Horse Population Research Articles

SISTEM PAKAR PENYAKIT KUDA (STUDI KASUS PEGASING ACEH TENGAH)

Disease is one of the factors that reduce the population of horses in Indonesia, in general, disease is a health problem. (T et al., 2015) In terms of origin, diseases can be grouped into two categories, namely diseases caused by infection and diseases caused by non-infection. Non-infectious diseases are diseases caused by the state of the body itself, such as allergies. and hormonal imbalance.
 The analytical method in this study uses the Certainty Factor (CF) method with several stages, namely data collection, problem identification, system design, system analysis, system implementation, and testing. Forward chaining reasoning technique which begins with the process of data collection and diagnostic facts. (Khoirul et al., 2021) forward chaining is carried out by using existing facts to draw conclusions, each fact will produce a conclusion in the form of a diagnosis and the process of indicating a measure of certainty against a fact or rule.
 The results of the study found that the results of collecting disease data, symptoms and rule bases obtained from an expert, can be made a disease rule chart, several symptoms of one type of disease and several symptoms with several diseases.
 Targeted outputs: Compulsory outputs are Monograph Books with ISBN with the title Application of Certainty Factor to detect racehorse disease (Case Study: Central Aceh Regency) and additional outputs of the Sinta 3 Accredited National journal.

Prerace venous blood gases and acid-base values in Standardbred horses: effects of geography, season, prerace furosemide, gender, age, and trainer using big data analytics.

A retrospective study was conducted to establish the prerace venous acid-base and blood gas values of Standardbred horses at rest using big data analytics. Venous blood samples (73,382) were collected during seven racing seasons from 3 regional tracks in the Commonwealth of Pennsylvania. Horses were detained 2 hours prior to race time. A mixed-effects linear regression model was used for estimating the marginal model adjusted mean (marginal mean) for all major outcomes. The interaction between age and gender, track, and the interaction between month, treatment (furosemide), and year were the major confounders included in the model. Random effects were set on individual animal nested within trainer. Partial pressure of venous carbon dioxide (PVCO2), partial pressure of oxygen (PVO2), and pH were measured, and base excess (BE), total carbon dioxide (TCO2), and bicarbonate (HCO3-) were calculated. Significant (P < .001) geographical differences in track locations were seen. Seasonal reductions in acid-base values started in January with significant (P < .001) decreases from adjacent months seen in June, July, and August followed by a gradual return. There were significant increases (P < .001) in BE and TCO2 and decreases in PVO2 with age. Significant differences (P < .001) in acid-base values were seen when comparing genders. A population of trainers were significantly different (P < .001) from the marginal mean and considered outliers. In a population of horses, big data analytics was used to confirm the effects of geography, season, prerace furosemide, gender, age, and trainer influence on blood gases and the acid-base profile.

Prevalence of radiographic changes in forelimb digits and metacarpophalangeal joints of South African endurance racehorses.

If the number of events alone is considered, endurance riding is the fastest growing and the second-most popular Fédération Equestre Internationale (FEI) discipline. Lameness is the most common cause of elimination from endurance races worldwide. To the authors' knowledge, no studies have been published investigating the prevalence of radiographic changes in the forelimb digits and metacarpophalangeal joints (MCP) of endurance racehorses in South Africa. Investigate the prevalence of radiographic changes in the forelimb digits and MCP joints of South African endurance racehorses. One hundred endurance racehorses registered with ERASA were volunteered by their owners to partake in the current study. Radiographs were obtained from horses competing in endurance races during the 2018-2019 endurance racing season. Radiographs included seven standard views of each distal forelimb. Radiographic images were independently evaluated by three observers, point prevalence and inter-rater reliability (IRR) was calculated. Data analysis of the forelimb digits revealed a large proportion of horses with bilateral signs of dorsopalmar hoof imbalance (95%); a diversion from a straight digital axis (91%), with an extended (broken back) proximal interphalangeal joint (67%) being the most common abnormality. Osteoarthritis of the proximal (16%) and distal (7%) interphalangeal joints was only observed in a low percentage of horses. Interestingly, the hoof-distal-phalanx-ratio of the majority (86%) of horses was more than 25% but none of these horses showed any other signs of chronic laminitis, indicating that hoof-distal-phalanx-ratio might not be a reliable indicator of chronic laminitis in this population of horses. Ossification of the ungular cartilages was observed in the majority (69%) of horses, either affecting one or both distal phalanges. Descriptive data analysis of the MCP joints showed that a large proportion of horses displayed radiological signs of MCP joint osteoarthritis (28%), with 10% being bilateral. The current study provides insight into radiographic changes and their prevalence in the distal front limbs of South African endurance racehorses. Knowledge about the prevalence of specific radiographic changes would enable equine practitioners to better evaluate and manage horses that are affected. Although no correlations were made with age, speed or number of competitive kilometres competed, the current study may serve as a basis for future research.

Effect of different adjuvant formulations on the antibody response of horses to porcine zona pellucida proteins

Immunization with porcine zona pellucida (PZP) proteins is being used successfully to induce infertility in wildlife including horses. However, widespread adoption of this method to control the growth of horse populations requires further refinement in order to induce long-term infertility, reduce the frequency and severity of injection site reactions, and make the vaccines easier to administer. The next generation of PZP-based vaccines will likely be a controlled-release formulation with different adjuvants from the Freund’s adjuvants used in existing vaccines. We evaluated the response of equine peripheral blood mononuclear cells to a cationic nanoparticle adjuvant, Nano-11, alone and with the TLR agonists poly(I:C) and CpG ODN as a screen to develop an adjuvant system suitable for immunization of horses. The secretion of IL-1β, TNF and CXCL10 were used as readouts. The combination of poly(I:C) with Nano-11 significantly increased the secretion of IL-1β and TNF in comparison with Nano-11 only, with little effect of further addition of CpG ODN. The efficacy of the Nano-11/poly(I:C) adjuvant to enhance the immune response to native PZP proteins was determined in horses. Horses were immunized twice with the licensed Zonastat-H vaccine or PZP with Nano-11/poly(I:C) emulsified in silicone oil. A third group received PZP with the saponin adjuvant QA-21 emulsified in silicone oil. The horse sera collected monthly after the injections had increased anti-PZP IgG antibodies with the strongest response observed with Zonastat-H. We conclude that Nano-11/poly(I:C) is a potential candidate for the development of a controlled release formulation of a next generation PZP-based immunocontraception.

Diagnosis and outcome following tenoscopic surgery of the digital flexor tendon sheath in German sports and pleasure horses.

Digital flexor tendon sheath (DFTS) pathology is an important cause of lameness in horses. The outcome after surgical treatment is variable and depends on the exact diagnosis. To (1) describe the prevalence of lesions associated with lameness caused by nonseptic DFTS tenosynovitis in a large population of German sports and pleasure horses; (2) determine the sensitivity and specificity of diagnostic imaging techniques for identifying lesions within the DFTS with tenoscopic diagnosis being the gold standard; (3) explore associations between tenoscopically diagnosed lesions and signalment, purpose, and limb affected; and (4) describe the outcome following DFTS tenoscopy with nonseptic DFTS tenosynovitis in this population. Retrospective case series. Medical records of horses admitted for tenoscopic surgery of nonseptic DFTS tenosynovitis between 2011 and 2020 were reviewed. Follow-up information was obtained via telephone contact. Sensitivity and specificity of ultrasonography and contrast tenography were determined using tenoscopic diagnosis as gold standard and univariable analysis was used to explore associations between signalment, case history, and tenoscopic diagnosis. Medical records from 131 horses were retrieved, of which 8 horses had bilateral disease and 6 horses were presented for tenoscopy on two separate occasions (3 for tenoscopy in the same limb, 3 in a different limb), thus, making a total of 145 limbs. Lesions were most commonly diagnosed in the deep (DDFT; n=55 limbs) and superficial (SDFT; n=55 limbs) digital flexor tendons. Manica flexoria (MF) lesions were detected in 44 limbs and palmar/plantar annular ligament (PAL) constriction in 99 limbs. In 36 limbs, only one structure within the DFTS was injured, whereas in 109 limbs a combination of lesions was noted, the most common being the combination of a SDFT lesion with PAL constriction. All affected limbs were examined with diagnostic ultrasonography; contrast tenography was performed in 86 limbs. For diagnosis of MF and DDFT tears, tenography was more sensitive (89% [confidence interval, CI: 65.4%-95.2%]; 72% [CI: 46.4%-89.3%], respectively) than specific (64% [CI: 52.5%-77.6%]; 53% [CI: 42.2%-73.3%], respectively) whereas ultrasonography was more specific (92% [CI: 84.5%-96.3%]; 92% [CI: 83.6%-96.0%]) with lower sensitivity (64% [CI: 47.7%-77.2%]; 54% [CI: 39.5%-67.9%]). For SDFT lesions, ultrasonography was highly specific (94% [CI: 86.9%-97.9%]) with lower sensitivity (66% [CI: 51.3%-77.4%]). Follow-up information following first surgery was obtained for 118 horses (132 limbs): 18 (15.3%) of 118 horses remained chronically lame, 40 (33.8%) performed at a reduced level and 60 (50.8%) performed at the same or higher level following rehabilitation after tenoscopy. Horses with DDFT lesions had the poorest outcomes with only 36.6% returning to the same or higher level of exercise. Retrospective analysis of clinical records and subjective outcome assessment based on owner follow-up with potential recall bias. Findings on diagnostic imaging are impacted by many factors including equipment quality and operator expertise and experience. Diagnostic imaging techniques were complimentary and contrast tenography was sensitive and ultrasonography was specific for the diagnosis of MF and DDFT lesions. Following tenoscopic surgery for nonseptic tenosynovitis of the DFTS, approximately half the cases were able to return to preinjury level of exercise.

Frequency of Detection of Respiratory Pathogens in Clinically Healthy Show Horses Following a Multi-County Outbreak of Equine Herpesvirus-1 Myeloencephalopathy in California.

Actively shedding healthy horses have been indicated as a possible source of respiratory pathogen outbreak, transmission, and spread. Using nasal swabs from clinically healthy sport horses submitted for qPCR testing after an outbreak of equine herpesvirus-1 (EHV-1) myeloencephalopathy (EHM) in the spring of 2022, this study aimed to identify the rate of clinically healthy horses shedding common and less characterized respiratory pathogens within the sport horse population to better understand their role in outbreaks. Swabs were collected during a required quarantine and testing period, according to the United States Equestrian Federation (USEF), and showed return-to-competition requirements. Common respiratory pathogens, such as equine influenza virus (EIV), EHV-4, and equine rhinitis B virus (ERBV), were found at low but stable frequencies within previously reported ranges, whereas EHV-1 and Streptococcus equi subspecies equi (S. equi) were found at or above previously reported frequencies. Less characterized respiratory pathogens, such as EHV-2, EHV-5, and S. equi subspecies zooepidemicus (S. zooepidemicus), were found within previously reported ranges. Common respiratory pathogens, especially EHV-1 following the multiple EHM outbreaks, were found to be circulating in clinically healthy sport horse populations, reflecting their silent transmission. The strategy of quarantine and EHV-1 qPCR testing of clinically healthy horses was successful at eliminating additional EHM outbreaks and facilitating safe return to competition with no reported respiratory disease outbreaks following the subsequent shows in California.

Are Horse Owners Able to Estimate Their Animals' Body Condition Score and Cresty Neck Score?

Simple SummaryObesity and overconditioning are becoming more prevalent in horses and could be the cause behind various diseases. Evaluation of body condition scores (BCS) and cresty neck scores (CNS) are important tools used to assess the risk of obesity, and owners and caretakers should be able to correctly evaluate their animals. The aim of this study was to compare the ability of owners to correctly assess the BCS and CNS of their animals, comparing them with the scores given by an experienced examiner. In our population, overconditioning was present in 29% and 24% of horses according to the owners and the vet, respectively, while obesity was detected by the owners and the vet in 2% and 1% of cases, respectively. Agreement between the owners and the vet was slight for both body condition score and cresty neck score, and it was influenced by age, breed, gender, and activity of the horse. Education of owners and caretakers to correctly assess their animals is important to prevent the development of obesity and overconditioning and related diseases.Obesity and overconditioning are becoming more prevalent in horses, and are influencing the animal’s health, activity, and reproductive efficiency. Body condition score (BCS) and cresty neck score (CNS) have been correlated with the development of various diseases. Many of the papers in the literature evaluate the prevalence of obesity and overconditioning in horse populations considering BCS given by owners. The aim of this study was to evaluate the validity of the owners’ estimation of the degree of equine obesity or overconditioning by comparing BCS and CNS provided by each owner and a board-certified vet to a cohort of 259 horses and their agreement based on age, breed, sex, and activity of the animals. Overconditioning was present in 29% and 24% of horses according to the owners and the vet, respectively, and obesity in 2% and 1%, respectively. Agreement between BCS and CNS given by the owners and the vet was slight, with owners scoring horses either lower or higher than the vet. Agreement between the owners and the vet assessment was also influenced by age, breed, sex, and activity of the animals. Education of owners and caretakers to correctly assess BCS and CNS and regular evaluation of the animals throughout the year is important to prevent the development of obesity and overconditioning and related diseases.

Body Condition Score Is Not Correlated to Gastric Ulcers in Non-Athlete Horses.

Simple SummaryEquine gastric ulcer syndrome (EGUS) is a worldwide disease, quite common in various categories of horses. Numerous clinical signs have been reported, including inappetence, poor performance, girthiness, and recurrent colic. In addition, weight loss and a low body condition score (BCS) are considered to be associated with EGUS. However, few studies have examined the relationship between BCS and gastric ulcers, and the results were contradictory. Gastroscopies were performed on 203 horses to detect the presence of gastric ulcers. At the same time, a board-certified veterinarian, blinded to the results of the gastroscopies, assessed the BCS of the horse. In our population, BCS was not correlated with the presence or severity of gastric ulcers. Gastric ulceration, therefore, cannot be excluded based only on the presence of a normal or high BCS.Equine Gastric Ulcer Syndrome (EGUS) is a worldwide disease of the stomach that can be found in different categories of horses. Different clinical signs may be present, but a large number of horses are asymptomatic. The aim of this study was to identify a possible correlation between body condition score (BCS) and EGUS in a population of horses. A total of 203 non-athlete horses were submitted for gastroscopies, and the presence and severity of lesions of the glandular and squamous mucosa were recorded. A board-certified veterinarian blinded to the gastroscopy results assessed the BCS of the horse. In the study population, no correlation was found between BCS and the presence of gastric lesions in either the glandular or the squamous mucosa. The disease of the squamous or glandular mucosa cannot be excluded based only on the presence of normal or increased BCS in non-athlete horses.

Shallow shotgun sequencing of the microbiome recapitulates 16S amplicon results and provides functional insights.

Prevailing 16S rRNA gene-amplicon methods for characterizing the bacterial microbiome of wildlife are economical, but result in coarse taxonomic classifications, are subject to primer and 16S copy number biases, and do not allow for direct estimation of microbiome functional potential. While deep shotgun metagenomic sequencing can overcome many of these limitations, it is prohibitively expensive for large sample sets. Here we evaluated the ability of shallow shotgun metagenomic sequencing to characterize taxonomic and functional patterns in the faecal microbiome of a model population of feral horses (Sable Island, Canada). Since 2007, this unmanaged population has been the subject of an individual-based, long-term ecological study. Using deep shotgun metagenomic sequencing, we determined the sequencing depth required to accurately characterize the horse microbiome. In comparing conventional vs. high-throughput shotgun metagenomic library preparation techniques, we validate the use of more cost-effective laboratory methods. Finally, we characterize similarities between 16S amplicon and shallow shotgun characterization of the microbiome, and demonstrate that the latter recapitulates biological patterns first described in a published amplicon data set. Unlike for amplicon data, we further demonstrate how shallow shotgun metagenomic data provide useful insights regarding microbiome functional potential which support previously hypothesized diet effects in this study system.

BREED-SPECIFIC FEATURES OF MICROSATELLITE DNA OF RIDING HORSES BRED IN BELARUS

Molecular-genetic identification of genes in horse breeding allows the targeted formation of the genetic structure of the population of horses of riding breeds, which will significantly improve the efficiency of selection work. The article presents the&#x0D; materials of the work in which the breed-specific features of microsatellite DNA of riding horses bred in Belarus were studied. It has been found that a higher level of genetic diversity compared to animals of the Hanoverian breed is inherent in halfbreed sport horses, in the genotypes of which 131 alleles were typed. Hanoverian horses were characterized by somewhat lower allelic diversity, but had a distinctive genetic profile, with rare alleles at thirteen loci detected. Thus, the data on genetic&#x0D; diversity will allow a more reasonable approach to the problem of stocking farms with animals with different alleles in order to maintain the genetic structure characteristic of a particular breed.

Metabolomic Profiles in Starved Light Breed Horses during the Refeeding Process.

Simple SummaryUnwanted horses and other equids continue to be a global issue throughout which the prevalence of malnourished equids persists as a welfare concern. Nutritional studies evaluating the refeeding or rehabilitation process are limited, and little data exists to explain how metabolic function changes during refeeding. Therefore, the objective of this study was to assess changes in metabolite profile (metabolome) of emaciated horses throughout rehabilitation via refeeding. Horses were fed specific diets over the rehabilitation period, and blood samples were collected and analyzed throughout. Comparison of equine within a malnourished state and equine during the refeeding process showed decreases in potentially toxic chemical compounds related to liver, kidney, and muscle function as well as shifts related to changing energy demands. This study concludes that the refeeding and rehabilitation process results in an overall change in the equine metabolome.The large population of emaciated horses continues to be an issue troubling the equine industry. However, little is known regarding the collection of equine metabolites (metabolome) during a malnourished state and the changes that occur throughout nutritional rehabilitation. In this study, ten emaciated horses underwent a refeeding process, during which blood samples were collected for a blood chemistry panel and metabolomics analysis via ultrahigh performance liquid chromatography–high resolution mass spectrometry (UHPLC-HRMS). Significant differences among blood chemistry analytes and metabolite abundance during the critical care period (CCP; Days 1–10 of rehabilitation) and the recovery period (RP; the remainder of the rehabilitation process) were observed. Potentially toxic compounds, analytes related to liver, kidney, and muscle function, as well as energy-related metabolites were altered during the refeeding process. The combination of blood chemistry and metabolomics analyses on starved equine during rehabilitation provide vital biological insight and evidence that the refeeding process has a significant impact on the equine metabolome.

Equus caballus Papillomavirus Type-9 (EcPV9): First Detection in Asymptomatic Italian Horses.

Papillomavirus (PV) infections may be related to anogenital lesions and cancer development in humans and several other animal species. To date, 11 different PVs have been reported in horses. Among them, a newly described PV named Equus caballus Papillomavirus Type9 (EcPV9) was thus far only reported in the semen of a stallion with penile lesions in Australia. This study reports for the first time the presence of EcPV9 in asymptomatic Italian horses. From July 2020 to January 2022, genital brush samples were collected from 209 horses with no apparent signs of neoplastic disease and no PV-associated lesions, clinically examined at the Didactic Veterinary University Hospital (OVUD) of Perugia and at the Veterinary University Hospital (OVU) of Turin. Brushes were submitted to real-time PCR targeting the EcPV9-L1 region. The first amplification targeted a region of ~116 bp, followed by the amplification and sequencing of ~533 bp of the positive samples. EcPV9-L1 DNA was found in eleven horses (5.3%), all female and mainly English Thoroughbred. Co-infection with EcPV2-L1 was found in 7 out of the 11 EcPV9-L1 positive horses (63.6%). This study contributes to the description of the prevalence of exposure or infection of EcPVs in the horse population in Italy, for which data are still limited. In this regard, here we provide a phylogenetic analysis and the completely reconstructed viral genomes of two Italian EcPV type 9 isolates, as well as four EcPV type 2 obtained from co-infected animals.

Surveillance of hepatitis E virus in the horse population of Korea: A serological and molecular approach.

Hepatitis E virus (HEV) is an emerging zoonotic pathogen causing hepatitis worldwide. Despite the prevalent evidence of interspecies HEV infection in various animal species, the role of horses in HEV epidemiology remains unclear. In this study, we investigated the prevalence of HEV infection in 283 blood and 114 fecal samples from 397 horses using sandwich enzyme-linked immunosorbent assay and nested reverse transcription-polymerase chain reaction. Among the 283 serum samples, 35 were positive for anti-HEV antibodies (12.4%; 95% confidence interval: 8.8-16.8), and four of the five sampling regions (80%) had these seropositive individuals. Analyses of the potential risk factors for HEV infection revealed that racing horses had a significantly higher risk of infection (P=0.01). However, HEV RNA was not detected in any of the tested serum and fecal samples. To the best of our knowledge, this is the first epidemiological HEV study on horses in Republic of Korea, thereby providing evidence of HEV exposure in the horse population in Korea and specifying the risk factors for HEV infection.

Temporally specific adrenocorticotropic hormone reference intervals for horses in South Africa

An endogenous adrenocorticotropic hormone (ACTH) concentration above the reference interval (RI) is commonly used as means for diagnosing equine pituitary pars intermedia dysfunction (PPID). Basal ACTH concentrations are highly dependent on photoperiod and RIs should be month- and location-specific. To date, no ACTH RIs have been specifically established for South Africa. This study aimed to determine geographically and seasonally relevant RIs for equine ACTH in the Gauteng province of South Africa. A longitudinal prospective study was conducted over twelve months to determine ACTH RIs for a representative population of healthy South African horses in the Gauteng province. Eighty clinically healthy horses under 12 years of age were recruited for monthly venous blood sample collection, from July 2019 to June 2020. ACTH was measured using a chemiluminescent assay. RIs were constructed for each month of the year. This South African population showed similar temporal changes in ACTH concentrations to those previously observed in other locations. Upper reference limits were at their lowest in early summer (21.4 pg/ml, 90% CI 20.8-21.7) with a pronounced increase in autumn (60.6 pg/ml, 90% CI 53.1-62.7), and tapered off in winter (22.3 pg/ml, 90% CI 19.9-23.2). The month-specific ACTH RIs generated in this study will improve the accuracy of diagnosis and monitoring of PPID in the local equine population. These results highlighted the previously recommended need for seasonal and location-specific RIs.

Lipidomic analysis of surfactant and plasma from horses with asthma and age-matched healthy horses.

To perform lipidomic analysis of surfactant and plasma from asthmatic and healthy horses. 30 horses with clinical signs of asthma and 30 age-matched control horses. Detailed history, physical examination, CBC, and bronchoalveolar lavage fluid (BALF) cytologies were obtained. Asthmatic horses were grouped based on their BALF inflammatory profile: severe equine asthma (SEA), mild equine asthma with neutrophilic airway inflammation (MEA-N), or mild equine asthma with eosinophilic airway inflammation (MEA-E). Each asthma group was assigned its own age-matched control group. Lipidomic analysis was completed on surfactant and plasma. Surfactant protein D (SP-D) concentrations were measured in serum and BALF. SEA surfactant was characterized by a phospholipid deficit and altered composition (increased ceramides, decreased phosphatidylglycerol, and increased cyclic phosphatidic acid [cPA]). In comparison, MEA-N surfactant only had a decrease in select phosphatidylglycerol species and increased cPA levels. The plasma lipidomic profile was significantly different in all asthma groups compared to controls. Specifically, all groups had increased plasma phytoceramide. SEA horses had increased plasma cPA and diacylglycerol whereas MEA-N horses only had increased cPA. MEA-E horses had increases in select ceramides and dihydrocermides. Only SEA horses had significantly increased serum SP-D concentrations. The most significant surfactant alterations were present in SEA (altered phospholipid content and composition); only mild changes were observed in MEA-N horses. The plasma lipidomic profile was significantly altered in all groups of asthmatic horses and differed among groups. Data from a larger population of asthmatic horses are needed to assess implications for diagnosis, prognosis, and treatment.

MONITORING THE CONDITION OF THE HORSES OF THE KOSTANAYBREEDS IN NORTHERN KAZAKHSTAN

The article provides an analysis of the current state of Kustanay breed of horses in the Northern region of Kazakhstan. More than 100 heads of breeding horses of Kustanay breed were recorded and described, incl. 9 breeders, 44 broodmare and 79 heads of young animals of different ages in three regions of Kazakhstan. 60% of the horse population of chestnut, 40% of bay. The height at the shoulder of the broodmares is 156 cm, the oblique body length is 155 cm, the chest girth is 180 cm, the girth of the metacarpus is 19.5 cm. Studhorses are 150-153 180-20.2 cm, respectively. 38% of studhorses are linear - belong to lines 464 Neon and 494 Fort. Average, measurements are somewhat lower than those of horses recorded in the IV volume of the State Book of breeding horses of Kustanay breed (2009), while they correspond to the standard. The probable reason is the evasion of selection and breeding work in the direction of improving the remote characteristics of the massif - orientation to the so-called “baiga” distances. An increase in the index of stretching was revealed against the background of a decrease in flattening and massiveness, with a stable bone index. The se characteristics contribute to ensuring endurance when used at "baiga" distances, which is confirmed by the performance results presented in the article.

Whole genome sequence analysis of equid gammaherpesvirus -2 field isolates reveals high levels of genomic diversity and recombination

BackgroundEquid gammaherpesvirus 2 (EHV2) is a gammaherpesvirus with a widespread distribution in horse populations globally. Although its pathogenic significance can be unclear in most cases of infection, EHV2 infection can cause upper respiratory tract disease in foals. Co-infection of different strains of EHV2 in an individual horse is common. Small regions of the EHV2 genome have shown considerable genetic heterogeneity. This could suggest genomic recombination between different strains of EHV2, similar to the extensive recombination networks that have been demonstrated for some alphaherpesviruses. This study examined natural recombination and genome diversity of EHV2 field isolates.ResultsWhole genome sequencing analysis of 18 EHV2 isolates, along with analysis of two publicly available EHV2 genomes, revealed variation in genomes sizes (from 173.7 to 184.8 kbp), guanine plus cytosine content (from 56.7 to 57.8%) and the size of the terminal repeat regions (from 17,196 to 17,551 bp). The nucleotide sequence identity between the genomes ranged from 86.2 to 99.7%. The estimated average inter-strain nucleotide diversity between the 20 EHV2 genomes was 2.9%. Individual gene sequences showed varying levels of nucleotide diversity and ranged between 0 and 38.1%. The ratio of nonsynonymous substitutions, Ka, to synonymous substitutions, Ks, (Ka/Ks) suggests that over 50% of EHV2 genes are undergoing diversifying selection. Recombination analyses of the 20 EHV2 genome sequences using the recombination detection program (RDP4) and SplitsTree revealed evidence of viral recombination.ConclusionsAnalysis of the 18 new EHV2 genomes alongside the 2 previously sequenced genomes revealed a high degree of genetic diversity and extensive recombination networks. Herpesvirus genome diversification and virus evolution can be driven by recombination, and our findings are consistent with recombination being a key mechanism by which EHV2 genomes may vary and evolve.

Epidemiological Study of Multiple Zoonotic Mosquito-Borne Alphaviruses in Horses in Queensland, Australia (2018-2020).

The increased frequency of extreme weather events due to climate change has complicated the epidemiological pattern of mosquito-borne diseases, as the host and vector dynamics shift to adapt. However, little is known about the seroprevalence of common mosquito-borne virus infections in horses in Australia. In this study, serological surveys for multiple alphaviruses were performed on samples taken from 622 horses across two horse populations (racehorses and horses residing on The University of Queensland (UQ) campus) in Queensland using the gold standard virus neutralization test. As is the case in humans across Australia, Ross River virus (RRV) is the most common arbovirus infection in horses, followed by Barmah Forest virus, with an overall apparent seroprevalence of 48.6% (302/622) and 4.3% (26/607), respectively. Horses aged over 6 years old (OR 1.86, p = 0.01) and residing at UQ (OR 5.8, p < 0.001) were significantly associated with seroconversion to RRV. A significant medium correlation (r = 0.626, p < 0.001) between RRV and Getah virus (GETV) neutralizing antibody titers was identified. Collectively, these results advance the current epidemiological knowledge of arbovirus exposure in a susceptible host in Australia. The potential use of horses as sentinels for arbovirus monitoring should be considered. Furthermore, since GETV is currently exotic to Australia, antibodies cross-reactivity between RRV and GETV should be further investigated for cross-protection, which may also help to inform vaccine developments.

Revealing the genetic diversity of Sumbawa endemic horse using microsatellite-based DNA fingerprint

Abstract. Sukri A, Dewi IN, Primawati SB, Wangiyana IGAS, Muttaqin Z, Winaya A. 2022. Revealing the genetic diversity of Sumbawa endemic horse using microsatellite-based DNA fingerprint. Biodiversitas 23: 4153-4159. Sumbawa horse (Equus caballus) is a genetic resource that must be preserved. Sumbawa horses have a significant economic, social, and cultural role. Information on the genetic status of the Sumbawa horse is needed as a step in developing a long-term conservation strategy. Therefore, this study aims to reveal the genetic diversity of the Sumbawa endemic horse using a microsatellite-based DNA fingerprint. DNA isolation was conducted from horse blood samples. Blood samples were taken from two horse farms with 24 individual horses from two different populations, namely Lalar and Liang,West Sumbawa District, Indonesia. Blood was taken from the jugular vein and collected by a qualified veterinarian from the Faculty of Veterinary Medicine, Universitas Pendidikan Mandalika. A total of 4 microsatellite primers were used in this study, INRA032, HEL09, CA425, and AHT4. This study revealed that the genetic diversity of horses in the Lalar population was higher than Liang. A greater number of alleles reinforces this; higher number and frequency of bands; and the presence of specific bands that indicate unique alleles. This research shows that the Sumbawa horse is unique from other horse breeds in the world. This is evidenced by the lower number of alleles per locus (Na) with a maximum number of two alleles per locus. Sumbawa horses have higher observed heterozygosity (Ho) than expected heterozygosity (He), with a Ho value less than 0.5. Analysis of Molecular Variance result has shown that variation within the population was higher than among the population. This is presumably due to the high gene flow in both horse populations caused by inbreeding. In general, AHT4 primers had the best ability to reveal the genetic diversity of Sumbawa horses with the highest Shannon's information index compared to other markers.

Testing individual variations of horses' tactile reactivity: when, where, how?

Tactile perception is involved in a variety of contexts (adaptations to climatic conditions, protection of the body against external dangers…) and is as important as the other sensory modalities for the survival of an individual. This tactile modality has been particularly well studied in humans, revealing high individual variations modulated by a variety of intrinsic and extrinsic factors such as age, sex, pathological disorders, or temperament. Tactility is also involved in animals' social lives, although there are disparities between species. For example, social tactile contact among horses is limited, but this does not mean that they do not react to tactile stimuli but rather with their very thin skin they are able to detect minute stimuli (although they respond more to larger stimuli). Despite a fairly large effort to characterize it, there are controversies concerning equine tactile sensitivity. In this review, we examine studies that have used the same tool (von Frey filaments) and try to disentangle what could explain the differences observed. It appears that many aspects are poorly known or controversial and that the procedures may be so different that the results of different studies cannot be compared. We went further by testing tactile reactivity of a population of unridden horses and found that four factors influenced their tactile reactivity (type of horse, filament size, body area, time of day). These results could explain some of the discrepancies observed in the literature and suggest, in particular, that more attention should be paid to the context of the test.