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.
Three-Dimensional Reconstruction of the Equine Palmar Metacarpal Region Using E12 Plastinated Sections. Digital technologies have improved the visualization of anatomical structures for veterinary education and clinical practice. In this study, a detailed three-dimensional anatomical model of the equine palmar metacarpal region was generated using E12-based epoxy sheet plastination combined with digital reconstruction in Amira V5.6 software. Serial cross-sections of the metacarpal region provided high-resolution visualization of bones, tendons, ligaments, nerves, vessels, fasciae, and synovial structures, with minimal shrinkage or deformation, ensuring improved anatomical accuracy. These section...
Left and right-side echocardiographic measurement of pulmonary artery stiffness in thoroughbred racehorses. Pulmonary Artery Stiffness (PAS) is a non-invasive echocardiographic index of pulmonary artery elasticity. In horses, PAS has been measured only from the right parasternal short-axis view, while the influence of alternative imaging windows remains unknown. Objective: To assess the repeatability and reproducibility of Acceleration Time (AT), Maximal Frequency Shift (MFS), and PAS measurements from the left parasternal angled view of the right ventricular inflow/outflow, and to compare these parameters with those obtained from the right parasternal short-axis view in Thoroughbred racehorses. Met...
Non-contrast enhanced visualization of the equine foot vasculature in a cadaver model using time-of-flight sequence. The objective of this study was to establish a non-contrast enhanced MR angiography (NC-MRA) sequence for the equine foot (EF) using a post-mortem angiography model. Unassigned: Time-of-flight (TOF) sequences were tested using variable parameter settings and 3 slice orientations during vascular perfusion of frozen-thawed cadaver EF with paraffine oil. Transverse and dorsal orientations were planned perpendicular or parallel to the sublamellar vascular plexus at the dorsal aspect of P3, or approximately perpendicular to the coronary plexus. Visibility of the coronary plexus, sublamellar plexus,...
Arteritis, aneurysm and thromboembolic colic caused by migration of Strongylus vulgaris larvae in equids. Strongylus vulgaris remains a significant cause of disease in equids, especially in regions with insufficient deworming practices. Objective: To describe the epidemiological, clinical, pathological, and parasitological findings of vascular and extravascular lesions associated with S. vulgaris in equids. Methods: A retrospective analysis was conducted on necropsy reports from equids examined at the Animal Pathology Laboratory, Federal University of Campina Grande (2000-2024), targeting cases of vascular lesions associated with S. vulgaris. Epidemiological, clinical, and pathological findings we...
Internal carotid artery dolichoarteriopathies in the horse: An endoscopic and anatomic study. Endoscopy of the guttural pouches in neonatal foals occasionally reveals atypical aspects in the course of the extracranial internal carotid arteries (ICAs) that are hardly seen in adult horses. While in veterinary medicine the data available on the presence of these anomalies in domestic mammals are limited and incomplete, in human medicine the morphological aspects of the ICAs have been the subject of extensive studies. Anomalies in the course and geometry of ICAs are commonly defined as dolichoarteriopathies, and should be classified as tortuous, kinked or coiled. To document whether the an...
The inability of spectral Doppler ultrasonography to identify stallions with testicular dysfunction. This retrospective study aimed to validate the usefulness of spectral Doppler ultrasonography in diagnosing testicular dysfunction in stallions. The first part of the study included a pony stallion with age-related testicular degeneration (18 - 21 yrs. old). Testicular dimensions, spectral Doppler parameters of testicular blood flow, and semen parameters were obtained numerous times from this pony over four consecutive years. While testicular volume decreased dramatically, and the stallion became azoospermic, there were no changes in any of the spectral Doppler parameters of testicular blood f...
Laparoscopic Inguinal Hernioplasty with a Polyether Ether Ketone Anchoring Device in Intact Male Horses Does Not Compromise Testicular Perfusion, Sperm Production or Motility Characteristics. A new surgical technique using a polyether ether ketone (PEEK) anchoring device for testicle-sparing laparoscopic inguinal hernioplasty in stallions was described in 2023 and is known as the PEEK harpoon technique (PHT). In breeding stallions, it is essential that the surgery is effective in preventing inguinal hernia but also that it does not impair the testicular function. This study aims to evaluate whether the PHT may affect testicular function. To achieve that, changes in the testicular blood flow, sperm production and motility characteristics were assessed 28 days after use of the PHT. S...
Dickkopf-1 is present in equine platelet-rich plasma and correlates to platelet concentration. To determine if equine platelet-rich plasma (PRP) contains Dickkopf-1 (Dkk-1) and, if so, to quantify the amount of Dkk-1 in bovine thrombin (BT)-activated PRP and a control platelet lysate created using a freeze-thaw (FT) method. Unassigned: 10 adult horses were used in this experimental study. Blood was collected and processed in November 2019 and stored at -80 °C until the ELISAs were performed in October of 2023. Blood was collected from each horse, and PRP was created using a commercially available kit. Known concentrations of platelets were activated using BT or by an FT cycle to create...
Changes in microcirculation variables in an acute endotoxaemic equine model. Microcirculation is the essential link between macrocirculation and cellular metabolism. Objective: To test our hypotheses that microcirculation variables will show a heterogeneous flow pattern during experimental endotoxaemia, and that fluid therapy and noradrenaline (NA) infusion will normalise altered microcirculation variables. Methods: In vivo experiments. Methods: Six healthy adult horses were anaesthetised with dexmedetomidine, ketamine, and diazepam and were mechanically ventilated under isoflurane anaesthesia. Endotoxaemia was induced with 30 ng kg Escherichia coli lipopolysacchar...
Dynamic Adaptation of Hematological Parameters, Albumin, and Non-Esterified Fatty Acids in Saddlebred and Standardbred Horses During Exercise. The response to exercise following a rest period may vary among horse breeds based on the importance of the hematological and hematochemical profiles of athletic horses. Ten Standardbred and ten Italian Saddlebred mares were subjected to a 4-week training program after a seasonal rest, and hematological parameters (red blood cells-RBCs; hemoglobin-Hb; hematocrit-Hct; platelets-PLTs; platelet aggregation-AG; aggregation slope-Slope; fibrinogen-Fb), as well as Albumin (Alb) and non-esterified fatty acids (NEFAs), were analyzed. Blood samples were obtained each week during the training program fo...
Profiling host- and parasite-derived miRNAs associated with Strongylus vulgaris infection in horses. The equine bloodworm, Strongylus vulgaris, is a common and highly pathogenic parasite in horses due to its migratory life cycle involving the intestinal arteries. Current diagnostic techniques cannot detect the prepatent migrating stages of S. vulgaris, highlighting the need for new biomarkers. Parasites release microRNAs (miRNAs) into their environment, which could potentially be detectable in host blood samples. Additionally, host miRNA expression patterns may change in response to infection. This study aimed to identify miRNAs associated with S. vulgaris infection by profiling the horse's m...
Vascular hamartoma in horse limbs: presentation, diagnosis, and treatment of two case studies. Vascular hamartoma is an abnormal development of endothelial tissue that rarely affects horses. Histopathological examination remains the gold standard for definitive diagnosis, yet the presence of abnormal vascular structures must be carefully differentiated from other vascular anomalies and neoplasms. This report describes two cases of vascular proliferation affecting the skin on the lateral side over the left tarsus and the dorsolateral region over the fetlock joint of two fillies. The clinical history, presentation, and radiographic and sonographic findings in both patients suggested a neo...
Intra-arterial contrast enhanced computed tomography of the deep digital flexor tendon and palmar veins in the distal forelimb in Jeju horses: Evaluating contrast-enhancing factors. Few studies have investigated the adequate contrast enhancement (CE) evaluation depending on concentration, volume, and rate of administration of contrast media (CM) and the scan parameters in equine contrast enhanced computed tomography (CECT). Objective: To investigate CE of the deep digital flexor tendon (DDFT) and veins depending on the computed tomography (CT) voltage and concentration, volume, and rate of CM administration during intra-arterial CECT of equine distal forelimbs. Methods: In vivo experiments. Methods: Six horses underwent 54 CT scans. First, the CE of DDFT and veins was eva...
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....
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...
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...
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...