Strongylids of Domestic Horses in Eastern Slovakia: Species Diversity and Evaluation of Particular Factors Affecting Strongylid Communities.

PURPOSE: This study aimed to examine the species diversity and structure of the strongylid community in domestic horses in Eastern Slovakia. Also, an analysis of the impact of age, sex, and collection location factors on the strongyid communities was performed. METHODS: Twenty-seven horses 1.5-21 years old from two farms in eastern Slovakia with different horse-management conditions were studied. Strongylids were collected after horse treatments with Noromectin (0.2 mg ivermectin); 66,170 specimens were collected and identified. Faecal egg count reduction test (FECRT) was performed following fenbendazole (FBZ) and ivermectin (IVM) treatments. RESULTS: Twenty-four strongylid species were found; horses were infected with 6 to 16 (average = 11.7) species. Six cyathostomin species (Cylicocyclus nassatus, Cyathostomum catinatum, C. pateratum, Cylicostephanus longibursatus, C. goldi, C. calicatus) were the most prevalent; C. catinatum was the dominant species in both farms (Berger-Parker index 0.34 and 0.42). The structure of the strongylid community was multimodal with dominant, subdominant, background, and rare species. The Mantel test showed that horse age and sex did not significantly affect the nematode infracommunity composition (p > 0.05), while the impact of the collection location (farm) was significant (p = 0.03). Additionally, C. longibursatus was identified as the species contributing significantly to the observed farm differences. Strong resistance to FBZ was documented on both farms (FECRT was 36.4% and 22.7%); IVM resistance was not observed (FECRT = 100%). CONCLUSION: This study presents the first report on the strongylids parasitizing domestic horses in Eastern Slovakia and gives basic information for further studies of horse parasites and their control in the region.

Decrease of ESKAPE virulence with a cationic heme-mimetic gallium porphyrin photosensitizer: The Trojan horse strategy that could help address antimicrobial resistance.

INTRODUCTION: Emerging antibiotic resistance among bacterial pathogens has forced an urgent need for alternative non-antibiotic strategies development that could combat drug resistant-associated infections. Suppression of virulence of ESKAPE pathogens' by targeting multiple virulence traits provides a promising approach. OBJECTIVES: Here we propose an iron-blocking antibacterial therapy based on a cationic heme-mimetic gallium porphyrin (GaCHP), which antibacterial efficacy could be further enhanced by photodynamic inactivation. METHODS: We used gallium heme mimetic porphyrin (GaCHP) excited with light to significantly reduce microbial viability and suppress both the expression and biological activity of several virulence traits of both Gram-positive and Gram-negative ESKAPE representatives, i.e., S. aureus and P. aeruginosa. Moreover, further improvement of the proposed strategy by combining it with routinely used antimicrobials to resensitize the microbes to antibiotics and provide enhanced bactericidal efficacy was investigated. RESULTS: The proposed strategy led to substantial inactivation of critical priority pathogens and has been evidenced to suppress the expression and biological activity of multiple virulence factors in S. aureus and P. aeruginosa. Finally, the combination of GaCHP phototreatment and antibiotics resulted in promising strategy to overcome antibiotic resistance of the studied microbes and to enhance disinfection of drug resistant pathogens. CONCLUSION: Lastly, considering high safety aspects of the proposed treatment toward host cells, i.e., lack of mutagenicity, no dark toxicity and mild phototoxicity, we describe an efficient alternative that simultaneously suppresses the functionality of multiple virulence factors in ESKAPE pathogens.

Single-Cell Transcriptome Sequencing Reveals Molecular Expression Differences and Marker Genes in Testes during the Sexual Maturation of Mongolian Horses.

This study aimed to investigate differences in testicular tissue morphology, gene expression, and marker genes between sexually immature (1-year-old) and sexually mature (10-year-old) Mongolian horses. The purposes of our research were to provide insights into the reproductive physiology of male Mongolian horses and to identify potential markers for sexual maturity. The methods we applied included the transcriptomic profiling of testicular cells using single-cell sequencing techniques. Our results revealed significant differences in tissue morphology and gene expression patterns between the two age groups. Specifically, 25 cell clusters and 10 cell types were identified, including spermatogonial and somatic cells. Differential gene expression analysis highlighted distinct patterns related to cellular infrastructure in sexually immature horses and spermatogenesis in sexually mature horses. Marker genes specific to each stage were also identified, including APOA1, AMH, TAC3, INHA, SPARC, and SOX9 for the sexually immature stage, and PRM1, PRM2, LOC100051500, PRSS37, HMGB4, and H1-9 for the sexually mature stage. These findings contribute to a deeper understanding of testicular development and spermatogenesis in Mongolian horses and have potential applications in equine reproductive biology and breeding programs. In conclusion, this study provides valuable insights into the molecular mechanisms underlying sexual maturity in Mongolian horses.

Cardiovascular Fitness and Stride Acceleration in Race-Pace Workouts for the Prediction of Performance in Thoroughbreds.

In-training racehorse physiological data can be leveraged to further explore race-day performance prediction. To date, no large retrospective, observational study has analysed whether in-training speed and heart rate recovery can predict racehorse success. Speed (categorised as 'slow' to 'fast' according to the time taken to cover the last 600 m from a virtual finish line) and heart rate recovery (from gallop to 1 min after exercise) of flat racehorses (n = 485) of varying age, sex and type according to distance (e.g., sprinter, miler and stayer) were obtained using a fitness tracker from a single racing yard in Australia. Race-pace training sessions on turf comprised 'fast gallop' (n = 3418 sessions) or 'jumpout' (n = 1419). A posteriori racing information (n = 3810 races) for all 485 racehorses was extracted and combined with training data. Race performance was categorised as win/not-win or podium or not, each analysed by logistic regression. Colts (p < 0.001), stayers (p < 0.001) and being relatively fast over the last 600 m of a benchmark test in training (p < 0.008) were all predictive of race performance. Heart rate recovery after exercise (p = 0.21) and speed recorded at 600 m of a 1 km benchmark test in training (p = 0.94) were not predictive. In-training physiological data analytics used along with subjective experience may help trainers identify promising horses and improve decision-making.

Nutritional Quality and Socio-Ecological Benefits of Mare Milk Produced under Grazing Management.

This review discusses the scientific evidence that supports the nutritional value of mare milk and how its properties are essentially achieved when mares are managed under grazing conditions. Mare milk's similarity with the chemical composition of human milk makes this food and its derived products not only suitable for human consumption but also an interesting food regarding human health. The contribution of horse breeding under grazing management to other socio-ecological benefits generated by equine farms is also highlighted. Both the high added value of mare milk and the socio-ecological benefits derived from pasture-based systems could be explored to improve the performance of equine farms located in arid and semi-arid areas or in regions with moderately harsh environmental conditions as equids have a strong adaptation capacity.

The Management of Xylazine Overdose With Naloxone.

This article discusses a rare case of isolated xylazine overdose in a human, treated successfully with naloxone. Xylazine, typically used as a veterinary tranquilizer, acts as a potent α2 adrenergic agonist, leading to sedation, muscle relaxation, and potential respiratory depression. In this case, a female mistakenly injected herself with xylazine mistaking it for a different medication. The report discusses naloxone's role beyond opioid overdose, especially regarding substances causing central nervous system (CNS) depression via mechanisms similar to those of opioids. While naloxone is traditionally associated with opioid receptor antagonism, its successful application here suggests potential benefits against non-opioid substances such as xylazine. The report emphasizes the need for higher naloxone dosages than those used for opioid toxicity and suggests more research into its use for treating xylazine intoxication, reflecting on the growing trend of xylazine as a recreational drug adulterant and the resulting health risks.

Dexmedetomidine preconditioning reduces ischaemia-reperfusion injury in equine model of large colon volvulus.

BACKGROUND: Large colon volvulus is a cause of colic in horses with high morbidity and mortality when not promptly treated. More treatment options are needed to improve the outcome of these cases by protecting against the damage caused by ischaemia and reperfusion injury. OBJECTIVES: To determine the effect of preconditioning with dexmedetomidine prior to induction of ischaemia-reperfusion (IR) injury in a large colon volvulus model in the horse. STUDY DESIGN: Randomised blinded in vivo experiments. METHODS: Horses received either a dexmedetomidine (DEX) or saline (CON) constant rate infusion (CRI) immediately following induction of anaesthesia. Venous, arterial, and transmural occlusion of a section of the large colon was performed for 3 h, after which the ligatures and clamps were removed to allow for reperfusion for 3 h. Biopsies of the large colon were taken at baseline, 1 and 3 h of ischaemia, and at 1 and 3 h of reperfusion. RESULTS: The severity of crypt epithelial loss (DEX = 2.1 [0.8-2.8], CON = 3.1 [2.5-4], p = 0.03) and mucosal haemorrhage was decreased (DEX = 2.1 [1.3-3], CON = 3.5 [2.5-4], p = 0.03) in group DEX compared to group CON when graded on a scale of 0-4. Crypt length remained longer (DEX = 369.5 ± 91.7 µm, CON = 238.5 ± 72.6 µm, p = 0.02) and interstitium to crypt (I:C) ratio remained lower (DEX = 1.4 (1-1.7), CON = 2.6 [1.8-5.9], p = 0.03) in group DEX compared to group CON during reperfusion. MAIN LIMITATIONS: Clinical applicability of pharmacologic preconditioning is limited. CONCLUSION: Preconditioning with a dexmedetomidine CRI prior to IR injury demonstrated a protective effect histologically on the large colon in the horse. Further investigation into postconditioning with dexmedetomidine is warranted as a possible intervention in colic cases suspected of being large colon volvulus.

Equine herpesvirus type 1 (EHV-1) replication at the upper respiratory entry site is inhibited by neutralizing EHV-1-specific IgG1 and IgG4/7 mucosal antibodies.

Equine herpesvirus type 1 (EHV-1) is a contagious respiratory pathogen that infects the mucosa of the upper respiratory tract (URT). Mucosal immune responses at the URT provide the first line of defense against EHV-1 and are crucial for orchestrating immunity. To define host-pathogen interactions, we characterized B-cell responses, antibody isotype functions, and EHV-1 replication of susceptible (non-immune) and clinically protected (immune) horses after experimental EHV-1 infection. Nasal secretion and nasal wash samples were collected and used for the isolation of DNA, RNA, and mucosal antibodies. Shedding of infectious virus, EHV-1 copy numbers, viral RNA expression, and host B-cell activation in the URT were compared based on host immune status. Mucosal EHV-1-specific antibody responses were associated with EHV-1 shedding and viral RNA transcription. Finally, mucosal immunoglobulin G (IgG) and IgA isotypes were purified and tested for neutralizing capabilities. IgG1 and IgG4/7 neutralized EHV-1, while IgG3/5, IgG6, and IgA did not. Immune horses secreted high amounts of mucosal EHV-1-specific IgG4/7 antibodies and quickly upregulated B-cell pathway genes, while EHV-1 was undetected by virus isolation and PCR. RNA transcription analysis reinforced incomplete viral replication in immune horses. In contrast, complete viral replication with high viral copy numbers and shedding of infectious viruses was characteristic for non-immune horses, together with low or absent EHV-1-specific neutralizing antibodies during viral replication. These data confirm that pre-existing mucosal IgG1 and IgG4/7 and rapid B-cell activation upon EHV-1 infection are essential for virus neutralization, regulation of viral replication, and mucosal immunity against EHV-1.IMPORTANCEEquine herpesvirus type 1 (EHV-1) causes respiratory disease, abortion storms, and neurologic outbreaks known as equine herpes myeloencephalopathy (EHM). EHV-1 is transmitted with respiratory secretions by nose-to-nose contact or via fomites. The virus initially infects the epithelium of the upper respiratory tract (URT). Host-pathogen interactions and mucosal immunity at the viral entry site provide the first line of defense against the EHV-1. Robust mucosal immunity can be essential in protecting against EHV-1 and to reduce EHM outbreaks. It has previously been shown that immune horses do not establish cell-associated viremia, the prerequisite for EHM. Here, we demonstrate how mucosal antibodies can prevent the replication of EHV-1 at the epithelium of the URT and, thereby, the progression of the virus to the peripheral blood. The findings improve the mechanistic understanding of mucosal immunity against EHV-1 and can support the development of enhanced diagnostic tools, vaccines against EHM, and the management of EHV-1 outbreaks.

Carbonate buffer mixture and fecal microbiota transplantation hold promising therapeutic effects on oligofructose-induced diarrhea in horses.

Diarrhea is a common gastrointestinal disorder in horses, with diet-induced diarrhea being an emerging challenge. This study aimed to investigate the gut microbiota differences in healthy and diet-induced diarrheic horses and evaluate the effectiveness of fecal microbiota transplantation (FMT) and carbonate buffer mixture (CBM) as potential therapeutic approaches. Twenty healthy horses were included in the study, with four groups: Control, Diarrhea, CBM, and FMT. Diarrhea was induced using oligofructose, and fecal samples were collected for microbiota analysis. FMT and CBM treatments were administered orally using donor fecal matter, and formula mixture, respectively. Clinical parameters, serum levels, intestinal tissue histopathology, and fecal microbiota profiles were evaluated. The results showed that diarrhea induction disbalanced the gut microbiota with decreased diversity and richness, affected clinical parameters including elevated body temperature and diarrhea score, and decreased fecal pH, increased inflammatory responses such as increased serum LPS, IL-17A, lactic acid and total protein, and caused damage in the colon tissue. CBM and FMT treatments altered the gut microbiota composition, restoring it towards a healthier profile compared to diarrheic, restored the gut microbiota composition to healthier states, improved clinical symptoms including decreased body temperature and diarrhea score, and increased fecal pH, decreased inflammatory responses such as increased serum LPS, IL-17A, lactic acid and total protein, and repaired tissue damage. CBM and FMT Spearman correlation analysis identified specific bacterial taxa associated with host parameters and inflammation. FMT and CBM treatments showed promising therapeutic effects in managing oligofructose-induced diarrhea in horses. The findings provide valuable insights into the management and treatment of diarrhea in horses and suggest the potential of combined CBM and FMT approaches for optimal therapeutic outcomes.

Radiological measurements of the feet of normal Straight Egyptian Arabian horses in Qatar.

The Arabian horse has been identified as carrying a risk locus for equine metabolic syndrome, predisposing this breed to development of laminitis. Radigraphy of the equine foot is widely considered the main diagnostic imaging technique for evaluation of the laminitic horse. Knowledge of 'normal' breed values allows assessment of the degree and severity of radiological changes associated with laminitis. The objective of this study was to investigate the normal values for radiological measurements of the feet of the Straight Egyptian Arabian horse in Qatar. The design was a clinical prospective study. Radiographs of the fore and hind feet of 10 clinically normal adult Straight Egyptian Arabian horses were taken. On the lateromedial views, 17 measurements were taken (13 distances and four angles). On the horizontal dorsopalmar/plantar views, two measurements were taken. On the dorsal 45 degree, proximo-palmarodistal oblique projections, four measurements were taken. Normal reference ranges were reported for radiological measurements of the feet of the Straight Egyptian Arabian horse. Several variables showed significant differences between fore and hind feet, including hoof angle, distal wall thickness, and two proximal inner layer measurements (p < 0.05). In addition, the Straight Egyptian Arabian horse was found to have a number of measurements which varied from previously published reports. The results reported within provide a useful reference for normal radiographic measurements of the Straight Egyptian Arabian horse with relevance for laminitis.

Monoclonal antibody development advances immunological research in horses.

Host immune analyses require specific reagents to identify cellular and soluble components of the immune system. These immune reagents are often species-specific. For horses, various immunological tools have been developed and tested by different initiatives during the past decades. This article summarizes the development of well characterized monoclonal antibodies (mAbs) for equine immune cells, immunoglobulin isotypes, cytokines, and chemokines.

Radiographic analysis in Thoroughbreds reveals morphological changes in healthy maturing stifle joints and possible association between subchondral lesions and femoral condyle width.

OBJECTIVE: Assess femorotibial features in foals with and without medial femoral condyle (MFC) subchondral radiolucencies (SR+ and SR-). METHODS: 3 independent, sequential radiographic studies were performed. Study 1 retrospectively measured femorotibial morphological parameters in repository radiographs (SR- and SR+). Study 2 qualitatively compared drawings of intercondylar notch shape in postmortem radiographs (SR-). Study 3 prospectively measured femorotibial parameters in 1-month-old foals (SR-). In studies 1 and 3, 13 morphologic parameters were measured. Limb directional asymmetry was assessed in 2 age groups (< 7 or ≥ 7 months). RESULTS: Study 1 (SR- group; n = 183 radiographs) showed increased femoral measurements with maturation, except the distal femoral intercondylar notch width (FINwal), which decreased. In contrast, in SR+ stifles (53 radiographs), 3 femoral parameters (MFC width [MFCwpf], MFC height, or FINwal) showed no changes. Tibial plateau width alone increased with maturation in both groups. Interobserver reliability was good to excellent. Study 2 (n = 53 radiographs) confirmed a distal FINw decrease in SR- foals. In study 1, left SR- stifles in greater than or equal to 7-month-old fillies had significantly larger femoral bicondylar width and FINw, while right SR+ stifles in fillies greater than or equal to 7 months had a significantly larger MFCw. In study 3 of 1-month-old foals (n = 94 SR- radiographs), the MFCw, femoral condyle bicondylar width, and lateral femoral condyle height were all greater on the left, whereas the intercondylar intereminence space width was larger on the right. CLINICAL RELEVANCE: In SR+ stifles, the distal femur exhibited divergent maturation, indicating a wider MFC in the right stifle in older foals. As SR lesions are more common on the right, this suggests a potential association with MFC morphology.

Nanolevel of detection of ascorbic acid using horse-radish peroxidase inhibition assay.

Ascorbic acid plays a significant role in regulation of various bodily functions with high concentrations in immune cells and being involved in connective tissue maintenance. Commonly it is detected through various colorimetric methods. In this study, we propose a one-step simple method based on the inhibitory activity of ascorbic acid on horseradish peroxidase and hydrogen peroxide. The detection is observed by colorimetric changes to TMB (3,3',5,5' tetramethylbenzidine). The enzyme inhibition unit was optimized with a high level of linearity (r2 = 0.9999) and the level of detection and level of quantification were found to be 1.35 nM and 4.08 nM, respectively with higher sensitive compared to the HPLC method (11 µM). Both intra and inter-assays showed high correlations at different AA concentrations. (r2 > 0.9999). Similar results were also observed for vitamin C tablets, ascorbate salts, fruits, and market products (r2 = 0.999). There was negligible effect of interference by citric acid, lactic acid, tartaric acids, and glucose with high recoveries (>98%) at 1 mg/mL to 0.0078 mg/mL concentration ranges. The recovery error (RE%) was found to be less than 10%. Our detection method is distinguished by its simplicity, nano-level of detection, reproducibility, and potential application and adaptability as a point-of-use test.

Isolation and molecular identification of Leptospira santarosai and Leptospira interrogans in equines from eastern Mexico.

Leptospirosis is an infectious disease with a worldwide distribution, which represents a major challenge in animal production across developing countries, mainly in tropical areas. Horses are particularly susceptible to the disease, presenting manifestations ranging from subclinical to the development of uveitis that compromises the visual health of the animals. In recent years, serological studies have been carried out in equid populations from America, demonstrating high exposure. For this reason, the aim of this study was to demonstrate microbiologically and molecularly the presence of the members of the genus Leptospira in urine samples from equids in an endemic state of leptospirosis in Mexico, and to detect the serological presence of anti-Leptospira antibodies in the sampled animals. For this reason, blood and urine samples were collected from 28 horses and one mule from three localities in the state of Veracruz, Mexico. Urine samples were inoculated in Ellinghausen-McCullough-Johnson-Harris (EMJH) medium, and the recovered isolates were typed using a short Multi Locus Sequence Typing scheme. Amplifications of the expected size were subjected to sequencing, and the recovered sequences were compared with those of reference deposited in GenBank using the BLAST tool. To identify their phylogenetic position, we performed a phylogenetic reconstruction using the maximum likelihood method. Additionally, Microscopic Agglutination test was performed on the serum samples to identify anti-Leptospira antibodies. We recovered 16 urine isolates which tested positive for the presence of Leptospira DNA. The phylogenetic reconstruction and the MLST analysis confirmed the presence of several genotypes of Leptospira interrogans and Leptospira santarosai. An overall serological frequency of 97.1% was detected. Our results represent the first record of the presence of Leptospira through bacteriological isolates in equids from Mexico.

Molecular cytogenetic screening of sex chromosome abnormalities in young horse populations.

BACKGROUND: Chromosomal abnormalities occur in the equine population at a rate of approximately 2%. The use of molecular cytogenetic techniques allows a more accurate identification of chromosomal abnormalities, especially those with a low rate of abnormal metaphases, demonstrating that the actual incidence in equine populations is higher. OBJECTIVES: Estimation of the number of carriers of karyotypic abnormalities in a sample from a population of young horses of various breeds, using molecular cytogenetic techniques. STUDY DESIGN: Cross-sectional. METHODS: Venous blood samples were collected from 500 young horses representing 5 breeds (Purebred Arabian, Hucul, Polish primitive horse [Konik], Malopolska, Coldblood, Silesian). Chromosomes and DNA were obtained from blood lymphocytes and evaluated by fluorescence in situ hybridisation (FISH) and PCR, using probes and markers for the sex chromosomes and select autosomes. RESULTS: Nineteen horses, 18 mares and 1 stallion, were diagnosed with different chromosomal abnormalities: 17 cases of mosaic forms of sex chromosome aneuploidies with a very low incidence (0.6%-4.7%), one case of a SRY-negative 64,XY sex reversal mare, and one mare with X-autosome translocation. The percentage of sex chromosomal aberrations was established as 3.8% in the whole population, 6.08% in females and 0.49% in males. MAIN LIMITATIONS: Limited sample size, confined to horses from Poland. CONCLUSIONS: The rate of sex chromosomal abnormalities we identified was almost double that reported in previous population studies that used classical chromosome staining techniques. FISH allowed the detection of aneuploid cell lines which had a very low incidence. The FISH technique is a faster and more precise method for karyotype examination; however, it is usually focused on only one or two chromosomes while banding karyotyping includes the entire chromosome set.

The application of a single session of capacitive resistive electric transfer 24 h before exercise modifies the accelerometric pattern in standardbred racing trotters.

BACKGROUND: It has been reported that capacitive resistive electric transfer (CRET) increases blood circulation, hemoglobin oxygenation and temperature in muscles. The attributed benefits of these changes have been linked to improved athletic performance, enhanced muscle flexibility and fastening recovery from exercise-induced fatigue. For all of this, the present research aims to investigate whether the application of CRET 24 h before exercise affects the accelerometric pattern in horses during exercise. Six sound Standardbred trotters were subjected to a CRET session of 40 min of duration, applied on both sides of the neck, back and croup, 24 h before a training session. Training sessions consisted of a warming-up (WU) for 6400 m and a training bout (TB) at their maximal training speed for 1600 m. The same protocol was followed for the device off (sham protocol), also applied 24 h before the training session. CRET and sham experiments were separated by one week, the order of application of both was randomly defined for each individual and drivers were blinded for the duration of the experiment. During the training sessions, horses wore an accelerometer fixed at the sternal level. Speed, stride frequency (SF), length (SL), regularity and symmetry and accelerometric activities were measured during WU and TB. RESULTS: CRET increased speed, mediolateral and total accelerometric activities during WU and speed, SL, dorsoventral, longitudinal and total accelerometric activities during TB, but stride regularity and symmetry decreased. CONCLUSION: The application of CRET 24 h before exercise increased speed and accelerometric activities, results that highlight the need to evaluate the interaction between CRET and training in order to develop new methods to limit fatigue. However, the decrease in stride regularity and symmetry after CRET application could be negative effects, which could be attributed to the increased speed.

Comparison of Xylazine and Lidocaine Infusion versus Medetomidine Continuous Rate Infusion during General Anesthesia with Isoflurane in Horses Undergoing Emergency Laparotomy.

(1) The main goals of general anesthesia include pain management and a safe anesthetic protocol for smooth recovery. In this retrospective study, we compared two anesthetic protocols for general anesthesia with isoflurane during emergency laparotomy: sedation with xylazine and the intraoperative infusion of lidocaine (X group) versus medetomidine as a preoperative sedation and intraoperative infusion (M group). (2) The medical records of horses who underwent emergency laparotomies between 2016 and 2023 were reviewed. According to the anesthetic protocol, patients were allocated to the X or M groups. Data about the horse, signalment, history, and anesthetic variables were analyzed. (3) Group X had a significantly higher heart rate (HR), lower respiratory rate (RR) and mean and diastolic arterial pressure (MAP/DAP). A progressive increase in HR and RR was observed in both groups. Group X underwent a decrease in RR and an increase in DAP. In Group M, a decrease in MAP and DAP was observed. Group M exhibited a longer recovery time with similar recovery scores. Both protocols provided safe anesthesia for emergency laparotomy, with minor cardiovascular and respiratory depression. Minor respiratory depression was detected when xylazine was used, while recovery was longer with medetomidine.

Numerical evaluation of internal femur osteosynthesis based on a biomechanical model of the loading in the proximal equine hindlimb.

Femoral fractures are often considered lethal for adult horses because femur osteosynthesis is still a surgical challenge. For equine femur osteosynthesis, primary stability is essential, but the detailed physiological forces occurring in the hindlimb are largely unknown. The objective of this study was to create a numerical testing environment to evaluate equine femur osteosynthesis based on physiological conditions. The study was designed as a finite element analysis (FEA) of the femur using a musculoskeletal model of the loading situation in stance. Relevant forces were determined in the musculoskeletal model via optimization. The treatment of four different fracture types with an intramedullary nail was investigated in FEA with loading conditions derived from the model. The analyzed diaphyseal fracture types were a transverse (TR) fracture, two oblique fractures in different orientations (OB-ML: medial-lateral and OB-AP: anterior-posterior) and a "gap" fracture (GAP) without contact between the fragments. For the native femur, the most relevant areas of increased stress were located distally to the femoral head and proximally to the caudal side of the condyles. For all fracture types, the highest stresses in the implant material were present in the fracture-adjacent screws. Maximum compressive (-348 MPa) and tensile stress (197 MPa) were found for the GAP fracture, but material strength was not exceeded. The mathematical model was able to predict a load distribution in the femur of the standing horse and was used to assess the performance of internal fixation devices via FEA. The analyzed intramedullary nail and screws showed sufficient stability for all fracture types.

Knowledge and perception of equine ticks and tick-borne diseases of Pennsylvania horse owners and caretakers.

There is limited data on current knowledge of Pennsylvania horse caretakers on tick-borne diseases (TBDs), tick identification, and tick management practices. This study aimed to determine tick knowledge, concern, and management among Pennsylvania equine caretakers using an online survey. Descriptive statistics and one-way ANOVA tests were used to analyze data. The survey received 894 responses (539 completed) from Pennsylvania equine owners and caretakers. The largest proportion of respondents cared for 3-5 horses (31%), followed by 2 horses (27%). Veterinarian-confirmed diagnosis rates of two TBDs, Lyme disease and anaplasmosis, were 38% and 22%, respectively. Most respondents (39%) were moderately confident in recognizing Lyme disease, while most (44%) were not confident at all in recognizing anaplasmosis. Most respondents (69%) were either extremely or very concerned about their horses contracting any TBDs. Tick bite and TBD prevention methods used by equine caretakers included performing tick checks, using on-animal repellents, and conducting pasture/landscape management. Ten knowledge-based questions were asked, and the mean correct score was 3.97 ± 2.18 out of 10 possible points. There were significant positive associations between higher knowledge scores and previous veterinarian-confirmed equine Lyme disease diagnosis, higher concern level of TBDs, and higher frequency of tick checks. With increased equine TBD prevalence and high levels of horse owner concern about TBD, Extension educators should focus on teaching about TBDs and managing ticks on horses and farms.

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.