Equine Veterinary Journal最新文献

Background: Racehorses undergo profound physiological changes with training and competition, but current biomarkers inadequately capture the complex molecular dynamics of exercise. This study aimed to identify novel plasma biomarkers of training adaptation and peak load using high-throughput proteomics.

Objectives: We hypothesised that systematic training and racing induce distinct plasma proteomic signatures, enabling the discovery of candidate biomarkers linked to training status, oxidative stress, inflammation and metabolic remodelling.

Study design: In vivo longitudinal study.

Methods: Forty-nine Arabian and Thoroughbred racehorses underwent standardised high-intensity training. Plasma samples were collected at rest, immediately post-exercise and after recovery during three phases: initial training (T1), mid-season conditioning (T2) and race-phase (R). In total, 314 samples were analysed using tandem mass tags based quantitative proteomics and Orbitrap mass spectrometry. Protein abundance changes were assessed with multiple-testing correction (q < 0.05), and pathway enrichment was performed using STRING and ShinyGO.

Results: Proteomic responses differed by phase. T1 showed broad activation of inflammatory (S100A8/A9), antioxidant (superoxide dismutase 1, catalase) and metabolic proteins (glucose-6-phosphate dehydrogenase, phosphoglycerate kinase 1). T2 displayed a more refined profile with remodelling and redox regulators (decorin, thymosin β4, glutathione S-transferase). Racing elicited the strongest response, with over 100 up-regulated proteins linked to energy metabolism, oxidative defense and cytoskeletal adaptation. Several proteins: including S100A8, thymosin β4, prothymosin-α, cofilin-1 and lipocalins, were consistently modulated across phases, highlighting their biomarker potential.

Main limitations: Breed imbalance and incomplete follow-up sampling may affect generalisability. Validation in larger, diverse cohorts with targeted assays is required.

Conclusions: This study identifies a panel of promising plasma proteins as candidate biomarkers of exercise adaptation and overload in racehorses. These findings may support improved monitoring of performance, training load and early detection of overtraining in equine athletes.

Background: Public scrutiny of racehorse welfare is increasing. The preparatory training phase preceding the racing season is potentially a critical period for physical and mental development. Structured welfare assessment protocols have recently been developed, but their use in field conditions remains limited.

Objectives: (1) To evaluate the field applicability of a racehorse-specific welfare assessment protocol in a professional French jump racing yard; and (2) to explore whether it can detect relevant physical and behavioural changes in young horses during season preparation.

Study design: Longitudinal observational study with repeated measures.

Methods: Sixteen two- to three-year-old racehorses (10 Thoroughbreds, 6 French Non-Thoroughbreds) from a single jump racing yard were assessed at three time points (T0, T1, T2) over 5 months before the racing season. Direct observations included environmental conditions, physical health, horse grimace scale (HGS), human-horse relationship tests, and behavioural activity budgets via scan sampling. Mixed-effects models evaluated temporal changes and associated factors.

Results: Horses were healthy, with adequate nutrition and comfort, though no free turn-out and social contact often limited to visual interaction (68%). Body condition score decreased significantly at T1 (β = -0.96; 95% CI: [-1.7, -0.26]; p = 0.007) and T2 (β = -2.0; 95% CI: [-2.9, -1.1]; p < 0.001). Lip commissure lesions were prevalent (external 65%, internal 75%). HGS scores increased significantly at T2 (β = 1.7; 95% CI: [0.85, 2.6]; p < 0.001), and horses with physical social contact had lower scores (β = -1.3; 95% CI: [-2.3, -0.22]; p = 0.02). Behavioural activity budgets showed inter-individual variability.

Main limitations: Small sample size and attrition limit generalisability. Assessments were conducted during routine training days without altering management, occasionally limiting evaluations.

Conclusions: Structured welfare assessments are feasible in field conditions, highlight areas for improvement, and can capture relevant changes during jump racing season preparation.

Background: Trigeminal-mediated headshaking (TMHS) in horses shares clinical features with human trigeminal neuralgia (HTN). Increased levels of the neuropeptide calcitonin gene-related peptide (CGRP) have been found in the blood and cerebrospinal fluid (CSF) of HTN patients. Inhibition of CGRP in humans has shown promise for pain relief. Data on CGRP in horses affected by TMHS are currently lacking but if quantifiable and validated, could assist in developing new diagnostic and more rational therapeutic approaches.

Objectives: This study aimed to quantify and correlate CGRP concentrations in the serum and CSF of horses with TMHS; compare CSF CGRP levels across horses with various neurological, painful, inflammatory and chronic conditions; analyse serum CGRP concentrations before and after exercise-induced headshaking in affected horses versus healthy controls.

Study design: Case-control study using bio-banked samples and prospective before-after study.

Methods: CGRP concentrations were measured in CSF and serum using a commercial ELISA kit across healthy controls (CONTROL, n = 5), TMHS-affected horses (n = 30), horses with cervical vertebral stenotic myelopathy (CVSM, n = 10) and horses with non-neurologic painful, inflammatory or chronic conditions (MIXED, n = 8).

Results: Median (interquartile range [IQR]) serum CGRP concentration in TMHS horses was 14.9 pg/mL (11.3-19.0 pg/mL), while mean ± SD CGRP CSF concentration was 64.9 ± 6.3 pg/mL. No correlation was found between serum and CSF CGRP (Spearman's rho = -0.04, p = 0.88). CSF CGRP levels were significantly higher in CVSM (73.8 pg/mL; p = 0.011) and lower in MIXED (52.0 pg/mL; p = 0.001) compared to TMHS. Serum CGRP concentrations showed no significant difference between TMHS and CONTROL groups.

Main limitations: Small sample size, lack of CSF samples from healthy controls.

Conclusions: Higher CSF CGRP levels in neurologic conditions may suggest shared underlying mechanisms such as nerve irritation or neuroinflammation. Further research is needed to elucidate CGRP's role in TMHS pathophysiology.

Background: Human-horse relationships encompass diverse roles, from companion to competition partner. The impact of such bonds informs owner decision-making regarding horse management and veterinary care, yet standardised instruments to measure these unique bonds are limited.

Objectives: To develop the Human-Equine Attachment Scale (HEAS), a novel instrument to measure the multi-faceted dimensions of human-horse attachment.

Study design: Cross-sectional design using a self-administered psychometric instrument.

Methods: Initial items were developed through a systematic review of human and animal attachment research, with adaptations made to reflect human-equine relationships. The preliminary scale contained 25 items across five hypothesised factors: Companionship, Wellbeing, Dependence, Status and Growth. Data were collected via an online survey (March-April 2022), recruiting participants through equestrian social media and professional networks using non-random convenience and snowball sampling.

Results: The final sample comprised 3611 predominantly female (92.9%) respondents. Principal components analysis (PCA) investigated the underlying structure of the scale. The final PCA revealed a six-factor solution explaining 60% of total variance: Companionship (19%), Personal Wellbeing (9.8%), Dependence (8.9%), Status (8.5%), Growth (7.5%) and Sacrifice (6.3%). The final 22-item scale demonstrated good internal reliability (Cronbach's α = 0.77).

Main limitations: The self-report instrument represents UK-only participants.

Conclusions: The emergence of Sacrifice as a distinct factor highlights unique aspects of horse ownership, particularly regarding financial and personal investment. The HEAS shows promise as a reliable tool for measuring human-horse attachment, with numerous potential applications. It could help bridge the gap in knowledge regarding owner motivation and human-horse relationships, supporting research into how attachment influences welfare, management, and veterinary care decisions. While the scale demonstrates good psychometric properties, further validation across cultural contexts and equestrian populations is recommended. The development of the HEAS represents an important step towards understanding the complex nature of human-horse bonds and their implications for owner decision-making and practice.

Background: Supplements claiming to improve metabolic profiles in equine metabolic syndrome (EMS) often lack scientific validation.

Objectives: To evaluate the effect of a supplement containing leucine, resveratrol and pyridoxine on the metabolic profile in ponies with EMS.

Study design: Unmasked randomised, placebo-controlled field trial.

Methods: Thirty-eight ponies completed the trial across five farms. Ponies were age and sex matched per farm and randomly assigned to the supplement (n = 20) or placebo group (n = 18) with owners masked to group assignments. Ponies were sampled at days -1/0 (T1), 7/8 (T2), 30/31 (T3) and 60/61 (T4). Measurements included morphometrics, insulin, triglycerides, nonesterified fatty acids, leptin and adiponectin, a two-step insulin tolerance test and oral sugar test (OST). Biochemical and dynamic testing results were compared across groups and times using pairwise comparisons of the estimated marginal means from mixed model, with significance set at a Tukey corrected p-value of <0.05. Chi² analyses assessed group differences from the trial onset and conclusion, with significance set at a p-value of <0.05.

Results: In the supplement group, maximum insulin post-OST was significantly reduced between T1/T2 and T3/T4, and bodyweight (bwt) decreased significantly between T1 and T4. By T4, more ponies in the supplement group lost ≥2% of their bwt (p = 0.006), with an average reduction of 8.1 kg (95% CI: -11.4, -4.7) while the placebo group gained an average of 2.6 kg (95% CI: -4.2, 9.4). Additionally, more ponies in the supplement group reduced maximum insulin post-OST by ≥40% (p = 0.01 average decrease 36.6 μU/mL; 95% CI: -60.8, -12.3), compared with the placebo group (average decrease of 3.5 μU/mL; 95% CI: -24.8, 17.8).

Main limitations: Small sample size across multiple farms may have increased variability and masked some effects.

Conclusions: Supplementation with leucine, pyridoxine and resveratrol may support weight loss and reduce post-prandial insulin concentrations in ponies with EMS.

Background: Arsenic poisoning in horses is rarely reported in the literature. However, arsenic compounds can be present in rodenticides, pesticides, and herbicides, representing a potential source of accidental exposure for horses.

Objective: To describe the epidemiological, clinical, and laboratory findings from a herd of 31 horses exposed to pasture treated with an overdose of sodium hydrogen methylarsonate, and to compare results in a group of horses exposed to the recommended dosage of the same product.

Study design: Observational field study.

Methods: Thirty-one horses were evaluated after grazing on a pasture sprayed with 7.9 kg/ha of MSMA. Sixteen animals underwent clinical examination, haematological and biochemical analyses, anatomopathological evaluation, and toxicological analysis. Arsenic concentrations were determined in biological and environmental samples to confirm exposure. The findings were compared with data collected from a group of horses grazing a paddock treated with the recommended dose.

Results: The outbreak had a morbidity rate of 45.2% (14/31), a mortality rate of 19.4% (6/31), and a case fatality rate of 42.9% (6/14). Toxicological analysis showed increased arsenic concentrations in biological and environmental samples, confirming the diagnosis of poisoning. Supportive therapy was administered until the definite diagnosis and recovery of the surviving horses. Animals in the comparative group remained clinically normal and showed low arsenic concentrations.

Main limitations: The observational nature of the study, the delayed initiation of monitoring, and prior therapeutic interventions limited the scope of clinical data. Moreover, the rarity of arsenic poisoning in horses and the paucity of reference data restricted interpretation.

Conclusions: Arsenic toxicosis in horses affects gastrointestinal, vascular, and renal systems. Diagnosis is supported by anatomopathological findings, biochemical alterations, and detection of arsenic in kidney, liver, and faecal samples.