Tissues Of Horses Research Articles

RNA-Seq analysis reveals the different mechanisms triggered by bovine and equine after infection with FMDV.

Foot-and-mouth disease virus (FMDV) is an important pathogen of the MicroRNA virus family. Infection of livestock can cause physical weakness, weight loss, reduced milk production, and a significant reduction in productivity for an extended period. It also causes a high mortality rate in young animals, seriously affecting livestock production. The host range of FMDV is mainly limited to cloven-hoofed animals such as cattle and sheep, while odd-toed ungulates such as horses and donkeys have natural resistance to FMDV. The mechanism underlying this resistance in odd-toed ungulates remains unclear. This study aimed to analyze the differences between FMDV-infected cattle and horses to provide valuable insights into the host-FMDV interaction mechanisms, thereby contributing to the control of foot-and-mouth disease and promoting the development of the livestock industry. We observed the distribution of integrins, which help FMDV enter host cells, in the nasopharyngeal tissues of cattle and horses using immunohistochemistry. Then, we employed high-throughput RNA sequencing (RNA-Seq) to study the changes in host gene expression in the nasopharyngeal epithelial tissues of cattle and horses after FMDV infection. We performed enrichment analysis of GO and KEGG pathways after FMDV infection and validated related genes through qPCR. The immunohistochemical results showed that both cattle and horses had four integrin receptors that could assist FMDV entry into host cells. The transcriptome analysis revealed that after FMDV infection, pro-apoptotic genes such as caspase-3 (CASP3) and cytochrome C (CYCS) were upregulated in cattle, while apoptosis-inhibiting genes such as NAIP and BCL2A1 were downregulated. In contrast, the expression trend of related genes in horses was opposite to that in cattle. Additionally, autophagy-related genes such as beclin 1, ATG101, ATG4B, ATG4A, ATG13, and BCL2A1 were downregulated in cattle after FMDV infection, indicating that cattle did not clear the virus through autophagy. However, key autophagy genes including ATG1, ATG3, ATG9, ATG12, and ATG16L1 were significantly upregulated in horses after viral infection. Both water buffaloes and Mongolian horses express integrin receptors that allow FMDV entry into cells. Therefore, the resistance of Mongolian horses to FMDV may result from more changes in intracellular mechanisms, including processes such as autophagy and apoptosis. Significant differences were observed between water buffaloes and Mongolian horses in these processes, suggesting that these processes influence FMDV replication and synthesis.

In search of epigenetic hallmarks of different tissues: an integrative omics study of horse liver, lung, and heart.

DNA methylation and microRNA (miRNA) expression are epigenetic mechanisms essential for regulating tissue-specific gene expression and metabolic processes. However, high-resolution transcriptome, methylome, or miRNAome data is only available for a few model organisms and selected tissues. Up to date, only a few studies have reported on gene expression, DNA methylation, or miRNA expression in adult equine tissues at the genome-wide level. In the present study, we used RNA-Seq, miRNA-seq, and reduced representation bisulfite sequencing (RRBS) data from the heart, lung, and liver tissues of healthy cold-blooded horses to identify differentially expressed genes (DEGs), differentially expressed miRNA (DE miRNA) and differentially methylated sites (DMSs) between three types of horse tissues. Additionally, based on integrative omics analysis, we described the observed interactions of epigenetic mechanisms with tissue-specific gene expression alterations. The obtained data allowed identification from 4067 to 6143 DMSs, 9733 to 11,263 mRNAs, and 155 to 185 microRNAs, differentially expressed between various tissues. We pointed out specific genes whose expression level displayed a negative correlation with the level of CpG methylation and miRNA expression and revealed biological processes that they enrich. Furthermore, we confirmed and validated the accuracy of the Next-Generation Sequencing (NGS) results with bisulfite sequencing PCR (BSP) and quantitative PCR (qPCR). This comprehensive analysis forms a strong foundation for exploring the epigenetic mechanisms involved in tissue differentiation, especially the growth and development of the equine heart, lungs, and liver.

Optimizing the preparation of paraffin sections from stallion testes.

The preparation of paraffin sections is an important experimental technique in animal histological research, and key factors that determine the quality of a section include the dehydration time, waxing time, and drying temperature of the paraffin section. Paraffin sections obtained from testis tissue of adult horses exhibited higher quality with clear tissue structure and complete cell morphology after they underwent gradient dehydration for 6 hours, were immersed in wax for 60 minutes, and were dried in a 75-degree oven for 15 minutes. The detailed, optimized procedures that are developed in the current study may simplify histological experiments and research on equine testes.

Effect of storage conditions on the quality of equine and canine mesenchymal stem cell derived nanoparticles including extracellular vesicles for research and therapy

Nanoparticles including extracellular vesicles derived from mesenchymal stem cells are of increasing interest for research and clinical use in regenerative medicine. Extracellular vesicles (EVs), including also previously named exosomes, provide a promising cell-free tool for therapeutic applications, which is probably a safer approach to achieve sufficient healing. Storage of EVs may be necessary for clinical applications as well as for further experiments, as the preparation is sometimes laborious and larger quantities tend to be gained. For this purpose, nanoparticles were obtained from mesenchymal stem cells from adipose tissue (AdMSC) of horses and dogs. The EVs were then stored for 7 days under different conditions (− 20 °C, 4 °C, 37 °C) and with the addition of various additives (5 mM EDTA, 25–250 µM trehalose). Afterwards, the size and number of EVs was determined using the nano tracking analyzing method. With our investigations, we were able to show that storage of EVs for up to 7 days at 4 °C does not require the addition of supplements. For the other storage conditions, in particular freezing and storage at room temperature, the addition of EDTA was found to be suitable for preventing aggregation of the particles. Contrary to previous publications, trehalose seems not to be a suitable cryoprotectant for AdMSC-derived EVs. The data are useful for processing and storage of isolated EVs for further experiments or clinical approaches in veterinary medicine.

Neutrophil extracellular traps and active myeloperoxidase concentrate in lamellar tissue of equids with naturally occurring laminitis

Laminitis is a pathology of the equine digit ultimately leading to a failure of the dermo-epidermal interface. Neutrophil activation is recognized as a major factor in SIRS-associated laminitis and has recently been described in induced endocrinopathic laminitis evidenced by the presence of myeloperoxidase (MPO). Neutrophil extracellular traps (NET) are released with neutrophil activation. This study aimed to investigate the presence and activity of MPO and NET in the lamellar tissue of equids presented with naturally occurring laminitis. Samples of lamellar tissue of five horses and five donkeys presented with laminitis, as well as eight control horses without laminitis, were collected. Lamellar tissue extracts were submitted to ELISA and specific immuno-extraction followed by enzymatic detection (SIEFED) assays to confirm the presence and activity of both MPO and NET. Lamellar sections were also immunohistopathologically stained for MPO and NET. Analysis of lamellar tissue extracts revealed that laminitis cases had significantly higher levels of total MPO concentration, MPO activity, and NET-bound MPO activity in comparison to control horses. Moreover, a strong correlation was identified between the activity of NET-bound MPO and the total MPO activity, which suggests that MPO activity partly originates from NET-bound MPO. Immunohistochemical staining showed that MPO and NET labelling in laminitis cases was moderate to marked, primarily in the epidermis and in inflammatory infiltrates containing neutrophils, while labelling in control horses was minimal. This article constitutes the first indication of the presence and activity of NET-bound MPO in the lamellar tissue of horses and donkeys with naturally occurring laminitis. Targeting these substances may provide new treatment possibilities for this debilitating disease.

Well-developed immunological tissue is present in the rostral oral cavity of horses as revealed by histological and immunohistochemical examination

Horses have a well-developed mucosal-associated lymphoid tissue in the naso-oropharynx for immunological defence and the development of immunological tolerance. The different components of this lymphoid tissue have been documented, but not all areas of the equine oral cavity have been investigated. In the present study, samples for histological and immunohistochemical examinations were collected from slaughtered horses of different ages, focusing on the rostral part of the oral cavity. Dense lymphatic tissue was found in the mucosa covering the bar area of the mandibles and the floor of the oral cavity, and it was present in horses of different ages. The most prominent lymphatic tissue, with large aggregates of lymph nodules, was present on either side of the lingual frenulum. The rostral location of this lymphatic tissue in horses renders support for application of antigens in allergen-specific immunotherapy via the oral mucosa.

Sex hormone-binding globulin improves lipid metabolism and reduces inflammation in subcutaneous adipose tissue of metabolic syndrome-affected horses.

Equine metabolic syndrome (EMS) is a steadily growing endocrine disorder representing a real challenge in veterinary practice. As a multifactorial condition, EMS is characterized by three main metabolic abnormalities including insulin resistance, increased adiposity or obesity and hoof laminitis. Adipose tissue dysfunction is recognized as a core pathophysiological determinant of EMS, as it strongly participates to lipotoxicity and systemic metaflammation, both of which have been closely linked to the development of generalized insulin resistance. Besides, sex hormone binding globulin (SHBG) is an important sex steroids transporters that has been recently proposed as an important metabolic mediator. Therefore, the aim of this study was to verify whether SHBG treatment may ameliorate subcutaneous adipose tissue metabolic failure under EMS condition in terms of lipidome homeostasis, lipid metabolism programs, insulin signalling and local inflammation. Subcutaneous adipose tissue (SAT) biopsies were collected post-mortem from healthy (n = 3) and EMS (n = 3) slaughtered horses. SHBG protein has been applied to SAT samples from EMS horses for 24h at a final concentration of 50nM, while control groups (healthy and untreated EMS) were cultured in the presence of SHBG-vehicle only. Tissues from all groups were afterwards secured for downstream analysis of gene expression using RT-qPCR, protein levels by Western blot and ELISA assay and lipidomics through GC-MS technique. Obtained results showcased that SHBG intervention efficiently normalized the altered fatty acids (FAs) profiles by lowering the accumulation of saturated and trans FAs, as well as the pro-inflammatory arachidonic and linoleic acids. Moreover, SHBG showed promising value for the regulation of adipocyte lipolysis and engorgement by lowering the levels of perilipin-1. SHBG exerted moderated effect toward SCD1 and FASN enzymes expression, but increased the LPL abundance. Interestingly, SHBG exhibited a negative regulatory effect on pro-adipogenic stimulators and induced higher expression of KLF3, IRF3 and β-catenin, known as strong adipogenesis repressors. Finally, SHBG protein showed remarkable ability in restoring the insulin signal transduction, IR/IRS/Pi3K/AKT phosphorylation events and GLUT4 transporter abundance, and further attenuate pro-inflammatory response by lowering IL-6 tissue levels and targeting the PDIA3/ERK axis. Overall, the obtained data clearly demonstrate the benefice of SHBG treatment in the regulation of adipose tissue metabolism in the course of EMS and provide new insights for the development of molecular therapies with potential translational application to human metabolic disorders.

Histopathological changes in the electrical conduction of cardiac nodes after acute myocardial infarction in dogs and horses, compared with findings in humans: A histological, morphometrical, and immunohistochemical study.

The heart conduction system is responsible for the occurrence of various types of cardiac arrhythmia. This study aimed to histologically and morphometrically describe damaged cardiac nodes during acute myocardial infarction and to compare them with normal tissues in dogs and horses. This study describes the morphometry of cardiac nodes in five dogs and five elderly horses that succumbed to sudden cardiac death (SCD). A computerized morphometric study was conducted to determine the number of cells composing the nodes, different shape and size parameters of nodes, and their relationship with degenerative changes due to cardiac conditions. In both species, the sinoatrial node (SAN) was ovoid in shape whereas the atrioventricular node (AVN) was pyramidal in shape. The percentage of collagen fibers inside the SAN of dogs (47%) and horses (50%) was found to be higher than that of cells. In contrast, the percentage of cells in the AVN of dogs (24%) and horses (16%) was higher than that of connective tissues. In the SAN, the area (p = 0.09), maximum diameter (<0.001), and mean diameter (0.003) of P cells were larger in dogs than in horses. Overall, the SAN cells and surrounding cardiomyocytes in dogs and horses as well as the AVN cells in dogs that succumbed to SCD decreased in size compared with those in normal hearts.

Relationship between selenium, copper, zinc and their biomarkers in blood and skeletal muscle tissue in adult horses from southern Chile.

Microminerals are necessary for all bodily functions. In animal species, selenium (Se), copper (Cu) and zinc (Zn) all form part of antioxidant enzymes. Micromineral deficiencies, particularly Se, are well recognized in large animal species in Chile. Glutathion peroxidase (GPx) is a widely used biomarker for Se nutritional status and to diagnose Se deficiency in horses. Superoxide dismutase (SOD) is a Cu and Zn-dependant antioxidant enzyme, although it is not commonly used as a proxy for the nutritional status of these minerals. Ceruloplasmin (CP) is used as a biomarker of Cu nutritional status. This study´s objective was to explore correlation between said minerals and biomarkers in adult horses from southern Chile. Se, Cu, Zn, GPx, SOD and CP were measured in whole blood of a group of 32 adult horses (5-15 years old). Further, a second group of 14 adult horses (5-15 years old) underwent gluteal muscle biopsies to determine Cu, Zn, GPx and SOD. Correlations were determined by means of Pearson´s r coefficient. Significant correlations were found for blood GPx and Se (r= 0.79), blood GPx and SOD (r= -0.6), muscular GPx and SOD (r= 0.78), and Cu and CP (r= 0.48). These results confirm previously described strong association between blood GPx and Se in horses, validating the former´s use as a diagnostic proxy of Se deficiency in Chilean horses, and suggest significant interactions between GPx and SOD in blood and muscle tissue.

Effect of ambulation following 18F-fluorodeoxyglucose injection on standing positron emission tomography of the healthy equine digit.

Measure 18F-FDG uptake in digital tissues of healthy horses subjected to different ambulatory conditions between the time of injection and positron emission tomography (PET) scan acquisition. 8 healthy adult horses. Horses were walked (AMB) or tied in stalls (NONAMB) immediately after injection with ∼1.5 MBq/kg 18F-FDG until scan acquisition using a randomized crossover design. Steps were quantified using accelerometers. Standardized uptake values (SUV; mean and maximum) in digital tissues including the dorsal lamellae (proximal, middle, and distal), quarter lamellae (medial and lateral), and coronary band were analyzed using a mixed-effects linear regression model. Mean (95% CI) step count for AMB (569[484-653]) was higher than NONAMB (88[24-152]) P = <.001. The SUVmax (but not SUVmean) was increased in AMB compared with NONAMB in the proximal (2.74[2.52-2.98] vs 2.42[2.05-2.78]; P = .04) and middle (2.74[2.37-3.11] vs 2.36[2.05-2.68]; P = .03) dorsal lamellae but was not different in the distal lamellae or coronary band. In the medial quarter lamellae, both SUVmax (2.53[1.58-3.48] vs 2.07[0.81-3.33]; P = .01) and SUVmean (1.90[1.55-2.25] vs 1.49[0.91-2.06]; P = .007) were increased in AMB compared with NONAMB. The medial quarter lamellae also had lower SUVmax (P = .002) and SUVmean (P = .04) compared with the lateral quarter and lower SUVmax compared with the mid-dorsal lamellae (P = .01). Lamellar 18F-FDG uptake was affected by ambulatory activity mostly in the medial quarter; however, this effect was relatively small and unlikely to interfere with clinical detection of laminitis.

Expression of genes with biomarker potential identified in skin from DSLD-affected horses increases with age.

Degenerative Suspensory Ligament Desmitis (DSLD) negatively impacts connective tissues in horses, which often leads to progressive chronic pain and lameness. DSLD has been shown to be a systemic disorder that affects multiple body systems, including tendons, sclerae, and the aorta. Currently, the diagnosis is confirmed by post mortem histological examination of a tendon or suspensory ligament. Histology reveals inappropriate accumulations of proteoglycans in the tendons and other tissues in DSLD-affected horses. Unfortunately, there is no reliable method to diagnose DSLD in living horses. Recently, bone morphogenetic protein 2 (BMP2) was identified in active DSLD lesions. In addition, recent data from RNA sequencing (RNA-seq) showed overexpression of numerous genes, among them BMP2, FOS and genes for keratins in DSLD skin biopsies-derived RNA. We hypothesized that some of these genes can be used as biomarkers for diagnosis of DSLD in a panel. Overexpression of some of them was verified in quantitative real time PCR. Immunohistochemistry and RNAscope in-situ hybridization (ISH) assays were used to determine the level of overexpression of specific genes in skin biopsies from control and DSLD-affected horses. The RNAscope ISH assay has shown to be more reliable and more specific that immunohistochemistry. ISH confirmed a significant increase in KRT83 and BMP-2 in hair follicles in DSLD cases, as well as abnormally high expression of FOS in the epidermis, especially in aging horses. Because statistically relevant specificity and sensitivity was documented only for FOS and BMP2, but not KRT83 we recommend the use of FOS and BMP2 panel to diagnose DSLD. We conclude that a panel of two markers from the studied group (BMP2 and FOS) can serve as an additional diagnostic tool for DSLD in living horses, especially in older animals. Further studies are necessary to confirm if this biomarker panel could be used as a prospective tool to identify DSLD in horses as they age.

Histological comparison of the lamellar tissue of Iberian origin breed horses created in semi-feral conditions or in an intensive system.

Although the external conformation of wild horse hooves has been proposed as an ideal model for domesticated modern horses, histological signs of laminitis have been reported among them. With the hypothesis that the lamellar tissue of horses of Iberian origin raised in semi-feral is healthier than those raised in an intensive management system (stall confinement and high-calorie diet intake), the objective was to compare their lamellar tissues. Lamellar tissue samples were taken from the forelimb hoof of eight domesticated Mangalarga Marchador (MM) horses and from six semi-feral Marajoara (MJ) and Puruca (MP) horses. Primary epidermal lamella (PEL) and secondary epidermal lamella (SEL) were measured (length and width) in several regions, and their shapes were morphologically classified into different types. Breed groups were compared using analysis of variance, followed by Tukey or Dunn tests (P<0.05). Early signs of laminitis such as abnormal keratinization of the abaxial primary dermal lamella, tapered tips of the axial PELs, pointed tips of the SEL, nuclei condensation, and abnormal spatial orientation of the secondary epidermal basal cells (SELBC), were seen only in MM horses. MP horses had a greater interface of epidermis/dermis contact than MJ horses and more rounded nuclei in the round SELBC than MM horses. In agreement with the study hypothesis, semi-feral MJ and MP horses' lamellae were classified as healthier than MM horses, which showed early signs of endocrinopathic laminitis.

The Therapeutic Effects of Autologous Platelet-Rich Plasma Gel on Cutaneous Wound Healing in Rescued Horses

This study explored the effect of platelet-rich plasma gel on skin wound healing in rescued horses. A total of twenty horses were used and allocated into two groups: PRP-treated Group A (n=10) and ASD-treated Group B (n=10). Group A animals were treated with autologous PRP gel, while group B animals were treated with sterile saline. A full-thickness (1.5 mm2) skin wounds were selected in each horse. Histopathological examination of wound tissue in horses was performed on days 8, 40, and 60. Wound epithelialization was assessed by HE staining, and collagen re-establishment was assessed by Masson’s trichrome staining. The CAT activity and MDA concentration were assessed in blood samples on days 8, 40, and 60. All data were subjected to statistical analysis. We observed a highly significant increase (P&lt;0.01) in re-epithelization at days 40 to 60 in the PRP wounds compared to the ASD wounds. Collagen was well organized (P&lt;0.01) in the PRP wounds compared with the ASD wounds at day 40 to day 60. MDA concentration was significantly decreased from day 40 to day 60 (P&lt;0.05) in the PRP wounds than the ASD wounds. CAT activity showed no difference (P&gt;0.05) between PRP wounds and ASD wounds. In conclusion, compared to ASD wounds, PRP wounds promoted cutaneous wound healing in horses by suppressing oxidative stress levels, accelerating wound epithelialization, and generating organized tissue, interlocking collagen bundles of dermal collagen. However, ultrasonographical assessment level study is needed to further investigate the effect of PRP gel on skin wound healing in rescued horses.&#x0D; Keywords: Horses, Oxidative stress, Platelet-Rich Plasma, Sterile saline, Skin Wound Healing.

Solving an eye condition by looking to the rear

Solving an eye condition by looking to the rear

Equine insulin dysregulation causes tissue specific alterations of proinflammatory cytokines and acute phase proteins in a NF-kB independent manner

Similar to human diabetes, equine metabolic syndrome (EMS) causes insulin dysregulation leading to debilitating sequela including laminitis. The pathophysiological mechanisms underlying EMS and laminitis are not well known. Therefore, using an insulin-resistant equine model, we hypothesized that insulin dysregulation induces an increased expression of inflammatory proteins in a tissue specific manner. Two groups of horses (n = -5/group) were categorized as insulin-resistant (IR) or insulin-sensitive (IS), using a frequently sampled intra-venous glucose tolerance test. Biopsies from skeletal muscle, and visceral and subcutaneous adipose tissues were collected in both groups. Protein expression was quantified via Western blotting in order to investigate HSP90, α 2 macroglobulin (A2M), Fibrinogen α, β, γ isoforms as well as cytokines, including interleukin-1β (IL-1β) and interleukin-6 (IL-6), in muscle and adipose tissues. Protein expression of HSP90, A2M and IL1-β was significantly greater in visceral adipose tissue of IR horses compared to IS horses. Fibrinogen (α and γ) expression was only significantly increased in subcutaneous adipose tissue of IR group compared to IS group. In contrast, no statistically significant difference in protein expression of proinflammatory cytokines and acute phase proteins was reported in skeletal muscle of IR vs. IS horses. Relative protein expression of total and phospho-NFκB protein expression was not statistically significantly changed in adipose tissues of IR horses compared to IS horses. In conclusion, proinflammatory cytokines and acute phase proteins were upregulated in adipose tissue, but not in skeletal muscle, through an NF-kB independent pathway. Insights from this study could reveal novel biomarkers and potential therapeutic targets for EMS.

ERAS Is Constitutively Expressed in the Tissues of Adult Horses and May Be a Key Player in Basal Autophagy.

ERas is a new gene of the Ras family found in murine embryonic stem (ES) cells. Its human ortholog is not expressed in human ES cells. So far ERas gene has only been found to be expressed in the tissues of adult cynomolgus monkeys and cattle; however, information about ERAS expression or its potential functions in equine tissues is lacking. This study was performed to investigate whether Eras is an equine functional gene and whether ERAS is expressed in the tissues of adult horses and determine its potential physiological role. Expression of the ERas gene was detected in all examined adult tissues, and the RT-PCR assay revealed ERAS transcripts. Protein expression was also detected by Western blot analysis. Quantitative real time RT-qPCR analysis revealed that different expression levels of ERAS transcripts were most highly expressed in the testis. Immunohistochemically, ERAS was found to be localized prevalently in the plasmatic membrane as well as cytoplasm of the cells. ERAS was a physical partner of activated PDGFβR leading to the AKT signaling. ERAS was found to interact with a network of proteins (BAG3, CHIP, Hsc70/Hsp70, HspB8, Synpo2, and p62) known to play a role in the chaperone-assisted selective autophagy (CASA), which is also known as BAG3-mediated selective macroautophagy, an adaptive mechanism to maintain cellular homeostasis. Furthermore, ERAS was found to interact with parkin. PINK1, BNIP3, laforin. All these proteins are known to play a role in parkin-dependent and -independent mitophagy. This is the first study demonstrating that Eras is a functional gene, and that ERAS is constitutively expressed in the tissues of adult horses. ERAS appears to play a physiological role in cellular proteostasis maintenance, thus mitigating the proteotoxicity of accumulated misfolded proteins and contributing to protection against disease. Finally, it is conceivable that activation of AKT pathway by PDGFRs promotes actin reorganization, directed cell movements, stimulation of cell growth.

Current Knowledge on the Bioavailability of Thymol as a Feed Additive in Humans and Animals with a Focus on Rabbit Metabolic Processes.

Simple SummaryThis review provides general information on the possible health benefits in animals and humans of herbal additives, particularly thymol, whose phenolic group is responsible for the neutralisation of free radicals, and information concerning its detection through body action, bioavailability and mechanisms in rabbits. Plants containing thymol have been used in traditional medicine for the treatment of various diseases, such as cardiovascular diseases, cancer and diabetes. Although a great number of in vitro studies of cardiovascular and cancer diseases are available, in vivo studies that confirm these findings have not been sufficiently reported. To determine the beneficial dose, further clinical studies are necessary, with preclinical comprehensive research on animal models.The aim of this review is to describe the therapeutic effect of thymol on various human diseases, followed by its bioavailability in humans and animals. Based on our knowledge from the current literature, after thymol addition, thymol metabolites—mostly thymol sulphate and glucuronide—are detected in the plasma and urine of humans and in the plasma, intestinal content, faeces and tissues in rats, pigs, chickens, horses and rabbits after enzymatic cleavage. In rabbits, thymol absorption from the gastrointestinal tract, its distribution within the organism, its accumulation in tissues and its excretion from the organism have been described in detail. It is necessary and important for these studies to suggest the appropriate dose needed to achieve the required health benefits not only for animals but also for humans. Information from this review concerning the mode of action of thymol in animal organisms could also be applied to human medicine and may help in the utilisation of herbal medicine in humans and in veterinary healthcare. This review summarises the important aspects of thymol’s effects on health and its bioavailability in organisms, particularly in rabbits. In future, herbal-based drugs must be extensively investigated in terms of their mode of action, efficiency of administration and clinical effect.

Presence of Myeloperoxidase in Lamellar Tissue of Horses Induced by an Euglycemic Hyperinsulinemic Clamp.

Laminitis is a pathology of the equine digit leading to a failure of the dermo-epidermal interface. Neutrophil activation is recognized as a major factor in SIRS-associated laminitis. Less is known about the role of neutrophil activation in laminitis associated with metabolic disorders. The aim of this descriptive study was to observe whether myeloperoxidase is increased in the laminae during early stage laminitis in three horses subjected to a prolonged euglycemic hyperinsulinemic clamp (pEHC). After 48 h of pEHC-treatment, horses were subjected to euthanasia. Two healthy horses are used as control. Histological sections of lamellar tissue from all horses were immunohistochemically stained for myeloperoxidase and counterstained with hematoxylin-eosin. Histopathological changes that characterize insulin-induced laminitis and increased presence of myeloperoxidase, especially in the dermal lamellae, were increased in histologic sections of pEHC-treated horses. Neutrophil myeloperoxidase release may contribute to the pathophysiology of endocrinopathic laminitis.

Influence of polyunsaturated fatty acids of feed on metabolic parameters in herd horses of Yakutia

The research of lipid metabolism is especially relevant for the breeds of herd horses in Yakutia, because the energy balance of their body under extreme conditions of the region in winter largely depends on the fat reserves in the body of animals and the efficiency of lipid assimilation in the body of horses, mainly from plant feed. Therefore, the study of the lipid composition of pasture feed of herd horses in Yakutia depending on the seasons of the year, their digestibility in the body of horses, the effect of the lipid composition of feed on the chemical composition of horse meat is very relevant. The purpose of the work was to investigate the effect of polyunsaturated fatty acids of feed on metabolic parameters in breeds of herd horses in Yakutia and to develop the technology for obtaining a concentrate with polyunsaturated fatty acids from the internal fat of foals. The object of research were: 1) samples of pasture grasses from horsetail and horsetail-free vegetation of the pastures in the Verkhoyansky area; 2) winter-green mass of oats and afterfeed of natural grass; 3) samples of flax press-cake; 4) samples of adipose tissue of young Yakut horses aged 6 months and adult horses; 5) meat samples of meat of types of Yakut breed such as Kolymsky, Yansky and Korennoy and horses of Megezheskaya breed; 6) horses of Yakut breed in OOO “Khoroobut” in the Megino-Kangalassky area, OOO “Sartansky” in the Verkhoyansky area. It has been found by studies that the consumption of dry matter of feed during the breeding of horses on the winter-green mass of oats was 31,3 % significantly higher than during the breeding on the afterfeed of natural grass and amounted to 14,7±0,30 kg (P ≥ 0,95). Differences were also found in the content of metabolic energy in 1 kg of dry matter of consumed feed. Thus, the content of metabolic energy in the winter grazing from the winter-green mass of oats was 16,2 % higher (9,9±0,04 MJ) than in the natural herbage (8,3±0,23 MJ), the difference was statistically significant (P ≥ 0,95). The internal fat of Yakut horses can serve as a highly valuable raw material as a source of polyunsaturated fatty acids for the production of functional food products.

Environmental organic pollutants in hair samples from sport horses

SummaryBackgroundPrevious studies have shown high levels of persistent organic pollutants (POPs) and their risks in humans and domestic animals, especially in cats and dogs. However, studies regarding the levels of POPs in horses are limited.ObjectivesTo study the concentration of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and organophosphate pesticides (OPs) in hair samples collected from 52 sport horses in Turkey and to investigate the possible relationship among current exposure situation, age and gender of horses.Study designOriginal article.MethodsHair samples were collected from 52 sport horses which were divided into three groups according to age: Group I: &lt; 5 years (n = 17), Group II: 5–10 years (n = 16) and Group III: &gt;10 years (n = 19). In addition to age, the samples were also analysed by location and gender. Thirty environmental pollutants (2 OPs, 7 OCPs, 15 PCBs and 6 PAHs) were analysed using a sensitive GC‐MS method.ResultsAll samples contained a minimum of one pollutant, and 23 of the 30 measured pollutants were identified in at least one sample. Number of positive samples and concentrations of POPs were higher in Group 2 and Group 3 than Group I (p &lt; 0.05). Females and males presented similar results. In terms of location, concentrations of almost all chemicals were higher in Sanliurfa than Ankara (p &lt; 0.05).Main limitationsFeed, drinking water and the other related environmental samples were not analysed to evaluate the relationship between those sources and POPs levels in hair samples collected from sport horses.ConclusionsThe concentration of POPs in the hair and other tissues of sports horses should be monitored periodically. To the best of our knowledge, this is the first report to investigate levels of the POPs in hair samples from sport horses in Turkey.