Evaluation of remote assistance for point-of-care ultrasonography in a large animal hospital: a controlled randomized trial.

OBJECTIVE: To assess whether remote assistance is beneficial to the accuracy of point-of-care ultrasound (POCUS) examinations during equine emergency evaluations. ANIMALS: Adult horses presenting to a tertiary care large animal emergency service for respiratory or gastrointestinal clinical signs. PROCEDURES: Prospective, randomized, controlled, clinical study. Cases were assigned to receive POCUS with remote assistance ("POCUS-R" group) or POCUS with no assistance ("POCUS" group). Accuracy of diagnosis, duration of sonograms and survival to discharge were the objective outcomes compared between groups. Perceptions about the use of teleultrasound were gathered using a survey. RESULTS: 29 cases were enrolled in the study over an 18-month period. Based on Cox regression estimates, sonogram duration was likely to be longer in the POCUS-R group (n = 13) relative to the POCUS group (16) hazard ratio 0.43 (95% CI, 0.9 to 0.2; P = .03). Whether the final diagnosis was included in the differential diagnosis list, number of diagnoses in the differential list and survival were not different between groups. Educational benefits were the most frequently mentioned benefit by clinician users while logistical and technical problems related to the use of the equipment and inconvenience of enrollment in the study was the most common negative aspect. CLINICAL RELEVANCE: Teleultrasound was generally not well adopted by users likely due to inconvenience and time constraints. Further work is indicated to assess differences in clinical outcomes in a setting that would allow a larger sample size to increase statistical power.

Chiropractic effects on stride parameters and heart rate during exercise in sport horses.

BACKGROUND: Equine veterinarians performing chiropractic treatments are frequently asked to evaluate and treat sound horses to improve their performance and address pain associated with the axial skeleton. Studies describing the effects and mechanisms of chiropractic treatments in horses without overt lameness are scarce. OBJECTIVES: This study aimed to evaluate the effect of chiropractic treatments on stride rate, length, symmetry, heart rate and rider-perceived quality of the ridden work in sport horses. STUDY DESIGN: A blind randomised controlled trial with crossover design. METHODS: Thirty-eight horses ridden in the hunter-jumper discipline were enrolled. Exercise tests were recorded before and after chiropractic or sham treatment while horses were wearing a fitness tracker. Stride length, rate and symmetry, heart rate and the perceived quality of the ridden work were compared. RESULTS: There was a difference in the qualitative assessment of the ridden work by riders between treatments (odds ratio 33.8, 95% CI [4.68, 458.71], p < 0.01). Stride length, rate, symmetry and heart rate were not different between treatments. MAIN LIMITATIONS: The quantitative outcomes measured may not be sensitive enough to detect changes that improve the ridden work. Terrain, weather and rider were not standard across horses making small changes difficult to detect. CONCLUSIONS: Riders participating in a blind randomised controlled trial perceived a positive effect of chiropractic treatments on the quality of the ridden work. There were no differences in stride length, stride rate, stride symmetry or heart rate. The mechanisms, indications and potential benefits of chiropractic treatments in horses need further study.

HISTORIAL: A los veterinarios de equinos que realizan tratamientos quiroprácticos, se les pide frecuentemente evaluar y tratar caballos que están sanos para mejorar su desempeño y tratar el dolor asociado con el esqueleto axial. Estudios que describen los efectos y mecanismos de los tratamientos quiropráctico en caballos sin cojeras aparentes, son pocos. OBJETIVOS: Este estudio tiene por objetivo evaluar el efecto de los tratamientos quiroprácticos sobre frecuencia, largo y simetría de la zancada, la frecuencia cardiaca y la calidad del trabajo montado percibida por el jinete en caballos de deporte. DISEÑO DEL ESTUDIO: Prueba aleatoria cegada controlada con diseño cruzado. MÉTODOS: Se enrolaron 38 caballos montados en la disciplina de caza-salto. Pruebas de ejercicio fueron anotadas antes y después de tratamientos quiropráctico reales o simulados mientras los caballos llevaban un monitor físico. Se compararon el largo, frecuencia y simetría de la zancada, frecuencia cardiaca y calidad del trabajo montado percibida por el jinete. RESULTADOS: Se encontró una diferencia en la evaluación cualitativa del trabajo montado por los jinetes entre los tratamientos (odds ratio 33.8, 95% CI [4.68, 458.71], p < 0.01). Largo, frecuencia y simetría de zancada y frecuencia cardiacas no difirieron entre tratamientos. LIMITACIONES PRINCIPALES: Los resultados cuantitativos medidos, pueden no ser lo suficientemente sensibles para detectar cambios que mejoran el trabajo montado. El terreno, tiempo y jinete no fueron estandarizados a través de los caballos, lo que hizo que cambios pequeños fuesen difíciles de detectar. CONCLUSIONES: Los jinetes que participaron en una prueba aleatoria cegada controlada, percibieron un efecto positivo de los tratamientos quiroprácticos sobre la calidad del trabajo montado. No hubo diferencia en largo de zancada, frecuencia de zancada, simetría de zancada o frecuencia cardiaca. Los mecanismos, indicaciones y beneficios potenciales de los tratamientos quiroprácticos en caballos necesitan ser estudiados mas.

Evaluation of a Self-Driven Large Animal Point of Care Ultrasound Learning Program for Veterinary Students.

Point of care ultrasound (POCUS) has the potential to improve healthcare outcomes and is increasingly used in veterinary primary care and specialty practice. The aim of this study was to evaluate a self-driven POCUS learning program during clinical rotations in a large animal teaching hospital. A randomized controlled trial of 94 students evaluated the hypotheses that access to a self-driven POCUS program would improve scores on a written test and the quality of subjective, objective, assessment and plan (SOAP) documents. Use of the POCUS devices and perceptions of veterinary students towards POCUS were analyzed. The self-driven POCUS learning program was feasible, and the perception of most students (94%) was that the program was useful for their education. Access to equipment, ability to scan individually, the hands-on learning aspect, and clinicians' help were the most valued aspects of the program. Earlier access to POCUS in the curriculum, hands-on tutorials/labs, and a more structured learning program were identified by students as aspects to improve. Access to the self-driven POCUS program resulted in significantly higher scores on the written test in a subpopulation of students with lower scores. No significant differences in results on the multiple-choice tests in the subpopulation with higher scores or in SOAP scores of the complete group or subpopulations were found. A self-driven POCUS learning program was perceived as beneficial by students, increased POCUS knowledge in students with lower test scores, and was possible to implement in a busy large animal teaching hospital.

Feasibility of a point-of-care ultrasound protocol for cardiorespiratory evaluation of horses in different clinical settings.

BACKGROUND: A point-of-care ultrasound (POCUS) protocol for evaluation of the cardiac and respiratory systems in horses does not exist. OBJECTIVES: (a) Describe the windows of a POCUS protocol for cardiorespiratory assessment of horses (CRASH); (b) Estimate the number of acoustic windows that can be acquired by a sonographer-in-training; (c) Estimate the time required to complete the protocol for specific groups of horses; (d) Describe the sonographic abnormalities detected in horses presented with cardiovascular, respiratory, or systemic disease. ANIMALS: Twenty-seven healthy horses, 14 horses competing in athletic events, and 120 horses with clinical disease. METHOD: A pocket-sized ultrasound device was used to acquire 7 sonographic cardiorespiratory windows in various clinical scenarios. The duration of the examination was timed, and images were evaluated for diagnostic quality. Abnormalities in horses with clinical disease were determined by an expert sonographer. RESULTS: The CRASH protocol could be performed in healthy and diseased horses in hospital, barn, and competition settings between 5.5 ± 0.9 (athletic horses) and 6.9 ± 1.9 min (horses with clinical disease). Thoracic windows were obtained most consistently, followed by right parasternal long-axis echocardiographic windows. Frequently detected abnormalities were pleural fluid, lung consolidation, B-lines, and moderate-to-severe left-sided heart disease. CONCLUSIONS: The CRASH protocol was feasible using a pocket-sized ultrasound device in various groups of horses, could be completed rapidly in a variety of settings, and frequently identified sonographic abnormalities when evaluated by an expert sonographer. The diagnostic accuracy, observer agreement, and utility of the CRASH protocol merit further evaluation.

Small Animal Teleultrasound.

Teleradiology is well established in many small animal practices, whereas teleultrasound is slowly gaining prominence. The demand for teleultrasound services in the veterinary profession has increased substantially because access to ultrasound to general practitioners increases faster than the number of imaging specialists and Point of Care Ultrasound (POCUS) becomes part of the standard of care. Two main methods of teleultrasound currently exist: asynchronous (eg, "store-and-forward") and synchronous (eg, real-time) interpretations. Few standardized protocols for teleultrasound in small animals are available. Similarly, there are no standardized training programs for sonographic examination acquisition and interpretation outside of the traditional diagnostic imaging residency under the purview of the American College of Veterinary Radiology. The success of a telesonographic evaluation largely depends on the relationship between the veterinarian requesting remote assistance and the expert providing support.

Investigating the Relationship Between Cardiac Function and Insulin Sensitivity in Horses: A Pilot Study.

Metabolic syndrome in humans is commonly associated with cardiovascular dysfunction, including atrial fibrillation and left ventricular diastolic dysfunction. Although many differences exist between human and equine metabolic syndrome, both of these conditions share some degree of insulin resistance. The aims of this pilot study were to investigate the relationship between insulin sensitivity and cardiac function. Seven horses (five mares, two geldings, aged 17.2 ± 4.2 years, weight 524 ± 73 kg) underwent insulin-modified frequently sampled intravenous glucose tolerance testing to determine insulin sensitivity (mean 2.21 ± 0.03 × 10-4 L/min/mU). Standard echocardiograms were performed on each horse, including two-dimensional, M-mode, and pulse-wave tissue Doppler imaging. Pearson and Spearman correlation analyses were used to determine the association of insulin sensitivity with echocardiographic measures of cardiac function in 5 horses. Insulin sensitivity was found to be significantly correlated with peak myocardial velocity during late diastole (r = 0.89, P = 0.0419), ratio between peak myocardial velocity in early and late diastole (r = -0.92, P = 0.0263), isovolumetric relaxation time (r = -0.97, P = 0.0072), and isovolumetric contraction time (ρ = -0.90, P = 0.0374). These preliminary data suggest that decreased insulin sensitivity is correlated with alterations in both systolic and diastolic function, as measured with tissue Doppler imaging (TDI). Due to the small sample size of this study, the relationship between insulin sensitivity and myocardial function in horses requires further investigation.

Effect of a long-term high-energy diet on cardiovascular parameters in Shetland pony mares.

BACKGROUND: Changes in cardiovascular parameters, including blood pressure (BP) and cardiac anatomical dimensions, are an inconsistent feature of the equine metabolic syndrome. The order in which these changes arise is unknown. OBJECTIVES: Determine the order in which EMS-associated changes in cardiovascular parameters arise. ANIMALS: Twenty Shetland pony mares. METHODS: High-energy (HE) diet mares were fed 200% of net energy requirements for 1 (n = 3) or 2 (n = 7) consecutive diet-years, with 17 weeks of hay-only between years. Noninvasive BP measurements and echocardiograms were performed during both years. Resting 24-hour ECGs and measurements of autonomic tone (splenic volume and packed cell volume [PCV]) were performed at the end of diet-year 1. Results were compared to control mares receiving a maintenance diet for 1 (n = 7) or 2 (n = 3) consecutive years. RESULTS: In year 1, HE mares had significantly higher values than control mares for mean relative left ventricular wall thickness (P = .001). After 2 diet-years, mean systolic (P = .003), diastolic (P < .001) and mean arterial BP (P = .001), heart rate (HR; P < .001), and mean left ventricular wall thickness (P = .001) also were significantly increased in HE compared to control mares. No pathological arrhythmias or differences in splenic volume or PCV were detected. CONCLUSIONS AND CLINICAL IMPORTANCE: Ingesting a HE diet first induced minor changes in BP, and progressed to left-sided cardiac hypertrophy in Shetland pony mares. These findings are of interest given the increasing incidence of obesity in horses.

Effectiveness of a digital interactive multimedia tutorial for preparing veterinary students to perform ultrasonography in horses.

OBJECTIVE: To determine the effectiveness of a digital interactive multimedia tutorial (DIMT) for preparing veterinary students to perform ultrasonography in horses. SAMPLE: 42 third-year veterinary students. PROCEDURES: Students were randomly assigned to 3 instructional methods: independent study (ie, 45 minutes to read a highlighted textbook chapter), lecture (ie, 45-minute lecture by a faculty member), or digital interactive multimedia tutorial (DIMT; ie, 45-minute narrated, interactive module). Written and practical tests were administered after each instruction session. For the practical test, each student was required to obtain a series of ultrasound images of a live horse, and images were later scored for quality by an individual unaware of the instructional method used. RESULTS: Higher-quality ultrasound images were obtained by veterinary students who had reviewed the DIMT rather than the analogous information in textbook chapters. No difference in scores was identified between students in the lecture group and those in the DIMT group. Students' perceptions suggested that practical instruction facilitated by clinicians was a key component of learning how to perform ultrasonography in horses. CONCLUSIONS AND CLINICAL RELEVANCE: Results supported the use of DIMTs in preparing veterinary students to perform ultrasonography in horses.

Ventricular arrhythmias in horses: Diagnosis, prognosis and treatment.

Ventricular arrhythmias (VAs) are often incidental or coincidental with systemic disease. Ventricular arrhythmias are also the most likely cause of many sudden cardiac deaths in horses. This dichotomy creates challenges in the management of horses with VAs. This review presents current knowledge of diagnosis, prognosis and treatment of VAs in horses.

Cardiovascular Response to Exercise and Training, Exercise Testing in Horses.

The physiology of exercise and training is fascinating, and hundreds of interesting studies have given insight into its mechanisms. Exercise testing is a useful clinical tool that can help veterinarians assess poor performance, fitness, and performance potential and prevent injuries. The clinically applicable aspects of cardiovascular adaptions to training and exercise testing are highlighted in this review. Different exercise tests should be used to evaluate horses performing in different disciplines and levels. Exercise tests that simultaneously assess several body systems can be beneficial when assessing poor performance, because this is often a multifactorial problem with signs not detectable at rest.

Bone Marrow Aspiration Does Not Induce a Measurable Pain Response Compared to Sham Procedure.

Bone marrow is commonly collected from horses for regenerative medicine applications. Little information is available regarding pain experienced by the horse during bone marrow aspiration. The objective of this study was to characterize horse reaction and pain response during bone marrow aspiration (BMA) compared to a sham (SHAM) procedure. We hypothesized there would be significantly greater horse reaction or pain response measured by salivary cortisol, heart rate variability, and depth and duration of sedation between BMA and SHAM. Twelve university owned horses underwent a BMA and sham procedure, 4 weeks apart in a randomized cross-over design, while sedated with 0.4 mg/kg xylazine hydrochloride. As measures of sedation depth, head height was recorded and sedation level was scored at specific procedural time points. Salivary cortisol was measured immediately before and 2 h after each procedure. Heart rate variability was assessed before, during, and after each procedure. There were no differences in head height, sedation score, or salivary cortisol between groups. No differences were noted between groups in heart rate variability before or during the procedure, but there was a significant decrease in low frequency/high frequency (LF/HF) ratio after the procedure in the BMA group. Over time, there was a significant reduction in LF/HF ratio during the procedure in both groups. Overall, BMA from the sternum did not result in a measurable pain response during, or in the 2 h following the procedure, in comparison to a sham procedure.

Advanced Atrio-Ventricular Blocks in a Foal Undergoing Surgical Bladder Repair: First Step to Cardiac Arrest?

A 3-day-old Swiss Warmblood colt was diagnosed with uroabdomen after urinary bladder rupture. The foal had classical electrolyte abnormalities (hyponatremia, hypochloremia and hyperkalemia) on presentation. The foal was supported prior to surgery with intravenous fluids and the electrolyte abnormalities were treated with physiologic saline, glucose and insulin. Urine could not be drained from the abdomen prior to surgery because the omentum was continuously occluding the drainage cannula and due to progressive abdominal distension, it was decided to pursue surgery without further correction of electrolyte abnormalities. After induction of anaesthesia, signs of hypoxemia were present. Controlled mandatory ventilation using a pressure-controlled ventilation mode with positive end-expiratory pressure was initiated. Urine was drained from the abdomen by free flow. Atrio-ventricular (AV) blocks unresponsive to intravenous antimuscarinic drugs developed. After low dose of epinephrine and cardiac massage, sinus rhythm was restored. Surgery was completed successfully and the foal recovered from anaesthesia. The postoperative period was uneventful and the foal was discharged from the hospital three days later. Based on a clinical case, the purpose of the manuscript is to provide the clinician with potential causes, prevention and treatment of this already known but rarely observed dysrhythmia which could lead to fatal consequences. Definitions of cardiac arrest and asystole are reappraised. We discuss the fact that advanced AV-blocks should be treated as a cardiovascular emergency with advanced life support. The early recognition of advanced AV blocks is the first step to reduce perioperative mortality and morbidity of foal suffering from uroabdomen.

Evaluation of coagulation and fibrinolysis in horses with atrial fibrillation.

OBJECTIVE: To evaluate horses with atrial fibrillation for hypercoagulability; plasma D-dimer concentrations, as a marker of a procoagulant state; and a relationship between coagulation profile results and duration of atrial fibrillation or presence of structural heart disease. DESIGN: Case-control study. ANIMALS: Plasma samples from 42 horses (25 with atrial fibrillation and 17 without cardiovascular or systemic disease [control group]). PROCEDURES: Results of hematologic tests (ie, plasma fibrinogen and D-dimer concentrations, prothrombin and activated partial thromboplastin times, and antithrombin activity) in horses were recorded to assess coagulation and fibrinolysis. Historical and clinical variables, as associated with a hypercoagulable state in other species, were also recorded. RESULTS: Horses with atrial fibrillation and control horses lacked clinical signs of hypercoagulation or thromboembolism. Compared with control horses, horses with atrial fibrillation had significantly lower antithrombin activity. No significant differences in plasma fibrinogen and D-dimer concentrations and prothrombin and activated partial thromboplastin times existed between horse groups. In horses with atrial fibrillation versus control horses, a significantly larger proportion had an abnormal plasma D-dimer concentration (10/25 vs 2/17), test results indicative of subclinical activated coagulation (18/25 vs 6/17), or abnormal coagulation test results (25/121 vs 7/85), respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Horses with atrial fibrillation did not have clinical evidence of a hypercoagulable state, but a higher proportion of horses with atrial fibrillation, compared with control horses, did have subclinical activated coagulation on the basis of standard coagulation test results.

Myocardial insult and arrhythmias after acute hemorrhage in horses.

OBJECTIVE: The objectives of this investigation were to: (1) Determine if acute hemorrhage is associated with increased plasma cardiac troponin I (cTnI) concentration or cardiac arrhythmias, (2) to describe the types of arrhythmias and their clinical course in horses following acute hemorrhage, (3) to determine the ability of clinical or clinicopathological variables to predict an increase in cTnI concentration and the presence of arrhythmias, and (4) to determine the associations of cTnI and cardiac arrhythmias with outcome. DESIGN: Prospective observational study. SETTING: Large animal veterinary teaching hospital. ANIMALS: Eleven client-owned adult horses admitted for treatment of acute hemorrhage (HG) and 4 adult horses undergoing controlled blood collection (BDG). METHODS: Serial cTnI concentrations were measured and continuous ECGs were obtained from the HG and BDG groups. Statistical tests were used to determine associations among acute hemorrhage and plasma cTnI concentrations, the presence of cardiac arrhythmias, clinicopathologic data (heart rate [HR], packed cell volume [PCV], total plasma protein [TPP], plasma lactate, and plasma creatinine concentrations), and outcome. RESULTS: Plasma cTnI concentration and ECG were within reference intervals at all time points in the BDG. All horses in the HG had increased cTnI (ranging from 0.1-29.9 ng/mL). Arrhythmias were detected in 8 of these horses. There was an association between acute hemorrhage and increased cTnI (P = 0.004, ρ = 0.77), and the presence of arrhythmias (P = 0.026, ρ = 0.64). There were associations among plasma cTnI concentration and the presence of arrhythmias (P = 0.005), arrhythmias requiring treatment (P = 0.036), and poor outcome (P = 0.024). CONCLUSIONS: Acute hemorrhage results in myocardial injury that can be detected by measuring cTnI concentration. Arrhythmias were frequent in hospitalized horses following acute hemorrhage.

Imaging diagnosis--muscular hypertrophy of the small intestine and pseudodiverticula in a horse.

A 14-year-old Thoroughbred gelding was presented for chronic colic and weight loss. Transcutaneous and transrectal abdominal ultrasonography revealed distended, thickened small intestine with primary thickening of the muscularis and a focally more thickened loop with an echoic structure crossing the wall from the mucosa to the serosa. Visualization of diffuse thickening of the muscularis (muscular hypertrophy of the small intestine) and a focal lesion (pseudodiverticulum) helped clinicians make informed decisions. This case illustrates the importance of transabdominal and transrectal ultrasonography in horses with chronic colic and the relevance of considering the abnormalities in layering pattern of the intestinal wall.

Hypertensive cardiomyopathy in horses: 5 cases (1995-2011).

OBJECTIVE: To describe the prognosis and clinical, echocardiographic, and pathological features of hypertensive cardiomyopathy in horses. DESIGN: Retrospective case series. ANIMALS: 5 horses with cardiac hypertrophy and systemic hypertension. PROCEDURES: Demographics, history, physical and cardiological examination findings, diagnosis, clinical progression, prognosis, and pathological findings were obtained from medical records. RESULTS: The primary diagnosis was chronic laminitis in 3 horses and chronic renal failure in 2. Persistent tachycardia, hypertension, chronic laminitis, or a combination of these prompted the cardiac evaluations. Blood pressure values (median [range]), measured noninvasively, were determined as 190 mm Hg (183 to 261 mm Hg) for systolic pressure, 126 mm Hg (100 to 190 mm Hg) for diastolic pressure, and 155 mm Hg (126 to 222 mm Hg) for mean pressure. No arrhythmias were reported. For the left ventricle, all horses had increased relative wall thickness, mean wall thickness, and ventricular mass. The interventricular septum was thickened at end diastole (n = 5) and in peak systole (4). The left ventricular internal diameter was small at end diastole (n = 4) and in peak systole (3). The left ventricular free wall was thickened at end diastole (n = 3) and in peak systole (4). No associations between blood pressure and variables consistent with hypertrophy were detected. All horses were euthanized because of the grave prognosis of the primary diseases. All 3 horses that underwent postmortem evaluation had cardiovascular abnormalities. CONCLUSIONS AND CLINICAL RELEVANCE: Hypertensive cardiomyopathy should be considered as a comorbid diagnosis in horses with laminitis or chronic renal failure. Information about the development, progression, reversibility, importance of early detection, and long-term sequelae of this condition is needed.

Transient diabetes mellitus in a neonatal Thoroughbred foal.

OBJECTIVE: To describe the clinical presentation, treatment, and outcome of a neonatal foal diagnosed with transient Type 1 diabetes mellitus. CASE SUMMARY: A 3-day-old Thoroughbred foal presented with a 24-hour history of diarrhea and depression. Coronavirus particles were observed in the feces via electron microscopy. During hospitalization the foal developed hyperglycemia concomitantly with low insulin concentration and an adequate response to exogenous insulin therapy supported a diagnosis of Type 1 diabetes mellitus. The foal required SC insulin for 26 days, but developed complications associated with insulin therapy that resolved with appropriate care. On follow up assessment the foal was found to be a healthy euglycemic animal with normal insulin concentration at 11 months of age. NEW OR UNIQUE INFORMATION PROVIDED: To our knowledge this is the first report of Type 1 diabetes in this age group and the first report of transient neonatal diabetes mellitus in horses. Type 1 diabetes mellitus should be considered a differential diagnosis for hyperglycemia in equine neonates and that it can be transient and managed successfully.