horses, immune-mediated vasculopathies can cause considerable morbidity, with variable clinical signs depending on severity and organ system affected. Examples include purpura hemorrhagica, systemic lupus erythematosus, drug-induced vasculitis, paraneoplastic vasculitis, and idiopathic immune-med...
The Application of Infrared Thermography in the Assessment of BEMER Physical Vascular Therapy on Body Surface Temperature in Racing Thoroughbreds: A Preliminary Study. The study aimed to evaluate the impact of BEMER (Physical Vascular Therapy) on body surface temperature using infrared thermography (IRT) in the distal parts of the forelimbs in Thoroughbreds. The study tested the hypothesis that BEMER therapy leads to an increase in body surface temperature and blood vessel diameter in the distal parts of the forelimbs. The study involved 16 horses, split into 2 groups: active BEMER ( = 8) and sham ( = 8). The active BEMER group had BEMER boots applied to the distal parts of the forelimbs, whereas the sham group had BEMER boots applied without activation of t...
Arterial Blood Supply of the Stifle Joint in Horses. The vascularization pattern of the equine stifle joint is insufficiently described in the literature, even though there is a growing need for knowledge of the exact blood supply, as (i) arthroscopy and endoscopic surgery techniques are increasingly performed in horses and (ii) ex vivo models of menisci need nutrient supply that mimic the in vivo situation. The aim of this study was to describe the vessels involved in the stifle joint supply and the exact branching pattern of the popliteal artery. Colored latex was injected into the arteries of nine pelvic limbs of equine cadavers (n = 6) to ev...
Measuring tissue oxygen saturation in the orad intestinal segment during equine colic surgery may aid in predicting the occurrence of postoperative ileus. To assess the histological injury and intestinal microperfusion measured by laser Doppler flowmetry and spectrophotometry (LDFS) of the small intestine orad to a strangulation during colic surgery. Methods: Horses with naturally occurring small intestinal strangulations undergoing colic surgery were included. Methods: In this prospective clinical trial, intestinal tissue oxygen saturation (tSO2) and tissue blood flow (tBF) were measured by LDFS orad to the strangulation following release of the strangulation (n = 18). The number of horses with postoperative reflux (POR) and the cases that surv...
Osteochondrosis in the central and third tarsal bones of young horses. Recently, the central and third tarsal bones of 23 equine fetuses and foals were examined using micro-computed tomography. Radiological changes, including incomplete ossification and focal ossification defects interpreted as osteochondrosis, were detected in 16 of 23 cases. The geometry of the osteochondrosis defects suggested they were the result of vascular failure, but this requires histological confirmation. The study aim was to examine central and third tarsal bones from the 16 cases and to describe the tissues present, cartilage canals, and lesions, including suspected osteochondrosis le...
Effect of shoeing horses with eggbar shoes and shoes with wedge pads on blood flow parameters in the lateral digital artery in the Doppler ultrasound. A sound knowledge of horseshoe impact on blood flow parameters is required for making shoeing decisions and selecting the most appropriate types of shoes. The aim of this study was to determine the effect of horse shoeing with egg bar shoes and shoes with wedge pads on blood flow parameters in the lateral palmar digital artery measured by Doppler ultrasound. The study was conducted on 16 horses divided into two groups. Horses from group 1 were shod with egg bar shoes. Horses from group 2 were shod with shoes with wedge pads. Doppler ultrasound parameters of the lateral palmar digital artery at...
Assessment and comparison of microcirculation and macrocirculation in horses undergoing emergency exploratory celiotomy versus elective surgical procedures. To assess oral buccal microcirculation by hand-held videomicroscopy in horses during colic surgery, comparing microcirculation values with macrocirculatory parameters and with those of healthy elective surgical horses. Methods: Clinical prospective study. Methods: Client-owned horses (nine in the colic group; 11 in the elective group). Methods: In the colic group, buccal mucosal side stream dark-field microscopy (DFM) videos, cardiac output (CO), mean arterial pressure (MAP), and lactate were obtained at three timepoints under general anesthesia (30, 90, and 150 min after induction). Video a...
Horse serum or equine platelet lysate increases total vascular endothelial growth factor A concentrations and correlates with vascular growth in an equine facial arterial ring assay. To evaluate ex vivo angiogenesis of equine arterial rings in response to various growth media. Methods: Facial arteries were dissected from 11 horses post-euthanasia. Equine platelet lysate (ePL) was harvested from 6 horses. Methods: Arteries were exposed to endothelial growth media (EGM) + horse serum (HS) for first sprout (FS), vascular regression (VR), and (basement membrane matrix [Matrigel]) lysis (ML) evaluation. Additional rings supplemented with (1) EGM, (2) EGM + EDTA, (3) endothelial basal media (EBM), (4) EBM + HS, or (5) EBM + human VEGF were compared for vascular network area (VNA...
Characterization of exercise-induced hemolysis in endurance horses. Exercise-induced hemolysis occurs as the result of intense physical exercise and is caused by metabolic and mechanical factors including repeated muscle contractions leading to capillary vessels compression, vasoconstriction of internal organs and foot strike among others. We hypothesized that exercise-induced hemolysis occurred in endurance racehorses and its severity was associated with the intensity of exercise. To provide further insight into the hemolysis of endurance horses, the aim of the study was to deployed a strategy for small molecules (metabolites) profiling, beyond standard molec...
Expression of cannabinoid (CB1 and CB2) and cannabinoid-related receptors (TRPV1, GPR55, and PPARα) in the synovial membrane of the horse metacarpophalangeal joint. The metacarpophalangeal joint undergoes enormous loading during locomotion and can therefore often become inflamed, potentially resulting in osteoarthritis (OA). There are studies indicating that the endocannabinoid system (ECS) modulates synovium homeostasis, and could be a promising target for OA therapy. Some cannabinoid receptors, which modulate proliferative and secretory responses in joint inflammation, have been functionally identified in human and animal synovial cells. Unassigned: To characterize the cellular distribution of the cannabinoid receptors 1 (CB1R) and 2 (CB2R), and the can...
Effects of dietary zinc chloride hydroxide and zinc methionine on the immune system and blood profile of healthy adult horses and ponies. The effects of dietary zinc on the immune function of equines have not been evaluated in detail so far. In the present study, eight healthy adult ponies and two healthy adult horses were fed a diet supplemented with either zinc chloride hydroxide or zinc methionine in six feeding periods of four weeks each (according to maintenance zinc requirement, 120 mg zinc/kg dry matter, and 240 mg zinc/kg dry matter, for both dietary zinc supplements, respectively). All animals received the six diets, with increasing amounts of zinc chloride hydroxide in the feeding periods 1-3, and with increasing a...
The equine patellar ligaments and the infrapatellar fat pad – a microanatomical study. Interpretation of patellar ligament (PL) ultrasonography may be difficult, as hypoechoic or heterogenous echogenicity are common findings. Verifying suspected disease of equine PLs by histopathology is also problematic as descriptions of normal PL vascularity and histology are scarce. The current study describes the PL and infrapatellar fat pad (IFP) vascular pattern from computed tomography scans of barium perfused normal equine specimens (n = 8; age 10 days to 18 years), as well as routine histology to serve as a reference for future investigations into PL pathology and IFP disease. Re...
Periodontal structures in horses with pituitary pars intermedia dysfunction: A histological evaluation. Pituitary pars intermedia dysfunction (PPID) and dental disorders are of major concern in horses older than 15 years. Although PPID in geriatric horses and dental disorders in all age groups are well described, a connection between this endocrine disease and pathological changes in equine dental structures has not yet been investigated. In humans, periodontitis is considered to be a complication of systemic diseases like diabetes mellitus type 2, obesity and various conditions leading to an impaired immune response. In PPID, cross links to insulin and immune dysregulations are proven. The aim ...
Effects of High-Intensity Laser Therapy (HILT) on Skin Surface Temperature and Vein Diameter in Healthy Racehorses with Clipped and Non-Clipped Coat. The aim of this study was to investigate the differences in the effects of high-intensity laser therapy (HILT) on skin surface temperature and vein diameter in the carpal joint region in racehorses with clipped and non-clipped treatment areas. The study included 20 Thoroughbreds split into two equal groups: clipped coat and non-clipped coat. Horses underwent thermographic examination to detect changes in skin surface temperature at the medial surface of the carpal joint, followed by ultrasonographic examination to assess changes in the diameter of the medial palmar vein before and after HILT. ...
Equine blood flow restriction training: Safety validation. Blood flow restriction (BFR) has become a key rehabilitative tool for human orthopaedic conditions. With modernised technology and evolution of clinical application, patient-specific delivery of occlusion percentages is now considered the standard of care in human patients due to improved therapeutic outcomes and minimised safety risks. Safety validation and limb occlusion pressure (LOP) data for horses, however, are lacking. Objective: (1) To determine if BFR exposure resulted in forelimb biomechanical gait dysfunction as safety validation and (2) to investigate inter-horse and inter-limb LOP...
Assessment of the microvascular perfusion using sidestream dark-field imaging in healthy newborn foals. Different methods to measure tissue perfusion are available in equine neonatology, but they are not representative of microvascular derangements. Objective: To evaluate the feasibility of the sidestream dark-field (SDF) capillaroscopy to visualize the capillary microvasculature in conscious newborn foals, the differences between two imaging sites and times of measurements, and the measurements' reproducibility. Methods: Seventeen healthy newborn foals were enrolled. Three sites at the upper and lower lip mucosa were assessed by SDF, using a hand-held capiscope, at 24 h and at 4-5 days after bi...
The Equine Dental Pulp: Analysis of the Stratigraphic Arrangement of the Equine Dental Pulp in Incisors and Cheek Teeth. In the crown pulp of brachydont teeth, a cell-free and a cell-rich zone are established beneath the odontoblastic layer, indicating a mature status. For the equine dental pulp, there are no descriptions which allow for a comparative analysis with regard to functional requirements in terms of lifelong secondary dentin production to compensate for occlusal wear. For histomorphological and immunohistological investigations, ten incisors and ten check teeth were used from seven adult horses and five foals. In the periphery of the equine dental pulp, a constant predentin and odontoblastic cell laye...
B-mode and color Doppler ultrasonography of normal external jugular vein in donkeys (Equus asinus). Although the jugular vein is a major important blood vessel in equine, the literature lacks this vessel's normal B-mode and Doppler ultrasonographic examinations in donkeys. Therefore, this study aimed to determine the reference ranges of B-mode and Doppler ultrasonographic indices of jugular veins in healthy adult donkeys (Equus asinus) and the possible effect of examination side (left and right), gender, and body condition on the ultrasonographic measurements of this vessel. B-mode and Doppler ultrasound imaging of the external jugular vein was conducted on 20 adult healthy donkeys of both s...
Study on NGF and VEGF during the Equine Perinatal Period-Part 1: Healthy Foals Born from Normal Pregnancy and Parturition. The importance of trophic factors, such as nerve growth factor (NGF), vascular endothelial growth factor (VEGF), and brain-derived neurotrophic factor (BDNF) during the perinatal period, is now emerging. Through their functional activities of neurogenesis and angiogenesis, they play a key role in the final maturation of the nervous and vascular systems. The present study aims to: (i) evaluate the NGF and VEGF levels obtained at parturition from the mare, foal and umbilical cord vein plasma, as well as in amniotic fluid; (ii) evaluate NGF and VEGF content in the plasma of healthy foals during t...
Low Flow versus No Flow: Ischaemia Reperfusion Injury Following Different Experimental Models in the Equine Small Intestine. In experimental studies investigating strangulating intestinal lesions in horses, different ischaemia models have been used with diverging results. Therefore, the aim was to comparatively describe ischaemia reperfusion injury (IRI) in a low flow (LF) and no flow (NF) model. Under general anaesthesia, 120 min of jejunal ischaemia followed by 120 min of reperfusion was induced in 14 warmbloods. During ischaemia, blood flow was reduced by 80% (LF, n = 7) or by 100% (NF, n = 7). Intestinal blood flow and oxygen saturation were measured by Laser Doppler fluxmetry and spectrophotometry. Clinical, hi...
Effect of Acetylsalicylic Acid on Uterine Blood Flow, Gestation Length, Foal Birth Weight and Placental Weight in Pregnant Thoroughbred Mares – A Clinical Pilot Study. The aim of this double-blinded placebo-controlled study was to investigate the effect of acetylsalicylic acid (ASA) on uterine blood flow, gestation length, placental and foal weights in pregnant mares. Sixteen Thoroughbred mares of different age (13.3 ± 4.1) and parity (7.4 ± 3.1) were randomly assigned to three treatment groups. Mares in group C (n = 4) served as controls and received 5,000 mg lactose orally once daily from D 120 (D 0 = day of ovulation) until parturition. Mares in group ASA1 (n = 7) received 5,000 mg ASA orally once daily from D 120 until parturition. Mares in group...