Effect of video angle on detection of induced front limb lameness in horses.

BACKGROUND: Lameness examinations are commonly performed in equine medicine. Advancements in digital technology have increased the use of video recordings for lameness assessment, however, standardization of ideal video angle is not available yielding videos of poor diagnostic quality. The objective of this study was to evaluate the effect of video angle on the subjective assessment of front limb lameness. A randomized, blinded, crossover study was performed. Six horses with and without mechanically induced forelimb solar pain were recorded using 9 video angles including horses trotting directly away and towards the video camera, horses trotting away and towards a video camera placed to the left and right side of midline, and horses trotting in a circle with the video camera placed on the inside and outside of the circle. Videos were randomized and assessed by three expert equine veterinarians using a 0-5 point scoring system. Objective lameness parameters were collected using a body-mounted inertial sensor system (Lameness Locator®, Equinosis LLC). Interobserver agreement for subjective lameness scores and ease of grading scores were determined. RESULTS: Induction of lameness was successful in all horses. There was excellent agreement between objective lameness parameters and subjective lameness scores (AUC of the ROC = 0.87). For horses in the "lame" trials, interobserver agreement was moderate for video angle 2 when degree of lameness was considered and perfect for video angle 2 and 9 when lameness was considered as a binary outcome. All other angles had no to fair agreement. For horses in the "sound" trials, interobserver agreement was perfect for video angle 5. All other video angles had slight to moderate agreement. CONCLUSIONS: When video assessment of forelimb lameness is required, a video of the horse trotting directly towards the video camera at a minimum is recommended. Other video angles may provide supportive information regarding lameness characteristics.

Identification of third stage larvae of strongyles and molecular diagnosis of Strongylus vulgaris in the feces of Thoroughbred horses kept in training centers in Rio de Janeiro, Brazil.

The aims of the present study were to identify strongyles in the feces of Thoroughbred horses based on larval morphology; to detect Strongylus vulgaris using molecular diagnosis and compare results to those of feces culture; and to determine the association between the presence of S. vulgaris with corresponding animal information (age range, gender, and anthelmintic use). Feces of horses kept in six Training Centers in Rio de Janeiro State, that showed the presence of ≥500 eggs per gram of feces (EPG) were subjected to strongyle identification. Of the 520 fecal samples collected, 35 had an EPG ≥ 500. After fecal culture for L3 larvae identification, DNA was extracted, subjected to PCR to amplify the ITS2 region DNA fragment of S. vulgaris, and sequenced. A total of 3500 larvae were analyzed. Most were classified as small strong (99.7%), with an emphasis on the type A subfamily of Cyathostominae. Forms of S. vulgaris only corresponded to 0.2%. In all, 25 samples showed amplified S. vulgaris DNA products and 11 showed nucleotide sequences with high sequence identity. Fecal culture and PCR results showed poor agreement (kappa = 0.105) for S. vulgaris diagnosis. Age, gender, anthelmintic use, and anthelmintic administration interval were not statistically significant. The present study showed the presence of S. vulgaris in the feces of horses kept in Rio de Janeiro Training Centers, mainly seen via PCR, which has emerged as the most effective tool for diagnosis. This study made it possible to identify strongyles that infect horses in the region, emphasizing upon the necessity for constant monitoring of the animals.

Molecular characterization of equine herpes viruses type 1 and 4 among Arabian horse populations in Egypt during the period between 2021 and 2022.

Background: Equine herpesvirus type 1 (EHV-1) is a major cause of abortion and respiratory disease. Equine herpesvirus type 4 (EHV-4), on the other hand, is exclusively associated with respiratory disease in horse populations worldwide, particularly in Egypt and Arabian countries. Aim: This study aims to investigate the circulation of EHV-1 and EHV-4 in the Arabian horse population through molecular detection and genetic characterization of EHV-1 and/or EHV-4 that may threaten the stability of horse industry. Methods: A total of 80 samples including 50 nasal swabs, 10 vaginal swabs and 20 whole blood samples were collected from vaccinated and registered pure-bred Arabian adult horses from different studs in the governorates of northern Egypt (Cairo, Dakahlyia and Qalyubia) from 2021 to 2022. The collected samples were screened using consensus PCR for detection of EHVs using specific primers targeting DNA polymerase gene. The positive samples were subjected to conventional PCR for detection of EHV-1 and/or EHV-4using specific primers targeting glycoprotein (gB) gene. EHV-1 and EHV-4 amplicons were partially sequenced and phylogenetically analyzed using Sanger method. Results: Consensus PCR revealed that 48 out of 80 samples were positive for EHVs with percentage of 60%. Typing of the selected positive samples using conventional PCR showed that 29 out of 80 were positive for EHV-1 with percentage 36.25%, while 24 out of 80 samples were positive for EHV-4 with percentage 30%. Mixed infections with both viruses were detected in five samples. The amplified products were sequenced using Sanger method and submitted to GenBank under accession number OM362231MG-1 for EHV-1 strain and OM362232 MG-4 for EHV-4 strain. Sequence analysis and alignments of the amplified fragments of the EHV-1 and EHV-4 glycoprotein B (gB) gene to that of GenBank-derived reference strains revealed a high degree of similarity. According to the phylogenetic tree, the obtained sequences of EHV-1 and 4 in the current study showed homogeneity with local Egyptian and foreign EHV-1 and 4 strains and heterogeneity with EHV-2 and 5. Conclusion: The current investigation showed that molecular methods are appropriate assays for an efficient and accurate diagnosis of EHVs. Furthermore, it supports earlier research findings about the prevalence of EHV-1 and 4 in Arabian horse populations in Egypt.

A cross-sectional observational study of birefringent particulates in bronchoalveolar lavage cytology in horses with equine asthma from the West v East coasts of the USA.

Equine asthma (EA) is an important cause of wastage in the USA horse industry. Exposure to organic particulates, from stable dust, airborne pollen, and fungal loads, is posited to be the main cause. Dust arising from the earth's crust has been largely ignored as a contributor to EA in the veterinary literature. The objectives of this study were to investigate the occurrence of birefringent particulates in the bronchoalveolar lavage fluid (BALF) of horses with a clinical complaint of EA residing in the arid West of the USA v. the East, in an effort to determine the contribution of geolocation to geogenic dust exposure. We analyzed BALF cytology and historical data sent to our referral clinical laboratory from 148 horses from the West Coast and 233 horses from the East Coast of the USA over a 6-year period, using light microscopy to determine cell proportions and other visible elements as well as a polarizing lens to detect birefringent material. Univariate analysis showed that horses from the West coast were significantly more likely to have birefringent particulates in the BALF than horses from the East coast (40.5% v. 8.6%, p < 0.001); while horses from the East had higher BALF neutrophil proportions. Horses from the West also had lower proportions of neutrophils in the BALF than those from the East (27.1 v. 10.9, p < .001). Using historical and BAL data in a forward stepwise binary logistic regression model with presence of birefringent particulates found within alveolar macrophages as the outcome, geographical location in the West retained significance as a predictor (OR 8.0, CI [4.3-14.8], p< .001). While the birefringent particulates cannot be identified on the basis of polarizing microscopy alone, this study provides evidence that horses from the West are exposed to inorganic particulates that may contribute to signs of equine asthma.

First confirmed case of equine pythiosis in Northern Veracruz, Mexico.

A clinical case of an adult horse with invasive, ulcerative, proliferative, pyogranulomatous disease of the skin (tumor) in the shoulder region is presented. The mass had a granulomatous and crater-shaped appearance, with serosanguinous discharge and the presence of fistulas with caseous material. The tumor was removed by surgery and sent to the laboratory for diagnosis. Histopathology was performed using Grocott-Gomori methenamine silver stain. The presence of necrotic material, fibrosis, infiltrated cells, and brown-colored hyphae, characteristic of members of the genus Pythium, were observed. To identify the infecting species, conventional PCRs for the amplification of the ITS-1 was carried out. Histopathological and PCR tests confirmed infection by a Pythium insidiosum strain closely associated with previous records from the US and Central America. Our report represents the first molecularly confirmed case of equine pythiosis in Mexico.

Performance of three techniques for diagnosing equine tapeworm infection.

Tapeworm infection in horses can cause serious health concerns, and recent data have documented treatment failures in the most common species, Anoplocephala perfoliata. The threat of anthelmintic resistance in A. perfoliata is of particular concern because of poor diagnostic performance of standard egg counting techniques for detecting this parasite. This study compared the performance of three diagnostic techniques 1) Mini-FLOTAC, 2) Cornell-Wisconsin, and 3) Proudman and Edwards used to detect and quantify A. perfoliata eggs in naturally infected horses. Eighteen adult female horses from the University of Kentucky's historic parasitology herd were included in this study. Fecal samples were collected from all horses at five collection time points two weeks apart and analyzed with the three techniques. A total of 90 samples were collected and 270 counts determined in the study. The proportions of positive samples determined by the three techniques were significantly different from each other (p<0.05): Mini-FLOTAC (16%), Cornell-Wisconsin (47%), and Proudman and Edwards (70%). The Proudman and Edwards technique counted consistently higher numbers of tapeworm eggs compared to the other two techniques throughout the study [p < 0.05]. Total raw counts of tapeworm eggs across the study for each technique were 16, 88, and 410 for the Mini-FLOTAC, Cornell-Wisconsin, and Proudman and Edwards, respectively. This study demonstrated that the Proudman and Edwards technique was superior in diagnosing A. perfoliata infection. Future work needs to assess this technique's potential for Fecal Egg Count Reduction Testing (FECRT).

Dermatitis, cellulitis, and osteomyelitis caused by Aspergillus nidulans in a horse with pituitary pars intermedia dysfunction.

Clinical and histologic examination of a 12-y-old client-owned Quarter Horse gelding with pituitary pars intermedia dysfunction revealed dermatitis, cellulitis, and osteomyelitis caused by Aspergillus nidulans, confirmed by a PCR assay. This novel presentation of a fungal disease in a horse was characterized by aggressive local invasion and failure to respond to all medical therapy attempted over a 1-y period. Treatments included systemic and topical antifungals, anti-inflammatories, and use of cellular matrices. Surgical excision was not attempted but should be strongly considered early in the disease process in similar cases if clean margins can be achieved. Postmortem findings were of locally aggressive disease with no dissemination.

Refinement and revalidation of the Equine Ophthalmic Pain Scale: R-EOPS a new scale for ocular pain assessment in horses.

This study addresses the refinement and revalidation of a composite pain scale that focuses on equine facial expressions and behavioural indicators as exhibitions of ophthalmic pain. This scale included only Behavioural and Facial and Ocular expression indicators and, compared to the first version of Equine Ophthalmic Pain Scale (EOPS), item descriptors and related ratings were changed. Thirteen horses with ocular diseases that required medical or surgical treatment were enroled (group P). In each animal, the refined EOPS (R-EOPS) was applied prior to any treatment (T0) and one week later (T7). The R-EOPS was applied twice, 7 days apart, to 16 healthy control horses (group C). Two 30-second videos were recorded each time to allow the retrospective analysis by eight observers. Inter-observer reliability of items was moderate or substantial (Krippendorff's alpha, Kα>0.40) while their intra-observer reliability was substantial or almost perfect for most items (Kα ≥0.61). Both inter- and intra-observer reliability of Total Score (TS) were however excellent (Intraclass Correlation Coefficients, ICC>0.75). The TS also showed good reproducibility (Kendall coefficient=0.786, ICC=0.684) and high consistency of its items (Cronbach's α=0.847). The comparison between groups as well as the sensitivity and specificity values supported the validity of the R-EOPS. In particular, for each extra point added to the TS, the risk of the horse having pain increased by more than two times (Odds Ratio=2.079, 95%CI=1.542-2.804; P<0.001). The Receiver Operating Characteristic analysis identified 6 as the threshold value of R-EOPS for discriminating horses with ocular pathology (sensitivity=83%, specificity=100%). This scale may be an effective tool for reliably assessing the pain level in horses with ophthalmic diseases and potentially guiding pain management although it still requires large-scale application and external validation.

Detection of paroxysmal atrial fibrillation preceding persistent atrial fibrillation in a horse using an implantable loop recorder with remote monitoring.

Implantable loop recorders (ILRs) are increasingly used in equine cardiology to detect arrhythmias in the context of collapse, poor performance or monitoring for recurrence of atrial fibrillation (AF). However to date, the ILR has never been reported to be used with a remote monitoring functionality in horses, therefore the arrhythmia is only discovered when a clinician interrogates the ILR using dedicated equipment, which might delay diagnosis and intervention. This case report describes the use of an ILR with remote monitoring functionality in a horse with recurrent AF. The remote monitoring consisted of a transmission device located in the stable allowing daily transmission of arrhythmia recordings and functioning messages to an online server, available for the clinician to evaluate without specialised equipment. The ILR detected an episode of paroxysmal AF approximately three months after implantation. Seven months after implantation, initiation of persistent AF was seen on an episode misclassified by the ILR as bradycardia, and the horse was retired. This report shows the feasibility and benefits of remote monitoring for ILRs in horses, but also the shortcomings of current algorithms to interpret the equine electrocardiogram.

Identification of asinine gamma herpesviruses in a donkey with interstitial pulmonary fibrosis, pleural effusion and thrombocytopenia.

A 23-year-old domestic donkey (Equus asinus) referred for severe respiratory distress due to suspected equine asthma. Ultrasound of the chest revealed bilateral irregular pulmonary consolidation and pleural effusion. Airway endoscopy and tracheal wash cytology showed severe neutrophilic inflammation and bacterial culture was positive for Streptococcus equi subsp. zooepidemicus. Despite aggressive treatment, the donkey died in 48 hours. On post-mortem examination, the lung was whitish, collapsed, and firm, with fibrotic multifocal nodular areas. Pleural effusion and pleuritis were detected. Histologically, the lung architecture was markedly replaced by interstitial fibrosis. The histological features observed were suggestive of a severe chronic fibrosing interstitial pleuropneumonia with type 2 pneumocyte hyperplasia and intralesional syncytial cells. Pulmonary fibrosis was associated with the presence of asinine gammaherpesvirus 2 and 5 infection, confirmed by PCR and sequence analysis. The macroscopic and histological pattern of fibrosis was diffuse and interstitial, and the nodular lesions were consistent with spared lung parenchyma, instead of the canonical nodular distribution of the fibrosis observed in equine multinodular pulmonary fibrosis. Asinine herpesviral pulmonary fibrosis is uncommon, but should be considered by clinicians in the list of differentials in donkeys with chronic respiratory signs.

Prevalence and risk factors for epizootic lymphangitis among equids in ethiopia during 2002-2023: A systematic review and meta-analysis.

In Sub-Saharan Africa (SSA), particularly in Ethiopia, Epizootic Lymphangitis (EL) is the most prevalent fungal disease of equids, which causes significant economic losses as well as a decrease in equid populations. Therefore, this systematic review and meta-analysis were designed to pool the results of individual studies and estimate the prevalence of EL among equids in Ethiopia. A systematic search of research articles on the prevalence and risk factors of EL among equids in Ethiopia was conducted in registers, databases, and other sources. Cochrane's Q, inverse variance (I2), sensitivity analysis, funnel plot, Begg's, and Egger's regression tests were used to check heterogeneity and publication bias. A random-effects model was used to calculate the pooled burden of EL among equids. For this meta-analysis, a total of 7217 equids were included in the 14 eligible studies. The overall pooled prevalence of EL among equids in Ethiopia was 20.24% (95% CI: 16.27, 24.21). According to the subgroup analysis, the highest prevalence was observed in cart horses (20.98%), the Amhara region (21.46%), and studies conducted using sample sizes of 384 equids or greater (24.67%) and from 2002 to 2018 (25.52%) study periods. Harness-inflicted wounds, sharing stables or yards with harnesses, and the presence of preexisting wounds were identified as factors significantly associated with EL magnitude. Early diagnosis and proper medication, as well as implementing appropriate prevention and control measures, are necessary for the management of EL in equids.

THEILERIA EQUI INFECTION IN WORKING HORSES OF PAKISTAN: EPIDEMIOLOGY, MOLECULAR CHARACTERIZATION, AND HEMATOBIOCHEMICAL ANALYSIS.

Theileria equi is 1 of the emerging and prevailing tick-borne hemoprotozoans adversely affecting the equids worldwide, including Pakistan. The current study aimed to investigate the prevalence and molecular characterization of T. equi in working horses (n = 194), the comparative efficacy of different diagnostic tests, associated risk factors, and hematobiochemical analysis. The blood samples of horses were subjected to microscopic examination, cELISA, and polymerase chain reaction (PCR) and the results revealed a prevalence of 9.79, 21.13, and 13.40%, respectively, for T. equi in working horses. The comparison of microscopy and cELISA results with PCR showed that cELISA had higher sensitivity (84.62%), but lower specificity (88.69%) and accuracy (88.14%) in comparison to microscopy (57.69, 97.62, and 92.27%). Molecular characterization of T. equi by phylogenetic analysis revealed a 61% resemblance of study isolates with each other OL662926, OL662925, and 82% similarity with isolate OL662924 while also showing homology with T. equi isolates of South Africa, South Korea, India, Pakistan, and Brazil. The risk factor analysis revealed a significant association (P < 0.05) of tick control status, previous tick history, tick infestation, house hygiene, deworming/vaccination, and the presence of other livestock species with T. equi infection in horses. The hematobiochemical profile revealed a significant (P < 0.05) decrease in red blood cells (RBCs), hemoglobin (Hb), packed cell volume (PCV), white blood cells (WBCs), platelet (PLT), phosphorus, and an increase in lymphocytes, granulocytes, aspartate aminotransferase (AST), glucose, bilirubin, blood urea nitrogen (BUN), and creatinine in T. equi-infected horses. The current study is the first comprehensive report for comparative evaluation of microscopy, cELISA, and PCR, assessment of epidemiological risk factors as well as hematobiochemical variations due to T. equi infection in Pakistan.

Equine Piroplasmosis in Asymptomatic Horses of Western Iran: Comparison of Microscopic Examination and Multiplex PCR.

PURPOSE: Piroplasmosis is responsible for anemia, fever, loss of physical activity and even death in equines. In epidemiological studies, accurate diagnostic tests are essential for detecting asymptomatic carriers. This study aimed to investigate the prevalence of infection in asymptomatic horses from Lorestan province, western Iran by developing a multiplex PCR. METHODS AND RESULTS: Blood samples were examined by microscopy and multiplex PCR targeting the SSU rRNA gene of Theileria equi and Babesia caballi. Out of the total of 165 horses, 19 (11.51%) and 31 (18.78%) cases were positive for piroplasms by microscopy and PCR, respectively. The detection rates of both genera were significantly higher in multiplex PCR compared to microscopy (p < 0.0001). Compared with multiplex PCR, the sensitivities of microscopy for the detection of Babesia were only 28.5%. The prevalence of T. equi infection was significantly higher in summer (p = 0.035). The prevalence of B. caballi was significantly higher in males (p = 0.038). CONCLUSION: Findings indicate that the multiplex PCR described here is a sensitive technique for the detection of piroplasm DNA in carriers. Furthermore, asymptomatic carriers must be considered as an important source of infection for equids living in this region.

[Retropharyngeal manifestation of T-cell-rich B-cell lymphoma in a 7-year-old Icelandic gelding]. / Retropharyngeale Manifestation eines T-Zell-reichen B-Zell-Lymphoms bei einem 7-jährigen Isländerwallach.

A 7-year-old Icelandic gelding was presented with acute severe dyspnea of one day duration and purulent nasal discharge that had been present for 6 weeks. Clinically, the initial examination focused on severe enlargement of the mandibular and retropharyngeal lymph nodes as well as a mixed dyspnea.The diagnosis of a malignant lymphoma was evident following laboratory diagnostics, endoscopy, and cytological examination of a fine needle aspiration of a mandibular lymph node. The gelding was euthanized due to the poor prognosis and a significantly disturbed general condition. Pathohistological examination revealed a multicentric T-cell-rich B-cell lymphoma.

Factors affecting measurement of basal adrenocorticotropic hormone in adult domestic equids: A scoping review.

Measurement of basal adrenocorticotropic hormone (ACTH) concentration is the most commonly used diagnostic test for pituitary pars intermedia dysfunction (PPID). Although several pre-analytical and analytical factors have been reported to affect basal ACTH concentrations in equids, the extent to which these have been evaluated in the context of PPID diagnosis is unclear. The objectives of this scoping review were to identify and systematically chart current evidence about pre-analytical and analytical factors affecting basal ACTH concentrations in adult domestic equids. Systematic searches of electronic databases and conference proceedings were undertaken in June 2022, repeated in October 2022 and updated in August 2023. English language publications published prior to these dates were included. Screening and data extraction were undertaken individually by the authors, using predefined criteria and a modified scoping review data extraction template. After removal of duplicates, 903 publications were identified, of which 235 abstracts were screened for eligibility and 134 publications met inclusion criteria. Time of year, exercise, breed/type and transportation were the factors most frequently associated with significant increases in ACTH concentration (n = 26, 16, 13 and 10 publications, respectively). Only 25 publications reported inclusion of PPID cases in the study population, therefore the relationship between many factors affecting basal ACTH concentration and diagnostic accuracy for PPID remains undefined. However, several factors were identified that could impact interpretation of basal ACTH results. Findings also highlight the need for detailed reporting of pre-analytical and analytical conditions in future research to facilitate translation of evidence to practice.

Cytological diagnosis of exercise-induced pulmonary haemorrhage: Comparison of tracheal wash and bronchoalveolar lavage in standardbred racehorses.

BACKGROUND: Cytology of airway samples is sensitive for diagnosis of exercise-induced pulmonary haemorrhage (EIPH), but the association between tracheal wash (TW) and bronchoalveolar lavage fluid (BALF) is unknown. The objective of this study was to determine whether diagnosis of EIPH, using haemosiderophages/macrophages (H/M) ratio, differs when based on TW or BALF. METHODS: A prospective cross-sectional study was conducted on 102 standardbred horses in training. TW and BALF were collected concomitantly from all horses at rest (at least 24 hours after their last training or race), and their H/M ratios were calculated. Spearman's correlation, Cohen's kappa and Gwet's coefficient tests were performed to evaluate the association between TW and BALF samples. RESULTS: With BALF, 21 horses met the cytological inclusion criteria for an EIPH diagnosis from individual and/or pooled samples. With TW, 20 horses had occasional (H/M < 10%) haemosiderophages, and nine, one and three horses had small (10%-25%), moderate (25%-50%) and large (>50%) proportions, respectively. Poor correlations and inconsistent concordances between TW and BALF were found for H/M ratio. LIMITATIONS: Limitations include the use of a single staining method and the absence of a total haemosiderin score. CONCLUSION: No association between TW and BALF was found for the cytological diagnosis of EIPH. Based on H/M ratio, BALF remains the sample type of choice for cytological diagnosis of EIPH.

Fractures in Thoroughbred racing and the potential for pre-race identification of horses at risk.

Risk rates for and predisposing factors to fractures occurring in Thoroughbred racing that have been published in peer reviewed journals are documented. The potential for currently available techniques to identify horses at increased risk for fracture is discussed on the bases of principles, practicalities, advantages, disadvantages and current data. All are reviewed in light of justifiable decision making and importance of fractures to horseracing's social license.

Measurement of 8-hydroxy-2'-deoxyguanosine in serum and cerebrospinal fluid of horses with neuroaxonal degeneration and other causes of proprioceptive ataxia.

BACKGROUND: Eight-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of oxidative damage evaluated in human neurodegenerative disease, has potential to correlate with postmortem diagnosis of neuroaxonal dystrophy/degenerative myeloencephalopathy (NAD/DM) in horses. HYPOTHESIS: We hypothesized that 8-OHdG will be higher in CSF and serum from NAD/DM horses compared with horses with other neurologic diseases (CVSM, EPM) and a control group of neurologically normal horses. We also hypothesized that 8-OHdG will be higher in CSF compared with serum from NAD/DM horses. ANIMALS: Fifty client-owned horses with postmortem diagnoses: 20 NAD/DM, 10 CVSM, 10 EPM, and 10 control horses. Serum and CSF samples were obtained between November 2010 and March 2022. METHODS: Case-control study using biobanked samples was performed and commercial competitive ELISA kit (Highly Sensitive 8-OHdG Check ELISA) utilized. Concentration of 8-OHdG was quantitated in both CSF and serum and compared between groups. RESULTS: No correlation was established between the measures of 8-OHdG in serum and CSF and group. CSF median [8-OHdG] for NAD/DM was 169.9 pg/mL (IQR25-75 : 67.18-210.6), CVSM 157.1 pg/mL (IQR25-75 : 132.1-229.1), EPM 131.4 pg/mL (IQR25-75 : 102.1-193.2), and control 149.8 pg/mL (IQR25-75 : 113.3-196.4). Serum median [8-OHdG] for NAD/DM was 130 pg/mL (IQR25-75 : 51.73-157.2), CVSM 125.8 pg/mL (IQR25-75 : 62.8-170.8), EPM 120.6 pg/mL (IQR25-75 : 87.23-229.7), and control 157.6 pg/mL (IQR25-75 : 97.15-245.6). Poisson regression analysis showed no difference established once confounding variables were considered. CONCLUSIONS: Eight-OHdG did not aid in antemortem diagnosis of NAD/DM in this cohort of horses. At the time of diagnosis horses with NAD/DM do not have ongoing oxidative stress.

Range and Pasture Plants Likely to Poison Horses.

Range and pasture toxic plants can poison horses. Many of these plants are noxious weeds that can dominate plant populations and replace healthy forages. Poisoning is often difficult to diagnose as the resulting plant-induced disease is similar to other infectious, toxic, and nutritional diseases. Identifying potentially problem plants, and observing what plants horses are eating, is essential in determining the risk of poisoning. If the risk is significant, it can drive management to invest in strategies to avoid exposure, animal disease, and suffering.

Sarcocystis in horses from Rio Grande do Sul, Brazil: Molecular identification of Sarcocystis bertrami and Sarcocystis neurona in muscle tissues.

Horses are intermediate hosts of Sarcocystis spp. capable of forming cysts in their musculature. This study aimed to detect sarcocysts and investigate the presence of nucleic acids from Sarcocystis spp. in samples of striated muscles from horses in the State of Rio Grande do Sul, Brazil, necropsied at the Veterinary Pathology Laboratory of the Federal University of Santa Maria. A total of 108 samples were collected from 24 horses and examined through direct examination. Microscopic tissue cysts were observed in three samples: tongue (2) and esophagus (1) from two animals. Extractions were performed on the found cysts and tissues, even though sarcocystosis detection was not present. DNA samples were subjected to Nested-PCR using Tg18s primers, and the amplified products were subjected to Restriction Fragment Length Polymorphism (RFLP) using DdeI and HpaII enzymes. DNA belonging to Sarcocystis spp. was amplified in tissues from 91.7% (22/24) of the equines, and 67.6% (73/108) of the samples tested positive in the Nested-PCR reaction. The tissues with the highest detection frequency were: diaphragm 92.3% (12/13), gluteal muscle 77.2% (17/22), and esophagus 66.7% (4/6). In RFLP, Sarcocystis spp. was detected in 21 tissues from 11/22 equines, and cysts, identified through nucleotide sequencing, were determined to be S. bertrami. S. neurona was identified in 11 samples from 7/22 animals, with co-infection detected in 5/22 cases. The high detection rate indicates a concerning circulation of the protozoan, particularly the zoonotic S. bertrami found in all tissues, which are commonly exported for human consumption.