This article traces the origination, distribution, kinematics, function, and nature of alternative lateral horse gaits, i.e. intermediate speed lateral-sequence gaits involving the synchronization of ipsilateral limbs in the swing phase. Such alternative lateral horse gaits (namely, the running walk, rack, broken pace, hard pace, and broken trot) have been prized by equestrians for their comfort, and have been found in select horse breeds for hundreds of years and even exhibited in fossil equid trackways. After exploring the evolution and development of alternative lateral gaits via fossil equid trackways, human art and historical writings, and the genetics and history of modern horse breeds, functional and biomechanical reasons are offered for the genesis of these gaits. The article concludes by tracing similarities and differences between and within the expression of these alternative lateral gaits by various horse breeds. Fast and low-swinging hard pacing gaits are common in several horse breeds of East and North Asia, high-stepping rack and running walk gaits are often displayed in European and North and South American breeds, the broken pace is found in breeds of Central Asia, Southeast Asia, West Asia, Western North America, and Brazil in South American, and the broken trot occurs in breeds of North Asia, South Asia, and the Southern United States, and Brazil South America.

This paper reviews the appearance of joint lesions during arthroscopic surgery of inter-est to the arthroscopic surgeon and their interpretation within the continuum of joint disease. It also points out the relevance of surgical findings as well as giving directions to the surgeon as to how to approach an appropriate decision-making process during an arthroscopic procedure and what therapeutic options are optimal.

Equine hepacivirus (EqHV, Flaviviridae, Hepacivirus) is a small, enveloped, RNA virus generally causing sub-clinical hepatitis with occasional fatalities. EqHV is reported in equids worldwide, but for Italy data are limited. To address this, a survey study was set up to estimate prevalence at national level and among different production categories (equestrian, competition, work and meat and reproduction) and national macro-regions (North, Central, South and Islands). Data obtained testing 1801 horse serum samples by Real-Time RT PCR were compared within the categories and regions. The NS3 fragment of the PCR-positive samples was sequenced by Sanger protocol for phylogenetic and mutational analysis. The tertiary structure of the NS3 protein was also assessed. The estimated national prevalence was 4.27% [1.97-6.59, 95%CI] and no statistical differences were detected among production categories and macro-regions. The phylogenesis confirmed the distribution in Italy of the three known EqHV subtypes, suggesting also a possible fourth sub-type that however requires further confirmation. Mutational profiles that could also affect the NS3 binding affinity to the viral RNA were detected. The present paper demonstrates that EqHV should be included in diagnostic protocols when investigating causes of hepatitis and in quality control protocols for blood derived products, due to its parental transmission.

Hoof capability of domesticated, barefoot-kept horses and ponies traversing artificial environments remains undocumented. In this study, four equines were walked in-hand for 16 days, covering a distance of 50 km, over three solid surfaces. Subsequently, we conducted an assessment of hoof morphology. Hooves (n = 16) were radiographed before and after the trial, spaced 3 weeks apart, for sole depth measurement. External measurements of feet were recorded 24 hours before day 1 and repeated on day 9. Radiographs revealed increased sole depth in 11 hooves, notably at the palmar process, and some misalignment in certain phalanges. On day 9, after a 36-km distance, all hooves exhibited calloused soles and frogs, and required trimming. The front hooves of the horses had a pronounced, natural concavity. Hard surfaces were found to stimulate sole growth, with a portion of sole thickness preferentially accumulating within the dermal zone. Collectively, the maintenance of short trimming cycles to prevent misalignment, minimize hoof-wall loading and maintain a load-sharing system, may be necessary for barefoot-kept horses considering their rapid growth rate.

Redox regulation and oxidative stress have become areas of major interest in spermatology. Alteration of redox homeostasis is recognized as a significant cause of male factor infertility and is behind the damage that spermatozoa experience after freezing and thawing or conservation in a liquid state. While for a long time, oxidative stress was just considered an overproduction of ROS, nowadays it is considered as a consequence of redox deregulation. Many essential aspects of spermatozoa functionality are redox regulated, with reversible oxidation of thiols in cysteine residues of key proteins acting as an “on-off” switch controlling spermatic function. However, if deregulation occurs, these residues may experience irreversible oxidation and oxidative stress leading to spermatic malfunction and ultimately death. Stallion spermatozoa are “professional producers” of ROS due to their intense mitochondrial activity, and thus sophisticated systems to control redox homeostasis are also characteristic of this species. As a result, combined with the fact that embryos can easily be collected in this species, horses are a good model for the study of redox biology in the spermatozoa and its impact on the embryo.

West Nile virus (WNV) is a global important mosquito-borne Flavivirus causing West Nile disease (WND). In Libya, evidence of WNV circulation has been reported in humans but never in animals. The aim of this study was to determine the seroprevalence of the WNV infection in horses and dogs in Libya. A total of 574 and 63 serum samples from horses and dogs, respectively, were collected from healthy unvaccinated animals between 2016 - 2019. A commercially available competitive ELISA (c-ELISA) kit was initially used to test the collected samples for the presence of WNV Ig-G antibodies. Positive and doubtful sera were also tested by using the more specific virus neutralization assays to confirm whether the ELISA positive results were due to WNV or Usutu virus (USUV) antibodies. The seroprevalence of WNV IgG ELISA antibodies was 13.2% (76/574) and 30.2% (19/63) in horses and dogs, respectively. Virus neutralization test (VNT) showed that 77.5% (62/80) and 89.5% (17/19) of positive and doubtful horse serum samples and dogs serum samples, respectively, were positive with WNV neutralising titers ranging from 1:10 to 1:640. The results of the present study provided novel evidence about the WNV circulation in Libya.

Obesity is one of the most prevalent health conditions in humans and companion animals across the world. Obesity is associated with multiple health conditions across species including premature mortality. It is therefore of importance across the fields of medicine and veterinary medicine. The regulation of body weight is a homeostatic process vulnerable to disruption by genetic and environmental factors. It is well established that the heritability of obesity is high in humans and laboratory animals, with ample evidence that the same is true in companion animals. In this review, we provide an overview of how genes link to obesity in humans, drawing on a wealth of information from laboratory animal models, and summarising the mechanisms by which obesity causes related disease. Throughout, we focus on how large-scale human studies and niche investigations of rare mutations in severely affected patients have improved our understanding of obesity biology and can inform our ability to interpret results of animal studies. For dogs, cats and horses, we review the similarities in obesity pathophysiology to humans and review those genetic studies that have been done to investigate them. Finally, we discuss how veterinary genetics may learn from humans about studying precise, nuanced phenotypes and implementing large-scale studies, but also how veterinary studies may be able to look past clinical findings to mechanistic ones and demonstrate translational benefits to human research.

In 2023, the Bureau of Land Management (BLM) estimated that there were 68,928 mustangs living on United States public lands in 10 western states. The agency uses Appropriate Management Levels to determine the number of mustangs who need to be removed from the land. Once removed and processed, mustangs are sent to adoptions or sales events or retained in short-or long-term holding facilities. Adoptions and sales are the leading avenues for rehoming mustangs; however, the number of horses the BLM can place fluctuates annually and never approaches the greater number removed from the range. To explore opportunities for increasing the number of mustang adoptions, we conducted in-depth interviews with 23 horse trainers located on the U.S. East Coast, asking about participants’ training programs, relationships with horses, perceptions of mustangs, and challenges that mustangs face in the dressage and eventing industries. Participants had varying experiences with mustangs; however, all were willing to work with a mustang in some capacity. Participants voiced the need for more satellite adoption locations on the East Coast to decrease barriers to acquiring a mustang, notably cost and time, and for expanding existing training programs to include eventing and dressage.

This study was conducted to investigate bit use in equestrian sports, focusing on welfare and performance as bit use has been subject of debate. The multi-faceted study combines a literature review, survey, and video analyses. Research on physiological and behavioral effects of bit use, discussing concerns and benefits, was evaluated. The survey involved 250 equestrians, gathering data on experiences, opinions, and practices regarding bit usage. Results demonstrate that different bits are used during competitions and that riders prioritize factors like horse satisfaction, consistent connection, and chewing behavior when riding at home, while show use focusses on factors like control. Video analyses showed high conformity between veterinary expert and show jumper, indicating reliability and validity. Pelham and loose ring bits were most used, while 3-ring and full cheek bits were associated with the most aversive movements, particularly opening of the mouth. Other defense movements included putting ears back, tail swishing, and head tilting. The study highlighted the need for understanding bit preferences in various settings and cautioned against generalizing bit usage based solely on show observations. It also emphasized the potential for developing new designs that prioritize horse comfort and responsiveness, to enhance communication and partnership between horses and riders.

Equine-assisted services (EAS) are being increasingly used as complementary interventions for military veterans who have experienced trauma. However, there is limited evidence of benefit for this population and almost no literature describing desired potential outcomes and possible mechanisms of action. The aim of this article is to address these gaps by reviewing the extant literature of animal-assisted interventions in general, and equine-assisted services in particular, with the goal of providing guidance for future investigations in the field. Currently, the field is in the early stage of scientific development, but published results are promising. Interventions that enhance treatment compliance and/or outcomes could benefit this population. Preliminary results, reviewed herein, indicate that EAS interventions might benefit the military veteran population by enhancing treatment engagement and therapeutic alliance, as well as contributing to symptom reduction and resulting in various transdiagnostic benefits. It is recommended that future studies include exploration of potential beneficial outcomes discussed herein as well as investigate suggested mechanisms of action.

Tendons and ligaments injuries are frequent in sport horses and humans, representing a great therapeutic challenge. Tissue regeneration and function recovery are the paramount of tendon and ligament lesions management. Nowadays, several regenerative treatments are being developed, based on the use of stem cell and stem cell-based therapies. In the present study, the preparation of equine synovial membrane mesenchymal stem cells (eSM-MSCs) for clinical use - collection, transport, isolation, differentiation, characterization, and application is described. These cells are fibroblast-like and grow in clusters. They retain an osteogenic, chondrogenic and adipogenic differentiation potential. 16 clinical cases of tendonitis and desmitis, treated with allogenic eSM-MSCs and autologous serum are also presented, including their evaluation, treatment and follow-up. The use of autologous serum as a vehicle concern to a decreased immunogenic response after the administration of this combination and to its healing properties, due to the presence of growth factors and immunoglobulins. Most of the cases (14/16), healed in 30 days and presented a good outcome. Treatment of tendon and ligament lesions with the mixture of eSM-MSCs and autologous serum appears to be a promising clinical option for this category of lesions in equine patients.

Horses are high performance athletes prone to sportive injuries such as tendonitis and desmitis. The formation of fibrous tissue in tendon repair becomes a therapeutic challenge to overcome. This impels regenerative medicine to develop innovative therapies that enhance tissue regenera-tion retrieving original tissue properties. Multipotent Mesenchymal Stem/ Stromal Cells (MSCs) have been successfully used to develop therapeutic products, as they secrete a variety of bioac-tive molecules that play a pivotal role in tissue regeneration. These factors are released in cul-ture media producing conditioned media (CM). The aforementioned assumptions led to the formulation of equine synovial membrane MSCs (eSM-MSCs) – the cellular pool that naturally regenerates joint tissue, combined with medium enriched in immunomodulatory factors (among other bioactive factors) produced by umbilical cord stroma-derived MSCs (eUC-MSCs), that nat-urally contribute to suppress the immune rejection in the maternal-fetal barrier. A clinical case of an equine acute desmitis, treated with this formulation is presented. Ultrasonographic ligament regeneration occurred in a reduced time frame, reducing stoppage time and allowing return to unrestricted competition after completion of a physical rehabilitation program. This study fo-cused on the determination of the formulation therapeutic potential and the evaluation of its synergistic effect in an equine desmitis treatment, utilizing the cells themselves and its secretome.

Horses are high performance athletes prone to sportive injuries such as tendonitis and desmitis. Fibrous tissue formation with loss of mechanical properties occurs in tendon repair, becoming a therapeutic challenge to overcome. This impels regenerative medicine to develop innovative therapies that enhance tissue regeneration retrieving original tissue properties. Mesenchymal stem cells (MSCs) have been successfully used to develop therapeutic products. They secrete a variety of bioactive molecules that play a pivotal role in tissue regeneration. These factors are released in culture media producing conditioned media (CM). The aforementioned assumptions impelled us to formulate equine synovial membrane stem cells (eSM-MSCs) – the cellular pool that naturally regenerates joint tissue, combined with medium enriched in immunomodulatory factors produced by umbilical cord stroma-derived MSCs (eUC-MSCs), that naturally contribute to suppress the immune rejection in the maternal-fetal frontier. A clinical case of an equine acute desmitis, treated with the abovementioned formulation is presented. Ligament regeneration occurred in a reduced time frame, reducing stoppage time, allowing return to unrestricted competition after completion of a physical rehabilitation program. This study focus was determination of the formulation therapeutic potential and the evaluation of its synergistic effect in an equine desmitis treatment, utilizing the cells themselves and its secretome.

Articular cartilage healing and repair is one of the biggest clinical challenges in trauma and orthopaedic medicine, leading to high economic loss due to athletic impairment in sport horses. Multipotent Mesenchymal stem/stromal cells are part of novel therapeutic arsenal aimed at tissue regeneration and restoring organ function. These cells release biomolecules and factors in the culture media, producing the so called conditioned medium, which have a pro-regenerative effect through paracrine mechanisms. Considering this, a therapeutic product combining equine synovial membrane derived Mesenchymal stem/stromal cells and equine umbilical cord stroma-derived Mesenchymal stem/stromal cells conditioned medium was employed. In this work the treatment of two articular defects, in the first phalanx and third metacarpus of the left front limb of a five-year-old horse, is described. Following surgical debridement of the lesions, the treatment comprised two intra-articular administrations of the above-mentioned therapeutic combination, 15 days apart. This was followed by a thorough rehabilitation program. A second-round treatment was performed 6 months later. Diagnostic imaging demonstrated significant improvement of the articular defects. The clinical outcome allowed a full return to the athletic performance demonstrating the safety and potential advantages of this approach when compared with other therapeutic options.