Endothelial glycocalyx degradation in critically ill foals.

BACKGROUND: Endothelial glycocalyx (EG) degradation occurs in septic humans and EG products can be used as biomarkers of endothelial injury. Information about EG biomarkers and their association with disease severity is lacking in hospitalized foals. OBJECTIVES: Measure serum syndecan-1 (SDC-1), heparan sulfate (HS), angiopoietin-2 (ANG-2), aldosterone (ALD), and plasma atrial natriuretic peptide (ANP) concentrations and to determine their association with disease severity and death in hospitalized foals. ANIMALS: Ninety foals ≤3 days old. METHODS: Prospective, multicenter, longitudinal study. Foals were categorized into hospitalized (n = 74; 55 septic; 19 sick nonseptic) and 16 healthy foals. Serum ([SDC-1], [HS], [ANG-2], [ALD]) and plasma (ANP) were measured over 72 hours using immunoassays. RESULTS: Serum ([SDC-1], [HS], [ANG-2], [ALD]) and plasma (ANP) were significantly higher in hospitalized and septic than healthy foals (P < .05). Serum (ANG-2) and plasma (ANP) were significantly higher in hospitalized nonsurvivors than in survivors (P < .05). On admission, hospitalized foals with serum (HS) > 58.7 ng/mL had higher odds of nonsurvival (odds ratio [OR] = 6.1; 95% confidence interval [CI] = 1.02-36.7). Plasma (ANP) >11.5 pg/mL was associated with the likelihood of nonsurvival in hospitalized foals (OR = 7.2; 95% CI = 1.4-37.4; P < .05). Septic foals with serum (ANG-2) >1018 pg/mL on admission had higher odds of nonsurvival (OR = 6.5; 95% CI =1.2-36.6; P < .05). CONCLUSION AND CLINICAL IMPORTANCE: Critical illness in newborn foals is associated with EG degradation and injury, and these biomarkers are related to the severity of disease on admission and the outcome of sick foals.

Diagnostic utility of acute phase proteins and their ability to guide antibiotic usage in pigs, horses, and cattle: a mapping review.

To mitigate the use of antibiotics for many of the multifactorial diseases seen in pigs, horses and cattle, new diagnostic tools are needed. Acute phase protein (APP) measurements can, in humans, be used to guide antibiotic treatment initiation, evaluate treatment efficacy, and make a prognosis. The aim of this review is to collect evidence on the clinical functionality of APP measurements as a tool to guide antibiotic treatment in pigs, horses, and cattle. Literature was retrieved using Medline, CAB Abstracts and Google Scholar. The acute phase response has been investigated for a plethora of diseases and clinical signs and the major acute phase proteins are elevated in diseased compared to healthy animals. Few studies correlated acute phase response with aetiology, antibiotic treatment efficacy, prognosis, or severity of disease. The existing research does not support that APP can be used to guide antibiotic treatment, but the reported studies indicate that C-reactive protein (CRP) might be able to differentiate between bacterial and non-bacterial causes of disease in pigs. Serum amyloid A (SAA) might reflect underlying aetiology in horses and infectious or non-infectious cases of mastitis in cows.

In vitro evaluation of the automated hematology analyzer XN-31 for rapid diagnosis of equine piroplasmosis.

Equine piroplasmosis (EP) is a protozoal disease affecting equids, caused by Theileria equi and Babesia caballi. EP is conventionally diagnosed using microscopic, molecular, and/or serological methods, which are time-consuming. Consequently, there is a need for faster testing methods. In this study, we evaluated the application of the Sysmex XN-31 automated hematology analyzer, originally a rapid test for detecting malaria in humans, for the diagnosis of EP. The cultured parasites were measured using the XN-31 that had been customized for horse blood samples (XN-31m). The following parameters were evaluated: limit of detection (LoD), limit of quantification (LoQ), linearity, carryover, precision, and correlation with microscopic examination. The XN-31m detected infected red blood cells (RBCs) in approximately 1 minute. The LoD and LoQ for B. caballi were 4.54 infected RBCs/µL and 14.10 infected RBCs/µL, while those for T. equi were 5.80 infected RBCs/µL and 11.44 infected RBCs/µL, respectively. Linearity showed excellent correlation (R2 > 0.99), and carryover never exceeded 0.5%. The coefficient of variation was under 5%. The correlation between the results obtained using XN-31m and microscopic examination was high (R2 > 0.98). In conclusion, the XN-31 analyzer detected B. caballi and T. equi parasites in approximately 1 minute with high sensitivity. The results indicate the potential of the XN-31 analyzer as a fast and user-friendly diagnostic method for EP. IMPORTANCE: In this study, we demonstrated that the automated hematology analyzer, XN-31, can detect red blood cells infected with Babesia caballi and Theileria equi in about 1 minute. We evaluated the diagnostic performance of the XN-31 analyzer for equine piroplasmosis, providing evidence of its potential as a diagnostic tool for this disease.

The prognostic importance of physiological and biochemical parameters in horses afflicted with colic.

Background: Colic, a primary cause of illness and death in horses, necessitates the development of improved prognostic tools. Aim: The aim of this study was to investigate the prognostic significance of physiological and biochemical parameters in horses suffering from colic. Methods: A comprehensive clinical evaluation of 117 horses included assessment of heart rate, mucous membranes, capillary refill time, rectal temperature, respiratory rate, gut motility, reflux, and limb pulse strength. Results: Stomach reflux, absence of gut noises, and increased heart rate (mean increase of 12 bpm) strongly correlate with a poor prognosis. Prolonged capillary refill time (mean increase of 3 seconds), rectal temperature (over 38.5°C), elevated packed cell volume (mean increase of 4%), and blood lactate levels (mean increase of 5 mmol/l) underscore the significance of these markers. Notably, blood lactate (p < 0.001), gut noises (p < 0.05), and heart rate (p < 0.001) demonstrate the highest predictive significance based on statistical analysis. Conclusion: Future research should investigate the prognostic potential of additional parameters and assess the impact of recommended treatments on colic prognosis. This data-driven study emphasizes the critical role of early recognition and thorough assessment in colic cases, offering vital insights into improving equine healthcare and mitigating mortality rates.

Association of Borrelia burgdorferi with nuchal bursitis and elevated outer surface protein A-specific serum antibodies in horses of the northeastern United States.

OBJECTIVE: Evaluate the incidence of Borrelia burgdorferi in cases of equine nuchal bursitis (NB) and investigate the relationship between elevated serum outer surface protein A (OspA) antibodies and the molecular identification of B burgdorferi in bursal tissue or synovial fluid. Additionally, describe clinical cases and compare the histologic changes in NB with and without detection of B burgdorferi. METHODS: This was a retrospective multicenter cohort study (2013 to 2022). Medical records from horses with a diagnosis of NB and B burgdorferi PCR testing on NB tissue or synovial fluid were reviewed. The study population included 11 horses with a postmortem diagnosis of NB, 19 horses from the northeastern US with an antemortem diagnosis of B burgdorferi PCR-positive NB, and 15 healthy controls without evidence of NB and unvaccinated for B burgdorferi. Where serum was available, Lyme multiplex assay results were compared with controls and ELISAs targeting individual B burgdorferi antigens were performed. Histologic findings in nuchal bursa tissue were compared between NB cases with and without B burgdorferi PCR detection. RESULTS: Serum OspA antibody values in B burgdorferi-positive NB cases (n = 13) were significantly elevated (P < .001) compared to controls (15), and OspA was the predominant antigen detected by ELISA (8). Histopathology did not vary between NB cases with (n = 9) and without (6) B burgdorferi PCR detection. CONCLUSIONS: The presence of B burgdorferi in the nuchal bursa of horses is associated with increased serum OspA antibodies. CLINICAL RELEVANCE: The role of B burgdorferi in equine NB may be underestimated, and targeted therapy requires investigation.

Application of blood parameters for the early diagnosis of natural ascending placentitis in pregnant mares.

Placental infection is an important cause of late-term pregnancy loss and neonatal diseases in horses. Detection of changes in blood parameters especially during early placentitis could improve the diagnostic accuracy, treatment decision, and potential outcomes. The objectives of this 2-part study were to identify differences in circulating immunological, inflammatory, and hormonal parameters between mares with natural ascending placentitis and control mares; evaluate each and combination of parameters as predictors of placentitis; and determine how these parameters indicate severity of placentitis. Reproductive examination and blood sampling were prospectively performed on pregnant mares in a natural setting. Study 1 enrolled mares diagnosed with early stage of ascending placentitis based on ultrasonographic findings (n = 12), and gestationally age-matched mares with healthy pregnancies as controls (n = 12). Blood samples were classified as pre-onset (before) and early onset (at the time of ultrasonographic changes) of placentitis. There were no detected statistically significant differences between groups and timepoints in immunological and inflammatory parameters, including peripheral lymphocyte subpopulations, cytokine, and serum amyloid A concentrations. The placentitis group showed a reduced (P = 0.01) DHP/20α-DHP ratio when compared to the control group at the early onset timepoint. Plasma estradiol-17ß concentration <359 pg/mL predicted ascending placentitis with acceptable accuracy (area under the curve, AUC = 0.71). Combined albumin <3.7 g/dL, estradiol-17ß < 499 ng/mL, and DHP <33 ng/mL predicted 100 % of cases of ascending placentitis. In study 2, samples were classified according to the presence and severity of the abnormal ultrasonographic findings as mild (n = 11) and moderate-severe (n = 23), and gestationally age-matched with samples from control mares (n = 34). Mares with moderate-severe ascending placentitis had increased (P = 0.03) plasma 20α-DHP concentration and reduced (P = 0.03) DHP/20α-DHP ratio when compared to control mares. Our results suggest that the early events of ascending placentitis detected by ultrasonographic findings include hormonal alterations of feto-placental metabolism measurable in the mare's circulation, yet without obvious systemic immunological and inflammatory changes. Additional studies are warranted to further assess how hormonal markers and cutoff values could guide decisions for timely therapeutic intervention.

Allergen-specific immunoglobulin-Es for dermatitis in the Japanese native Noma horses.

Noma horses are native Japanese horses. Health checkups revealed that many Noma horses developed dermatitis during summer, which subsided in winter. Seasonal development and signs of itching, suggestive of allergic dermatitis, were observed. In this study, allergen-specific IgE was measured using blood samples collected from 15 Noma horses in summer and winter to identify allergens highly associated with dermatitis. The presence of dermatitis in the subject individuals was recorded during blood sample collection. White blood cell and eosinophil counts, serum total IgE concentration, and serum allergen-specific IgE units (ARUs) were measured. White blood cell and eosinophil counts were significantly higher in horses with dermatitis in summer compared to winter. On the other hand, there was no significant difference in serum total IgE concentration regardless of the presence of dermatitis or the season. Horses with dermatitis in summer showed higher ARUs derived from red ants, horseflies, biting midges, cockroaches, deerflies, and mosquitoes than those in winter. These ARUs were positively correlated with white blood cell and eosinophil counts. The factor analysis results suggested that sensitization to some insects, such as mosquitoes and deerflies, may be a cause of dermatitis. In conclusion, insect-derived allergens could be associated with the onset of dermatitis in Noma horses.

Large-scale study of blood markers in equine atypical myopathy reveals subclinical poisoning and advances in diagnostic and prognostic criteria.

Equine atypical myopathy (AM) is a severe rhabdomyolysis syndrome primarily caused by hypoglycin A (HGA) and methylenecyclopropylglycine protoxins. This study aimed to refine diagnostic and prognostic criteria for AM while exploring apparently healthy cograzers. Blood samples from 263 horses, including AM cases (n= 95), cograzers (n= 73), colic horses (n= 19), and controls (n= 76), were analyzed for HGA, its toxic metabolite, and acylcarnitines profile. Diseased horses exhibited alterations in acylcarnitines that strongly distinguished them from controls and colic horses. Regression analyses identified distinct acylcarnitines profiles among groups, with cograzers showing intermediate alterations. Age and gelding status emerged as protective factors against AM. Furthermore, serum acylcarnitines profiling was valuable in predicting AM survival, with isovaleryl-/2-methylbutyrylcarnitine (i.e., C5 acylcarnitine) showing promise as both a diagnostic and prognostic marker. Subclinical alterations in cograzers underscore a novel aspect: the presence of subclinical cases of AM.

The use of serum paraoxonase-1 to assess inflammation in horses with colitis.

BACKGROUND: Paraoxonase-1 (PON-1) has been suggested as a marker of inflammation and oxidative stress in horses and could potentially be used for prognostication in horses with colitis. OBJECTIVES: Assessment of PON-1 in horses with colitis and comparison of two methods. METHODS: Serum PON-1 was measured by two methods (paraoxon and p-nitrophenyl acetate) in 161 horses with colitis and 57 controls. Follow-up samples obtained during hospitalization were available from 106 horses with colitis. The two methods were compared. RESULTS: Serum PON-1 was significantly lower in horses with colitis than in healthy horses (P < .0001 for both methods) as well as in nonsurvivors compared with survivors (P = .0141 [paraoxon-based method] and P < .0001 [p-nitrophenyl acetate-based method]), but with marked overlap between groups. PON-1 activity did not change parallel to a change in inflammatory status in response to treatment when assessed at admission and in up to seven follow-up samples. Admission PON-1 activity could not reliably classify horses as survivors or nonsurvivors, with sensitivity and specificity ranging between 53.1% and 72.9%. Results from the two methods were comparable. CONCLUSIONS: Both methods reliably measured serum PON-1 activity. Significant differences in PON-1 activity were found between healthy horses and horses with colitis and between survivors and nonsurvivors. However, PON-1 activity varied considerably within groups. Both the proposed reference intervals as well as alternative cutoff values resulted in suboptimal diagnostic and prognostic performance, and the use of serum PON-1 in horses with colitis thus seems to add little to existing diagnostic and prognostic markers.

Seroprevalence of Toxoplasma gondii and Neospora spp. in horse population of Tehran, Iran.

Neospora spp. and Toxoplasma gondii are two closely related protozoan parasites that are widely distributed throughout the world. Horses can act as intermediate hosts for both parasites and can acquire disease. Blood samples were taken from 487 clinically healthy horses from 17 different mechanized stables in Tehran, the capital of Iran, during September and November of 2022. IFAT and ELISA were employed to detect antibodies directed against Neospora spp. and T. gondii. The anti-N. caninum antibodies were detected in 52 of the horses (10.67%) based on IFAT and in 86 of the 487 horses (17.65%) based on the ELISA test. Also, antibodies against T. gondii were detected in 41 horses (8.42%) based on IFAT and in 63 of 487 horses (12.94%) based on the ELISA test. Also, in 6 of the horses (1.23%) based on IFAT and in 13 of the 487 horses (2.67%) based on the ELISA test, double positivity suggested co-infection with both parasites. Gender, age groups, and the presence of dogs for neosporosis, and age groups and the presence of cats for toxoplasmosis, could be considered factors having an influence on the seroprevalences (P < 0.05). The results proved the importance of the urgent implementation of stringent regulatory measures to prevent and control the spread of these parasites.

Plasma concentration of serum amyloid A and lipopolysaccharide binding protein in horses with laminitis resulted from hindgut acidosis.

Many studies have shown a strong correlation between Hindgut Acidosis (HGA) and the occurrence of laminitis in horses; therefore, the early diagnosis of HGA is essential. In this study, we investigated changes in the plasma concentrations of lipopolysaccharide-binding protein (LBP) and serum amyloid A (SAA) as inflammatory markers in horses with laminitis. Sixteen healthy male Arabian horses that had cecal cannulation without visible laminitis or general symptoms were randomly divided into two groups. The horses were fed two different diets in a forage-to-concentrate ratio. Blood samples were collected on Days 1, 10, and 20. The primary objective of this study was to analyze plasma levels of LBP and SAA. Cecal specimens were obtained from each equine subject on three designated days: days 1, 10, and 20. The second objective was to assess the levels of pH and volatile fatty acids (VFA) in the samples. Throughout the study period, horses fed a high-concentrate diet exhibited a significantly elevated average lameness grade on days 10 and 20 compared to the initial stage (P < 0.001). On day 20, a significant increase in the concentration of SAA was observed in horses fed a high-concentrate diet, in contrast to the initial stage of the study. LBP levels in the plasma were significantly elevated on days 10 and 20 in horses fed a high-concentrate diet. Based on our findings, it is recommended that the evaluation of plasma LBP concentrations is more effective than SAA for the early identification of HGA in horses fed a high-grain diet.

Prevalence of insulin dysregulation in the non-obese stock-type horse and relationship with morphometric neck measurements.

Insulin dysregulation (ID), core to equine metabolic syndrome, may present without obesity. Testing for ID risk is commonly based on breed and obese phenotype but might be valuable for non-obese stock-type horses. This study aimed to determine the prevalence of ID in non-obese stock-type horses and evaluate if morphometric neck measurements (MNM) correlate with ID. Sixty-two, non-obese (BCS 5, range 2.5-6/9) stock-type horses were assessed for MNM: neck circumference at 25%, 50% (NC50), and 75% (NC75) length, and crest height. An oral sugar test (OST; 0.15 mL/kg BW corn syrup) was performed with blood taken pre- and 60 min post-OST for insulin (PREI, POSTI) and glucose (PREG, POSTG). Insulin dysregulation was defined as insulin concentration > 45 µIU/mL POSTI. Three of 62 horses were ID (4.8%; 95% CI 1.0%-13.5%). Horses with ID had greater PREG (121.0 ± 7.56 vs. 105.3 ± 1.72 mg/dL; LS means ± SEM; P = 0.04) and PREI (15.7 ± 2.63 vs. 10.5 ± 0.59 µIU/mL; P = 0.05) than normal responders. Mares had greater PREI than geldings (11.7 ± 0.76 vs. 9.4 ± 0.89 µIU/mL; P = 0.04). Stepwise regression indicated a weak relationship with crest height and POSTG (y = 51.27 + (0.88 x NC50); R2 = 0.09; P = 0.02). Post-glucose correlated with NC50 (r = 0.30; P = 0.04) and NC75 (r = 0.29; P = 0.03). This study showed 4.8% of non-obese horses had ID, warranting testing irrespective of phenotype, but only a weak association between MNM and POSTG was found.

Limited association between stallion-like behavior and hormonal indicators of testicular remnants in geldings.

Persistent stallion-like behavior is a common sign of cryptorchidism in supposed geldings. The presence of testicular tissue can be evaluated by analyzing hormones such as testosterone and anti-Müllerian hormone (AMH). Here, we used hormonal analysis to investigate relationships between the likely presence of testicular tissue and stallion-like behavior in samples submitted from presumptive geldings (n = 1,202), retrospectively. Most geldings with stallion-like behaviors had serum concentrations of testosterone (851/1,056; 80.6 %) and AMH (682/877; 77.8 %) below the laboratory reference range for cryptorchids (< 60 pg/mL and ≤ 0.15 ng/mL for testosterone and AMH, respectively). A total of 13 samples (13/716; 1.8 %) showed AMH concentrations typical for geldings but testosterone above the cryptorchid range. Conversely, 31 samples (31/716; 4.3 %) had high AMH, suggesting cryptorchidism, but testosterone concentrations implied no testicular tissue. Among the cryptorchid stallions, the AMH and testosterone concentrations did not vary based on the season. However, age categories affected the concentration of both hormones among the presumptive true cryptorchid stallions. The results of this study demonstrate that undesirable behavior in geldings is rarely associated with the presence of testicular tissue, as assessed by these two hormonal biomarkers. This information highlights the complexity of behavior and demonstrates that persistent stallion-like behavior in geldings could be related to factors other than the presence of testicular tissue.

Detection of Equine Parvovirus-Hepatitis Virus and Equine Hepacivirus in Archived Sera from Horses in France and Australia.

Reports of newly discovered equine hepatotropic flavi- and parvoviruses have emerged throughout the last decade in many countries, the discovery of which has stimulated a great deal of interest and clinical research. Although commonly detected in horses without signs of disease, equine parvovirus hepatitis (EqPV-H) and equine hepacivirus (EqHV) have been associated with liver disease, including following the administration of contaminated anti-toxin. Our aim was to determine whether EqPV-H and EqHV are present in Australian horses and whether EqPV-H was present in French horses and to examine sequence diversity between strains of both viruses amongst infected horses on either side of the globe. Sera from 188 Australian horses and 256 French horses from horses with and without clinical signs of disease were collected. Twelve out of 256 (4.7%) and 6 out of 188 (3.2%) French and Australian horses, respectively, were positive for the molecular detection of EqPV-H. Five out of 256 (1.9%) and 21 out of 188 (11.2%) French and Australian horses, respectively, were positive for the molecular detection of EqHV. Australian strains for both viruses were genomically clustered, in contrast to strains from French horses, which were more broadly distributed. The findings of this preliminary survey, with the molecular detection of EqHV and EqPV-H in Australia and the latter in France, adds to the growing body of awareness regarding these recently discovered hepatotropic viruses. It has provided valuable information not just in terms of geographic endemicity but will guide equine clinicians, carers, and authorities regarding infectious agents and potential impacts of allogenic tissue contamination. Although we have filled many gaps in the world map regarding equine hepatotropic viruses, further prospective studies in this emerging field may be useful in terms of elucidating risk factors and pathogenesis of these pathogens and management of cases in terms of prevention and diagnosis.

Effect of hospitalization on equine local intestinal immunoglobulin A (IgA) concentration measured in feces.

During hospitalization horses may develop gastrointestinal conditions triggered by a stress-associated weak local immune system. The prospective, clinical trial was conducted to find out whether fecal immunoglobulin A (IgA) concentrations could be determined in hospitalized horses and how they changed during hospitalization and in response to various stressors. Samples were obtained from 110 horses and a control group (n = 14). At arrival in the hospital, horses were categorized into pain grades (1-5), and elective versus strenuous surgery (> 2 hours, traumatic and emergency procedures). Feces were collected on day 1, day 2, day 3, and day 7 in all horses. Blood samples were obtained at the same intervals, but additionally after general anaesthesia in horses undergoing surgery (day 2). IgA concentration in feces was determined by ELISA and measured in optical density at 450nm. The control group showed constant IgA concentrations on all days (mean value 0.30 OD450 ±SD 0.11, 1.26 mg/g; n = 11). After general anaesthesia fecal IgA concentrations decreased considerably independent of duration and type of surgery (P < 0.001 for elective and P = 0.043 for traumatic surgeries). High plasma cortisol concentrations were weakly correlated with low fecal IgA on the day after surgery (P = 0.012, day 3, correlation coefficient r = 0.113). Equine fecal IgA concentrations showed a decline associated with transport, surgery, and hospitalization in general, indicating that stress has an impact on the local intestinal immune function and may predispose horses for developing gastrointestinal diseases such as enterocolitis.

Monitoring of inflammatory blood biomarkers in foals with Rhodococcus Equi pneumonia during antimicrobial treatment.

Rhodococcus equi (R. equi), a gram-positive facultative intracellular pathogen, is a common cause of pneumonia in foals and represents a major cause of disease and death. The aim of the present study was to investigate the time-depended changes in White Blood Cells (WBC), basophils (Baso), neutrophils (Neu), lymphocytes (Lymf), monocytes (Mon), eosinophils (Eos), platelet (PLT) counts, fibrinogen (Fbg) concentration, interferon (IFN-α, IFN-γ) and interleukins (IL-2 and IL-10) in foals with clinical R. equi pneumonia. The main treatment was with azithromycin-rifampicin for 14 days. Blood was sampled prior to, 7 and 14 days after starting therapy. Treatment was associated with significantly decreased counts of WBC, (25.6 ± 6.7 and 14.2 ± 2,7 × 103/ml), Neu (18.6 ±6.2 and 10.7 ± 3.1 × 103/ml), Mon (1.5 ± 0.5 and 0.9 ± 0.2 × 103/ml) and Fbg (539 ± 124 and 287 ± 26 g/dl) between day 0 and day 14. IL-2 and IL-10 concentrations were significantly increased (P = 0.028, P = 0.013, respectively) after treatment, whereas IFN-α and IFN-γ concentrations were not. The diagnostic potentials of INF-α, INF-γ, IL-2 and IL-10 per se seems not very high, however, the study suggests that the activity change of selected interleukins in the course of the disease may be associated with amelioration. We concluded that patterns of serum concentration changes of INF-α, INF-γ, IL-2 and IL-10 may help in the study of the innate immune response in foals during infection and treatment of R. equi pneumonia.

Obesity and gestation in Criollo mares: endocrine and metabolic profiles.

The aim of this study was to determine the effect of body condition score (BCS) on metabolic and endocrine parameters in pregnant Criollo mares (n=41), which were categorized according to their BCS as obese (7 to 9 BCS, n=26) or normal (5 to 7, n=15). Blood samples were taken during gestation in 3 periods: between 3.5 and 5 months (I), 8 and 9 months (II) and in the last month of gestation (III). The data was analyzed in the statistical model by mixed procedures, including BCS, gestational period and their interaction as fixed effects. BCS was only different in period I, as normal mares increased their BCS in the later periods. Leptin concentrations were greater in obese mares when compared to non-obese mares during all sampling periods (P<0.01), while glucose concentrations were also greater in the former group (P<0.01) but only during the first sampling period. Insulin concentrations and homeostatic model assessment for insulin resistance (HOMA-IR) index were greater also in obese mares in periods I and III (P<0.05). Adiponectin concentrations in period I were lower in obese mares (P<0.05). Cholesterol concentrations increased during gestation, and obese mares tended to have greater concentrations than nonobese mares (P<0.1). Triglyceride concentrations were not affected by group or gestational period. This study revealed adaptations in carbohydrate and lipid metabolism during gestation in mares. Several parameters are dependent on the degree of body fat reserves, which are reflected in the concentrations of biomarkers such as leptin and adiponectin. Insulin concentration in obese mares was higher than non-obese mares at the end of gestation, a similar profile was observed for HOMA-IR although cutoff values are yet still to be validated.

Evaluation of gastrointestinal tract lesions and serum malondialdehyde levels after repeated oral administration of phenylbutazone in horses.

Phenylbutazone (PBZ) is a widely used nonsteroidal anti-inflammatory drug for horses. However, because of its gastrointestinal side effects, its administration requires careful attention in veterinary practice. Malondialdehyde (MDA) is a serum biomarker associated with increased damage to the equine gastrointestinal system. This study investigated the hematological effects and alterations in the gastrointestinal tract and assessed serum MDA concentrations following repeated oral PBZ administration at clinical doses. Fourteen horses were randomly divided into control and treatment groups. All horses in the treatment group were administered 4.4 milligrams per kilogram of body weight of PBZ syrup orally twice a day for 7 days, whereas the control group received syrup as a placebo. The development of gastrointestinal side effects was investigated using gastroscopy, abdominal ultrasound, and fecal pH; serum MDA concentrations were assessed using a commercially available enzyme-linked immunosorbent assay kit. Data were compared between PBZ-treated and control horses before and after the treatment period. The treatment group exhibited decreased albumin and total protein concentrations. Moreover, this group exhibited a higher thickness of the right dorsal colon wall (p = 0.03) and had higher scores for squamous gastric ulcers (p = 0.01). Fecal pH was lower in the treatment group than in the control group after PBZ administration (p < 0.01). Although MDA concentrations were higher in the treatment group after PBZ administration, they did not differ significantly from those of the control group. This study highlighted the changes in hematological and gastrointestinal lesions resulting from PBZ administration in horses at clinical doses, even without clinical signs. However, MDA may not be an optimal biomarker for the early detection of gastrointestinal damage due to PBZ treatment in horses.

Serum concentrations of selenium, copper, and zinc in neonatal foals: Influence of failure of passive transfer and age-related changes.

Background: An adequate supply of trace elements is very important for equine neonates, as deficiencies can lead to health problems and even death. Objective: This study investigated serum concentrations of selenium (Se), copper (Cu), and zinc (Zn) in neonatal foals up to the 8th day of life. The influences of disease, age, and failure of passive transfer (FPT) on these concentrations were analyzed. Animals and procedure: Serum concentrations of Se, Cu, and Zn were determined from blood samples of 93 foals by means of inductively coupled plasma mass spectrometry. The foals were divided into 2 groups based on health status: clinically sick (n = 51) and clinically healthy (n = 42). The latter group was further divided into foals with FPT (n = 20) and those without (n = 22). Results: Mean serum concentrations for Se, Cu, and Zn were 60 ± 40 µg/L, 0.25 ± 0.22 mg/L, and 605 ± 285 µg/L, respectively. A significant influence of age on serum Cu concentration was observed (P < 0.0001). No differences were observed between any of the serum concentrations in clinically sick and clinically healthy foals on the 1st day of life. The FPT status was not associated with reduced serum concentrations of Se, Cu, or Zn. Conclusion and clinical relevance: It is not necessary to supplement trace elements in all foals with FPT.

Concentrations sériques de sélénium, de cuivre et de zinc chez les poulains nouveau-nés : influence de l'échec du transfert passif et des changements liés à l'âge. Contexte: Un apport suffisant en oligo-éléments est très important pour les nouveau-nés équins, car des carences peuvent entraîner des problèmes de santé, voire la mort. Objectif: Cette étude a examiné les concentrations sériques de sélénium (Se), de cuivre (Cu) et de zinc (Zn) chez les poulains nouveau-nés jusqu'au 8ème jour de vie. Les influences de maladies, de l'âge et de l'échec du transfert passif (FPT) sur ces concentrations ont été analysées. Animaux et procédure: Les concentrations sériques de Se, Cu et Zn ont été déterminées à partir d'échantillons de sang de 93 poulains au moyen d'une spectrométrie de masse à plasma à couplage inductif. Les poulains ont été divisés en 2 groupes en fonction de leur état de santé: cliniquement malades (n = 51) et cliniquement sains (n = 42). Ce dernier groupe a été divisé en poulains avec FPT (n = 20) et ceux sans (n = 22). Résultats: Les concentrations sériques moyennes de Se, Cu et Zn étaient respectivement de 60 ± 40 µg/L, 0,25 ± 0,22 mg/L et 605 ± 285 µg/L. Une influence significative de l'âge sur la concentration sérique de Cu a été observée (P < 0,0001). Aucune différence n'a été observée entre les concentrations sériques chez les poulains cliniquement malades et cliniquement sains au premier jour de leur vie. Le statut FPT n'était pas associé à une réduction des concentrations sériques de Se, Cu ou Zn. Conclusion et pertinence clinique: Il n'est pas nécessaire de supplémenter tous les poulains en oligo-éléments avec FPT.(Traduit par Dr Serge Messier).

Nine-year seroepidemiological study of severe fever with thrombocytopenia syndrome virus infection in feral horses in Cape Toi, Japan.

Severe fever with thrombocytopenia syndrome (SFTS) is a fatal zoonosis caused by ticks in East Asia. As SFTS virus (SFTSV) is maintained between wildlife and ticks, seroepidemiological studies in wildlife are important to understand the behavior of SFTSV in the environment. Miyazaki Prefecture, Japan, is an SFTS-endemic area, and approximately 100 feral horses, called Misaki horses (Equus caballus), inhabit Cape Toi in Miyazaki Prefecture. While these animals are managed in a wild-like manner, their ages are ascertainable due to individual identification. In the present study, we conducted a seroepidemiological survey of SFTSV in Misaki horses between 2015 and 2023. This study aimed to understand SFTSV infection in horses and its transmission to wildlife. A total of 707 samples from 180 feral horses were used to determine the seroprevalence of SFTSV using enzyme-linked immunosorbent assay (ELISA). Neutralization testing was performed on 118 samples. In addition, SFTS viral RNA was detected in ticks from Cape Toi and feral horses. The overall seroprevalence between 2015 and 2023 was 78.5% (555/707). The lowest seroprevalence was 55% (44/80) in 2016 and the highest was 92% (76/83) in 2018. Seroprevalence was significantly affected by age, with 11% (8/71) in those less than one year of age and 96.7% (435/450) in those four years of age and older (p < 0.0001). The concordance between ELISA and neutralization test results was 88.9% (105/118). SFTS viral RNA was not detected in ticks (n = 516) or feral horses. This study demonstrated that horses can be infected with SFTSV and that age is a significant factor in seroprevalence in wildlife. This study provides insights into SFTSV infection not only in horses but also in wildlife in SFTS-endemic areas.