Medium- and Long-Term Outcomes of Autologous Fat Grafting to Hands and Feet for Patients With Raynaud Phenomenon.

BACKGROUND: Autologous fat grafting (AFG) has emerged as a promising treatment option for Raynaud phenomenon. However, existing studies are limited by short follow-up, and there is little evidence regarding predictive factors for successful outcomes. METHODS: A retrospective chart review and standardized phone interviews were performed for all patients (n = 17, 65% response rate) treated with AFG to the hands or feet at our institution for primary or secondary Raynaud from 2010 to 2021. Each occurrence of AFG was defined as a separate surgery (n = 23), with an average follow-up of 3.7 years. RESULTS: At follow-up, patients reported a 31% reduction in cold attack frequency, a 45% reduction in the intensity of individual attacks, a 29% reduction in the duration of attacks, and a 40% improvement in overall Raynaud Condition Score (P < 0.01). Although initial AFG to an extremity significantly improved symptoms, subsequent attempts were not shown to statistically improve outcomes. Digital ulcers were present in 65% of cases, and AFG resulted in ulcer healing in 87% of those cases. Median duration of maximum symptom relief was 1 year postoperatively, with 74% of patients reporting diminishing symptom relief by 4 years postoperatively. Those with a BMI ≥25, with primary Raynaud phenomenon or without preoperative ulcers experienced significantly longer symptom relief (P < 0.05). Average patient satisfaction was 7.7 of 10, and 91% would recommend the procedure to others. CONCLUSIONS: Autologous fat grafting is an effective, albeit sometimes temporary, treatment for Raynaud and digital ulcers. Certain patients may be more likely to experience lasting symptom relief beyond 1 year.

Comparison of physiological demands in Warmblood show jumping horses over a standardized 1.10 m jumping course versus a standardized exercise test on a track.

BACKGROUND: A greater understanding of exercise physiology and biochemistry is required for the sport horse disciplines, including show jumping. Conditioning of horses for show jumping is empirical because they are primarily trained on flat ground, however the equivalent workload between jumping and flat work is currently unknown. The objectives of the study were therefore to compare the physiological demands of Warmblood show jumpers over a standardized 1.10 m course vs a 600 m standardized incremental exercise test on flat ground, and to report reference field test values for competitive show jumping horses. In this prospective field study, 21 healthy, actively competing Warmblood show jumping horses were assessed to determine physiological variables after a standardized jumping course at 6.4 m/s (average speed) and track standardized incremental exercise test at 5 m/s, 8 m/s and 11 m/s. Heart rate, velocity, blood lactate, blood pH, pCO2, bicarbonate, PCV and TP concentrations were recorded. V200, V170 and VLa4 were calculated. Parametric statistics were performed on analysis of all 21 horses' variables. RESULTS: Contrary to exercise at 5 m/s and 11 m/s, cantering at 8 m/s did not induce any significant difference in blood lactate, mean heart rate or mean venous blood pH compared to after completion of the jumping course. CONCLUSIONS: Jumping a 1.10 m course demands a statistically similar workload to cantering around a flat track at 8 m/s. This study will help to test fitness and design conditioning programs for Warmblood show jumping horses.

Effect of injected dexamethasone on relative cytokine mRNA expression in bronchoalveolar lavage fluid in horses with mild asthma.

BACKGROUND: Mild equine asthma is a common inflammatory airway disease of the horse. The primary treatment of mild equine asthma is corticosteroids. The purpose of this study was to investigate the effects of injected dexamethasone on relative IL-1ß, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p35, IL-17, IL-23, IFN-γ, Eotaxin-2 and TNF-α mRNA expression in bronchoalveolar lavage (BAL) fluid in healthy Thoroughbred horses (n = 6), and those with mild equine asthma (n = 7). RESULTS: Horses with mild equine asthma had a significantly greater bronchoalveolar lavage mast cell percentage than healthy horses both before and after treatment. Mild equine asthma was associated with a 4.95-fold up-regulation of IL-17 (p = 0.026) and a 2.54-fold down-regulation of IL-10 (p = 0.049) compared to healthy horses. TNF-α was down-regulated in response to dexamethasone treatment in both healthy horses (3.03-fold, p = 0.023) and those with mild equine asthma (1.75-fold, p = 0.023). IL-5 was also down-regulated in horses with mild asthma (2.17-fold, p = 0.048). CONCLUSIONS: Horses with mild equine asthma have a lower concentration of IL-10 in BAL fluid than healthy controls which concurs with human asthmatics. The marked up-regulation of IL-17 in horses with mild asthma suggests these horses had a true tendency of "allergic" airway inflammation in response to environmental allergens. Dexamethasone administration exerted anti-inflammatory effects associated with down-regulation of TNF-α in all horses, and decreased levels of IL-5 mRNA expression in horses with mild equine asthma. The inhibition of the Th-2 response, without any alterations to the airway cytology, indicates that maintained exposure to environmental allergens perpetuates airway inflammation.

Upper and lower respiratory tract microbiota in horses: bacterial communities associated with health and mild asthma (inflammatory airway disease) and effects of dexamethasone.

BACKGROUND: The microbial composition of the equine respiratory tract, and differences due to mild equine asthma (also called Inflammatory Airway Disease (IAD)) have not been reported. The primary treatment for control of IAD in horses are corticosteroids. The objectives were to characterize the upper and lower respiratory tract microbiota associated with respiratory health and IAD, and to investigate the effects of dexamethasone on these bacterial communities using high throughput sequencing. RESULTS: The respiratory microbiota of horses was dominated by four major phyla, Proteobacteria (43.85%), Actinobacteria (21.63%), Firmicutes (16.82%), and Bacteroidetes (13.24%). Fifty genera had a relative abundance > 0.1%, with Sphingomonas and Pantoea being the most abundant. The upper and lower respiratory tract microbiota differed in healthy horses, with a decrease in richness in the lower airways, and 2 OTUs that differed in abundance. There was a separation between bacterial communities in the lower respiratory tract of healthy and IAD horses; 6 OTUs in the tracheal community had different abundance with disease status, with Streptococcus being increased in IAD horses. Treatment with dexamethasone had an effect on the lower respiratory tract microbiota of both heathy and IAD horses, with 8 OTUs increasing in abundance (including Streptococcus) and 1 OTU decreasing. CONCLUSIONS: The lower respiratory tract microbiota differed between healthy and IAD horses. Further research on the role of Streptococcus in IAD is warranted. Dexamethasone treatment affected the lower respiratory tract microbiota, which suggests that control of bacterial overgrowth in IAD horses treated with dexamethasone could be part of the treatment strategy.

Workload of horses on a water treadmill: effect of speed and water height on oxygen consumption and cardiorespiratory parameters.

BACKGROUND: Despite the use of water treadmills (WT) in conditioning horses, the intensity of WT exercise has not been well documented. The workload on a WT is a function of water height and treadmill speed. Therefore, the purpose of this study was to determine the effects of these factors on workload during WT exercise. Fifteen client-owned Quarter Horses were used in a randomized, controlled study. Three belt speeds and three water heights (mid cannon, carpus and stifle), along with the control condition (dry treadmill, all three speeds), were tested. Measured outcomes were oxygen consumption (V̇O2), ventilation (respiratory frequency, tidal volume (VT)), heart rate (HR), and blood lactate. An ergospirometry system was used to measure V̇O2 and ventilation. Linear mixed effects models were used to examine the effects of presence or absence of water, water height and speed (as fixed effects) on measured outcomes. RESULTS: Water height and its interaction with speed had a significant effect on V̇O2, VT and HR, all peaking at the highest water level and speed (stifle at 1.39 m/s, median V̇O2 = 16.70 ml/(kg.min), VT = 6 L, HR = 69 bpm). Respiratory frequency peaked with water at the carpus at 1.39 m/s (median 49 breaths/min). For a given water height, the small increments in speed did not affect the measured outcomes. Post-exercise blood lactate concentration did not change. CONCLUSIONS: Varying water height and speed affects the workload associated with WT exercise. The conditions utilized in this study were associated with low intensity exercise. Water height had a greater impact on exercise intensity than speed.

FEASIBILITY FOR ULTRASOUND-GUIDED INJECTION OF THE COLLATERAL LIGAMENTS OF THE DISTAL INTERPHALANGEAL JOINT IN HORSES.

Desmitis of the collateral ligament of the distal interphalangeal joint is a cause of lameness in performance horses. The objective of this prospective, experimental, ex vivo feasibility study was to evaluate the success of ultrasound-guided injection of the collateral ligaments of the distal interphalangeal joint in the equine forelimb. Seventy-six ultrasound-guided dye injections of the collateral ligament of the distal interphalangeal joint were performed on horses' cadaver limbs. The hooves were sectioned transversely to verify the location of the dye relative to the collateral ligaments and surrounding structures. Evaluations of transverse sections were performed independently by two experienced observers. A scoring system was used to assess injection of the collateral ligament of the distal interphalangeal joint at the proximal, middle, and distal aspect over the length of the ligament. The collateral ligament was injected at any point in 97.4% of cases. The ligament was injected over the entire scored length in 43.2% of cases (32/74), over two scored length areas in 45.9% of cases (34/74), and in one area in 10.8% of cases (8/74). The distal interphalangeal joint and the common digital extensor tendon were also injected in 81.6% (62/76) and 43.4% (33/76) of the cases, respectively. Use of the ultrasound had a positive and negative predictive value of 98% and 9%, respectively. In this study, ultrasound guidance was useful for confirming injection of the collateral ligament of the distal interphalangeal joint but did not prevent injecting the distal interphalangeal joint and the common digital extensor tendon.

A CONSORT-guided, randomized controlled clinical trial of nebulized administration of dexamethasone and saline on lower airway cytokine mRNA expression in horses with moderate asthma.

BACKGROUND: Nebulized administration of dexamethasone on cytokine regulation in horses with moderate asthma has not been investigated. OBJECTIVE: To investigate the changes in expression of inflammatory cytokine mRNA after nebulized administration of dexamethasone treatment of horses with moderate asthma. ANIMALS: Horses with naturally occurring moderate asthma (n = 16) and healthy control horses (n = 4). All horses were kept in a dusty environment during the study. METHODS: Prospective, parallel, randomized, controlled, blinded clinical trial. Blood endogenous cortisol, tracheal mucus, and bronchoalveolar lavage (BAL) were sampled before and after 13 days treatment with either nebulized administration of dexamethasone (15 mg once daily) or 0.9% saline (3 mL). Treatment groups were randomly allocated via randomization function (Microsoft Excel). Amplification of target mRNA in BAL fluid (IL-1ß, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-17, IL-23, IFN-γ, Eotaxin-2, and TNF-α) was achieved by qPCR, and the relative expression software tool was used to analyze BAL inflammatory cytokine mRNA. RESULTS: Horses treated with nebulized administration of dexamethasone had increased relative expression of IL-5 (1.70-fold), IL-6 (1.71-fold), IL-17 (3.25-fold), IL-12 (1.66-fold), and TNF-α (1.94-fold), and decreased relative expression of IL-23 (1.76-fold; P = .04) in samples collected on Day 14, in comparison to samples collected on Day 0 (all P < .05). Horses treated with nebulized administration of saline had no significant difference in the relative expression of any gene (all P > .05). CONCLUSIONS AND CLINICAL IMPORTANCE: Nebulized administration of dexamethasone was associated with increased expression of inflammatory cytokine mRNA. There was no improvement in inflammatory airway cytology associated with either dexamethasone or saline treatment.

Applying Iterative Student Feedback across Flipped Classroom and Flexible Teaching Approaches: Impact on Veterinary Students' Learning Experience.

No single teaching strategy supports all learning styles in veterinary science students. To facilitate more convenient and flexible teaching, learning, and revision, an innovative online digital learning platform-VetCloud-was developed to provide access to modularized programme content across courses to promote active, integrated learning. This study aimed to understand student perceptions regarding the enhancement of the student learning experience in a foundational course in gastrointestinal anatomy and physiology at The University of Queensland across two learning cycles, via applying iterative student feedback in transitioning a flipped classroom approach using VetCloud for the delivery of lecture content in 2022 to a flexible learning approach in 2023. By 2023, the use of VetCloud in the flexible learning approach improved students' work/study/life balance, reduced their stress levels, and enabled a more efficient use of their time when studying, compared to the flipped classroom approach in 2022. Surveying student perceptions was integral to maximizing their learning experience. Data clearly demonstrates that students will mix-and-match how they interact with available options provided via flexible delivery on an individualized basis. This teaching method offers veterinary educators an innovative and efficient approach to veterinary student education in anatomy and physiology while enhancing student well-being.

Dynamic nasopharyngeal collapse in horses: What we know so far.

Dynamic nasopharyngeal collapse (NPC) is an obstructive upper airway disease that affects mainly the inspiratory phase of respiration in horses undergoing strenuous exercise. It occurs when the neuromuscular activity of the nasopharynx is overwhelmed by the intense negative pressures generated during exercise. This leads to collapse of at least one of the four components of the nasopharynx which is comprised of the two lateral walls, the dorsal roof and the ventral soft palate. As a result, the airway diameter and thus airflow become compromised. Even small changes in the airway diameter produces profound increases in negative inspiratory pressure, perpetuating the cycle of collapse. Compared to other dynamic upper respiratory tract disorders, the amount of literature on NPC as a disease entity is limited. The exact pathophysiology of NPC is unknown; however, it impacts up to one quarter of high-performance equine athletes presenting for poor performance. There is currently no definitive treatment for this severely performance-limiting condition. Thus, the prognosis for future athletic prognosis is guarded, with most horses being retired from racing or athletic use in general. Further research is warranted in this field to reduce the impact of disease and in turn, reduce the turnover rate and economic loss by enhancing the career longevity of elite equine athletes diagnosed with NPC.

Topography of the respiratory, oral, and guttural pouch bacterial and fungal microbiotas in horses.

BACKGROUND: The lower respiratory tract microbiota of the horse is different in states of health and disease, but the bacterial and fungal composition of the healthy respiratory tract of the horse has not been studied in detail. HYPOTHESIS: The respiratory tract environment contains distinct niche microbiotas, which decrease in species richness at more distal sampling locations. OBJECTIVE: Characterize the bacterial and fungal microbiotas along the upper and lower respiratory tract of the horse. ANIMALS: Healthy Argentinian Thoroughbred horses (n = 11) from the same client-owned herd. METHODS: Prospective cross-sectional study. Eleven upper and lower respiratory tract anatomical locations (bilateral nasal, bilateral deep nasal, nasopharynx, floor of mouth, oropharynx, arytenoids, proximal and distal trachea, guttural pouch) were sampled using a combination of swabs, protected specimen brushes, and saline washes. Total DNA was extracted from each sample and negative control, and the 16S rRNA gene (V4) and ITS2 region were sequenced. Community composition, alpha-diversity, and beta-diversity were compared among sampling locations. RESULTS: Fungal species richness and diversity were highest in the nostrils. More spatial heterogeneity was found in bacterial composition than in fungal communities. The pharyngeal microbiota was most similar to the distal tracheal bacterial and fungal microbiota in healthy horses and therefore may serve as the primary source of bacteria and fungi to the lower respiratory tract. CONCLUSIONS AND CLINICAL IMPORTANCE: The pharynx is an important location that should be targeted in respiratory microbiota research in horses. Future studies that investigate whether biomarkers of respiratory disease can be reliably detected in nasopharyngeal swab samples are warranted.

The Revised Baux Score as a Predictor of Burn Mortality: A Systematic Review and Meta-Analysis.

Mortality following a severe burn is influenced by both patient- and injury-factors, and a number of predictive models have been developed or applied. As there is no consensus on the optimal formula to use, we aimed to investigate the predictive value of the revised Baux score in comparison to other models when determining mortality risk in patients with burn injuries. A systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The review yielded 21 relevant studies. The Prediction model Risk Of Bias ASsessment Tool quality appraisal checklist was used with many studies classified as "high" quality. All studies assessed the utility of the revised Baux score in comparison to other scoring systems such as the original Baux, Belgian Outcome in Burn Injury, Abbreviated Burn Severity Index, Acute Physiology and Chronic Health Evaluation II, Sequential Organ Failure Assessment, Boston Group/Ryan scores, the Fatality by Longevity, APACHE II score, Measured Extent of burn, and Sex model, and the Prognostic Burn Index. There was a range of 48 to 15975 participants per study, with a mean age range of 16 to 52 years old. The area under the curve (AUC) values of the rBaux score ranged from 0.682 to 0.99, with a summary AUC of 0.93 for all included studies (CI 0.91-0.95). This summary value demonstrates that the rBaux equation is a reliable predictor for mortality risk in heterogeneous populations. However, this study also identified that the rBaux equation has a diminished ability to predict mortality risk when applied to patients at both extremes of age, highlighting an important area for future research. Overall, the rBaux equation offers a relatively easy means to quickly assess the mortality risk from burn injury in a broad range of patient populations.

Comparing the Efficiency of Tumescent Infiltration Techniques in Burn Surgery.

Tangential excision and grafting of burn wounds result in significant intraoperative blood loss, and infiltration of a dilute epinephrine solution (tumescence) is routinely performed to reduce such bleeding. Tumescent infiltration has been described using both a manual technique (syringe) and a pump device. The purpose of this study is to compare the efficiency of these two methods in terms of time and economy of motion. Consecutive adult burn patients at a single center requiring excision and grafting were enrolled in the study and randomized into either the manual or pump technique. Excisions involving less than 2% TBSA were excluded, along with specific anatomic regions (eg, head and neck). Infiltration with epinephrine solution (1:500,000) was performed to the endpoint of tumescence by a single surgeon and filmed/coded for duration, number of maneuvers, and volume of tumescence injected. Fourteen patients were enrolled, and 16 cases were randomized to either manual (N = 8) or pump infiltration (N = 8). The pump method required less time (2.0 vs 1.1 cm2/s, P < .001) and fewer maneuvers (37.8 vs 1.1 cm2/move, P < .001) to reach the desired endpoint of tumescence. Use of the infiltration pump also resulted in a reduced volume of tumescent fluid required to reach this point of tumescence (1.7 vs 2.4 mL/cm2, P = .01). Compared to the manual technique, an infiltration pump was significantly more efficient in terms of both time and economy of motion. These reductions are potentially useful for improving operating room efficiency as well as minimizing operator fatigue.

Review of Health Insurance Policy Inclusivity of Gender Nonconforming and Nonbinary Individuals Seeking Gender-Affirming Health Care.

Background: An increasing number of individuals who present to health care professionals identify as transgender, gender nonconforming (GNC), and gender nonbinary (NB). GNC/NB individuals experience higher rates of discrimination in health care settings compared with their binary (e.g., trans male and trans female) counterparts. Outdated language excludes the nuances of gender identity. The goal of this study was to evaluate whether current terminology found in health insurance policies may be a barrier to gender-affirming health care for GNC/NB individuals. Methods: Health insurance policies for a diverse subset of government (n=4) and private (n=6) payers were obtained in May 2020. Policies were reviewed independently by two members of the research team to determine whether each was supportive or unsupportive to GNC/NB individuals. An arbitrary scoring system was designed that allowed the reviewers to assign a specific number of points to each policy based on the aggregation of mention, coverage, and inclusivity. Results: Most policies performed poorly as indicated by a support score less than zero. It was also noted that most policies used binary, gendered language, and terminology that excludes the unique gender identities of many GNC/NB individuals. Conclusions: Most policies currently failed to provide clear, inclusive coverage to GNC/NB individuals for relevant and important aspects of their care. In their current state, these policies are a source of confusion, uncertainty, and discouragement for these individuals, which can present as a barrier to accessing quality, inclusive, gender-affirming health care.

Nonclassical Pathogens as Causative Agents of Proctitis in Men who Have Sex With Men.

BACKGROUND: This study aimed to identify enteric and sexually acquired rectal pathogens, other than chlamydia and gonorrhea, associated with symptomatic proctitis in men who have sex with men (MSM). METHODS: Anorectal swab samples were obtained from MSM presenting with rectal symptoms and a clinical diagnosis of proctitis at the Melbourne Sexual Health Centre between January 2017 and March 2019. Samples that tested positive for Neisseria gonorrhoeae and Chlamydia trachomatis were excluded. As a comparison group, anorectal samples were also obtained from MSM not reporting symptoms of proctitis between November 2018 and February 2019. Samples from both groups were tested for 15 viral, bacterial, and protozoal enteric pathogens using polymerase chain reaction. RESULTS: Anorectal samples from 499 men with symptomatic proctitis and 506 asymptomatic men were analyzed. Age, HIV status, and pre-exposure prophylaxis (PrEP) use did not differ between men with proctitis and asymptomatic men. Treponema pallidum was more common in men with proctitis (risk difference [RD], 3.6%; 95% CI, 2.0%-5.2%). Most men with anorectal T. pallidum presented with painful anal primary infections. Shigella spp. was more common among men with proctitis compared with asymptomatic men (RD, 1.8%; 95% CI, 0.1%-3.5%). Most men with Shigella did not report diarrhea. Mycoplasma genitalium was more common in men with proctitis (RD, 4.3%; 95% CI, 1.1%-7.5%). Herpes simplex virus (HSV)-1 (RD, 10.1%; 95% CI, 6.8%-13.3%) and HSV-2 (RD, 7.2%; 95% CI, 4.5%-10.0%) were more common with proctitis. CONCLUSIONS: Testing for T. pallidum, Shigella, and HSV should be considered in MSM presenting with symptomatic proctitis. These data provide support for M. genitalium as a significant cause of proctitis. A comprehensive diagnostic evaluation is required for MSM with proctitis.

Recent advances in understanding and combatting Mycoplasma genitalium.

Mycoplasma genitalium has emerged over the last 30 years as a sexually transmitted infection (STI). As data have accumulated, our understanding of this pathogen and its role in disease continues to evolve. This in turn creates new challenges and complexities. Questions remain regarding the natural history of M. genitalium, its contribution to disease and long-term sequelae. A decline in cure rates for first-line anti-microbials has been observed. This is likely in part due to high usage of single-dose azithromycin in the sexual health field but also due to the intrinsic ability of M. genitalium to rapidly acquire anti-microbial resistance. Consequently, the term 'the new STI superbug' is not infrequently used by the media to describe this pathogen. Currently available antibiotics have side effects that, though rare, are potentially serious. This leads to inherent questions regarding the benefit of testing for and treating M. genitalium, particularly in asymptomatic individuals or in genital syndromes where the benefit of treatment is not well established. In this review, we summarize the most recent evidence and literature regarding M. genitalium and explore areas of research where disparities exist. We discuss the contribution of M. genitalium to genital syndromes, particularly those where data are conflicting, in order to inform indications for testing and treatment. Avoidance of increasing anti-microbial resistance with astute anti-microbial stewardship is paramount if we are to successfully manage M. genitalium infection. We examine the state of play regarding anti-microbial resistance and how to combat this, including currently available anti-microbials, resistance-guided therapy and novel therapeutic approaches. We aim to provide an overview of the current understanding of M. genitalium and the implications for current clinical practise and suggestions for future research.

Effects of nebulized dexamethasone on the respiratory microbiota and mycobiota and relative equine herpesvirus-1, 2, 4, 5 in an equine model of asthma.

BACKGROUND: Prolonged exposure to environmental antigens or allergens elicits an immune response in both healthy horses and those with mild asthma. Corticosteroids often are used to treat lower airway inflammation. OBJECTIVE: To investigate the changes in equine herpesvirus (EHV)-1,2,4,5 glycoprotein B gene expression and changes in respiratory bacterial and fungal communities after nebulized dexamethasone treatment of horses with asthma. ANIMALS: Horses with naturally occurring mild asthma (n = 16) and healthy control horses (n = 4). METHODS: Prospective, randomized, controlled, blinded clinical trial. Polymerase chain reaction amplification of EHV-1,2,4,5 in bronchoalveolar lavage fluid, and 16S (microbiome) and ITS2 (mycobiome) genes with subsequent sequencing was performed on DNA extracted from nasal swabs and transendoscopic tracheal aspirates before and after 13 days treatment with nebulized dexamethasone (15 mg q24h) and saline (control). RESULTS: Nebulized dexamethasone treatment decreased microbial diversity; relative abundance of 8 genera in the upper respiratory tract were altered. For both the microbiota and the mycobiota, environment had a dominant effect over treatment. Alternaria, an opportunistic pathogen and allergen in humans recognized as a risk factor for asthma, asthma severity, and exacerbations, was increased with treatment. Treatment affected relative quantification of the equine gamma herpesviruses (EHV-2 and -5); EHV-2 DNA levels increased and those of EHV-5 decreased. CONCLUSIONS: Nebulized dexamethasone treatment affected the upper respiratory tract microbiota, but not the mycobiota, which was overwhelmed by the effect of a sustained dusty environment.

Efficacy of dexamethasone, salbutamol, and reduced respirable particulate concentration on aerobic capacity in horses with smoke-induced mild asthma.

BACKGROUND: Mild asthma in horses decreases racing performance and impairs gas exchange. The efficacy of treatment on performance is unknown. HYPOTHESIS: Treatment targeting lung inflammation improves V ˙ O2 peak in horses with mild asthma. ANIMALS: Thoroughbred polo horses (n = 12) with smoke-induced mild asthma. Horses were exposed to increased ambient particulate matter (35.51 µg/m3 [PM2.5 ]; day mean, centrally measured) from day -33 to 0, from bushfire smoke (natural model). METHODS: Prospective, randomized, placebo-controlled, double-blinded clinical trial. All horses completed 3 V ˙ O2 peak tests, measuring aerobic and anaerobic variables: day 0 -baseline; day 16 -after dexamethasone (20 mg IM q24h; DEX, n = 6) or saline treatment (SALINE, n = 6), under improved ambient PM2.5 concentrations (7.04 µg/m3 ); day 17-15-30mins after inhaled salbutamol (1500 µg). Bronchoalveolar lavage and mucus scoring were performed on day -8 and day 20. Linear mixed effects models were used to examine the effects of timepoint and treatment group on BAL differential cell counts, mucus scores, aerobic and anaerobic variables. RESULTS: Horses' mucus scores improved significantly from day -8 to 20 by 1.27 ± .38 (P = .01). There was a significant increase in V ˙ O2 peak of 15.5 ± 4.0 mL(min.kg)-1 from day 0 to 17 (P = .002), representing an average (mean) increase in V ˙ O2 peak of 13.2%. There was no difference in V˙O2 peak between treatment groups (SALINE versus DEX) at any timepoint. CONCLUSIONS AND CLINICAL IMPORTANCE: This study highlighted the key role of improved air quality on functionally important airway inflammation. Evidence provided is central to increasing owner compliance regarding improved air quality for the treatment and prevention of mild asthma.

Conditioning equine athletes on water treadmills significantly improves peak oxygen consumption.

Equine water treadmills (WT) were initially designed for rehabilitation of musculoskeletal injuries, but are also commonly used for conditioning sport horses, however the effects are not well documented. The purpose of this study was to test the effect of an 18-day WT conditioning programme on peak oxygen consumption (V̇O2peak). Nine unfit Thoroughbreds were used in a randomised controlled trial. Six horses worked daily for 18 days in stifle-height water (WT group), while 3 control horses worked without water (dry treadmill group (DT)). Preconditioning and postconditioning maximal exercise racetrack tests (800 m) were performed using a portable ergospirometry system. Measured outcomes were V̇O2, tidal volume, minute ventilation, breathing frequency, heart rate, blood lactate and instantaneous and average speed. The workload as assessed by V̇O2 was 21.7 per cent of preconditioning V̇O2peak values for WT horses. V̇O2peak on the racetrack increased by 16.1 per cent from preconditioning to postconditioning in the WT horses (P=0.03), but did not change in the DT horses. Therefore, exercising horses in high water heights may improve conditioning.