Veterinary research in horses encompasses the study of diseases, health management, and medical treatments specific to equine species. This field investigates various aspects of horse health, including infectious diseases, metabolic disorders, and musculoskeletal conditions. Researchers focus on understanding the pathophysiology of equine ailments, developing diagnostic tools, and evaluating therapeutic interventions. The study of horse health also involves examining preventive measures such as vaccination protocols and nutritional management to promote overall well-being. This page collects peer-reviewed research studies and scholarly articles that explore the diverse areas of veterinary science related to horses, providing insights into disease mechanisms, treatment strategies, and advancements in equine healthcare.
Busechian S, Bindi F, Pieramati C, Orvieto S, Pisello L, Cozzi S, Ortolani F, Rueca F.Equine gastric ulcer syndrome (EGUS) is a worldwide disease, and includes two different syndromes, Equine Squamous Gastric Disease (ESGD), affecting the squamous mucosa, and Equine Glandular Gastric Disease (EGGD), affecting the glandular mucosa. These two diseases are present in different categories (different activities, ages, etc.) and breeds of horses. The effect of sex on gastric health is not clear: some studies found a higher prevalence of ESGD in geldings and stallions, while others found no influence of sex on the squamous mucosa. The few studies conducted on glandular diseases failed...
Tesena P, Vinijkumthorn R, Preuksathaporn T, Piyakul P, Chotikaprakal T, Sirireugwipas R, Wong-Aree K, Prapaiwan N.Phenylbutazone (PBZ) is a widely used nonsteroidal anti-inflammatory drug for horses. However, because of its gastrointestinal side effects, its administration requires careful attention in veterinary practice. Malondialdehyde (MDA) is a serum biomarker associated with increased damage to the equine gastrointestinal system. This study investigated the hematological effects and alterations in the gastrointestinal tract and assessed serum MDA concentrations following repeated oral PBZ administration at clinical doses. Fourteen horses were randomly divided into control and treatment groups. All h...
Zečević I, Picardeau M, Vince S, Hađina S, Perharić M, Štritof Z, Stevanović V, Benvin I, Turk N, Lohman Janković I, Habuš J.Leptospirosis is one of the most common zoonotic infections and a major problem in terms of both veterinary medicine and public health. However, the disease is under-recognised and under-diagnosed worldwide, particularly in horses. Clinical leptospirosis in horses is mainly associated with recurrent uveitis (ERU), which has recently been studied more intensively, and reproductive disorders, the epidemiology of which is still relatively poorly understood. To enhance our comprehension of abortions caused by leptospirosis in horses and to identify the causative strains, a serological study was ca...
Miglio A, Falcinelli E, Mezzasoma AM, Busechian S, Rueca F, Gresele P, Antognoni MT.Physical exercise has an activating effect on platelet function that differs between trained and untrained subjects, depending on the type of exercise and training status. In humans, soluble P-selectin (sP-sel) and platelet-derived extracellular vesicles (PEVs) are considered reliable markers of platelet activation during exercise. In untrained humans, they increase after transient physical exercise, whereas long-term training induces a decrease in their resting levels due to an improved ability to adapt to hemodynamic changes. The aim of this study was to assess whether circulating levels of...
French KM, Musiał AD, Karczewski M, Daugnora L, Shiroukhov R, Ropka-Molik K, Baranowski T, Bertašius M, Skvortsov K, Szymański P....Horse sacrifice and deposition are enigmatic features of funerary rituals identified across prehistoric Europe that persisted in the eastern Baltic. Genetic and isotopic analysis of horses in Balt cemeteries [1st to 13th centuries CE (Common Era)] dismantle prevailing narratives that locally procured stallions were exclusively selected. Strontium isotope analysis provides direct evidence for long-distance (~300 to 1500 kilometers) maritime transport of Fennoscandian horses to the eastern Baltic in the Late Viking Age (11th to 13th centuries CE). Genetic analysis proves that horses of both sexe...
Oliveira BE, Canola PA.Ultrasonographic imaging of the diaphragm is a non-invasive alternative for respiratory function evaluation in horses. This study aimed to measure diaphragm thickness, thickening (change in thickness with contraction) and thickening fraction in healthy adult horses during tidal breathing and forced vital capacity. Correlation between body weight (≤400 kg and >400 kg) and diaphragm thickness was investigated. To that purpose, 20 adult horses, weight 409±50 kg, height 1.47±0.05 m, and age 16±6 years were included in the study. Diaphragm thickness was measured at end-inspiration and end-e...
Houben RMAC, Newton JR, van Maanen C, Waller AS, Sloet van Oldruitenborgh-Oosterbaan MM, Heesterbeek JAP.Strangles, a disease caused by infection with Streptococccus equi subspecies equi (S. equi), is endemic worldwide and one of the most frequently diagnosed infectious diseases of horses. Recent work has improved our knowledge of key parameters of transmission dynamics, but important knowledge gaps remain. Our aim was to apply mathematical modelling of S. equi transmission dynamics to prioritise future research areas, and add precision to estimates of transmission parameters thereby improving understanding of S. equi epidemiology and quantifying the control effort required. A compartmental deter...
Bampidis V, Azimonti G, Bastos ML, Christensen H, Durjava M, Kouba M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of tinctures obtained from the dried leaves of L. (ginkgo tinctures) when used as sensory additives. The tinctures are water/ethanol solutions with a dry matter content of 5.7% (tincture A) and 3.0% (tincture B). The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additives under assessment are safe for the target species at the following concentrations in complete feed: (i) ginkgo tincture A at 240 mg/kg for horses and ...
Sanigavatee K, Poochipakorn C, Huangsaksri O, Wonghanchao T, Yalong M, Poungpuk K, Thanaudom K, Chanda M.Strenuous exercise in traditional polo matches creates enormous stress on horses. Hematological and physiological measures may vary across different field-play positions. This study aimed to investigate the effort intensity and the impact of exertion on hematology and heart rate variability (HRV) in polo ponies with different positions. Thirty-two ponies, divided equally into eight teams, were studied. Each comprises forwards (number 1), midfielders (numbers 2 and 3), and defenders (number 4). Team pairs played the first chukka in four low-goal polo matches. Percent maximum heart rate (%HRmax)...
Steensma MJ, Doekes HP, Pook T, Derks MFL, Bakker N, Ducro BJ.In the past, small population sizes and unequal ancestor contributions have resulted in high inbreeding rates (ΔF) in the Friesian horse. Two decades ago, the studbook implemented a mating quota and started publishing individual kinships and reduced ΔF below 1% per generation. However, since then, the breeding population size has decreased and this raises the question whether current breeding strategies are sufficient to keep ΔF below desired rates. The aim of this study was to (1) reflect on past inbreeding trends and their main determinants, using pedigree analysis and (2) evaluate the ef...
Watkins A, Engiles J, Long A, Brandly J, Hopster K.Large colon volvulus is a cause of colic in horses with high morbidity and mortality when not promptly treated. More treatment options are needed to improve the outcome of these cases by protecting against the damage caused by ischaemia and reperfusion injury. Objective: To determine the effect of preconditioning with dexmedetomidine prior to induction of ischaemia-reperfusion (IR) injury in a large colon volvulus model in the horse. Methods: Randomised blinded in vivo experiments. Methods: Horses received either a dexmedetomidine (DEX) or saline (CON) constant rate infusion (CRI) immediately ...
Sala-Ayala L, Martínez-Boví R, Querol-Paajanen A, Cuervo-Arango J.The aims of this study were to determine the effect of the embryo flushing technique and the number of flushing attempts performed by operators of different experience on embryo recovery (ER). Ten non-lactating mares were inseminated with the same stallion in six cycles each (n = 60). Embryo flushing (EF) was performed 7-9 days after ovulation by three operators (OP; 20 EF cycles each): OP1 had performed >500 EF before the study, while OP2 and 3 had performed 0 EF. Each EF was performed with 2 flushing attempts (FA) using 1L of ringer's lactate "in-and-out" using two EF techniques: 1) ...
Hallowell KL, Dembek K, Horne CR, Knych HK, Messenger KM, Schnabel LV.Steroid-associated laminitis remains a major concern with use of corticosteroids in horses. Individual case factors such as joint pathology, pre-existing endocrinopathies, or corticosteroid type, dose, and timing influencing steroid-induced laminitis risk have not been investigated. This study aimed to determine if systemic absorption of triamcinolone acetonide (TA) varies between intrasynovial (antebrachiocarpal) and extrasynovial (sacroiliac) injection sites, and to determine the effects of TA absorption on glucose, insulin, cortisol, and adrenocorticotropic hormone (ACTH). Twenty adult hors...
Tikmehdash HT, Dehnad A, Mosavari N, Naghili Hokmabadi B, Mahmazi S.Glanders caused by Burkholderia mallei is one of the most dangerous zoonotic diseases in solipeds. Clinical diagnosis of this disease in its early stages in horses, is difficult. This study investigated serological and molecular identification of B. mallei in East Azerbaijan province. In the third and fourth quarters of 2020, throughout 2021, and in the first and second quarters of 2022, the complement fixation test (CFT) was performed on 350 horses. The malleination was used to confirm the positive CFT cases. Blood samples were taken for culture and for preparing serums to perform the enzyme-...
Li C, Mellbin Y, Krogager J, Polikovsky S, Holmberg M, Ghorbani N, Black MJ, Kjellström H, Zuffi S, Hernlund E.Studies of quadruped animal motion help us to identify diseases, understand behavior and unravel the mechanics behind gaits in animals. The horse is likely the best-studied animal in this aspect, but data capture is challenging and time-consuming. Computer vision techniques improve animal motion extraction, but the development relies on reference datasets, which are scarce, not open-access and often provide data from only a few anatomical landmarks. Addressing this data gap, we introduce PFERD, a video and 3D marker motion dataset from horses using a full-body set-up of densely placed over 100...
Mattei DN, Harman RM, Van de Walle GR, Smith R, Grivel JC, Abdelalim EM, Vinardell T.Mesenchymal stromal cells (MSCs) have regenerative and immunomodulatory potential and may be used to treat injured tissues. Pregnancy has been associated with increased MSCs in the peripheral circulation in multiple species, but to date, there are no reports on this matter in horses. This study aimed to evaluate the effect of pregnancy on isolation efficiency and proliferation capacity of equine MSCs derived from the peripheral blood (PB) of mares. Venous blood samples were collected at the 11th month of gestation and 1 month after delivery from clinically healthy Arabian mares that presented ...
Nieforth LO, Leighton SC.The incorporation of animals into interventions focused on military families is a relatively new concept. Though animal-assisted interventions (AAIs) have been studied in the context of military veterans, few studies incorporate members of the military family or focus on the family members' experiences. Unassigned: This systematic review investigates the effects of AAIs on the wellbeing of military family members beyond the veteran themselves through three aims: (1) by describing the characteristics of AAIs for military family members, (2) by evaluating the quality of the methodology present w...
Wadbled L, Finck C, Santschi EM, Morehead JP, Fogarty U, Lemirre T, Beauchamp G, Richard H, Laverty S.Assess femorotibial features in foals with and without medial femoral condyle (MFC) subchondral radiolucencies (SR+ and SR-). Methods: 3 independent, sequential radiographic studies were performed. Study 1 retrospectively measured femorotibial morphological parameters in repository radiographs (SR- and SR+). Study 2 qualitatively compared drawings of intercondylar notch shape in postmortem radiographs (SR-). Study 3 prospectively measured femorotibial parameters in 1-month-old foals (SR-). In studies 1 and 3, 13 morphologic parameters were measured. Limb directional asymmetry was assessed in 2...
Pereira R, Gillespie S, Rapezzano G, Withers J, Duz M, Foote A.A 15-month-old, grey, Thoroughbred filly presented for investigation of a 6-week history of corneal oedema and blepharospasm on the right eye (OD). The filly was otherwise healthy. Following ophthalmic examination, glaucoma on the OD was diagnosed. A space occupying mass within the anterior chamber was documented on transpalpebral ultrasonographic examination. This mass obliterated most of the anterior intraocular structures on the peripheral nasal side (corneal endothelium and drainage angle), leading to secondary glaucoma. After systemic and topical treatment addressing secondary glaucoma, t...
Perry EB, Handlos GC, Fenton JM.Anise has demonstrated equine palatability but its olfactory effect is underexplored. The objective was to investigate the effect of the aroma of anise on consumptive behavior. Stock-type horses (n = 8) were used in a crossover 6-day preference test. Palatability stocks were utilized. Bowls containing oats were situated on plates holding gauze soaked with 0.375 ml of anise or corn oil (control). Variables included first diet sniffed (FS), first consumed (FC), first action (FA), and amount consumed (AC). Each trial was video-recorded. Behavior data were analyzed using chi square and Kruskal...
Sanigavatee K, Poochipakorn C, Huangsaksri O, Wonghanchao T, Rodkruta N, Chanprame S, Wiwatwongwana T, Chanda M.Athletic horses are usually retired from equestrian competition at an advanced age. Aged horses may then continue to have regular exercise or are sedentary. The comparison of autonomic regulation between sedentary aged horses (SAH) and trained aged horses (TAH) after retirement remains unpublished. This study compared daily heart rate (HR) and heart rate variability between 11 SAH and 11 TAH over 22 hours (07.00 h to 05.00 h on an alternate day) and during the day and night. An increase in mean beat-to-beat (RR) intervals (p < 0.01-0.0001) and parasympathetic nervous system (PNS) index (p &...
Onzere CK, Bastos RG, Bishop RP, Suarez CE, Fry LM. () is an apicomplexan parasite that causes severe hemolytic anemia in equids. Presently, there is inadequate knowledge of the immune responses induced by in equid hosts impeding understanding of the host parasite relationship and development of potent vaccines for control of infections. The objective of this study was to evaluate the host-parasite dynamics between merozoites and infected horses by assessing cytokine expression during primary and secondary parasite exposure, and to determine whether the pattern of expression correlated with clinical indicators of disease. Our findings showe...
Ferreira JD, Méndez-Angulo JL.Several tooth extraction techniques are described in equine literature, and oral extraction techniques in standing sedated horses are popular among equine practitioners. The objectives of this study were to develop the corkscrew technique for cheek tooth extraction (CSET) in equine cadaver heads and evaluate this technique in clinical cases. We hypothesized that the CSET could be performed safely to extract cheek teeth in standing sedated horses. First, the CSET was attempted and developed in eight equine cadaver heads. Second, the CSET was performed in clinical cases between 2016 and 2020, an...
Wang Y, Huang Y, Zhen Y, Wang J, Wang L, Chen N, Wu F, Zhang L, Shen Y, Bi C, Li S, Pool K, Blache D, Maloney SK, Liu D, Yang Z, Li C, Yu X, Zhang Z....Domesticated herbivores are an important agricultural resource that play a critical role in global food security, particularly as they can adapt to varied environments, including marginal lands. An understanding of the molecular basis of their biology would contribute to better management and sustainable production. Thus, we conducted transcriptome sequencing of 100 to 105 tissues from two females of each of seven species of herbivore (cattle, sheep, goats, sika deer, horses, donkeys, and rabbits) including two breeds of sheep. The quality of raw and trimmed reads was assessed in terms of base...
Lang JJ, Li X, Micheler CM, Wilhelm NJ, Seidl F, Schwaiger BJ, Barnewitz D, von Eisenhart-Rothe R, Grosse CU, Burgkart R.Femoral fractures are often considered lethal for adult horses because femur osteosynthesis is still a surgical challenge. For equine femur osteosynthesis, primary stability is essential, but the detailed physiological forces occurring in the hindlimb are largely unknown. The objective of this study was to create a numerical testing environment to evaluate equine femur osteosynthesis based on physiological conditions. The study was designed as a finite element analysis (FEA) of the femur using a musculoskeletal model of the loading situation in stance. Relevant forces were determined in the mu...
Mady EA, Osuga H, Toyama H, El-Husseiny HM, Inoue R, Murase H, Yamamoto Y, Nagaoka K.The gut microbiota (GM) is essential for mammalian health. Although the association between infant GM and breast milk (BM) composition has been well established in humans, such a relationship has not been investigated in horses. Hence, this study was conducted to analyze the GM formation of foals during lactation and determine the presence of low-molecular-weight metabolites in mares' BM and their role in shaping foals' GM. The fecal and BM samples from six pairs of foals and mares were subjected to 16S ribosomal RNA metagenomic and metabolomic analyses, respectively. The composition of foal G...
Green de Freitas M, Gonçalves Lino Borges D, Henrique Conde M, Takemi Muchon Nakatani M, Francieli Tutija J, Fuzaro Scaléa GO, Reckziegel GH....The aim of the present study was to validate methods of stool sample conservation for the egg hatch test (EHT). This study involved the use of a bovine naturally infected predominantly by Cooperia spp. and one equine naturally infected predominantly by cyathostomins characterized as susceptible to benzimidazoles in the EHT. Fecal samples were submitted to three treatments: aerobic methods (anaerobic storage in plastic bottles, anaerobic storage in vacuum-sealed bags or aerobic storage in plastic bags), under two temperature conditions (room temperature and refrigeration) analyzed at four diffe...
Witkowska-Piłaszewicz O, Malin K, Dąbrowska I, Grzędzicka J, Ostaszewski P, Carter C.Domestic horses routinely participate in vigorous and various athletic activities. This enables the horse to serve as a model for studying athletic physiology and immunology in other species, including humans. For instance, as a model of physical efforts, such as endurance rides (long-distance running/aerobic exercise) and races (anaerobic exercise), the horse can be useful in evaluating post-exercise response. Currently, there has been significant interest in finding biomarkers, which characterize the advancement of training and adaptation to physical exercise in the horse. The parallels in c...
Nelson GR, Mama KR, Weiner D, McKemie DS, Kass PH, Steinmetz SJ, Knych HK.This study describes the pharmacokinetics and pharmacodynamics, including antinociceptive effects, of a transdermal buprenorphine solution in horses. It was hypothesized that transdermal application would lead to sustained blood concentrations and antinociceptive effects with fewer adverse effects compared with intravenous (IV) injection. Methods: Prospective nonrandomized four-part parallel experimental study. Methods: A group of eight horses (three mares and five geldings) aged 6-12 years. Methods: Horses were administered incremental doses of 15, 30 and 45 μg kg of buprenorphine transderma...
Rusenova N, Rusenov A, Chervenkov M, Sirakov I.The aim of this study was to analyze the seroprevalence of West Nile virus (WNV) among equids in Bulgaria, confirm the results of a competitive ELISA versus the virus neutralization test (VNT) and investigate some predisposing factors for WNV seropositivity. A total of 378 serum samples from 15 provinces in northern and southern Bulgaria were tested. The samples originated from 314 horses and 64 donkeys, 135 males and 243 females, aged from 1 to 30 years. IgG and IgM antibodies against WNV protein E were detected by ELISA. ELISA-positive samples were additionally tested via VNT for WNV and Usu...
Donnelly KS, Giuliano EA, Sharm A, Mohan RR.To explore the effect of suberoylanilide hydroxamic acid (SAHA) (i) on corneal fibroblast differentiation, morphology, and viability; and (ii) on the expression levels of matrix metalloproteinases (MMPs) 2 and 9 using an in vitro model of equine corneal fibrosis. Methods: Healthy donor corneas were used to generate primary cultures of equine corneal fibroblasts. The fibroblasts were exposed to 5 ng/mL TGFβ1 to induce myofibroblast formation. The cultures were treated with either 5 μm or 10 μm SAHA for 72 h in the presence of TGFβ1. Real-time PCR and immunocytochemistry were used to determi...
Baise E, Habyarimana JA, Amory H, Boemer F, Douny C, Gustin P, Marcillaud-Pitel C, Patarin F, Weber M, Votion DM.Ingestion of sycamore seeds (Acer pseudoplatanus) is the likely source of hypoglycin A in atypical myopathy (AM) but ingestion of seedlings in spring might also contribute to intoxication. Objective: To test for hypoglycin A in seeds and seedlings collected on pastures where AM cases were reported and compare its concentration in serum of affected and healthy horses. Methods: Field investigation of clinical cases. Methods: Whenever present, samaras (the winged nuts that each contain one seed) and/or seedlings were collected from pastures of 8 AM cases and 5 unaffected horses from different pre...
Geurden T, van Doorn D, Claerebout E, Kooyman F, De Keersmaecker S, Vercruysse J, Besognet B, Vanimisetti B, di Regalbono AF, Beraldo P, Di Cesare A....The objective of the present study was to evaluate the efficacy of an oral treatment with ivermectin (IVM) or moxidectin (MOX) against gastro-intestinal strongyles in naturally infected horses by performing a faecal egg count reduction test (FECRT) and by monitoring the egg reappearance period (ERP) after treatment. Therefore, a field efficacy study with a randomised complete block design for each study site was conducted, with the individual animal as the experimental unit. At least 10 study sites in Italy, Belgium and The Netherlands were selected and animals were allocated to one of the two...
Garrett LA, Brown R, Poxton IR.This study compares quantitatively the microbiota of the gastrointestinal tract of healthy horses with that of horses with equine grass sickness (EGS). Faecal and ileal samples were cultured quantitatively on selective and non-selective media. Confirmed anaerobes were identified to species level. Overall faecal counts gave a ratio of aerobes:anaerobes of approximately 1:1. However, the mean counts in healthy horses of 4.4x10(8) aerobes:3.7x10(8) anaerobes per gram wet weight were different from counts in EGS (means were 10-100-fold higher), with statistically significant differences for the an...
Hines SA, Ramsay JD, Kappmeyer LS, Lau AO, Ojo KK, Van Voorhis WC, Knowles DP, Mealey RH.The apicomplexan hemoparasite Theileria equi is a causative agent of equine piroplasmosis, eradicated from the United States in 1988. However, recent outbreaks have sparked renewed interest in treatment options for infected horses. Imidocarb dipropionate is the current drug of choice, however variation in clinical response to therapy has been observed. Methods: We quantified the in vitro susceptibility of two T. equi isolates and a lab generated variant to both imidocarb dipropionate and a bumped kinase inhibitor compound 1294. We also evaluated the capacity of in vitro imidocarb dipropionate ...
Côté GP, Smillie LB.Whereas skeletal muscle tropomyosin binds strongly to muscle F-actin in a buffer containing 30 mM KCl and 1-2 mM free Mg2+, equine platelet tropomyosin only binds stoichiometrically (1 tropomyosin molecule per 6 actin monomers) at higher Mg2+ concentrations (7-8 mM free Mg2+). At low free Mg2+ concentrations (1.5 mM) the binding of the platelet protein is only marginally increased by raising the KCl concentration to an optimal value (0.10-0.20 M). This weaker binding can be attributed to the relatively poor head-to-tail polymerization of platelet tropomyosin and its fewer actin-binding sites. ...
Oberste MS, Schmura SM, Weaver SC, Smith JF.Phylogenetic analysis of 20 strains of Venezuelan equine encephalitis (VEE) virus subtype IE isolated from 1961 to 1996 in Mexico and throughout Central America showed that VEE virus subtype IE was monophyletic with respect to other VEE virus subtypes. Nonetheless, there were at least three distinct geographically separated VEE virus IE genotypes: northwestern Panama, Pacific coast (Mexico/Guatemala), and Gulf/Caribbean coast (Mexico/Belize). Strains from the Caribbean coast of Guatemala, Honduras, and Nicaragua may cluster with the Gulf/Caribbean genotype, but additional isolates from the reg...
van Loon JPAM, Van Dierendonck MC.Objective pain assessment is important to guide and tailor therapy in clinical practice. This study describes the clinical applicability and validity of two pain scales, the Composite Pain Scale (CPS) and the Equine Utrecht University Scale for Facial Assessment of Pain (EQUUS-FAP) in horses with orthopaedic trauma or after orthopaedic surgery. A cohort follow-up study was performed using 77 adult horses (n=43 with orthopaedic trauma or injury; n=34 controls). Composite and facial expression-based pain scores were assessed by direct observations of pairs of two independent observers. All horse...
Stout TA, Allen WR.A growing equine conceptus must suppress the cyclical release of PGF(2 alpha) from the endometrium to effect maternal recognition of its presence in the uterus. Paradoxically, the conceptus itself secretes PGF(2 alpha), together with other prostaglandins. In this study, the PGF(2 alpha) and PGE(2) content of, and production in vitro by, day 10-32 equine conceptuses were measured and the influence of pregnancy on the concentrations of these prostaglandins in the uterine lumen was examined. In vitro, the release of both prostaglandins per mg conceptus tissue was very high on day 10 after ovulati...
Lindahl SB, Aspán A, Båverud V, Paillot R, Pringle J, Rash NL, Söderlund R, Waller AS.Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) is generally considered a commensal and an opportunistic pathogen of the upper airways in horses. Establishing whether certain strains of S. zooepidemicus can cause upper respiratory disease as a host-specific pathogen of horses, and if there are certain genogroups of S. zooepidemicus that are more virulent than others is of major clinical importance. In this study, we describe an outbreak of upper respiratory disease in horses that was associated with S. zooepidemicus. Upper respiratory samples were cultured, analyzed by real-time PCR...
Théon AP, Wilson WD, Magdesian KG, Pusterla N, Snyder JR, Galuppo LD.To determine outcome associated with cutaneous tumors treated via intratumoral chemotherapy with cisplatin and identify risk factors affecting local tumor control and complications in equidae. Methods: Retrospective case series. Methods: 573 equidae with 630 cutaneous tumors. Methods: Medical records of horses, mules, donkeys, and ponies with cutaneous tumors treated via intratumoral chemotherapy with cisplatin were analyzed. Results: 549 horses, 13 mules, 8 donkeys, and 3 ponies with 630 histologically confirmed cutaneous tumors were included. Tumors included sarcoids (n = 409), squamous cell...
Janova E, Matiasovic J, Vahala J, Vodicka R, Van Dyk E, Horin P.The major histocompatibility complex genes coding for antigen binding and presenting molecules are the most polymorphic genes in the vertebrate genome. We studied the DRA and DQA gene polymorphism of the family Equidae. In addition to 11 previously reported DRA and 24 DQA alleles, six new DRA sequences and 13 new DQA alleles were identified in the genus Equus. Phylogenetic analysis of both DRA and DQA sequences provided evidence for trans-species polymorphism in the family Equidae. The phylogenetic trees differed from species relationships defined by standard taxonomy of Equidae and from trees...
Gustafsson A, Båverud V, Gunnarsson A, Rantzien MH, Lindholm A, Franklin A.In Sweden there are several reports of mares developing acute colitis while their foals were being treated orally for Rhodococcus equi pneumonia with the combination of erythromycin and rifampicin. In this study 6 adult horses were given low oral dosages of these antibiotics, singly or in combination. Within 3 days post administration of erythromycin, in one case in combination with rifampicin, 2 horses developed severe colitis (one fatal). Clostridium difficile was isolated from one of the horses, whereas no specific pathogens were isolated from the other. Both horses had typical changes in b...
Gonzalez-Salazar D, Estrada-Franco JG, Carrara AS, Aronson JF, Weaver SC.To assess the role of horses as amplification hosts during the 1993 and 1996 Mexican Venezuelan equine encephalitis (VEE) epizootics, we subcutaneously infected 10 horses by using four different equine isolates. Most horses showed little or no disease and low or nonexistent viremia. Neurologic disease developed in only 1 horse, and brain histopathologic examination showed meningeal lymphocytic infiltration, perivascular cuffing, and focal encephalitis. Three animals showed mild meningoencephalitis without clinical disease. Viral RNA was detected in the brain of several animals 12-14 days after...
Ferris DJ, Frisbie DD, McIlwraith CW, Kawcak CE.Medications are frequently employed to treat intra-articular (IA) problems in the performance horse. Actual usage of the different IA medications in horses is not available. Objective: To determine the most common usage of these medications, members of the American Association of Equine Practitioners (AAEP) were surveyed. Methods: An email link to an online survey was electronically sent to 6305 AAEP members and the responses tabulated and analysed with a logistic regression model. Results: A total of 831 survey responses were submitted and tabulated. Eighty per cent of the respondents indicat...
Martínez-Valladares M, Geurden T, Bartram DJ, Martínez-Pérez JM, Robles-Pérez D, Bohórquez A, Florez E, Meana A, Rojo-Vázquez FA.The objective of this study was to evaluate the status of anthelmintic resistance (AR) in ruminants and horses in Spain. The efficacy of commonly used macrocyclic lactones (MLs) - ivermectin (IVM) and moxidectin (MOX) - was measured in sheep, cattle and horses. In addition, albendazole (ABZ) and levamisole (LEV) were evaluated in sheep and oxibendazole (OXI) and pyrantel (PYR) in horses. Efficacy was evaluated based on the difference between the arithmetic mean pre- and post-treatment faecal egg count (in cattle and horses), or compared to an untreated control group (in sheep). AR was present ...
Höglund J, Ljungström BL, Nilsson O, Lundquist H, Osterman E, Uggla A.A survey was performed on the occurrence of some internal parasites in 461 horses (1-30 years old) slaughtered from October 1992 to September 1993 at the Linköping abattoir in central Sweden. Macroscopical examination was carried out specifically for parasites of the tear ducts and conjunctival sacs of the eyes, and of selected parts of the alimentary tract and cardio-vascular system. The following parasites were found in selected parts of the large intestine: encapsulated cyathostome larvae (in 35.6% of the horses), and mature strongyle worms (17.4%); in the stomach: Gasterophilus intestinal...
Spiesz EM, Thorpe CT, Thurner PJ, Screen HRC.Structure-function relationships in tendons are directly influenced by the arrangement of collagen fibres. However, the details of such arrangements in functionally distinct tendons remain obscure. This study demonstrates the use of quantitative polarised light microscopy (qPLM) to identify structural differences in two major tendon compartments at the mesoscale: fascicles and interfascicular matrix (IFM). It contrasts functionally distinct positional and energy storing tendons, and considers changes with age. Of particular note, the technique facilitates the analysis of crimp parameters, in w...
Hughes KJ, Nicolson L, Da Costa N, Franklin SH, Allen KJ, Dunham SP.Inflammatory airway disease (IAD) is a common disorder of performance horses and is associated with poor performance and accumulation of mucus and inflammatory cells in lower airway secretions. Horses with IAD frequently have increased relative counts of neutrophils in bronchoalveolar lavage fluid (BALF); less commonly relative counts of eosinophils and/or mast cells may be increased. The aetiopathogenesis of IAD is unknown and may involve innate and/or acquired immune responses to various factors including respirable dust constituents, micro-organisms, noxious gases and unconditioned air. The...
Avila F, Mickelson JR, Schaefer RJ, McCue ME.Selective breeding for athletic performance in various disciplines has resulted in population stratification within the American Quarter Horse (QH) breed. The goals of this study were to utilize high density genotype data to: (1) identify genomic regions undergoing positive selection within and among QH subpopulations; (2) investigate haplotype structure within each QH subpopulation; and (3) identify candidate genes within genomic regions of interest (ROI), as well as biological pathways, predicted to play a role in elite performance in each group. For that, 65K SNP genotyping data on 143 elit...
Bergmann F, Trachsel DS, Stoeckle SD, Bernis Sierra J, Lübke S, Groschup MH, Gehlen H, Ziegler U.Following the introduction of the West Nile virus (WNV) into eastern Germany in 2018, increasing infections have been diagnosed in birds, equines, and humans over time, while the spread of WNV into western Germany remained unclear. We screened 437 equine sera from 2018 to 2020, excluding vaccinated horses, collected from convenience sampled patients in the eastern and western parts of Germany, for WNV-specific antibodies (ELISAs followed by virus/specific neutralization tests) and genomes (RT-qPCRs). Clinical presentations, final diagnoses, and demographic data were also recorded. In the easte...
Ellis SA, Martin AJ, Holmes EC, Morrison WI.Nineteen horse MHC class I specificities have been serologically identified previously at a single locus (ELA-A), and two other specificities appear to be coded at other loci. Biochemical studies indicate that there are at least two expressed loci. In order to establish the number of transcribed horse MHC class I genes, we made a cDNA library from a heterozygous animal (ELA-A3/A7), and screened for positive clones using a bovine class I probe. More than 200 class I clones were isolated in this way, and so far seven unique full length sequences have been identified. All of the sequences are pre...
Rodrigues A, Fighera RA, Souza TM, Schild AL, Barros CS.The clinical signs and pathology of the central nervous system in 9 horses with naturally occurring neurologic disease due to Trypanosoma evansi are described. The clinical course was 2 to 20 days; clinical signs included marked ataxia, blindness, head tilt and circling, hyperexcitability, obtundity, proprioceptive deficits, head pressing, and paddling movements. Grossly, asymmetric leukoencephalomalacia with yellowish discoloration of white matter and flattening of the gyri were observed in the brain of 7 of 9 horses. Histologically, all 9 horses had necrotizing encephalitis that was most sev...
Davidson EJ.Lameness examination is commonly performed in the athletic horse. A skilled lameness diagnostician must have keen clinical and observational skills. Evaluation starts with a detailed history and thorough physical examination. Next, gait evaluation in the moving horse is performed. Lame horses have asymmetrical body movement due to unconscious shift of body weight. Recognition of the resultant head nod and pelvic hike is the basis for lameness diagnosis. Lameness identification is enhanced by circling, limb flexions, and riding. Most lame horses do not exhibit pathognomonic gait characteristics...
Breathnach CC, Soboll G, Suresh M, Lunn DP.A commercial bovine IFN-gamma-specific monoclonal antibody was used to measure antigen-specific IFN-gamma production by equine lymphocytes. Paired PBMC samples were collected from six ponies prior to and 10 days after challenge infection with equine herpesvirus-1 (EHV-1). Each sample was stimulated in vitro with EHV-1, virus-free medium, or PMA and ionomycin, and labelled with monoclonal antibodies specific for various equine lymphocyte subset markers. Following fixation, intracellular IFN-gamma was detected using a FITC-conjugated bovine IFN-gamma-specific monoclonal antibody. In vitro restim...
Donnelly KS, Giuliano EA, Sharma A, Tandon A, Rodier JT, Mohan RR.To explore (i) the potential of polyethylenimine (PEI) nanoparticles as a vector for delivering genes into equine corneal fibroblasts (ECFs) using green fluorescent protein (GFP) marker gene, (ii) whether PEI nanoparticle-mediated decorin (DCN) gene therapy could be used to inhibit fibrosis in the equine cornea using an in vitro model. Methods: Polyethylenimine-DNA nanoparticles were prepared at nitrogen-to-phosphate (N-P) ratio of 15 by mixing 22 kDa linear PEI and a plasmid encoding either GFP or DCN. ECFs were generated from donor corneas as previously described. Initially, GFP was introduc...
Magnarelli LA, Ijdo JW, Van Andel AE, Wu C, Padula SJ, Fikrig E.To determine whether horses living in tick-infested areas of northeastern United States with clinical signs of borreliosis or granulocytic ehrlichiosis had detectable serum antibodies to both Borrelia burgdorferi and Ehrlichia equi. Methods: Prospective study. Methods: Serum samples from 51 clinically normal horses, 14 horses with clinical signs of borreliosis, and 17 horses with clinical signs of granulocytic ehrlichiosis. Methods: Serum B burgdorferi or E equi antibodies were measured by use of an ELISA, immunoblot analysis, or indirect fluorescent antibody (IFA) staining. Results: Of the 82...
Russell KA, Koch TG.Multipotent mesenchymal stromal cells (MSC) are often culture-expanded in vitro. Presently, expansion medium (EM) for MSC is supplemented with fetal bovine serum (FBS). However, increasing cost, variable composition and potential risks associated with bovine antigens call for alternatives. Platelet lysate (PL) has shown promise as an alternative supplement. Objective: To determine how equine umbilical cord blood (CB) MSC proliferate in EM enriched with PL or FBS at various concentrations. Methods: Randomised dose escalation study. Methods: Platelet concentrate was generated from 5 equine whol...
Craigo JK, Montelaro RC.Equine infectious anemia (EIA), identified in 1843 [1] as an infectious disease of horses and as a viral infection in 1904, remains a concern in veterinary medicine today. Equine infectious anemia virus (EIAV) has served as an animal model of HIV-1/AIDS research since the original identification of HIV. Similar to other lentiviruses, EIAV has a high propensity for genomic sequence and antigenic variation, principally in its envelope (Env) proteins. However, EIAV possesses a unique and dynamic disease presentation that has facilitated comprehensive analyses of the interactions between the evolv...
Smith KC, Whitwell KE, Binns MM, Dolby CA, Hannant D, Mumford JA.From 1988 to 1991, 51 pregnant pony mares were challenged intranasally or by aerosol with an isolate of EHV-1 (AB4) originally recovered from a quadriplegic mare. This resulted in 32 abortions, occurring from 9 to 29 days after infection. In 14 of the early abortions (Days 9-14), EHV-1 was not demonstrated in the foetal tissues by virus isolation or immunostaining despite no other non-viral cause for the abortion being evident. Application of the polymerase chain reaction to foetal tissues from 9 of these cases also proved negative. One of the 14 mares was destroyed immediately after abortion,...
