Search Results (44)

Per rectum examination (PRE) is commonly used in the triage of horses with acute abdominal pain, despite reports of associated risk factors for both horses and personnel, but its diagnostic accuracy is questionable. This multicenter, observational study aimed to evaluate the agreement between PRE findings and surgical findings obtained via exploratory laparotomy in horses with colic. A total of 201 cases from four equine referral hospitals across Europe were included. Rectal findings were categorized as primary (most likely cause of colic) or additional. Agreement with surgical findings was assessed using kappa statistics. The influence of examiner demographic data (age, gender, and qualification status) on diagnostic accuracy was also evaluated. The agreement between primary rectal and primary surgical diagnosis was 57.2% (115/201; kappa coefficient, 0.490; 95% confidence interval, 0.394–0.586). When both primary and additional findings were considered, agreement increased to 71.6% (144/201, kappa coefficient, 0.720; 95% confidence interval, 0.156–0.927; 65.1–77.4%). The highest agreement was seen in cases of gas-distended large colon (90.3%), small intestinal distension (75.8%), and left dorsal displacement of the large colon (66.7%). Detection of small intestine distension in PRE had the highest sensitivity (85.7%) and negative predictive value (92.8%) among the evaluated parameters. Examiner demographics had no significant impact on diagnostic accuracy. PRE is a valuable but imperfect diagnostic tool. Given the dynamic nature of colic and possible changes between examination and surgery, some discrepancies are expected. Other variables, such as horse size or the examiner’s hand dominance, were not investigated in this study but may have had an impact on the observed outcomes. Overall, PRE remains a practical, accessible technique that provides clinically useful information regardless of examiner experience. Full article

Progesterone (P4) exerts important vascular and immunomodulatory effects that influence platelet (PLT) activation and serotonin (5-HT) handling across mammalian species; nevertheless, its role in modulating PLT physiology during diestrus in mares remains poorly defined. This study hypothesized that physiological variations in luteal activity during diestrus are associated with changes in PLT activation and 5-HT-related parameters. The first objective was to determine whether changes in circulating P4 during diestrus are associated with alterations in PLT aggregation, circulating 5-HT, and PLT morphological indices in healthy mares; the second objective was to identify a diestrus day providing consistent physiological conditions for assessing PLT-related biomarkers. Twenty clinically healthy Spanish Purebred mares aged 4–9 years old were monitored. Blood samples were collected on days 5, 14, and 16 post-ovulation, with luteal status confirmed by ultrasonography. P4 concentrations were determined using a solid-phase I-125 radioimmunoassay (RIA), 5-HT concentrations were quantified using a competitive enzyme immunoassay, and PLT indices were measured using an ADVIA 2120i hematology analyzer. Data were compared using appropriate parametric or non-parametric tests after assessing distribution, and correlations were analyzed using rank-based correlation analysis, using Pearson or Spearman coefficients according to variable distribution. P4 concentrations were higher on days 14 and 16 compared with day 5 (p < 0.05), with no significant differences between days 14 and 16. Platelet aggregates (AGREG) showed the greatest variation, with significantly higher values on day 14 compared with day 5 (p < 0.05). In contrast, circulating 5-HT and all PLT morphological indices (PLT count, PCT, MPV, PLCR, PDW, PCDW, MPM, and PMDW) remained unchanged across diestrus. PLT aggregation showed a strong positive association with circulating P4 concentrations (r = 0.88, p < 0.05), whereas no meaningful correlations were observed between 5-HT and AGREG or between 5-HT and PLT morphological parameters. Internal correlations among PLT indices followed expected biological patterns, confirming the stability of structural PLT traits over short physiological intervals. These findings demonstrate that during diestrus, PLT activation—but not PLT morphology or circulating 5-HT—varies in parallel with P4 in mares. Day 14, corresponding to mid-diestrus, characterized by high luteal activity, represents an informative time point for assessing PLT activation and related biomarkers, providing a framework for standardizing sampling protocols for PLT-derived products in equine reproductive medicine. Full article

Colic is a leading cause of mortality in horses, particularly when associated with systemic inflammation and organ dysfunction. In human medicine, these complications are associated with sepsis, defined as organ dysfunction caused by a dysregulated, life-threatening host response to infection. However, no consensus sepsis score exists for adult horses. This retrospective study aimed to develop a diagnostic sepsis score for adult horses. Medical records from 295 horses admitted for colic to the Oniris equine emergency department (Nantes, France) between July 2011 and November 2021 were analyzed. Horses were classified as having sepsis or colic based on their final diagnosis. Clinical and laboratory parameters were assessed, and univariate and multivariate logistic regression analyses yielded a predictive score. The optimal threshold was determined by maximizing sensitivity and specificity. Sepsis was diagnosed in 89 horses (30.2%). Six parameters—temperature, heart rate, leukocyte count, red blood cells, creatine kinase, and lactate—were included in the model. The score showed 79% accuracy, with 59% sensitivity and 88% specificity. At a threshold of 3, sensitivity was 52.7%, specificity was 91.6%, and the Youden index was 0.44. This study proposes a rapid, practical sepsis diagnostic score for adult horses with acute gastrointestinal disease, serving as a highly specific tool for confirming sepsis. Full article

Amino acid (AA) metabolism and the adaptation of muscles to increased physical performance are interdependent. This field study examined changes in plasma amino acid (PAA) concentrations and two metabolites (ammonia and urea) before and after cross-country (CC) competitions throughout an entire eventing season and their associations with performance outcomes in eventing horses. Twenty horses from nine different Warmblood breeds were evaluated between two and seven times across 14 international eventing competitions over a 23-week period. A total of 55 rides were sampled. Blood samples were collected at four time points: before the start (TP0), 10 min after completion of the CC ride (TP1), 30 min post-CC (TP2), and the next morning (TP3). A mixed ANOVA revealed significant effects (p < 0.05) of calendar week on PAA concentrations for asparagine, ornithine, and proline. Correlations between CC scores and PAA concentrations were observed for 4 of the 25 measured parameters. TP0 leucine concentrations and TP2 histidine concentrations correlated negatively with CC penalty score, whereas TP1 proline concentrations and TP3 alanine concentrations correlated positively with CC penalty score. These results indicate that higher plasma leucine concentrations may contribute to improved performance in eventing horses. Additionally, alanine and proline show potential as performance-related diagnostic biomarkers. Full article

Asthma is a multifactorial respiratory disease that naturally occurs in horses, humans, and cats, presenting common clinical signs and species-specific mechanisms. This review addresses the impact of asthma on the cardiovascular and neurological systems, with a primary focus on horses. It highlights the need for new biomarkers beyond the respiratory system due to diagnostic difficulties in animals. A comprehensive literature search was conducted using PubMed and Google Scholar, focusing on cardiovascular and neurological manifestations of asthma in humans, horses, cats, and experimental animal models. Studies were qualitatively compared, noting species-specific differences and mechanisms. Humans with asthma show an increased risk of cardiovascular disease and elevated cardiac biomarkers during exacerbations, while horses develop pulmonary hypertension and vascular remodeling. Cats exhibit significant pulmonary vascular changes. Heart rate variability analysis reveals altered autonomic function in humans and horses. Increased peripheral airway innervation and cough reflex sensitivity are noted across species. The renin–angiotensin–aldosterone system (RAAS) plays a crucial role in asthma pathophysiology in murine models. Asthma impacts the cardiovascular and nervous systems differently across species, emphasizing the importance of comparative medicine. Future research should integrate cardiovascular, autonomic, and inflammatory pathways to develop effective therapeutic approaches in human and veterinary medicine, leveraging insights from naturally occurring asthma models. Full article

Left atrial mechanical dysfunction is common in horses following the treatment of atrial fibrillation (AF). This study aimed to evaluate the use of an acoustic cardiography monitor (Audicor^®) in quantifying cardiac mechanical and hemodynamic function in horses with AF before and after treatment and to correlate these findings with echocardiographic measures. Twenty-eight horses with AF and successful transvenous electrical cardioversion were included. Audicor^® recordings with concomitant echocardiographic examinations were performed one day before, one day after, and two to seven days after cardioversion. Key variables measured by Audicor^® included electromechanical activating time (EMAT), heart rate-corrected EMATc, left ventricular systolic time (LVST), heart rate-corrected LVSTc, systolic dysfunction index (SDI), and intensity and persistence of the third and fourth heart sound (S3, S4). A repeated-measures ANOVA with Tukey’s test was used to compare these variables over time, and linear regression and Bland–Altman analyses were applied to assess associations with echocardiographic findings. Following conversion to sinus rhythm, there was a significant decrease in EMATc and LVSTc (p < 0.0001) and a significant increase in LVST (p = 0.0001), indicating improved ventricular systolic function, with strong agreement between Audicor^® snapshot and echocardiographic measures. However, S4 quantification did not show clinical value for assessing left atrial function after conversion. Full article

Plasma amino acid (PAA) concentration in horses vary according to the exercise type. This study evaluated the changes in PAA levels and the associated metabolites, urea and ammonia, following short-duration, high-intensity cross-country exercise in eventing horses. Twenty eventing horses participated in 55 rides at 14 international competitions (2* to 4* levels) across five venues in Germany and Poland. Blood samples were collected at four timepoints: before exercise (TP0), at 10 min (TP1), and at 30 min (TP2) post-exercise, as well as in the morning on the day after the competition (TP3). A total of 23 different PAAs and two metabolites (ammonia and urea) were analyzed. PAA concentration difference over time was assessed by a mixed ANOVA. Significant fluctuations were observed in 18/25 parameters. For 21/23 PAAs, levels increased at TP1 and/or TP2, while cysteine concentrations decreased. Concentrations returned to pre-competition levels for 21/23 PAAs by TP3. Proline levels remained elevated (p = 0.002), while those of glycine significantly decreased (p = 0.027) at TP3. Plasma ammonia and urea levels increased at TP1, TP2 and TP3. This study provides foundations for supplementation strategies and can inform future works exploring PAAs’ role in performance and training adaptation in eventing horses and their potential as performance-related biomarkers. Full article

Extracellular vesicles (EVs) are important mediators of cell–cell communication thanks to their ability to transfer their bioactive cargo, thus regulating a variety of physiological contexts. EVs derived from amniotic mesenchymal/stromal cells (eAMC-EVs) are internalized by equine endometrial cells (eECs) with positive effects on regenerative medicine treatments. As the cellular uptake of EVs is influenced by the glycan profile of both EVs and target cells, this study is focused on the role of surface glycans in the uptake of eAMC-EVs by recipient eECs. Equine ECs were obtained by enzymatic digestion of uteri from healthy mares. Equine AMC-EVs were isolated from amniotic cell cultures according to a standardized protocol. The glycan pattern was studied using a panel of lectins in combination with fucosidase and neuraminidase treatment. Both eECs and eAMC-EVs expressed N-linked high mannose glycans, as well as fucosylated and sialylated glycans. All these glycans were involved in the uptake of eAMC-EVs by eECs. The internalization of eAMC-EVs was strongly reduced after cleavage of α1,2-linked fucose and α2,3/α2,6-linked sialic acids. These results demonstrate that surface glycans are involved in the internalization of eAMC-EVs by eECs and that fucosylated and sialylated glycans are highly relevant in the transfer of bioactive molecules with effects on regenerative medicine treatments. Full article

Complete fractures of the third metacarpal bone (MC III) diaphysis pose a significant clinical challenge, prompting advanced veterinary medicine to utilize constitutive and biomechanical modeling to better understand bone behavior. This study aims to compare the elastic modulus of the MC III cortical bone, supported by measurements of cortical bone thickness and relative density, across the dorsal, lateral, medial, and palmar aspects of the MC III, as well as to evaluate the cortical bone’s response to compressive forces applied in different directions. Given the bone structure can exhibit sex-related differences, MC III bones were isolated from six equine cadaver limbs collected exclusively from mares and imaged using computed tomography (CT) to measure thickness and density. Cortical bone samples were collected from the four aspects of the MC III and subjected to mechanical testing followed by the elastic modulus calculation. Bone thickness and elastic modulus varied across the MC III aspects. Thinner cortical bone on the palmar aspect coincided with a lower sample reaction force-based elastic modulus in the externo-internal direction and a lower axial compression force elastic modulus in the proximo-distal direction. Regardless of the MC III aspect, the cortical bone demonstrated greater resistance to compressive forces when loaded in the vertical plane than in the horizontal plane. The returning of different values in mechanical tests depending on the direction of loading may be attributed to the anisotropic behavior of the cortical bone, which may implicate the increased risk of complete fractures of the MC III diaphysis due to a kick from another horse or a fall, rather than from training or competition-related overload. Full article

Gastric pH is a key factor in the development of equine squamous gastric disease (ESGD). Although acid injury is unlikely the primary cause of equine glandular gastric disease (EGGD), low pH may promote mucosal damage. Gastric pH is influenced by roughage uptake, as chewing increases the alkaline saliva production. The proton pump inhibitor omeprazole is currently recommended by the American/European College of Veterinary/Equine Internal Medicine (ACVIM/ECEIM) for ESGD and EGGD. We hypothesized that dental disorders decrease saliva production and gastric pH, predisposing horses to EGUS. Gastroscopy, intragastric pH measurement and dental examinations were performed (n = 54). Omeprazole therapy was recommended (n = 32), dental disorders were corrected (n = 22) and gastroscopy was repeated 4 weeks later (n = 9). An influence of moderate to severe dental disorders on ESGD (grade ≥ 2/4) (p = 0.394) and EGGD (grade ≥ 2/3) (p = 0.857) could not be determined. Nevertheless, there was a trend that moderate to severe dental disorders were associated with a low gastric pH ≤ 4 (p = 0.100). Horses with no or mild dental problems had a mean pH of 5.4 versus 4.2 in moderate to severe dental disorders. In conclusion, our study results do not show a direct relationship between dental disorders and EGUS, but a gastric and oral cavity examination should still be considered in patients presented for weight loss or inappetence. Full article

(1) Background: Horses infected by a tick-borne encephalitis virus (TBEV) can develop clinically apparent infections. In humans, vaccination is the most effective preventive measure, while a vaccine is not available for horses. The objective of this study was to describe the immune response in horses after a TBEV vaccination with a human vaccine. (2) Materials and Methods: Seven healthy horses were randomised to a treatment or a control group in a stratified fashion based on TBEV–IgG concentrations on day −4. The treatment group (n = 4) was intramuscularly vaccinated using an inactivated human TBEV vaccine on days 0 and 28; the control group (n = 3) did not receive an injection. A clinical examination and blood sampling were performed on day –4, 0, 2, 4, 6, 8, 10, 14, 28, 30, 32, 34, 36, 38, 43, 56, 84, and 373. A linear mixed model analysis was used to compare IgG and IgM concentrations, neutralising antibody (nAb) titres, leucocyte count, serum amyloid A (SAA), and fibrinogen and globulin concentrations between the groups and time points. (3) Results: The clinical examination was normal in all horses at all time points. There were no significant changes in SAA, globulin, and fibrinogen concentrations and leucocyte count between the groups or time points (all p > 0.05). There was no significant increase in IgG, IgM, or nAb titres in the control group over time (all p > 0.05). In the vaccination group, there was a significant increase in IgG concentration and nAb titres after the second vaccination (p < 0.0001). There was no significant increase in IgM antibodies after the TBEV vaccination (all p > 0.05). One horse in the vaccination group had an IgM concentration above the laboratory reference on day 10. (4) Conclusions: The human TBEV vaccine did not have side effects when used in healthy horses in this study. A significant rise in TBEV-specific IgG antibodies and nAbs after the second vaccination was observed. However, IgG and nAb titres have been shown to decrease within 1 year after vaccination. The results of this study indicate that a vaccination with a human vaccine only induces a mild rise in IgM antibodies and only in previously naive horses. With no significant changes to inflammatory parameters in the vaccinated horses, it remains unclear whether vaccination with the human vaccine leads to protective immunity. Full article

Due to the growing interest among veterinarians and the increasing market demands, the development of equine cardiology is necessary. Currently, veterinary medicine for companion animals needs to catch up to human medicine—equine medicine included. A common condition in older horses is aortic valve regurgitation resulting from fibrosis, while its more severe form occurs in younger horses or develops due to a bacterial infection. Mitral valve regurgitation, especially dangerous due to the possibility of sudden death, has a better prognosis if the horse has valve prolapse. Tricuspid valve regurgitation usually does not pose a clinical problem, although its severe cases may lead to heart failure. Some pathologies can be treated surgically, which requires excellent knowledge of anatomy. The object of this study consisted of twenty domestic horse hearts. The focus was on the normal and comparative anatomy of the left and right subvalvular apparatus. The number of muscular bellies of the papillary muscles and the type of connection of the muscles were analysed. Moreover, the height of muscle originating from the ventricle wall was determined, the morphological regularity of the papillary muscle was assessed, and the chordae tendineae originating from the papillary muscles were examined. The conducted research allowed for comparing domestic horses with different species through other studies, the authors of which described this particular aspect. Interspecies similarities which may be correlated with the evolutionary relatedness, as well as differences that could reflect adaptation to different lifestyles, environmental conditions, or metabolic requirements of the animals, have been found. This study expands the knowledge of animals’ normal and comparative anatomy, and contributes to the development of veterinary surgery, internal medicine, and biology. Full article

Postural adaptation is a prominent feature in horses affected by laminitis. Laminitis induces intense pain, especially in the forelimbs, prompting affected horses to assume a caudally displaced trunk posture, resulting in the hyperflexion of the thoracolumbar spine. This study assessed the nature and prevalence of thoracolumbar injuries in horses with chronic laminitis compared to horses without it. Sixty horses were used (thirty laminitic and thirty non-laminitic) of different athletic purposes and ages (2–20 years). The experimental protocol entailed a single assessment of horses’ thoracolumbar spines, utilizing physical examination by MACCTORE, a scoring system developed specifically for this study. Additional evaluations included the Grimace Equine Pain Scale (HGS) and ultrasound exams. Statistical tests were used to compare values (Mann–Whitney or t-test) and lesions prevalences (Fisher) between groups (p < 0.05). The results showed a higher pain manifestation (HGS and heart rate, p < 0.0001) and thoracolumbar-spine-injury levels in chronic laminitis horses, both in MACCTORE clinical examinations (11.7 ± 4.8 vs. 4.2 ± 3.3, p < 0.0001) and general ultrasonographic indices (39.6 ± 12.0 vs. 20.7 ± 7.1, p < 0.0001), including specific examination approaches for various spinal elements. Horses with laminitis presented with a 14-fold higher prevalence of ultrasound-relevant lesions in the thoracolumbar spine (CI: 4.4 to 50.6, p < 0.0001) compared to controls. These findings constitute new evidence of an association between chronic laminitis and the presence of thoracolumbar spine injuries in horses, which may be confirmed by more sophisticated study designs. Full article

Malignant melanomas (MMs) are the abnormal proliferation of melanocytes and are one of the lethal skin cancers in humans, equines, and canines. Accordingly, MMs in companion animals can serve as naturally occurring animal models, completing conventional cancer models. The common constitutive activation of the MAPK and PI3K pathways in MMs has been described in all three species. Targeting the related pathways is considered a potential option in comparative oncologic approaches. Herein, we present a cross-species comparative analysis exposing a set of ten melanoma cell lines (one human, three equine, and six canine) derived from primary tumors or metastasis to a pan-RAF and RAF dimer inhibitor (LY3009120). Cellular response (proliferation, biomass, metabolism, early and late apoptosis/necrosis, and morphology) and the presence of pathogenic single-nucleotide variants (SNVs) within the mutational hotspot genes BRAF exon 11 and 15, NRAS exon 2 and 3, KRAS exon 2, and KIT exon 11 were analyzed. This study showed that equine malignant melanoma (EMM) cells (MelDuWi) harbor the KRAS p.Q61H mutation, while canine malignant melanoma (CMM) cells (cRGO1 and cRGO1.2) carry NRAS p.G13R. Except for EMM metastasis cells eRGO6 (wild type of the above-mentioned hotspot genes), all melanoma cell lines exhibited a decrease in dose dependence after 48 and 72 h of exposure to LY3009120, independent of the mutation hotspot landscape. Furthermore, LY3009120 caused significant early apoptosis and late apoptosis/necrosis in all melanoma cell lines except for eRGO6. The anti-tumor effects of LY3009120 were observed in nine melanoma cell lines, indicating the potential feasibility of experimental trials with LY3009120. The present study reveals that the irradiation-resistant canine metastasis cells (cRGO1.2) harboring the NRAS p.G13R mutation are significantly LY3009120-sensitive, while the equine metastases-derived eRGO6 cells show significant resistance to LY3009120, which make them both valuable tools for studying resistance mechanisms in comparative oncology. Full article

Horses and cattle have shown low susceptibility to SARS-CoV-2, and there is no evidence of experimental intraspecies transmission. Nonetheless, seropositive horses in the US and seropositive cattle in Germany and Italy have been reported. The current study investigated the prevalence of antibodies against SARS-CoV-2 in horses and cattle in Switzerland. In total, 1940 serum and plasma samples from 1110 horses and 830 cattle were screened with a species-specific ELISA based on the SARS-CoV-2 receptor-binding domain (RBD) and, in the case of suspect positive results, a surrogate virus neutralization test (sVNT) was used to demonstrate the neutralizing activity of the antibodies. Further confirmation of suspect positive samples was performed using either a pseudotype-based virus neutralization assay (PVNA; horses) or an indirect immunofluorescence test (IFA; cattle). The animals were sampled between February 2020 and December 2022. Additionally, in total, 486 bronchoalveolar lavage (BAL), oropharyngeal, nasal and rectal swab samples from horses and cattle were analyzed for the presence of SARS-CoV-2 RNA via reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). Six horses (0.5%; 95% CI: 0.2–1.2%) were suspect positive via RBD-ELISA, and neutralizing antibodies were detected in two of them via confirmatory sVNT and PVNA tests. In the PVNA, the highest titers were measured against the Alpha and Delta SARS-CoV-2 variants. Fifteen cattle (1.8%; 95% CI: 1.0–3.0%) were suspect positive in RBD-ELISA; 3 of them had SARS-CoV-2-specific neutralizing antibodies in sVNT and 4 of the 15 were confirmed to be positive via IFA. All tested samples were RT-qPCR-negative. The results support the hypotheses that the prevalence of SARS-CoV-2 infections in horses and cattle in Switzerland was low up to the end of 2022. Full article