The equine cardiovascular system, particularly the heart, is fundamental to maintaining the health and performance of horses. The heart is responsible for pumping oxygenated blood throughout the body, supporting vital functions and physical activity. In horses, the heart's structure and function are adapted to meet the demands of both rest and exertion, with notable features such as a large cardiac output and efficient blood circulation. Conditions affecting the equine heart, such as arrhythmias, valvular diseases, and myocardial disorders, can significantly impact a horse's well-being and athletic capability. This page aggregates peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, and pathophysiology of the equine heart, as well as diagnostic and therapeutic approaches to managing cardiac health in horses.
HOLT JP, RHODE EA, PEOPLES SA, KINES H.Studies of left ventricular volume and pressure have been carried out in the control state in four classes of intact anesthetized mammals (horses, cattle, swine, and dogs), body weights of which varied 54-fold. On the basis of these studies of both large and small hearts, extending over a wide range, a pattern of function for the left ventricle of all mammals has been described. Mathematical equations are given describing the interrelationships between left ventricular end-diastolic volume and end-systolic volume, stroke volume, cardiac output, stroke-work, heart rate, and total peripheral res...
WEGELIUS O.The number of mast cells per area and volume have been counted in the pleura, pericardium and capsula hepatis of cattle and horse.
The capsula hepatis of cattle contains a 5—10 times larger number of mast cells than the other tissues. The pleura pulmonalis showed a content of mast cells which was only a fraction of that in the liver capsule. The high histamine content found by Riley and coworkers when analyzing ox pleura seem to indicate that histamine is liberated not only from the mast cells, but also from other elements of the tissues.
Piotrowski IL, Junge HK, Schwarzwald CC.Mitral and aortic valve insufficiencies have been commonly reported in horses. The objective of this study was to establish the use of acoustic cardiography (Audicor®) in horses with aortic (AI) or mitral valve insufficiency (MI). A total of 17 healthy horses, 18 horses with AI, and 28 horses with MI were prospectively included. None of the horses was in heart failure. Echocardiography and Audicor® analyses were conducted. Electromechanical activating time (EMAT), rate-corrected EMATc, left ventricular systolic time (LVST), rate-corrected LVSTc, and intensity and persistence of the third and...
Fernandez-Barrientos MA, Flynn H, Ratliff B, Kilcoyne I.To highlight the use of procainamide as a potential alternative treatment modality in cases of ventricular tachycardia that are refractory to lidocaine and magnesium sulfate. Methods: 1 adult horse weighing 380 kg. Unassigned: A 25-year-old Arabian gelding presented with severe colic signs. Due to persistent pain, it was elected to carry out an exploratory laparotomy. During the procedure a diagnosis of severe, unstable ventricular tachycardia was made based on the ECG findings, with an initial heart rate of 195 beats per minute and severe hypotension. Results: Initial treatment consisted of d...
Lacerenza MD, Arantes JA, Reginato GM, Passarelli D, Balieiro JCC, Amaral AR, Vendramini THA, Brunetto MA, Dória RGS.β-glucan is part of the cell wall of fungi and yeasts and has been known for decades to have immunomodulating effects on boosting immunity against various infections as a pathogen-associated molecular pattern that is able to modify biological responses. β-glucan has been used in rat models and in vitro studies involving sepsis and SIRS with good results, but this supplement has not been evaluated in the treatment of endotoxemia in horses. This study aims to evaluate the effects of preventive supplementation with β-glucan in horses submitted to endotoxemia by means of inflammatory response m...
Interlandi C, Tabbì M, Di Pietro S, D'Angelo F, Costa GL, Arfuso F, Giudice E, Licata P, Macrì D, Crupi R, Gugliandolo E.The aim of this study was to evaluate the effect of oral cannabidiol (CBD) administration in addition to a conventional analgesic protocol on the clinical signs of 20 horses with mild joint osteoarthritis. The horses were randomly assigned to either the control group (C group) or the cannabidiol group (CBD group). Both groups were treated with phenylbutazone for 5 days. The CBD group received 0.03 mg/kg cannabidiol in hemp oil orally once daily for 14 days in addition to phenylbutazone treatment. All subjects were monitored for clinical parameters, oxidative status and blood counts. Pain...
de Preux M, Precht C, Guevar J, Graubner C, Thenhaus-Schnabel S, Buser L, Lukes A, Koch C.A 16-year-old warmblood mare was referred with a progressive history of behavioral changes and left-sided blindness. Following neuroanatomical localization to the forebrain, magnetic resonance imaging of the head revealed a well-delineated, 4.5 cm in diameter, round pituitary mass causing marked compression of the midbrain and optic chiasm. Euthanasia was recommended but declined by the owners. Veterinary specialists and a human neurosurgeon collaboratively prepared for surgical case management. A novel navigated transmandibular lateral transsphenoidal approach was developed to access the re...
Munsters C, Siegers E, Sloet van Oldruitenborgh-Oosterbaan M.To optimise the performance and welfare of horses during equestrian competitions in hot climates, it is advised to acclimate them to the heat. The effects of training in a heated indoor arena were studied. Four Olympic horses (13.3 ± 2.2 years; three eventers, one para-dressage horse) were trained for 14 consecutive days in a heated indoor arena (32 ± 1 °C; 50-60% humidity) following their normal training schedule in preparation for the Tokyo Olympic games. Standardised exercise tests (SETs) were performed on Day 1 and Day 14, measuring heart rate (HR; bpm), plasma lactate concentration (LA...
Hermange T, Ruault B, Couroucé A.The aim of this study is to describe clinical data associated with acorn intoxication and to find variables associated with survival. Data from horses presented at CISCO-ONIRIS from 2011 to 2018 with a diagnosis of acorn intoxication were included. Diagnosis was based on the following: season, the presence of acorns in the environment, clinical and hemato-biochemical parameters suggestive of a digestive/renal disease, the co-morbidity of companion animals, and post-mortem findings. Statistical analysis was completed using Student's t-test for mean comparisons and a Chi-square test for group co...
Wonghanchao T, Sanigavatee K, Poochipakorn C, Huangsaksri O, Yalong M, Poungpuk K, Thanaudom K, Lertsakkongkul P, Lappolpaibul K, Deethong N, Chanda M.Cooling down is essential for horse recovery before veterinary inspection during an endurance ride. As salt potentially decreases water temperature, we tested whether adding salt to the water used to cool horses could aid their recovery. Twelve healthy Arabian horses participating in a novice endurance ride were divided evenly into two groups. Heart rate variability (HRV) variables, including time and frequency domains, non-linear results, and autonomic nervous system indices, were determined before recovery and at 1-min intervals for 9 min during recovery using either cold or cold-saline wa...
Poochipakorn C, Joongpan W, Tongsangiam P, Phooseerit A, Leelahapongsathon K, Chanda M.The severe outbreak of African horse sickness (AHS) in Thailand has forced horses to reside full-time inside barns that are covered by a small mesh net to prevent minuscule AHS insect vectors from gaining access. However, housing in the net-covered barn induces stress in horses, which compromises their welfare. Implementing strategic airflow adjustment while retaining the vector-protection characteristics has been proposed to help alleviate this problem. The present study aimed to investigate the effect of strategic ventilation adjustment on blood cortisol levels, heart rate and behaviour in h...
Bozzola C, Ortolina A, Guffanti I, Alberti E, Bronzo V, Zucca E.The digital stethoscope (DS) is a cost-effective single-lead digital stethoscope that allows simultaneous electrocardiographic (ECG) and phonocardiographic recordings on a smartphone. Despite its application in small animals and horses, there are currently no studies on its use in donkeys. The aim of this study was to evaluate the use of a new smartphone-based DS device in recording ECG tracings in donkeys. Standard base-apex lead ECG (sECG) and single-lead DS ECG (dECG) were simultaneously recorded for at least 30 s. Both sECG and dECG tracings were analysed by the same operator, recording he...
Cardiovascular changes have been reported in late pregnancy in mares. However, there are no data on changes in peripheral blood flow. Doppler ultrasound represents a sensitive method for assessing the blood flow directed to the hoof. The aims of this study were to evaluate the blood flow parameters of the lateral palmar digital artery (LPDA) in pregnant mares and to assess intra- and interrater agreement between two observers with different levels of experience. The LPDAs of pregnant Italian Standardbred mares were examined. The vessels were located with B-mode ultrasound and analyzed with col...
Vernemmen I, Van Steenkiste G, Buschmann E, Cornelis K, Schauvliege S, Ibrahim L, Decloedt A, van Loon G.Radiofrequency ablation has been successfully applied to treat right atrial arrhythmias in horses. Ablation of left-sided arrhythmias requires a retrograde transarterial approach which is complicated. In human medicine, the left atrium is accessed through transseptal puncture (TSP) of the fossa ovalis (FO) using a caudal approach via the femoral vein. Objective: To develop a zero fluoroscopy TSP technique for horses using a jugular vein (cranial) and transhepatic (caudal) approach. Methods: In vivo experimental study. Methods: Transseptal puncture was performed in 18 horses admitted for euthan...
Paranjape VV, Knych HK, Berghaus LJ, Cathcart J, Giancola S, Craig H, James C, Saksena S, Reed RA.Matrix type transdermal buprenorphine patches have not been investigated in horses and may provide an effective means of providing continuous pain control for extended period and eliminating venous catheterization. Unassigned: Assessment of the physiological variables (heart rate, respiratory rate, body temperature) and thermal nociceptive threshold testing, and describing the pharmacokinetic profile of transdermal buprenorphine matrix-type patch (20 μg h and 40 μg h dosing) in healthy adult horses. Unassigned: Randomised experimental study with a Latin-square design. Unassigned: Six adu...
Vullo C, Gugliandolo E, Biondi V, Biffarella M, Catone G, Tambella AM.The aim of this study was to determine the most appropriate sedation protocol for a standing magnetic resonance imaging (MRI) examination in horses, comparing continuous rate infusions (CRIs) of detomidine and romifidine combined with a single bolus of morphine. Sixteen horses referred for standing low-field open-magnet MRI were randomly assigned to one of two sedation protocols. The horses were premedicated with 0.03 mg/kg of intramuscular acepromazine, and those animals belonging to Group D received an intravenous (IV) loading dose of detomidine (0.01 mg/kg) 30 min later, while those of Grou...
Reed RA, Berghaus LJ, Reynolds RM, Holmes BT, Krikorian AM, Sakai DM, Ishikawa Y, Knych HK.Understanding the pharmacokinetics and pharmacodynamics of fentanyl in horses is crucial for optimizing pain management strategies in veterinary medicine. Unassigned: Six adult horses were enrolled in a randomized crossover design. Treatments included: placebo, two 100 mcg/h patches (LDF), four 100 mcg/h patches (MDF), and six 100 mcg/h patches (HDF). Patches were in place for 72 h. Blood was obtained for fentanyl plasma concentration determination, thermal threshold, mechanical threshold, heart rate, respiratory rate, and rectal temperature were obtained prior patch placement and at m...
Neville E, Pigott J.To describe the clinical presentation of a Thoroughbred filly with acute hemoperitoneum from a splenic source immediately after racing. Methods: A 3-year-old Thoroughbred filly used for racing and that had raced shortly before presentation to the hospital. Unassigned: On presentation, the filly was quiet, alert, and responsive with a heart rate of 76 beats/min, pale mucous membranes, and absent borborygmi. All other physical examination parameters were within normal limits. Abdominal ultrasound was performed and revealed echogenic free abdominal fluid and a splenic hematoma. Abdominocentesis y...
Mozo Vives B, Mainguy-Seers S, Lavoie JP.Salbutamol and hyoscine butylbromide (HBB) are commonly used bronchodilators in horses with severe asthma (SA). Objective: To compare the bronchodilation potency, duration, and adverse effects of salbutamol and HBB in SA. Methods: Six horses in exacerbation of SA. Methods: The effects of inhaled salbutamol (1000 μg) and HBB (150 mg, IV) were compared in a randomized, blinded, crossover experiment. Lung function, intestinal borborygmi and heart rate were assessed before and sequentially until 180 minutes after drug administration, and analyzed with 2-way repeated-measures ANOVA and Dunne...
Massie S, Bayly W, Ohmura H, Takahashi Y, Mukai K, Léguillette R.Comparatively little is known regarding the initial cardiorespiratory response of young racehorses to training. The objectives were to compare physiological parameters before and after introductory training and determine whether young Thoroughbreds show endoscopic signs of exercise-induced pulmonary hemorrhage (EIPH). Ten Thoroughbreds (20-23 months) underwent 12-weeks of introductory training, including weekly speed sessions. Two 600 m high-speed exercise tests (HSET) were performed following weeks 4 and 12 while wearing a validated ergospirometry facemask. Peak oxygen consumption (V̇Opk...
Felici M, Cogger N, Nanni Costa L, Riley CB, Padalino B.Studies on equine air transport practices and consequences are scarce. This prospective study aimed to describe horse and air journey details and practices, document how horse behavior and health changed during the air transport phases, quantify the occurrence of welfare issues, and identify possible associations between horse and journey details, air transport practices, and welfare issues. Results: Data were collected from before departure to five days after arrival on 118/597 horses traveling on 32 commercial air journeys on different routes, varying in duration and conditions. Most horses ...
