The fertilization of oocytes ovulated by pigs, sheep, cows, and horses is not considered a limiting factor in successful establishment of pregnancy. Pig, sheep, and cow embryos undergo cleavage to the blastocyst stage, hatch from the zona pellucida, and undergo central-type implantation. Hatched blastocysts of pigs, sheep, and cows transition from tubular to long filamentous forms to establish surface area for exchange of nutrients and gases with the uterus. The equine blastocyst, surrounded by external membranes, does not elongate but migrates throughout the uterine lumen before attaching to the uterine luminal epithelium (LE) to begin implantation. Pregnancy recognition signaling in pigs requires the trophectoderm to express interleukin 1 beta, estrogens, prostaglandin E2, and interferon gamma. Sheep and cow conceptus trophectoderm expresses interferon tau that induces interferon regulatory factor 2 that inhibits transcription of estrogen and oxytocin receptors by uterine epithelia. This prevents oxytocin-induced luteolytic pulses of prostaglandin F2-alpha from regressing the corpora lutea, as well as ensuring the secretion of progesterone required for maintenance of pregnancy. The pregnancy recognition signal produced by equine blastocysts is not known. Implantation in these species requires interactions between extracellular matrix (ECM) proteins and integrins as the conceptus undergoes apposition and firm attachment to the uterine LE. This review provides details with respect to early embryonic development and the transition from spherical to filamentous conceptuses in pigs, sheep, and cows, as well as pre-implantation development of equine blastocysts and implantation of the conceptuses.

The aim of the present study was to investigate eye temperature modifications after road transport in athletic horses habituated to travel. Eight adult Italian saddle horses traveled 100 km and, two weeks later, 300 km. Eye temperature (ET), rectal temperature (RT) and serum cortisol concentration were assessed before (T1), after (T2) and 60 min (T3) after the road transport. ET was evaluated with infrared thermography (IRT) in three regions of interest: EL1 (medial canthus), EL2 (central cornea) and EL3 (lateral canthus). Two-way analysis of variance (ANOVA) for repeated measures showed statistically higher values at T2 and T3 for EL1 (p < 0.01), EL2 (p < 0.01) and EL3 (p < 0.01) following the 100 km journey. RT (p < 0.01) showed higher values at T2 and T3 after the 100 km journey and higher values at T2 (p < 0.01) following the 300 km journey. ET values were positively correlated with RT at T1, T2 and T3 following the 100 km journey and at T2 following the 300 km journey and positively correlated with serum cortisol concentration at T1, T2 and T3 following the 100 km journey and at T2 and T3 following the 300 km journey. Eye temperature monitoring with IRT allows quick and practical strategies to monitor an animal\'s physiological state and welfare during daily activities.

BACKGROUND: The pleiotropic effects of the melanocortin system show promise in overcoming limitations associated with large variations in opioid analgesic effectiveness observed in equine practice. Of particular interest is variation in the melanocortin-1-receptor (MC1R) gene, which dictates pigment type expression through its epistatic interaction with the agouti signalling protein (ASIP) gene. MC1R has previously been implicated in opioid efficacy in other species; however, this relationship is yet to be explored in horses. In this study, analgesic effectiveness was scored (1-3) based on noted response to dura penetration during the performance of cerebrospinal fluid centisis after sedation and tested for association with known genetic regions responsible for pigmentation variation in horses.
RESULTS: The chestnut phenotype was statistically significant (P < 0.05) in lowering analgesic effectiveness when compared to the bay base coat colour. The 11bp indel in ASIP known to cause the black base coat colour was not significant (P>0.05); however, six single nucleotide polymorphisms (SNPs) within the genomic region encoding the ASIP gene and one within MC1R were identified as being nominally significant (P<0.05) in association with opioid analgesic effectiveness. This included the location of the known e MC1R variant resulting in the chestnut coat colour.
CONCLUSIONS: The current study provides promising evidence for important links between pigmentation genes and opioid effectiveness in horses. The application of an easily identifiable phenotype indicating variable sensitivity presents a promising opportunity for accessible precision medicine in the use of analgesics and warrants further investigation.

OBJECTIVE: To describe the treatment of subcutaneous lipomas in the horse.
METHODS: 3 horses.
METHODS: The horses were aged 1 to 2 years old, with lipoma of the abdomen, prepuce, and tarsus.
RESULTS: Recurrence of an invasive thoracic lipoma occurred in case 1 at the exit site of a passive drain. The recurrence was treated unsuccessfully with injectable cisplatin, and a second revision surgery with the use of an active drain resulted in resolution. In case 2, complete resection of an encapsulated lipoma of the lateral prepuce was successful with no recurrence. In case 3, incomplete resection of a tarsal lipoma resulted in a sound horse, with no further growth. Histopathologic analysis revealed that all masses were composed of well-differentiated adipocytes with no evidence of malignancy.
CONCLUSIONS: Subcutaneous lipomas are relatively rare and affect horses ≤ 2 years of age. They are benign, although their presence can be deleterious due to invasion of local structures or the impact on normal locomotion. Invasive tumors are difficult to identify margins due their integration with normal tissue. Incomplete removal may allow for mass recurrence. Active suctions drains are beneficial if dead space is a concern..

BACKGROUND: Prioritising equine welfare, making evidenced-based policy, and consistent decision-making across sports are crucial to maintaining the social licence for equestrian sport. Regulations on the use of omeprazole during competition differ; all regulators argue that their rules prioritise welfare. This discrepancy is a matter of concern to the public and equestrian stakeholders.
OBJECTIVE: To apply Campbell\'s Ethical Framework for the use of Horses in Sport to the question: \'Should the use of omeprazole be allowed during equestrian competition?\'
METHODS: A desk-based ethico-legal study.
METHODS: Campbell\'s Ethical Framework for the Use of Horses in Sport was applied in a stepwise fashion: definition of the ethical question; analysis of the evidence base; consideration of stakeholders\' interests; harm:benefit analysis; application of the three central tenets of the framework, and formulation of conclusions and recommendations.
RESULTS: Stakeholders in equine sports have a variety of (frequently conflicting) interests; all of them share an interest in optimising equine welfare. The incidence of EGUS in competition horses is high. Omeprazole is a cornerstone treatment. There are currently discrepancies in regulation about the use of omeprazole during competitions. Recent evidence suggests that withholding omeprazole treatment for two clear days before competition allows the recurrence of squamous EGUS, whereas withholding treatment on the day of competition only does not have that effect.
CONCLUSIONS: The current state of scientific knowledge about the use of omeprazole in horses. The analysis did not consider possible health and thus welfare effects of the out-of-competition treatment with omeprazole.
CONCLUSIONS: Based on recent scientific evidence, if horses are being treated with omeprazole outside of competition then treatment on the day of competition should be permitted on welfare grounds. Revision of regulations around the use of omeprazole during competition by governing bodies is necessary to safeguard the ethical use of horses in sport.
UNASSIGNED: Priorizar o bem‐estar equino, elaborar políticas baseadas em evidências e tomar decisões consistentes em todos os esportes são cruciais para manter a licença social para o esporte equestre. As regulamentações sobre o uso de omeprazol durante a competição diferem; todos os reguladores argumentam que suas regras priorizam o bem‐estar. Essa discrepância é motivo de preocupação para o público.
OBJECTIVE: Aplicar o Modelo Ético de Campbell para o Uso de Cavalos em Esportes1 à pergunta: ‘Deve o uso de omeprazol ser permitido durante a competição equestre?’ DESENHO DO ESTUDO: Um estudo ético‐legal baseado em pesquisa documental.
METHODS: O Modelo Ético de Campbell para o Uso de Cavalos em Esportes1 foi aplicado de forma gradual: definição da questão ética; análise da base de evidências; consideração dos interesses do público alvo; uma análise de dano:benefício; aplicação dos três princípios centrais do modelo; e formulação de conclusões e recomendações.
RESULTS: O público de esporte equino têm uma variedade de interesses (frequentemente conflitantes), enquanto todos compartilham o interesse em otimizar o bem‐estar equino. A incidência de EGUS (Síndrome da Úlcera Gástrica Equina) em cavalos de competição é alta, a qual o omeprazol é um tratamento fundamental. Atualmente, há discrepâncias na regulamentação sobre o uso de omeprazol durante competições. Evidências recentes sugerem que a suspensão do tratamento com omeprazol por 2 dias antes da competição permite a recorrência da EGUS da porção escamosa, enquanto a suspensão do tratamento apenas no dia da competição não tem esse efeito. PRINCIPAIS LIMITAÇÕES: O estado atual do conhecimento científico sobre o uso de omeprazol em cavalos. A análise não considerou possíveis efeitos sobre a saúde e, portanto, sobre o bem‐estar do tratamento com omeprazol fora da competição. CONCLUSÕES: Com base em evidências científicas recentes, se os cavalos estão sendo tratados com omeprazol fora da competição, o tratamento no dia da competição deve ser permitido por razões de bem‐estar. A revisão das regulamentações sobre o uso de omeprazol durante a competição pelos órgãos reguladores é necessária para salvaguardar o uso ético dos cavalos no esporte.

BACKGROUND: Castration is the most common surgical procedure in domesticated equids; surgical techniques used and perioperative management vary considerably.
OBJECTIVE: To identify and chart the current evidence on perioperative complications associated with different methods of surgical castration in domesticated equids.
METHODS: Joanna Briggs Institute systematic scoping review.
METHODS: CAB Abstracts, Medline and Embase databases were searched using terms related to equine castration complications. Two authors independently and blindly screened publications against eligibility criteria. Data on study methods, perioperative management, surgical techniques, and perioperative complications were extracted. Surgical techniques were grouped into categories depending on technique; open, closed or half-closed, and whether the parietal tunic was open or closed at the end of surgery.
RESULTS: The search identified 1871 publications; 71 studies met the final inclusion criteria. The data reported 76 734 castrations, most of which were open or closed, with the vaginal tunic remaining open at the end of surgery. Twenty-five studies reported information regarding surgical techniques and perioperative management, allowing detailed charting and comparisons, of which analgesia and antimicrobial usage varied notably. Eighteen different complications were reported, with swelling or oedema being the most common. Evisceration was most commonly reported in draught breeds and Standardbreds, and the risk appeared low if the parietal tunic was closed at the end of surgery.
CONCLUSIONS: Grey literature and studies not available in English were not included. Existing studies varied greatly in perioperative management, surgical techniques and reporting of outcomes, making evidence consolidation problematic.
CONCLUSIONS: A lack of consensus regarding complication definitions creates uncertainty and discrepancies between complication rates associated with different surgical techniques and perioperative management. The implementation of standardised systems for describing surgical techniques and complications is recommended for future studies. A number of studies did not follow current recommendations for perioperative analgesia and use of antimicrobials.

Defining the optimal therapy for endometritis remains a significant challenge for clinicians. Given the public health threat posed by antibiotic resistance and the inconclusiveness of traditional therapies, regenerative medicine has been proposed as an alternative. The objective of this study was to conduct a comprehensive systematic review and meta-analysis, to investigate the efficacy of regenerative medicine products in the treatment of both post-breeding persistent and chronic degenerative endometritis (PBIE/CDE) in mares, following the PRISMA guidelines. This research could be a comprehensive scientific reference for determining appropriate treatments and clinical strategies. All studies exploring the use of regenerative medicine therapies (i.e., plasma products, autologous conditioned serum, mesenchymal stem cells MSCs, and MSC derivatives) in the treatment of PBIE/CDE were included, regardless of the specific protocol used, the evaluated outcomes, or the diagnostic method employed. Two authors independently gathered data and evaluated the risk of bias for each study. Treatment effects were assessed using risk ratios for dichotomous data, accompanied by 95 % confidence intervals. Data were aggregated utilizing the fixed-effects model. The quality of evidence for each outcome was evaluated using GRADE criteria. Eighteen studies were included in the systematic review, while fifteen trials were included in the meta-analysis. A sub-meta-analysis was conducted separately on platelet-derived products, as well as on MSCs and their derivatives. The results demonstrated an overall positive effect of regenerative therapies in treating PBIE/CDE, particularly those involving MSCs and their derivatives. The positive outcomes include an anti-inflammatory effect, characterized by reduced intrauterine fluid accumulation, neutrophils, and cytokine concentrations. Additionally, improvements in pregnancy, foaling, and embryo recovery rates have been observed in some cases. Despite the limited number of randomized controlled studies and the high variability among protocols, including the timing of treatment, type, and volume of products used, the use of regenerative products, especially MSCs and their derivatives, has promising results in terms of both efficacy and safety for treating PBIE/CDE in mares.

BACKGROUND: Cervical articular process joint (CAPJ) therapy is advocated for horses with neck disorders. Several ultrasound-guided CAPJ techniques have been described in cadaver studies with 72%-89% intra-articular injection accuracy; however, the CAPJ injection accuracy in clinical equine practice has not been extensively reported.
OBJECTIVE: To describe a modified cranial approach for ultrasound-guided caudal CAPJ injections, to investigate the accuracy of this CAPJ injection technique in live horses, and to assess the effect of CAPJ injection location, laterality, operator, and radiographic CAPJ enlargement on injection accuracy.
METHODS: Retrospective case study.
METHODS: Medical records of adult horses in which ultrasound-guided caudal (C4-T1) CAPJ injections were performed using a modified cranial approach between November 2006 and December 2020 were reviewed. Radiographic images of caudal cervical vertebrae were assessed by a blinded radiologist and the degree of CAPJ enlargement was graded using a previously described grading system (Rgrade 1-5b). Ultrasound-guided caudal CAPJ injection accuracy was determined by synovial fluid retrieval during an individual CAPJ injection. Statistical analysis was performed using mixed-effects multivariable logistic model to evaluate the association of CAPJ injection accuracy and the CAPJ injection location, Rgrade, laterality (right, left), and operator.
RESULTS: The study included 149 horses with 177 hospital admissions. Synovial fluid was obtained from 586/658 (89.1%) caudal CAPJs using modified cranial ultrasound-guided approach for CAPJ injections. C6-C7 CAPJ injections had 7-fold higher likelihood (OR = 6.78, 95% CI: 1.67-27.52; p = 0.007) of synovial fluid retrieval compared with C4-C5 CAPJ injections. Operator, CAPJ injection side (left, right), and degree of radiographic CAPJ enlargement did not have significant effects on the success of synovial fluid retrieval from ultrasound-guided caudal CAPJ injections.
CONCLUSIONS: Retrospective study design.
CONCLUSIONS: Intra-articular ultrasound-guided caudal CAPJ injections using a modified cranial approach can be performed accurately in live horses with and without CAPJ arthropathy.
摘要 背景: 开始提倡颈椎关节突关节(CAPJ)治疗用于马的颈部疾病。几种超声引导的CAPJ技术已经在尸体研究中宣称有72‐89%的关节内注射准确率，但是临床活马实践中的CAPJ注射准确率尚未有广泛报道。. 目的: 描述一种改进的前侧入路，用于超声引导下的尾侧CAPJ注射，研究这种CAPJ注射技术在活马体内的准确性，并评估CAPJ注射位置、侧边、操作人员和影像学CAPJ扩大对注射精度的影响。. 研究设计: 回顾性案例研究. 方法: 回顾了2006年11月至2020年12月间，采用改良前侧入路对成年马进行超声引导尾侧(C4‐T1) CAPJ注射的医疗记录。由盲态放射科医师核查评估椎骨尾侧的影像学图像，并使用先前描述的分级系统(Rgrade 1‐5b)对CAPJ扩大程度进行分级。超声引导的尾侧CAPJ注射准确性是通过单个CAPJ注射时的滑液回流来确定。采用混合效应多变量logistic模型进行统计分析，评估CAPJ注射准确率与CAPJ注射位置、Rgrade、侧边度(右、左)和操作者之间的关系。. 结果: 这项研究包括了149匹马及177个住院病例。采用改良前侧超声引导入路对尾侧CAPJ进行注射，其中586/658(89.1%)有滑液回流。C6‐C7的CAPJ注射与C4‐C5注射CAPJ相比，准确率/滑液回流可能性高7倍(OR = 6.78， 95% CI: 1.67–27.52；p = 0.007)。操作人员、CAPJ注射侧(左、右)和x线片CAPJ扩大程度对超声引导下尾侧CAPJ注射滑液成功回流无显著影响。. 主要局限性: 回顾性研究设计. 结论: 超声引导下经改良前侧入路的尾侧CAPJ关节内注射可以准确地用于有或没有CAPJ关节病的活马。.

BACKGROUND: Currently, lack of standardization for fecal microbiota transplantation (FMT) in equine practice has resulted in highly variable techniques, and there is no data on the bacterial metabolic activity or viability of the administered product. The objectives of this study were to compare the total and potentially metabolically active bacterial populations in equine FMT, and assess the effect of different frozen storage times, buffers, and temperatures on an equine FMT product. Fresh feces collected from three healthy adult horses was subjected to different storage methods. This included different preservation solutions (saline plus glycerol or saline only), temperature (-20 °C or -80 °C), and time (fresh, 30, 60, or 90 days). Samples underwent DNA extraction to assess total bacterial populations (both live and dead combined) and RNA extraction followed by reverse transcription to cDNA as a proxy to assess viable bacteria, then 16s rRNA gene amplicon sequencing using the V1-V2 region.
RESULTS: The largest difference in population indices and taxonomic composition at the genus level was seen when evaluating the results of DNA-based (total) and cDNA-based (potentially metabolically active) extraction method. At the community level, alpha diversity (observed species, Shannon diversity) was significantly decreased in frozen samples for DNA-based analysis (P < 0.05), with less difference seen for cDNA-based sequencing. Using DNA-based analysis, length of storage had a significant impact (P < 0.05) on the bacterial community profiles. For potentially metabolically active populations, storage overall had less of an effect on the bacterial community composition, with a significant effect of buffer (P < 0.05). Individual horse had the most significant effect within both DNA and cDNA bacterial communities.
CONCLUSIONS: Frozen storage of equine FMT material can preserve potentially metabolically active bacteria of the equine fecal microbiome, with saline plus glycerol preservation more effective than saline alone. Larger studies are needed to determine if these findings apply to other individual horses. The ability to freeze FMT material for use in equine patients could allow for easier clinical use of fecal transplant in horses with disturbances in their intestinal microbiome.

OBJECTIVE: To optimize and evaluate methods for the detection of the inflammatory biomarkers myeloperoxidase (MPO) and calprotectin (CP) in equine feces by ELISA.
METHODS: Healthy horses (n = 28) and horses with intestinal inflammation (n = 10).
METHODS: Feces were suspended in buffer to create fecal supernatant. Serum and fecal supernatant were analyzed using ELISA kits validated for the detection of MPO and CP in equine serum. Assay validation steps included intra- and interassay variability (coefficient of variation [CV]), dilution linearity, spike recovery, and sample type correlation. Variations in sample handling protocols (centrifugation speed, extraction buffer, and filtration) were evaluated.
RESULTS: 17 paired fecal and serum samples were used for initial analysis (10 healthy horses, 7 colitis). Previously reported sample handling protocols resulted in detectable MPO and CP but poor CV, linearity, and spike recovery. There was a linear correlation between serum and fecal samples for CP but not MPO. There was a significant difference between the concentration and CV of alternative sample handling protocols for CP and MPO, with improved CV for CP (2.1% to 18.6%) but not MPO (14.4% to 53.4%). Processing fresh feces with a fecal extraction buffer and filtration of supernatant resulted in the best CV (0.5% to 3.8%) and recovery (45% to 64%) for CP. Detection of MPO was inconsistent regardless of method.
CONCLUSIONS: There are few reliable diagnostic modalities for inflammation of the equine large colon. Findings support quantification of CP in equine feces using the described ELISA kit and protocol. With additional study to establish reference interval and clinical utility, the fecal inflammatory biomarker CP may allow for noninvasive quantification of intestinal inflammation in horses.