Prevalence and risk factors associated with nasal carriage of methicillin-resistant staphylococci in horses and their caregivers.

Antimicrobial resistance is a global threat, and pet-associated strains may pose a risk to human health. Equine veterinarians are at high risk of carrying methicillin-resistant staphylococci (MRS), but specific risk factors remain elusive, and few data are available for other personnel involved in the horse industry. The prevalence, characteristics, and risk factors for nasal carriage of MRS in horses and their caregivers were studied in northwestern Italy. Nasal swabs from 110 asymptomatic horses housed at 21 barns and 34 human caregivers were collected. Data on barns, horses, and personnel were acquired through questionnaires. The samples were incubated in selective media, and the bacterial isolates were identified by mass spectrometry. Risk factors were investigated by Poisson regression. MRS were isolated from 33 horses (30%), 11 humans (32.4%) and 3 environmental samples (14.2%). Most isolates were multidrug resistant (MDRS). The prevalence of MRS and MDRS was greater in racehorses and their personnel than in pleasurable and jumping/dressing horses. MRS carriage in caregivers was associated with an increased prevalence of MRS carriage in horses. The frequency of antimicrobial treatments administered in the barn during the last 12 months was a risk factor for MRS carriage in horses [prevalence ratio (PR) 3.97, 95% CI 1.11, 14.13] and caregivers (PR 2.00, 95% CI 1.05, 3.82), whereas a good ventilation index of the horse tabling environment was a protective factor (PR 0.43, 95% CI 0.20, 0.92). Our data reveal relevant interactions occurring between bacterial communities of horses and humans that share the same environment, suggesting that One Health surveillance programs should be implemented.

The equine asthma model of airway remodeling: from a veterinary to a human perspective.

Human asthma is a complex and heterogeneous disorder characterized by chronic inflammation, bronchospasm and airway remodeling. The latter is a major determinant of the structure-function relationship of the respiratory system and likely contributes to the progressive and accelerated decline in lung function observed in patients over time. Corticosteroids are the cornerstone of asthma treatment. While their action on inflammation and lung function is well characterized, their effect on remodeling remains largely unknown. An important hindrance to the study of airway remodeling as a major focus in asthma research is the lack of reliable non-invasive biomarkers. In consequence, the physiologic and clinical consequences of airway wall thickening and altered composition are not well understood. In this perspective, equine asthma provides a unique and ethical (non-terminal) preclinical model for hypothesis testing and generation. Severe equine asthma is a spontaneous disease affecting adult horses characterized by recurrent and reversible episodes of disease exacerbations. It is associated with bronchoalveolar neutrophilic inflammation, bronchospasm, and excessive mucus secretion. Severe equine asthma is also characterized by bronchial remodeling, which is only partially improved by prolonged period of disease remission induced by therapy or antigen avoidance strategies. This review will focus on the similarities and differences of airway remodeling in equine and human asthma, on the strengths and limitations of the equine model, and on the challenges the model has to face to keep up with human asthma research.

Elevated serum IgE, oral corticosteroid dependence and IL-17/22 expression in highly neutrophilic asthma.

Information on the clinical traits associated with bronchial neutrophilia in asthma is scant, preventing its recognition and adequate treatment. We aimed to assess the clinical, functional and biological features of neutrophilic asthma and identify possible predictors of bronchial neutrophilia.The inflammatory phenotype of 70 mild-to-severe asthma patients was studied cross-sectionally based on the eosinophilic/neutrophilic counts in their bronchial lamina propria. Patients were classified as neutrophilic or non-neutrophilic. Neutrophilic asthma patients (neutrophil count cut-off: 47.17 neutrophils·mm-2; range: 47.17-198.11 neutrophils·mm-2; median: 94.34 neutrophils·mm-2) were further classified as high (≥94.34 neutrophils·mm-2) or intermediate (47.17- <94.34 neutrophils·mm-2). The effect of smoking ≥10 pack-years was also assessed.Neutrophilic asthma patients (n=38; 36 mixed eosinophilic/neutrophilic) had greater disease severity, functional residual capacity, inhaled corticosteroid (ICS) dose and exacerbations, and lower forced vital capacity (FVC) % pred and forced expiratory volume in 1 s (FEV1) reversibility than non-neutrophilic asthma patients (n=32; 28 eosinophilic and four paucigranulocytic). Neutrophilic asthma patients had similar eosinophil counts, increased bronchial CD8+, interleukin (IL)-17-F+ and IL-22+ cells, and decreased mast cells compared with non-neutrophilic asthma patients. FEV1 and FVC reversibility were independent predictors of bronchial neutrophilia in our cohort. High neutrophilic patients (n=21) had increased serum IgE levels, sensitivity to perennial allergens, exacerbation rate, oral corticosteroid dependence, and CD4+ and IL-17F+ cells in their bronchial mucosa. Excluding smokers revealed increased IL-17A+ and IL-22+ cells in highly neutrophilic patients.We provide new evidence linking the presence of high bronchial neutrophilia in asthma to an adaptive immune response associated with allergy (IgE) and IL-17/22 cytokine expression. High bronchial neutrophilia may discriminate a new endotype of asthma. Further research is warranted on the relationship between bronchoreversibility and bronchial neutrophilia.

The Contribution of Oxidative Stress and Inflamm-Aging in Human and Equine Asthma.

Aging is associated with a dysregulation of the immune system, leading to a general pro-inflammatory state of the organism, a process that has been named inflamm-aging. Oxidative stress has an important role in aging and in the regulation of immune responses, probably playing a role in the development of age-related diseases. The respiratory system function physiologically declines with the advancement of age. In elderly asthmatic patients, this may contribute to disease expression. In this review, we will focus on age-related changes affecting the immune system and in respiratory structure and function that could contribute to asthma occurrence, and/or clinical presentation in the elderly. Also, naturally occurring equine asthma will be discussed as a possible model for studying the importance of oxidative stress and immun-aging/inflamm-aging in humans.

Epidemiology of musculoskeletal injuries in a population of harness Standardbred racehorses in training.

BACKGROUND: There is a substantial paucity of studies concerning musculoskeletal injuries in harness Standardbred racehorses. Specifically, little is known about the epidemiology of exercise-related musculoskeletal injuries. Most studies on this subject involve Thoroughbred racehorses, whose biomechanics and racing speed differ from Standardbred, making comparisons difficult. Here, a population of Standardbred racehorses trained at the same racecourse was studied over four years and a classification system for exercise-related musculoskeletal injuries was designed. The incidence rates of musculoskeletal injuries causing horses' withdrawal from training for 15 days or longer were investigated. A mixed-effects Poisson regression model was used to estimate musculoskeletal injury rates and to describe significance of selected risk factors for exercise-related injuries in this population. RESULTS: A total of 356 trotter racehorses from 10 different stables contributed 8961 months at risk of musculoskeletal injuries. Four-hundred-and-twenty-nine injuries were reported and classified into 16 categories, based on their aetiology and anatomical localisation. The overall exercise-related injury rate was 4.79 per 100 horse months. When considering risk factors one by one in separate univariable analyses, we obtained the following results: rates did not differ significantly between genders and classes of age, whereas one driver seemed to cause fewer injuries than the others. Racing speed and racing intensity, as well as recent medical history, seemed to be significant risk factors (p < 0.001), while being shod or unshod during racing was not. On the other hand, when pooling several risk factors in a multivariable approach, only racing intensity turned out to be significant (p < 0.001), since racing speed and the racing intensity were partially confounded, being strongly correlated to one another. CONCLUSION: Characterizing epidemiology of exercise-related musculoskeletal injuries in trotter racehorses provides baseline incidence rate values. Incidence rates of stress fracture are lower in Standardbreds compared to Thoroughbreds, whereas the opposite is true for tendon and suspensory ligament injuries. In addition to identification of risk factors for musculoskeletal injuries among Standardbred racehorses, results suggest that racing intensity seems to be a protective predictor of risk and recent medical history could be used to identify horses at risk of injury.

Minimally invasive metatarsal fracture repair with locking plates in a guanaco (Lama guanicoe).

An open grade I transverse diaphyseal fracture of the metatarsal bone in a 5-yr-old female guanaco (Lama guanicoe) was successfully stabilized with a locking plate system, which is a minimally invasive approach. A conical coupling screw-plate locking system with 3.0-mm-thick plates and 3.5-mm locking head screws was applied, after closed and indirect reduction of the bone segments, with an orthogonal configuration of the plates. The implants were protected postoperatively with a splinted bandage. The fracture healed without complications, the limb function was successfully recovered, and no major complications were observed at the 2-yr follow-up. The surgical procedure was carried out with biologic internal fixation supports and an adequate functional union within a time period similar to that reported for this species following other fracture fixation methods. This case highlights the potential benefit of combining minimally invasive plate osteosynthesis and plate-locking systems for fracture repair in camelids.

Determinants of joint effusion in tarsocrural osteochondrosis of yearling Standardbred horses.

Tarsocrural osteochondrosis (OCD) is a developmental orthopedic disease commonly affecting young Standardbreds, with different fragment localization and size. Clinically, it is characterized by variable synovial effusion in the absence of lameness, whose determinants are ill-defined. We hypothesized that localization and physical characteristics of the osteochondral fragments like dimensions, multifragmentation, and instability influence joint effusion and correlate with synovial markers of cartilage degradation and inflammation. Clinical data, synovial fluid and intact osteochondral fragments were collected from 79 Standardbred horses, aged between 12 and 18 months, operated for tarsocrural OCD. The severity of tarsocrural joint effusion was assessed semi-quantitatively. The osteochondral fragment site was defined radiographically at the distal intermediate ridge of the tibia (DIRT), medial malleolus (MM) of the tibia, and/or lateral trochlear ridge (LTR) of the talus. Size, stability, and arthroscopic appearance (unique or multi-fragmented aspect) of the fragments were determined intra-operatively. Synovial concentrations of C-terminal cross-linked telopeptides of type II collagen (CTX-II), leukotriene B4 (LTB4), and prostaglandin E2 (PGE2) were quantified. Tarsocrural synovial effusion was significantly affected by localization and stability of the fragments, with MM-located and unstable fragments being associated with highest joint effusion. Concentrations of CTX-II, LTB4, and PGE2 positively correlated with the severity of synovial effusion. This study underlines characteristics of the osteochondral fragments determining higher synovial effusion in OCD-affected tarsocrural joints and suggests both inflammation and extra-cellular matrix degradation are active processes in OCD pathology.

Mycoplasma bovis-associated verminous pneumonia in alpine chamois (Rupicapra rupicapra).

Pneumonia is a common disease affecting Alpine chamois. However, little is known concerning the etiological agents involved. We investigated whether Mycoplasma spp. infection occurs in Alpine chamois and describe the microscopic lesions associated with Mycoplasma-associated bronchopneumonia in this species. Lung tissues obtained from 45 chamois with gross evidence of pneumonia were analysed. The histological lesions and the presence of lungworms within the lungs were evaluated blindly. The presence of Mycoplasma spp. was assessed by immunohistochemistry (Mycoplasma bovis and Mycoplasma mycoides subsp. mycoides) and by end-point PCR. M. bovis was detected by immunohistochemistry and confirmed by PCR and sequencing in 6/45 (13%) cases, while all lungs were negative for M. mycoides subsp. mycoides. A significant association was found between the detection of M. bovis and the presence of severe lungworms infection in the examined lungs. We report for the first time M. bovis as a bacteria associated with verminous pneumonia in chamois.

Giant Multinucleated Cells Are Associated with Mastocytic Inflammatory Signature Equine Asthma.

Equine asthma is currently diagnosed by the presence of increased neutrophil (>5%), mast cell (>2%), and/or eosinophil (>1%) differential cell count. Macrophages are normal resident cells within the alveoli. Their presence in BALF is considered normal, but the clinical implication of the presence of activated or fused macrophages (giant multinucleated cells, GMC) is currently overlooked. We aimed to assess the prevalence, cytological determinants, and clinical significance of increased GMC counts in BALF of 34 asthmatic horses compared to 10 controls. Counts were performed on 15 randomly selected high magnification fields per cytospin slide (40×), and expressed as GMC:single macrophage (GMC:M) ratio. Regression models were used for statistical analysis. GMC was frequently observed in both asthmatic and control horses, with an increased prevalence of equine asthma (p = 0.01). GMC:M ratio was significantly higher in severe vs. mild to moderate equine asthmatic and control horses. In asthmatic horses, an increased GMC:M ratio was significantly associated with BALF mastocytosis (p = 0.01), once adjusting for age and the presence and severity of clinical signs of the horses. Tachypnea was the only clinical sign that tended to be positively associated with GMC:M ratio after adjustment (p = 0.08). In conclusion, our data suggest that a relationship might exist between molecular mechanisms regulating GMC formation and mast cell recruitment in the equine lung. The same mechanisms could lead to tachypnea even in the absence of respiratory effort at rest. We suggest including GMC count in the basic cytological assessment of BALF samples to gain more insights into their role in equine asthma.

Fetlock Joint Angle Pattern and Range of Motion Quantification Using Two Synchronized Wearable Inertial Sensors per Limb in Sound Horses and Horses with Single Limb Naturally Occurring Lameness.

Fetlock joint angle (FJA) pattern is a sensitive indicator of lameness. The first aim of this study is to describe a network of inertial measurement units system (IMUs) for quantifying FJA simultaneously in all limbs. The second aim is to evaluate the accuracy of IMUs for quantifying the sagittal plane FJA overground in comparison to bi-dimensional (2-D) optical motion capture (OMC). 14 horses (7 free from lameness and 7 lame) were enrolled and analyzed with both systems at walk and trot on a firm surface. All enrolled horses were instrumented with 8 IMUs (a pair for each limb) positioned at the dorsal aspect of the metacarpal/metatarsal bone and pastern and acquiring data at 200 Hz. Passive markers were glued on the center of rotation of carpus/tarsus, fetlock, and distal interphalangeal joint, and video footages were captured at 60 Hz and digitalized for OMC acquisition. The IMU system accuracy was reported as Root Mean Square Error (RMSE) and Pearson Correlation Coefficient (PCC). The Granger Causality Test (GCT) and the Bland−Altman analysis were computed between the IMUs and OMC patterns to determine the agreement between the two systems. The proposed IMU system was able to provide FJAs in all limbs using a patented method for sensor calibration and related algorithms. Fetlock joint range of motion (FJROM) variability of three consecutive strides was analyzed in the population through 3-way ANOVA. FJA patterns quantified by IMUs demonstrated high accuracy at the walk (RMSE 8.23° ± 3.74°; PCC 0.95 ± 0.03) and trot (RMSE 9.44° ± 3.96°; PCC 0.96 ± 0.02) on both sound (RMSE 7.91° ± 3.19°; PCC 0.97 ± 0.03) and lame horses (RMSE 9.78° ± 4.33°; PCC 0.95 ± 0.03). The two systems' measurements agreed (mean bias around 0) and produced patterns that were in temporal agreement in 97.33% of the cases (p < 0.01). The main source of variability between left and right FJROM in the population was the presence of lameness (p < 0.0001) and accounted for 28.46% of this total variation. IMUs system accurately quantified sagittal plane FJA at walk and trot in both sound and lame horses.

Effect of intravenous tiludronate disodium administration on the radiographic progression of osteoarthritis of the fetlock joint in Standardbred racehorses.

OBJECTIVE: To compare the effects of tiludronate disodium and 3 other medical treatments on clinical and radiographic findings and biomarkers of disease progression in horses with osteoarthritis of the fetlock joint. ANIMALS: 100 Standardbred racehorses with spontaneous traumatic injury of the fetlock joint. PROCEDURES: Horses were retrospectively grouped by whether they received tiludronate IV or triamcinolone acetonide and hyaluronan, polysulfated glycosaminoglycan, or interleukin-1 receptor antagonist protein intra-articularly. Data were collected on clinical, radiographic, and ultrasonographic findings and results for serum and synovial samples obtained before and 6 months after treatment. Lameness score, joint flexion test response, radiographic score, serum concentrations of tumor necrosis factor-α and carboxy-terminal telopeptides of collagen types I and II (CTX-I and II, respectively), and synovial fluid concentrations of interleukin-1ß, prostaglandin E2, and CTX-II were compared among treatments. RESULTS: All treatments resulted in a significant improvement in lameness score and joint flexion test response at 6 months. In horses that received triamcinolone acetonide and hyaluronan, synovial fluid interleukin-1ß, prostaglandin E2, and CTX-II concentrations decreased after treatment, suggesting this treatment inhibited progression of hyaline cartilage degeneration and inflammatory processes. Horses that received tiludronate were the only group that had a decrease in radiographic score and serum CTX-I concentration after treatment, supporting the effect of tiludronate on bone metabolism. Tiludronate treatment was also followed by increases in serum and synovial fluid concentrations of CTX-II, a marker of cartilage damage. CONCLUSIONS AND CLINICAL RELEVANCE: Tiludronate appeared to inhibit the radiographic progression of osteoarthritis in high-motion joints of racehorses at 6 months after treatment by inhibiting subchondral bone remodeling. Whether this effect was associated with a worsening of progressive cartilage damage remains to be ascertained.

Within-Breath Oscillatory Mechanics in Horses Affected by Severe Equine Asthma in Exacerbation and in Remission of the Disease.

Oscillometry is a technique that measures the resistance (R) and the reactance (X) of the respiratory system. In humans, analysis of inspiratory and expiratory R and X allows to identify the presence of tidal expiratory flow limitation (EFLt). The aim of this study was to describe inspiratory and expiratory R and X measured by impulse oscillometry system (IOS) in horses with severe asthma (SEA) when in clinical remission (n = 7) or in exacerbation (n = 7) of the condition. Seven healthy, age-matched control horses were also studied. Data at 3, 5, and 7 Hz with coherence > 0.85 at 3 Hz and >0.9 at 5 and 7 Hz were considered. The mean, inspiratory and expiratory R and X and the difference between inspiratory and expiratory X (ΔX) were calculated at each frequency. The data from the three groups were statistically compared. Results indicated that in horses during exacerbation of severe asthma, X during expiratory phase is more negative than during inspiration, such as in humans in presence of EFLt. The evaluation of X during inspiration is promising in discriminating between horses with SEA in remission and control horses.

Radiofrequency Thermoablation On Ex Vivo Animal Tissues: Changes on Isolated Swine Thyroids.

The use of Radiofrequency thermoablation (RFA) for treating large thyroid nodules is limited by the modest efficiency of the available systems in terms of volume of the ablation zones (AZs). This increases the risk of incomplete ablation of the nodule. Systems employing perfused electrodes have been developed to increase the volume of the AZ. Aim of this study is to compare the size of the AZ induced by RFA systems using internally cooled perfused vs. non-perfused electrodes in swine thyroids. RFAs were performed on 40 freshly isolated swine thyroids using both systems. The perfused system was tested using 0.9% saline, 7% and 18% hypertonic saline solutions. Energy delivery to the tissue was stopped when tissue conductivity dropped (real life simulations) and after an established time of 20 seconds (controlled duration). Following RFA, thyroids were transversally and longitudinally cut. Photographs were taken for macroscopic morphometry of the ablated zones before and after formalin fixation, to evaluate tissue shrinkage. Microscopic morphometry was performed on PAS stained sections. In real life simulation experiments, gross morphometry revealed that AZs produced with electrodes perfused using 7.0% saline are larger compared to isotonic saline. Microscopically, all the conditions tested using the perfused system produced larger AZs compared to non-perfused system after 20 seconds of RFA. In conclusion, the perfusion with 7.0% NaCl solution increased the electrical conductivity of the tissue in real life simulations, resulting in larger ablated areas compared to the use of isotonic saline.

Use of a biopolymer delivery system to investigate the influence of interleukin-4 on recruitment of neutrophils in equids.

OBJECTIVE: To use a biopolymer delivery system to investigate the ability of interleukin (IL)-4 to recruit neutrophils into subcutaneous tissues of equids. ANIMALS: 16 horses and 2 ponies. PROCEDURES: Animals were assigned to 3 experiments (6/experiment). Effects of recombinant equine (Req) IL-4 (100, 250, or 500 ng/site) versus a positive control (ReqIL-8; 100 ng, 250 ng, or 1 µg/site) and a negative control (Dulbecco PBSS or culture medium) on neutrophil chemotaxis were assessed after SC injection into the neck with an injectable biopolymer used as the vehicle. Tissue samples including the biopolymer plug were collected by biopsy at various time points from 3 hours to 7 days after injection. Neutrophil infiltration was evaluated by histologic scoring (experiments 1, 2, and 3) or flow cytometry (experiment 3). RESULTS: Histologic neutrophil infiltration scores did not differ significantly among treatments at most evaluated time points. On flow cytometric analysis, log-transformed neutrophil counts in biopsy specimens were significantly greater for the ReqIL-8 treatment (1 µg/site) than the negative control treatment at 3 but not 6 hours after injection; results did not differ between ReqIL-4 and control treatments at either time point. Negative control treatments induced an inflammatory response in most equids in all experiments. CONCLUSIONS AND CLINICAL RELEVANCE: Flow cytometry was a more reliable method to estimate neutrophil migration than histologic score analysis. The ReqIL-4 treatment did not induce a detectable neutrophil response, compared with the negative control treatment in this study. Evidence of inflammation in negative control samples suggested the biopolymer is not a suitable vehicle for use in equids.

Severe asthma is associated with a remodeling of the pulmonary arteries in horses.

Pulmonary hypertension and cor pulmonale are complications of severe equine asthma, as a consequence of pulmonary hypoxic vasoconstriction. However, as pulmonary hypertension is only partially reversible by oxygen administration, other etiological factors are likely involved. In human chronic obstructive pulmonary disease, pulmonary artery remodeling contributes to the development of pulmonary hypertension. In rodent models, pulmonary vascular remodeling is present as a consequence of allergic airway inflammation. The present study investigated the presence of remodeling of the pulmonary arteries in severe equine asthma, its distribution throughout the lungs, and its reversibility following long-term antigen avoidance strategies and inhaled corticosteroid administration. Using histomorphometry, the total wall area of pulmonary arteries from different regions of the lungs of asthmatic horses and controls was measured. The smooth muscle mass of pulmonary arteries was also estimated on lung sections stained for α-smooth muscle actin. Reversibility of vascular changes in asthmatic horses was assessed after 1 year of antigen avoidance alone or treatment with inhaled fluticasone. Pulmonary arteries showed increased wall area in apical and caudodorsal lung regions of asthmatic horses in both exacerbation and remission. The pulmonary arteries smooth muscle mass was similarly increased. Both treatments reversed the increase in wall area. However, a trend for normalization of the vascular smooth muscle mass was observed only after treatment with antigen avoidance, but not with fluticasone. In conclusion, severe equine asthma is associated with remodeling of the pulmonary arteries consisting in an increased smooth muscle mass. The resulting narrowing of the artery lumen could enhance hypoxic vasoconstriction, contributing to pulmonary hypertension. In our study population, the antigen avoidance strategy appeared more promising than inhaled corticosteroids in controlling vascular remodeling. However, further studies are needed to support the reversibility of vascular smooth muscle mass remodeling after asthma treatment.

Characterization of the ablation zones produced by three commercially available systems from a single vendor for radiofrequency thermoablation in an ex vivo swine liver model.

BACKGROUND: Radiofrequency Ablation (RFA) is rarely performed in veterinary medicine. A rationale exists for its use in selected cases of canine liver tumours. RFA induces ablation zones of variable size and geometry depending on the technique used and on the impedance of the targeted organ. OBJECTIVES: (a) to describe the geometry and reproducibility of the ablation zones produced by three commercially available systems from a single company, using isolated swine liver parenchyma as a model for future veterinary applications in vivo; (b) to study the effects of local saline perfusion into the ablated parenchyma through the electrode tip and of single versus double passage of the electrode on size, geometry and reproducibility of the ablation zones produced. METHODS: Size, and geometry of ablation zones reproduced in six livers with one cooled and perfused (saline) and two cooled and non-perfused systems, after single or double passage (n = 6/condition), were assessed macroscopically on digitalized images by a blinded operator. Longitudinal and transverse diameters, equivalent diameter, estimated volume and roundness index were measured. Reproducibility was assessed as coefficient of variation. RESULTS AND CONCLUSIONS: Ablation zone reproducibility was higher when expressed in terms of ablation zone diameters than estimated volume. Local saline perfusion of the parenchyma through the electrode tip during RFA increased the ablation zone longitudinal diameter. Ablation zone estimated volume increased with saline perfusion only when double passage was performed. These data may provide useful information for those clinicians who intend to include RFA as an additive tool in veterinary interventional radiology.

Equine Asthma: Current Understanding and Future Directions.

The 2019 Havemeyer Workshop brought together researchers and clinicians to discuss the latest information on Equine Asthma and provide future research directions. Current clinical and molecular asthma phenotypes and endotypes in humans were discussed and compared to asthma phenotypes in horses. The role of infectious and non-infectious causes of equine asthma, genetic factors and proposed disease pathophysiology were reviewed. Diagnostic limitations were evident by the limited number of tests and biomarkers available to field practitioners. The participants emphasized the need for more accessible, standardized diagnostics that would help identify specific phenotypes and endotypes in order to create more targeted treatments or management strategies. One important outcome of the workshop was the creation of the Equine Asthma Group that will facilitate communication between veterinary practice and research communities through published and easily accessible guidelines and foster research collaboration.