Equids are members of the family Equidae, which includes modern horses, donkeys, and zebras, as well as extinct species. Equids are characterized by their long limbs, single-toed hooves, and herbivorous diet, which is primarily composed of grasses. Horses, specifically, have been domesticated for thousands of years and have played significant roles in agriculture, transportation, and sport. This page compiles peer-reviewed research studies and scholarly articles that explore various aspects of equids and horses, including their evolution, physiology, behavior, and interactions with humans. The collected works provide insights into the genetic diversity, adaptive traits, and conservation efforts related to equid species.
Lacerenza MD, Arantes JA, Reginato GM, Finardi GLF, Marchi PH, Vendramini THA, Corrêa RR, Pereira PAM, Valadão CAA, Dória RGS.This study investigated the oral microbiome of horses maintained on a high soluble carbohydrate diet based on sugarcane, in comparison to those fed a pasture-based diet composed of spp., aiming to identify associations between dietary intake, the composition of oral microbial communities, and the occurrence of dental caries and diastemata. A total of 20 healthy horses, both male and female, with an average age of 9 ± 3 years and weight of 400 ± 100 kg, without a defined breed, were selected. They were divided into two groups: the High Soluble Carbohydrate Group (HSCCG), consisting of 10 hor...
Buckman PN, Brinker BA, Kapeller LE, Komáromy AM.To determine the accuracy of the EYEMATE-SC suprachoroidal tracer for telemetric tonometry in canine and equine globes. Methods: The EYEMATE-SC sensor (7.8 mm × 3.8 mm × 1 mm) was implanted in the suprachoroidal space of four freshly enucleated normal canine and two normal equine eyes. The anterior chambers were cannulated and connected to a reservoir of Plasma-Lyte A and a manometer. Starting at a manometric IOP of 5 mmHg, the pressure was progressively increased to 80 mmHg by raising the reservoir. At each setpoint (5, 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, and 80 mmHg), t...
Science (New York, N.Y.)August 28, 2025
Volume 389, Issue 6763 925-930 doi: 10.1126/science.adp4581
Liu X, Jia Y, Pan J, Zhang Y, Gong Y, Wang X, Ma Y, Alvarez N, Jiang L, Orlando L.Horsepower revolutionized human history through enhanced mobility, transport, and warfare. However, the suite of biological traits that reshaped horses during domestication remains unclear. We scanned an extensive horse genome time series for selection signatures at 266 markers associated with key traits. We detected a signature of positive selection at -known to be a modulator of behavior in mice-occurring ~5000 years ago (ya), suggesting that taming was one of the earliest steps toward domestication of horses. Intensive selection at began ~4750 ya with the domestication bottleneck, leading ...
Hacilarlioglu S, Bilgic HB, Karagenc T, Aydin HB, Toker H, Kanlioglu H, Pekagirbas M, Bakirci S.Equine piroplasmosis (EP), caused by and , is a tick-borne disease posing significant threats to equine health and the horse industry worldwide. Other vector-borne blood parasites, including , spp., and spp., can also infect horses; however, their prevalence remains poorly characterized in Türkiye. This study aimed to determine the molecular prevalence of , , , spp., and spp. in equids from the Western Aegean Region of Türkiye. Blood samples were collected from 388 clinically healthy equines across İzmir, Aydın, Denizli, and Muğla provinces. Species-specific PCR assays were performed...
Stasiak K, Dunowska M, Rola J.Equid herpesvirus 5 (EHV-5) comprises a group of heterogeneous viruses with a worldwide distribution. Primary infection typically occurs early in life, which is followed by latency and periodic recrudescence of the virus. The aim of this study was to determine the genetic variation of EHV-5 in individual animals over time and to determine the dynamics of EHV-5 spread among selected mare-foal pairs at three horse studs. The partial glycoprotein B () gene was amplified from archival nasal swab samples. Sequences from 3-5 clones from each PCR product were compared using identity matrix, phylogeny...
Chwirot A, Niedźwiedź A, Stygar D, Siwińska N, Paszkowska M, Niżański W, Napierkowska S, Migdał P, Kublicka A, Marynowska M, Matczuk A....This study investigated the presence of antibodies to human adenovirus type 36 (HAdV-D36) in horses with different metabolic statuses, including normal, overweight, and those diagnosed with equine metabolic syndrome (EMS). A total of 151 serum samples were tested, of which 47.6% were positive for anti-HAdV-D36 antibodies. Although the horses were confirmed to be susceptible to HAdV-D36 infection, there was no significant correlation between infection and blood glucose or cholesterol levels. However, the triglyceride levels showed significant differences-they were particularly elevated in the s...
Loyd A, Neto R, Caldwell F, Boone L, White A.This study aimed to determine the safety and macroscopic/microscopic effects of fluorescence biomodulation (FBM) on experimentally induced, full-thickness, distal limb wounds in horses.This was an experimental study ( = 6 horses). Two full-thickness wounds were created on both dorsal metacarpi of six adult horses. Each forelimb was randomly allocated to either control (no FBM) or treatment (FBM) and randomly allocated to visual or histological assessment of healing. Wounds were treated within each experimental group every 7 days for four treatments. Fluorescence biomodulation wounds were ...
Pereira EL, Pereira GR, Osório ML, Terra JLA, Gayger JB, Gularte JS, Demoliner M, Pereira VMAG, Filippi M, de Matos QS, Tessman A, Canal CW, Daudt C....Papillomaviruses (PV) are significant agents capable of inducing simple, multiple, and/or proliferative lesions in the dermis and epidermis of animals, known as cutaneous papillomatosis. These lesions can be benign or malignant and have been identified in various hosts, including mammals, birds, reptiles, and fish. PVs are strictly species- and tissue-specific, although some established and unusual cases of cross-infection, such as BPV in equine sarcoids, have been reported. Sarcoids are horses' most common skin tumors, which can be locally aggressive and cause significant clinical signs. It i...
Merari A, Fielding L.To describe patient characteristics, laboratory data, fetal orientation, methods of correction, survival, and treatment in miniature equids with dystocia. Methods: Retrospective study conducted from January 2002 to June 2023. Methods: Equine referral hospital and field service. Methods: Seventy animals with a total of 78 instances of dystocia. Methods: None. Results: Recorded variables included signalment, clinicopathologic data, fetal presentation, correction method, survival to discharge, and complications. The survival of miniature equid mares was 94% (73/78), while survival of foals was 17...
Majcher AM, Troillet A, Gerlach K, Tönnies PR, Brehm W, Ulrich R.Nine days after a surgical intervention due to an injury of the left hind hoof capsule, a 9-y-old, 538-kg female Wielkopolski horse was found recumbent in its stall with an unplugged permanent intravenous catheter positioned in the left jugular vein. Despite immediate resuscitation attempts, the animal died within minutes. Suspecting venous air embolism, radiographic imaging and detailed postmortem examinations were performed. However, visualization of the heart by radiography was hindered by the animal's body mass and postmortem changes. The autopsy followed a modified Richter method, origina...
Kovarikova S, Blahova J, Steffenova V, Vaskova N, Jahn P.Currently, there is relatively little published information on the urine protein-to-creatinine (UPC) ratio in horses, a parameter commonly used in dogs and cats. The aim of this study was to determine the reference range of UPC in urine samples of apparently healthy horses and to assess the influence of age and sex. Urinalysis and the determination of urinary protein and creatinine concentrations and ratios were performed. A total of 118 urine samples from apparently healthy horses were included in the study: 10 from foals younger than 6 months and 108 from horses older than 1 year. The median...
Chinyere CN, Ajaebili AC, Peter-Ajuzie IK, Galadima HB, Daodu OB, Fatola OI, Okolo CC, Alaba BA, Akinniyi OO, Omoniwa DO, Edeh ER, Olorunfemi AB....African horse sickness (AHS) is a severe, infectious arthropod-borne disease of equids caused by the AHS virus (AHSV). It is endemic in Sub-Saharan Africa, and several sporadic outbreaks of the disease have been reported in Nigeria in the past 5 decades. Following a recent outbreak of the disease in Lagos State, this study was conducted to investigate the prevalence of (AHSV) antibodies in apparently healthy horses and some selected wildlife sampled in four geographical regions of Nigeria. Using a competitive enzyme-linked immunosorbent assay, 575 serum samples collected from horses in five ...
Toda J, Miyasaka J, Osako H, Murata K, Yunus M, Amalia R, Soe BK, Sato H.Food poisoning caused by consuming raw horsemeat contaminated with Sarcocystis is a significant public health concern. Two morphotypes of sarcocysts in horsemeat, characterized by upright and folded villar protrusions, are typically identified as Sarcocystis fayeri and S. bertrami, respectively. However, recent molecular studies focusing on the ribosomal RNA gene (rDNA) and mitochondrial cytochrome c oxidase subunit I gene (cox1) have indicated a conspecific relationship between these two morphotypes using a limited number of specimens. To explore further genetic diversity in equid sarcocysts,...
Jebbawi F, Olomski F, Inversini V, Keller G, Rhiner T, Waldern N, Lam J, Pantelyushin S, Canonica F, Birkmann K, Johansen P, Kündig TM....Skin allergies are among the most frequent types of allergies, where continuous investigation of the pathological immune mechanisms is required for a better understanding and a more effective treatment of the disease. In this study, we aimed to investigate the effect of interleukin (IL)-5 vaccination on allergen-specific IgE antibodies as well as T cell cytokine modulation in skin allergy using a mouse model and a naturally occurring disease in horses. Methods: Ovalbumin (OVA)-sensitized mice, as well as horses affected by equine insect bite hypersensitivity (IBH) were administered an anti-IL-...
de Souza LWG, Oliveira EA, Vieira JW, Farias WAWA, de Souza Santos W, Neves LP, Perini AP.Portable X-ray equipments are commonly used in diagnostic radiology of equine patients. Despite its benefits, the exposure to ionizing radiation can pose a health risk to workers as physical restraint of patients is typically required. In this context, the aim of this study was to apply Monte Carlo simulation to investigate occupational exposure in the diagnosis of horses. The simulations were carried out by the Monte Carlo N-Particle 6.2 (MCNP6.2) code. The workers were represented by a FASH3 (female) and MASH3 (male) virtual anthropomorphic phantoms. To simulate the horse, a realistic virtua...
Janshoff S, Plümers R, Ramsauer AS, Cavalleri J, Vollmer T, Todt D, Brown RJP, Steinmann E, Gömer A.The emergence of new pathogens poses a significant threat to global health, exacerbated by climate change, biodiversity loss, and increased globalization. Ticks, as vectors for various pathogens, contribute to the rising incidence of diseases. Surveillance programs are crucial for identifying and controlling emerging pathogens. This study focuses on the Alongshan virus (ALSV), a segmented flavi-like virus first identified in humans in China in 2017. Despite its ability to infect a wide range of mammals, the natural hosts and transmission pathways of ALSV remain poorly understood. Therefore, we...
Maas LT, Morgan JM, Case J, Chell DD, McLean AK.Mules and donkeys are the 5th largest equine population in the U.S., yet basic information such as heart rate and arrhythmia prevalence in mules has not been described. Analysis of heart rate variability (HRV) provides valuable insight into physiologic and autonomic differences between mules, horses, and donkeys. We aimed to pilot the evaluation of heart rate and variability in a healthy population of mules using a 24 h electrocardiogram. Twenty-four-hour ambulatory electrocardiogram (aECG) recordings were collected from an athletic population of seven privately owned healthy mules in Northern...
The Shagya Arabian horse breed was created to address the need of Imperial Hussars (Hungarian light horsemen) for a horse with the intelligence, essential characteristics, and endurance of the Arabian breed, but also of a bigger size and having a better weight-carrying capacity and jumping ability. The present study aimed to explore the genetic variability and population structure of the uninvestigated Shagya Arabian horse population in Bulgaria based on genotyping at 15 equine microsatellite markers. A total of 140 horses belonging to six genealogical lines (Dahoman, Gazal, Ibrahim, Kuhailan ...
Huisman I, Groenestein CM, Vellinga TV, Pishgar-Komleh SH.Sustainability is gaining growing attention within the equine sector. Sustainability consists of various subjects including feed and nutrition, resource efficiency, animal welfare, carbon footprint (CFP) and biodiversity, for example. Studies in horse research focus mainly on behaviour and welfare. Little information is available about the environmental impact of equids. The few studies that can be found are principally concerned with local impact, such as nitrogen leaching or ammonia concentrations in bedding. Little is known about greenhouse gas emissions (GHG) for horses, although GHG emiss...
Liu F, Zhang J, Kong L, Wu R, Jiang Q, Lu Y, Li X.As an interspecies hybrid inheriting genetic material from horse and donkey lineages, mules provide a unique model for studying allele-specific regulatory dynamics. Here, we isolated adult fibroblasts (AFs) and placental fibroblasts (PFs) from mule tissues and reprogrammed them into induced pluripotent stem cells (iPSCs). Intriguingly, placental fibroblast-derived iPSCs (mpiPSCs) exhibited reduced reprogramming efficiency compared to adult fibroblast-derived iPSCs (maiPSCs). Through allele-specific expression (ASE) analysis, we systematically dissected transcriptional biases in parental cell t...
Medina-Bolívar AL, Muñoz-Duque JD, Martínez-Aranzales JR.Information regarding Survivin protein expression in the gastric mucosa of equids is scarce. This protein has been associated with functions related to modulating apoptosis and promoting mitosis in epithelial cells and is considered part of gastric cytoprotection mechanisms in humans and mice, maintaining mucosal integrity and regulating cellular renewal. Objective: This study aimed to determine the expression of cytoplasmic and nuclear Survivin in gastric mucosae of equids (horses, donkeys, and mules). Methods: A total of 30 healthy stomachs, 10 from each species, were evaluated using histolo...
Raidal SL, Freccero F, Carstens A, Weaver S, Padalino B.Transportation of horses has been associated with colic and changes to the gastrointestinal microbiome. Percutaneous abdominal ultrasonography using wireless, point-of-care transducers can be used to assess gastrointestinal motility in field settings. Unassigned: Characterization of intestinal motility and salivary cortisol responses of horses completing commercial transportation of 10-12h. Unassigned: Prospective observational study of 30 horses with diverse signalment and transport histories. Clinical parameters, sonographic assessment of intestinal motility and saliva samples, were collecte...
Bergeler J, Liske-Schmitz A, Schmitz T, de Camp NV.The First Night Effect is a phenomenon whereby sleep duration and quality are compromised in unfamiliar environments or situations. Horses are often transported to new locations, such as sporting events. We wanted to know if the First Night Effect is also detectable in horses in two different populations. To investigate this, we compared five horses from a professional sports horse barn that are regularly used in competitions, with six horses from a breeding barn, that are less frequently transferred to unfamiliar places. Despite the significant differences observed in electroencephalography (...
Van Buren SL, Petersen JL, Brown CT, Finno CJ.With advancing genomic technologies, single-nucleotide polymorphism (SNP) arrays and whole genome sequencing (WGS) have become essential tools in equine genetic research. In this study, we assessed the concordance in SNP calls and trait-mapping efficacy by comparing data of 21 horses both genotyped on the Equine 670 K SNP array and sequenced at either ~12× or ~30× depth. Our analysis revealed that higher sequencing depths were significantly associated with fewer discordant calls between platforms. Additionally, we investigated the most frequent no-call and discordant positions and identifi...
Aboelmaaty AM, El-Seadawy IE, Kotp MS, Mohamed AA, El-Debaky HA, El-Badry DA, Anwer AM, Tsvetkov T, Daneva T, Elgabry MA.Alpha-tocopherol is one of the non-enzymatic lipophilic antioxidants. Butylated hydroxytoluene (BHT) is a synthetic analog with similar modes of action in protecting the cryopreserved sperms. Objective: This study hypothesized that a certain concentration of any antioxidant is suitable for improving the post-thaw semen quality of stallions. Methods: To determine the optimum BHT concentration, a synthetic antioxidant similar to vitamin E in potency and scavenging oxidative stress power in concentrations of 0.0, 0.25, 0.50, 1.0, 2.0, and 4.0 mM/ml were added to semen extender. The post-thaw sper...
Wunderlich G, Bull M, McGilchrist N, Zhao C, Ross T, Rose M, Chapman B.The equine gut microbiome is a complex and dynamic ecosystem, housing a diverse consortium of bacteria and anaerobic fungi (AF) capable of breaking down complex plant matter and converting it into vital energy sources for their host. The aim of this study was to broaden our current understanding of bacterial and AF diversity in the equine hindgut and how it differs between cohorts and responds to dietary shifts. Results: Faecal samples were collected from 48 horses and the bacteriome and anaerobic mycobiome analysed using long-read amplicon sequencing. Samples were collected from racehorses (R...
Ferreira I, Pinto JG, Oliveira EGL, Azevedo MCBS, Marcolino LMC, Ferreira-Strixino J.Habronema muscae is a parasitic nematode that causes habronemiasis in horses, leading to chronic skin lesions. The parasite is transmitted via flies, and larvae deposited in wounds result in difficult-to-heal "summer sores". This case study involved treating a 9-year-old gelding male horse with recurrent habronemiasis using photodynamic therapy (PDT) concurrent with conventional treatments. The horse presented with ulcerated, exudative wounds on its limbs and face, unresponsive to traditional treatments. PDT was applied over six months, using methylene blue (MB) as a photosensitizer, combined ...
McFarlane D, Donaldson MT, McDonnell SM, Cribb AE.To investigate effects of sample handling, storage, and collection time and season on plasma alpha-melanocyte-stimulating hormone (alpha-MSH) concentration in healthy equids. Methods: 11 healthy Standardbreds and 13 healthy semiferal ponies. Methods: Plasma alpha-MSH concentration was measured by use of radioimmunoassay. Effects of delayed processing were accessed by comparing alpha-MSH concentrations in plasma immediately separated with that of plasma obtained from blood samples that were stored at 4 degrees C for 8 or 48 hours before plasma was separated. Effects of suboptimal handling were ...
Ghafar A, Abbas G, Beasley A, Bauquier J, Wilkes EJA, Jacobson C, McConnell E, El-Hage C, Carrigan P, Cudmore L, Tennent-Brown B, Hurley J....This review is aimed to (i) appraise the literature on the use of molecular techniques for the detection, quantification and differentiation of gastrointestinal helminths (GIH) of equids, (ii) identify the knowledge gaps and, (iii) discuss diagnostic prospects in equine parasitology. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews, we retrieved 54 studies (horses: 50/54; donkeys and zebras: 4/54) from four databases. Polymerase chain reaction (PCR) was employed in all of the studies whereas PCR amplicons were sequenced...
Rendle DI, Cottle HJ, Love S, Hughes KJ.In equids, chorioptic mange is a common dermatitis for which there are no licensed medications in the uk. Doramectin and fipronil are licensed for the control of ectoparasites in other species and were evaluated for the treatment of 17 cases of chorioptic mange in 13 equids. Equids were included if clinical findings were indicative of chorioptic mange, chorioptes mites were positively identified and concurrent disease that could affect response to disease was not evident. A random number table was used to allocate subjects to receive doramectin (group D, eight animals) or fipronil (group F, ni...
Schvartz G, Farnoushi Y, Berkowitz A, Edery N, Hahn S, Steinman A, Lublin A, Erster O.In this report we describe the molecular and pathological characteristics of West Nile virus (WNV) infection that occurred during the summer and fall of 2018 in avian species and equines. WNV is reported in Israel since the 1950s, with occasional outbreaks leading to significant morbidity and mortality in birds, high infection in horses and humans, and sporadic fatalities in humans. Methods: Animal and avian carcasses in a suitable condition were examined by post-mortem analysis. Tissue samples were examined for WNV by RT-qPCR and the viral load was quantified. Samples with sufficient material...
Costantini D, Seeber PA, Soilemetzidou SE, Azab W, Bohner J, Buuveibaatar B, Czirják GÁ, East ML, Greunz EM, Kaczensky P, Lamglait B, Melzheimer J....Viruses may have a dramatic impact on the health of their animal hosts. The patho-physiological mechanisms underlying viral infections in animals are, however, not well understood. It is increasingly recognized that oxidative stress may be a major physiological cost of viral infections. Here we compare three blood-based markers of oxidative status in herpes positive and negative individuals of the domestic horse (Equus ferus caballus) and of both captive and free-ranging Mongolian khulan (Equus hemionus hemionus) and plains zebra (Equus quagga). Herpes positive free-ranging animals had signifi...
Geigl EM, Grange T.The Equidae have a long evolutionary history that has interested palaeontologists for a long time. Their morphology-based taxonomy, however, is a matter of controversy. Since most equid species are now extinct, the phylogenetic tree based on genetic data can be established only imperfectly via deduction of present day genomes and little is known about the past genetic diversity of these species. Recent studies of ancient DNA preserved in fossil bones have led to a simplification of the phylogenetic tree and the classification system. The situation is still particularly unclear for the wild ass...
Gadella BM, Rathi R, Brouwers JF, Stout TA, Colenbrander B.During sexual reproduction, the sperm and oocyte must fuse before the production of a diploid zygote can proceed. In mammals such as equids, fusion depends critically on complex changes in the plasma membrane of the sperm and, not surprisingly, this membrane differs markedly from that of somatic cells. After leaving the testes, sperm cease to synthesize plasma membrane lipids or proteins, and vesicle-mediated transport stops. When the sperm reaches the female reproductive tract, it is activated by so-called capacitation factors that initiate a delicate reorientation and modification of molecul...
Durham AE, Potier JF, Huber L.Use of plasma adrenocorticotropic hormone (ACTH) concentrations for the diagnosis of PPID in equids requires awareness of other factors that might influence ACTH concentrations, including breed and time of year. This study was designed to investigate effects of breed on plasma ACTH concentrations and potential interactions between breed and time of year. Ten breeds were selected from a laboratory database containing data on plasma ACTH concentrations. Breeds represented were Arabians, Cobs, Connemara ponies, donkeys, Irish Sports horses, New Forest ponies, Shetland ponies, Thoroughbreds, Warmb...
Deshiere A, Berthet N, Lecouturier F, Gaudaire D, Hans A.Equine infectious anemia virus (EIAV) is responsible of acute disease episodes characterized by fever, anemia, thrombocytopenia and anorexia in equids. The high mutation rate in EIAV genome limited the number of full genome sequences availability. In the present study, we used the SureSelect target enrichment system with Illumina Next Generation Sequencing to characterize the proviral DNA of Equine Infectious Anemia Virus (EIAV) from asymptomatic horses. This approach allows a direct sequencing of the EIAV whole genome without cloning or amplification steps and we could obtain for the first ti...
Matthee S, Krecek RC, McGeoch MA.The intestinal helminth communities of 8 horses, 12 donkeys, 21 Hartmann's mountain zebras, and 44 Burchell's zebras were compared using the original data from 6 studies in South Africa and Namibia. Necropsy and worm recovery techniques were comparable between the studies. Sixty helminth species (58 nematode, 1 cestode, and 1 trematode species) were recorded. There were significant differences in the helminth community structures of the 4 Equus species. The helminth communities of the 2 closely related zebra subspecies were most similar, and they jointly shared 7 helminth species with donkeys ...
How MJ, Gonzales D, Irwin A, Caro T.Of all hypotheses advanced for why zebras have stripes, avoidance of biting fly attack receives by far the most support, yet the mechanisms by which stripes thwart landings are not yet understood. A logical and popular hypothesis is that stripes interfere with optic flow patterns needed by flying insects to execute controlled landings. This could occur through disrupting the radial symmetry of optic flow via the aperture effect (i.e. generation of false motion cues by straight edges), or through spatio-temporal aliasing (i.e. misregistration of repeated features) of evenly spaced stripes. By r...
Anderson JR.Although some definitions of thanatology-broadly definable as the study of death and dying-exclude nonhumans as subjects, recognition of the scientific value of studying how other species respond to sick, injured, dying and dead conspecifics appears to be growing. And whereas earlier literature was largely characterized by anecdotal descriptions and sometimes fanciful interpretations, we now see more rigorous and often quantitative analysis of various behaviors displayed towards conspecifics (and sometimes heterospecifics) at various stages of incapacitation, including death. Studies of social...
D'Ambrosia AR, Clyde WC, Fricke HC, Gingerich PD, Abels HA.Abrupt perturbations of the global carbon cycle during the early Eocene are associated with rapid global warming events, which are analogous in many ways to present greenhouse warming. Mammal dwarfing has been observed, along with other changes in community structure, during the largest of these ancient global warming events, known as the Paleocene-Eocene Thermal Maximum [PETM; ~56 million years ago (Ma)]. We show that mammalian dwarfing accompanied the subsequent, smaller-magnitude warming event known as Eocene Thermal Maximum 2 [ETM2 (~53 Ma)]. Statistically significant decrease in body size...
Tardif S, Brady HA, Breazeale KR, Bi M, Thompson LD, Bruemmer JE, Bailey LB, Hardy DM.Zonadhesin is a rapidly evolving protein in the sperm acrosome that confers species specificity to sperm-zona pellucida adhesion. Though structural variation in zonadhesin likely contributes to its species-specific function, the protein has not previously been characterized in organisms capable of interbreeding. Here we compared properties of zonadhesin in several animals, including the horse (Equus caballus), donkey (E. asinus), and Grevy's zebra (E. grevyi) to determine if variation in zonadhesin correlates with ability of gametes to cross-fertilize. Zonadhesin localized to the apical acroso...
Bogle OA, Carrasco RA, Ratto MH, Singh J, Adams GP.The objectives of the study were to compare the presence and localization of ovulation-inducing factor (OIF)/nerve growth factor (NGF) in male reproductive organs and determine the abundance in ejaculates of species representative of both spontaneous and induced ovulators. We hypothesized that the protein is a widely conserved component of semen among mammals, but is most abundant in camelids. Immunohistochemical analysis was performed on tissues from the male reproductive system of llamas, rats, cattle, bison, elk, and white-tailed deer (n = 2 males/species), and the abundance of OIF/NGF in...
Schutzer SE, Schlater LR, Ronning CM, DeShazer D, Luft BJ, Dunn JJ, Ravel J, Fraser-Liggett CM, Nierman WC.Burkholderia mallei is an understudied biothreat agent responsible for glanders which can be lethal in humans and animals. Research with this pathogen has been hampered in part by constraints of Select Agent regulations for safety reasons. Whole genomic sequencing (WGS) is an apt approach to characterize newly discovered or poorly understood microbial pathogens. Results: We performed WGS on a strain of B. mallei, SAVP1, previously pathogenic, that was experimentally infected in 6 equids (4 ponies, 1 mule, 1 donkey), natural hosts, for purposes of producing antibodies. Multiple high inocula wer...
Jones KE.The specialization of equid limbs for cursoriality is a classic case of adaptive evolution, but the role of the axial skeleton in this famous transition is not well understood. Extant horses are extremely fast and efficient runners, which use a stiff-backed gallop with reduced bending of the lumbar region relative to other mammals. This study tests the hypothesis that stiff-backed running in horses evolved in response to evolutionary increases in body size by examining lumbar joint shape from a broad sample of fossil equids in a phylogenetic context. Lumbar joint shape scaling suggests that st...
Burnik Šturm M, Ganbaatar O, Voigt CC, Kaczensky P.1. Competition among sympatric wild herbivores is reduced by different physiological, morphological, and behavioral traits resulting in different dietary niches. Wild equids are a rather uniform group of large herbivores which have dramatically declined in numbers and range. Correlative evidence suggests that pasture competition with livestock is one of the key factors for this decline, and the situation may be aggravated in areas where different equid species overlap. 2. The Dzungarian Gobi is currently the only place where two wild equid species coexist and share the range with the domestica...
Blanchard TL, Taylor TS, Love CL.Breeding records from a herd of mammoth asses (Equus asinus americanus) maintained on pasture in southeast Texas from 1990 to 1998 were reviewed. Jennies were pasture or hand mated, and estrus was either observed while the jennies were on pasture or when exposed to a jack after being penned. Eighty-one estrus periods and 43 diestrus intervals were recorded in 33 jennies over 4 seasons of the year (January-March, April-June, July-September, and October-December). Estrous cycle length and the duration of estrus were similar among seasons. Over all seasons, estrous cycle length was 23.3 +/- 2.6 d...
Sandmann D, Boycott BB, Peichl L.The morphology of horizontal cells chiefly of the horse, but also of asses, mules, and a zebra, has been examined by Lucifer yellow injections into lightly fixed retinae and by immunocytochemistry. In common with other mammals, equids have a B-type horizontal cell, i.e., a cell with dendrites synapsing with cones and possessing a single axon synapsing with rods. Most mammalian retinae have a further type of horizontal cell, the A-type, also synapsing with cones but without an axon. The second type of horizontal cell in equids also has no axon; otherwise, it is most unusual. Compared with other...
Smith D, Hamblin A, Edington N.Antisera to activated equine endothelial cells, which detected surface molecules of 116 kD, 97 kD, 42 kD and 38 kD, were made to investigate the role of endothelial adhesion molecules in equid herpes virus 1 infection. These putative adhesion molecules could be induced by 17-beta oestradiol, chorionic gonadotrophin, or IL-2, as well as by LPS and PWM. In an in vitro flow system, using equine veins or arteries, equid herpesvirus 1 in leucocytes was only transferred to infect endothelial cells if both leucocytes and endothelial cells expressed these surface molecules. Blocking of the membrane mo...
Malik P, Khurana SK, Dwivedi SK.Glanders, a notifiable highly contagious disease primarily of equids, is a disease of high zoonotic importance. Caused by gram-negative bacillus, Burkholderia mallei, the disease was restricted to certain pockets of India with sporadic cases. Recently, a major outbreak of glanders occurred in India starting from Maharashtra. Following clinical signs and symptoms and laboratory investigations on serum, nasal swab and pus swab samples, it was confirmed as glanders among equines in Pune and Panchgani areas of Maharashtra. One pus sample and three nasal swabs yielded B. mallei isolates while 23 se...
Haspeslagh M, Vlaminck LE, Martens AM.OBJECTIVE To evaluate outcomes following treatment of sarcoids in equids and to identify risk factors for treatment failure in these patients. DESIGN Retrospective case series. ANIMALS 230 equids with 614 sarcoids. PROCEDURES Records were searched to identify equids treated for ≥ 1 sarcoid between 2008 and 2013. A standardized protocol was used to determine treatment choice (electrosurgery, electrosurgery with intralesional placement of cisplatin-containing beads, topical administration of imiquimod or acyclovir, cryosurgery, bacillus Calmette-Guerin vaccine injection, or intralesional injec...
Luethy D, Frimberger AE, Bedenice D, Byrne BS, Groover ES, Gardner RB, Lewis T, MacDonald VS, Proctor-Brown L, Tomlinson JE, Rassnick KM, Johnson AL.Prognosis associated with lymphoma in horses is poorly characterized, and treatment is often palliative. Long-term outcome after chemotherapy for horses with lymphoma is not well documented. Objective: To report long-term outcome of horses with lymphoma treated with chemotherapy. Methods: Fifteen equids. Methods: Retrospective case series. Medical record search and call for cases on the ACVIM listserv for horses treated with chemotherapy for lymphoma. Results: Fifteen cases with adequate data were identified. Complete remission was achieved in 5 horses (33.3%), partial response was achieved in...
Skelton MS, Kremer DE, Smith EW, Gladden LB.Transport of lactate across the erythrocyte membrane proceeds by three distinct pathways: 1) nonionic diffusion of lactic acid, 2) inorganic anion exchange (band 3), and 3) a monocarboxylate-specific (MC) carrier mechanism. This study determined the contributions of these three pathways in the red blood cells (RBCs) of "athletic" and "nonathletic" species. Blood samples were obtained from four male animals of each species: 1) Canis familiaris (dogs), 2) Capra hircus (goats), 3) Equus caballus (horses), and 4) Bos taurus (cattle). Contribution of each pathway to total lactate influx was determi...
Musilova P, Kubickova S, Zrnova E, Horin P, Vahala J, Rubes J.Using laser microdissection we prepared a set of horse chromosome arm-specific probes. Most of the probes were generated from horse chromosomes, some of them were derived from Equus zebra hartmannae. The set of probes were hybridized onto E. grevyi chromosomes in order to establish a genome-wide chromosomal correspondence between this zebra and horse. The use of arm-specific probes provided us with more information on the mutual arrangement of the genomes than we could obtain by means of whole-chromosome paints generated by flow sorting, even if we used reciprocal painting with probe sets from...
Rørvang MV, Christensen JW, Ladewig J, McLean A.Prima facie, the acquisition of novel behaviors in animals through observation of conspecifics seems straightforward. There are, however, various mechanisms through which the behavior of animals can be altered from observing others. These mechanisms range from simple hard-wired contagious processes to genuine learning by observation, which differ fundamentally in cognitive complexity. They range from social facilitation and local enhancement to true social learning. The different learning mechanisms are the subject of this review, largely because research on learning by observation can be conf...
Barlaam A, Traversa D, Papini R, Giangaspero A.Over the past few decades, among equine parasitoses caused by gastrointestinal nematodes, habronematidosis has been discontinuously studied worldwide. Habronematidosis is a parasitic disease distributed all over the world. It is caused by Habronema microstoma, Habronema muscae, and Draschia megastoma (Spirurida, Habronematidae), and it is maintained in the environment by muscid flies which act as intermediate hosts. At larval and adult stages these species live in the stomach of domestic and wild equids. However, the larvae can also be found on the skin, causing lesions known as "summer sores"...
Zedda M, Sathe V, Chakraborty P, Palombo MR, Farina V.The microstructural features of the tissue of long bones subjected to different biomechanical stresses could be a helpful tool for a better understanding of locomotor behavior in extant and extinct mammals, including equids. However, few researches have attempted to describe the bone tissue of extinct horses. In our study, we analyze and compare the histomorphometric features of the bone tissue in extant modern horses, Equus caballus, and Equus namadicus, a Pleistocene Indian extinct wild horse. The number, position, and size of the osteons and Haversian canals of the bone tissue, classifiable...
Wise LN, Kappmeyer LS, Knowles DP, White SN.The equine parasite Theilera equi continues to curtail global equine commerce due primarily to its ability to persist indefinitely in the immunocompetent horse. Details regarding the parasite life cycle, pathogenesis and mechanism of persistence remain unclear. The recently discovered T. haneyi is also capable of persistence in the horse, creating a potential reservoir for additional infections. These two divergent parasites share a unique gene family that expresses surface merozoite antigens, or equi merozoite antigens (EMAs). The EMA family was maintained in number and size in both parasites...
