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.
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 ...
Sharif MB, Mohaseb AF, Orlando L, Saliari K, Kunst GK, Czeika S, Mashkour M, Cucchi T, Peters J, Trixl S, Mohandesan E.The Roman conquest of the northern Alpine foreland in 15 BCE introduced larger-sized horses and hybrid mules to the region. To investigate their genetic profiles and influence on local breeding, we analyzed our previously generated shallow shotgun DNA data from 402 Late Iron Age and Roman equids, supplemented with mitochondrial and nuclear capture data from 40 to 31 equids from the same regions and periods. Late Iron Age and Roman horses exhibit high matrilineal diversity, with unique haplogroups in the latter indicating exogenous animals. The preferred use of male mounts in army service menti...
Badr C, Arbi M, Souiai O, Larbi I, Nsiri J, Elbehi I, Bouslama Z, Bennour MA, Essaied MS, Ines Khosrof , Chabchoub A, Ben Aoun B, Ghram A, Lachheb J.Equine influenza (EI) is a highly contagious viral respiratory disease affecting equids, with the potential of causing widespread outbreaks across Europe, the Americas, Asia, and other regions of the world. In Tunisia, in the spring of 2021, an EI virus outbreak occurred in a farm housing purebred Arabian horses that exhibited respiratory signs. This outbreak led to a national lockdown on horse movements and the cancellation of equestrian events. A total of 432 serum samples, collected from 2018 to 2021, were tested using ELISA competition assay. In addition, 100 Nasal swabs were collected dur...
Kuzmina TA, Königová A, Burcáková L, Syrota Y, Babják M, Várady M.Strongylids and parascarids are the most widespread equine parasites worldwide; however, up-to-date data from Slovakia remain limited. This work bridges that gap by examining the prevalence and level of gastrointestinal helminth infections in Slovak horses. In the study, 392 fecal samples from horses on 24 farms were analyzed using the McMaster method with a sensitivity of 50 eggs per gram (EPG) for detecting nematode eggs and a double-centrifugation/combined sedimentation-flotation protocol for detecting Anoplocephala spp. eggs. Information on the age and breed of horses, management condition...
Tramboo SR, Shahardar RA, Allaie IM, Bulbul KH.Benzimidazole (BZ) anthelmintics have been used indiscriminately in equids to control nematode infections throughout the world including India and has led to the development of BZ resistance. In order to determine the current status of BZ resistance in equids of Kashmir against intestinal strongyles (IS), the present study was conducted using faecal egg count reduction test (FECRT) and Allele specific PCR (AS-PCR). The study was conducted on ponies from three major tourist destinations of Kashmir viz; Gulmarg, Pahalgam and Sonamarg in accordance with the WAAVP guidelines. The animals which wer...
Oliveira LLV, Caldas MCAR, Marval LME, Marval CA, Carvalho JGS, Matos JJRT, Malacarne BD, Paz CFR.A 2-year-old mixed-breed mare was examined at the property due to swelling and fistula on the right mandible. Oral examination and radiographs revealed the presence of an apical abscess involving the 410 tooth. The tooth was extracted entirely and confirmed radiographically. One year later, the owner reported a reoccurrence of clinical signs. A new radiographic evaluation revealed a radiopaque area in the alveolar socket of the 410 tooth filled with spongy-looking bone. An extraoral approach to the alveolar socket was performed, and the content removed had the appearance of a dental element.
Cutarelli A, Buonavoglia A, Fusco G, Pellicanò R, Napoletano M, Brandt S, Roperto S.Sarcoids are benign and locally aggressive skin lesions that commonly affect horses and other equid species. Sarcoids are generally considered to be caused by bovine delta-papillomaviruses (δPVs) types 1 and 2 (BPV1 and BPV2, respectively). Moreover, while bovine δPV types 13 and 14 (BPV13 and BPV14, respectively) are also suspected to induce sarcoids, information regarding this possibility and the occurrence of multiple bovine δPV infections in sarcoids is scarce. This study aimed, for the first time, to assess BPV1, BPV2, BPV13, and BPV14 infections and co-infections in equine sarcoid sam...
Bailey VN, Gilbert BM, Vetter M, Oberhaus EL.The mechanism by which photoperiod influences the hypothalamic-pituitary-gonadal (HPG) axis and regulates seasonal reproduction in horses has yet to be fully elucidated. The hypophyseal pars tuberalis (PT) has been indicated as a critical site for the transduction of melatonin signals through melatonin-responsive, PT-specific cells that produce thyroid-stimulating hormone (TSH) in many mammalian species. However, this has yet to be investigated in horses. The objective of this study was to explore the interaction of melatonin and thyroid-stimulating hormone in the equine HPG axis. Pituitaries ...
Amari M, Brioschi FA, Auletta L, Ravasio G.Radiofrequency ablation (RFA) and pulsed radiofrequency (PRF) are non-pharmacological techniques employed in humans for chronic pain, but their veterinary application is unexplored. This pilot study evaluated clinical effects of RFA and PRF in twenty-four horses with chronic distal forelimb lameness. Ultrasound-guided RFA (N = 8; 60-90 °C, 2-8 min) or PRF (N = 16; 42 °C; 12 min) was applied to palmar digital nerves. Lameness was scored (American Association of Equine Practitioners scale) at baseline and monthly for six months (T1-T6). At T2, partial- and non-responders in both groups receive...
Ye T, Li XM, Tan WX, Wang CL, Jiang J, Zhao Q.Toxoplasmosis is a zoonotic infectious disease caused by T. gondii, a widely distributed obligate intracellular parasite. It has received widespread attention because it can infect a large number of domestic and wild animals, thereby posing a threat to public health and the economy on a global scale. Among them, equine animals are critical intermediate hosts. However, studies on T. gondii infection in equine animals are currently not systematic on a global scale. For this purpose, we conducted a systematic review and meta-analysis. Methods: This study searched for relevant studies in six signi...
Wasiński B, Złotnicka J, Kubajka M, Olejarczyk M, Szulowski K.Contagious equine metritis (CEM) is a cosmopolitan infectious, venereal disease of equids caused by the bacterium . Its frequently asymptomatic course leads to its prevalence sometimes being underestimated, and knowledge of the spread of infections with its causative agent is insufficient. The aim of this study is to summarise and present data on the incidence of infections in horses in Poland. Unassigned: In the years 2018-2023, routine laboratory tests of horses for CEM were carried out. Between 52 and 99 horses were examined annually. Swabs from the external parts of the urogenital system ...
Campos Schweitzer A, Vercherin A, Rossignol F.To report successful stabilization of three cervical fracture types with articular involvement using different ventral cervical intervertebral fusion constructs. Methods: A 9-year-old French sport pony gelding, a 5-year-old Anglo-Arabian gelding and a 2-year-old French Warmblood mare. Methods: Short case series. Methods: Ventral cervical intervertebral fusion was performed in three cervical fracture cases: A vertebral body, a vertebral arch and a unilateral facet joint fracture. Selected implants for this purpose were an 11-hole 4.5/5.0 LCP, a three-dimensional (3D)-printed titanium cervical i...
Sohn Y, An SJ, Forbes E, Yoon J, Kim BS, Kim JG, Ryu SH.To model lactate recovery kinetics in relation to sex, age, running speed, and racing experience, and to estimate blood lactate clearance time under passive recovery conditions that reflect current management practices in Jeju horses, a less well-characterized pony-sized indigenous breed. Unassigned: From October through December 2022, BLC was measured at baseline, 10 minutes after 800-m barrier trials (time [T]-1), and 50 minutes (T2) after 800-m barrier trials in 40 race-trained Jeju horses (2 to 4 years old). Lactate clearance was modeled using nonlinear regression with an exponential decay...
Rabei ȘO, Pivariu D, Cocian AI, Vaccaro D, Costache-Bobescu P, Mihalca AD.This study aimed to assess the efficacy of pyrethroid-based insecticides against Gasterophilus spp. egg-laying activity and to establish the seasonality patterns in the specific climatic area of Transylvania, Romania. To fulfil the aims of the study, a total of 40 horses were treated every 4 weeks and inspected every 2 weeks between 11 May and 6 November (Pilo et al. Parasitol Res 114:1693-1702, 2024). Through this period, eggs were found between 24 June and 2 November. The eggs were found on 34 out of 40 horses (prevalence = 85%, CI 95% = 73.43-96.56%). Overall, a total of 50,029 G...
Staiger EA, Pereira de Toledo A, Rizzato Paschoal V, Patterson Rosa L.Horse gaits are a trait highly selected and prized in diverse breeds. Meanwhile, gait classification relies mostly on subjective visual observations by evaluators. Noninvasive equipment able to track locomotion in horses and output quantitative gait parameters is not only helpful in evaluating locomotion but also in designating gait types and its variations. Equine locomotion pattern designation based solely on observer evaluation can be subjective; therefore, utilizing tools that provide quantitative results and track individual limb movements, especially during intermediate-speed gaits, can ...
Neto ME, Curcio BR, Rafael LA, Pivato GM, Silva GC, Souza RP, Mousquer MA, Nogueira CEW.The cesarian section (C-section) is a potential risk factor for retained fetal membranes (RFM) in mares, requiring prompt diagnosis and treatment to enhance outcomes. This study aimed to evaluate the use of umbilical vessel infusion for the treatment of RFM after elective C-section in mares. Ten pregnant criollo type-mares at 315 days of gestation were monitored daily and underwent elective C-section upon readiness for birth. All mares exhibited RFM, with placentas retained beyond three hours careful extraction of the foal by C-section. Those were randomly assigned into two groups: Umbilical v...
Carroll AT, Reed RA, Perlini M, Clough AE, Rocha M, Moorman VJ.To evaluate the effect of cervical epidural injection of morphine alone and morphine in combination with detomidine on recovery from anesthesia in horses. Methods: Blinded, randomized, crossover, Latin square design. Methods: A group of six healthy adult horses aged 9 ± 3 years and weighing 471 ± 76 kg (mean ± standard deviation). Methods: Horses were administered each of three treatments during a 1 hour general anesthetic with a 4 day washout period. Treatments were: 1) cervical epidural injection of saline 0.011 mL kg (S); 2) morphine 0.1 mg kg (M); and 3) morphine 0.1 mg kg with detomidi...
Shaffer SK, Medjaouri O, Swenson B, Eliason T, Nicolella DP.The ability to quantify equine kinematics is essential for clinical evaluation, research, and performance feedback. However, current methods are challenging to implement. This study presents a motion capture methodology for horses, where three-dimensional, full-body kinematics are calculated without instrumentation on the animal, offering a more scalable and labor-efficient approach when compared with traditional techniques. Kinematic trajectories are calculated from multi-camera video data. First, a neural network identifies skeletal landmarks (markers) in each camera view and the 3D location...
El-Shafaey ES, Hamed M, Amin Y, Alkhodair KM, Shousha S, Aljazzar A, El Sebaei MG, Mosbah E.External genitalia swellings represent diagnostic and treatment challenges in equids. Thus, the present study aimed to describe the clinical, histopathological, and treatment outcomes of external genitalia swellings in horses and donkeys. Unassigned: Seventy-five equids (49 horses and 26 donkeys) from 6 months to 8 years were enrolled based on the clinical evidence of external genital swellings. The descriptive details, including sex, age, lesion location, and treatment outcomes, for each case were recorded and analyzed. Unassigned: Twenty forms of external genital swellings were recorded ...
Zimmerman KL, Diehl KA.To determine if serum α2-macroglobulin (A2M) concentration varies based on donor species-canine or equine-and signalment. Methods: Serum A2M concentration ([A2M]) was measured in healthy dogs (n = 30) and horses (n = 31) using species-specific ELISAs. Results: Canine and equine [A2M] median (IQR; range) were 98.70 ng/mL (92.79 ng/mL; 34.33-696.18 ng/mL) and 557 000 ng/mL (437 900 ng/mL; 62 600-3 042 900 ng/mL), respectively. Equine [A2M] was significantly higher than canine [A2M]. Depending on the statistical analysis performed, sex had either no statistical (p...
Taylor DEF, Lancaster BE, Ellis AD.Visual observation to record grass intake is time-consuming and labour-intensive. Technological methods, such as activity monitors, have been used but only record head position. This study aimed to evaluate sound recorders attached to headcollars to acoustically measure grass intake behaviour in horses as a low-cost alternative method. Pilot Study 1 assessed 6 × 11 min periods comparing bites/min and chews/min between video footage (VD) and sound recorders (SR). Grazing was identified audibly (SR) and visually through soundwave pattern software (SR). Chew rates (SR: 47 ± 5 chews/min, VD: 43 ...
Horses have inhabited Iberia (present-day Spain and Portugal) since the Middle Pleistocene, shaping a complex history in the region. Iberia has been proposed as a potential domestication centre and is renowned for producing world-class bloodlines. Here, we generate genome-wide sequence data from 87 ancient horse specimens (median coverage = 0.97X) from Iberia and the broader Mediterranean to reconstruct their genetic history over the last ~26,000 years. Here, we report that wild horses of the divergent IBE lineage inhabited Iberia from the Late Pleistocene, while domesticated DOM2 horses, nati...
Equestrian sports play a significant economic role in the horse industry. In recent years, numerous equine viruses have emerged, among which are equine Pegiviruses and the re-emerging Equine coronavirus (ECoV). These viruses are distributed globally and primarily cause subclinical infections with unknown morbidity, even if ECoV can occasionally induce febrile and diarrheic episodes. To broaden the data on the Italian equine population, a study was conducted to assess their prevalence in two distinct horse populations belonging to the Carabinieri Corps (CC) and the Italian Army (IA) of the Ital...
Pinn-Woodcock TL, Llanos-Soto SG, Ivanek R, Goodrich E, Frye E, Wells A, Mullen K, Arbittier E, Hughes L, Berryhill E, Brosnahan P, Buslinger L....To determine whether seasonal variation in equine plasma ACTH concentrations is affected by latitude between 29.7°N and 45.0°N in the US. Unassigned: A cohort study was performed between June 2019 and May 2020 in which plasma ACTH was measured monthly by chemiluminescence immunoassay. The study involved 201 apparently healthy horses from 9 locations within the US classified into northern, central, and southern latitude cohorts. Data analysis was performed with 3 major objectives: (1) identify outlier ACTH concentrations and horses; (2) estimate ACTH upper reference limits to define expected ...
Bosch K, Zsoldos RR, Hartig A, Licka T.The influence of soft tissue structures, including ligaments spanning one or more intervertebral junctions and the nuchal ligament, on motion of the equine cervical joints remains unclear. The present study addressed this using four post-mortem horse specimens extending from head to withers with all ligaments intact. Three-dimensional kinematics was obtained from markers on the head and bone-anchored markers on each cervical and the first thoracic vertebra during rotation, lateral bending, flexion and extension of the whole head, and neck segment. Yaw, pitch, and roll angles in 8 cervical join...
Heun F, Delarocque J, Feige K, Hellige M.Nerve atrophy results in trigeminal nerve (TN) asymmetry detectable by magnetic resonance imaging (MRI) in humans, but similar studies have not been performed in horses with idiopathic trigeminal-mediated headshaking (ITMHS). Objective: Horses with ITMHS show greater MRI-detected trigeminal-nerve asymmetry than controls. Methods: A total of 20 adult horses with ITMHS and six unaffected control horses. Methods: Retrospective case-control study of the TN cross-sectional area (TNCSA) based on 3-Tesla MRI scans of the equine brain. TNCSA and its side-to-side differences at four defined measurement...
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...
