Veterinary medicine for horses encompasses the study and application of medical practices to diagnose, treat, and prevent diseases in equine species. This field involves a comprehensive understanding of equine anatomy, physiology, pathology, and pharmacology. Veterinary practitioners employ a range of diagnostic tools and therapeutic interventions to address health issues in horses, including lameness, gastrointestinal disorders, respiratory conditions, and infectious diseases. Preventative care, such as vaccination and deworming programs, is also a significant aspect of equine veterinary medicine. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of veterinary medicine as it pertains to horses, including advancements in diagnostic techniques, treatment protocols, and preventive health strategies.
Slavik K, Underwood C, Lowndes C, Skelton G, van Eps A.To examine the effects of botulinum toxin inoculation into the deep digital flexor (DDF) muscle on foot biomechanics. Unassigned: 6 healthy horses were injected with botulinum toxin in the DDF of 1 forelimb. The opposite forelimb was untreated. Ground reaction forces (GRF) were measured using a pressure sensor in regions of interest, including the dorsal hoof wall (toe). The location of the center of pressure (COP) was measured relative to the dorsal hoof wall during static standing and at peak stance during walking. Repeat measurements 3, 7, 14, 28, and 42 days after injection were compared t...
Billmann P, Durham A, Christen G, Savioli G, Gross JJ, Gerber V, Fouché NE.Limited published data are available regarding the relationships among clinical signs associated with pituitary pars intermedia dysfunction (PPID), age, and concentrations of proopiomelanocortin-derived peptides and cortisol. Objective: Identify clinical signs associated with age, beta-endorphin (β-END), adrenocorticotropic hormone (ACTH), and cortisol concentrations and compare β-END and cortisol concentrations between horses with PPID and geriatric controls. Methods: A total of 113 horses aged 18-32 years. Methods: Cross-sectional study. Clinical signs were scored, plasma β-END, ACTH, an...
Loy J, Sornalingam K, Cawley A, Scrivener C, Keledjian J, Noble GK.Altrenogest is a synthetic progestogen widely used in equine reproductive management. Adverse effects to altrenogest have been reported in people with cutaneous exposure reported as the highest exposure pathway. Despite these reports, there has been no quantitative research to determine the capacity for altrenogest to be absorbed through skin. This study aimed to determine if cutaneous application of oral altrenogest results in systemic absorption in mares and to evaluate the influence of application site. A randomized, two-period, two-treatment crossover study was undertaken in eight mares. M...
Paulussen E, Delhaas T, Decloedt A, van Loon G, Van Steenkiste G.Twelve-lead electrocardiography (ECG) is essential in human cardiology but remains poorly investigated in equine medicine due to a lack of standardization and inconsistent findings. Objective: Describe the normal vectorcardiogram (VCG) variation in horses at rest and during exercise using Delta 12-lead ECG, including repeatability and intra- and interobserver variations. Methods: One hundred two healthy Warmblood horses, aged 3-20 years, were examined at rest, of which 30 also during exercise. Methods: Prospective, observational study. Electrocardiograms were recorded using a Δ 12-lead confi...
Hodgson E, Romano TR, Stewart A, Bond S, Wise J.The pathogenesis of gastric ulceration is not well understood in foals, and its relationship with gastric acidity requires further investigation. A wireless capsule, designed for intraesophageal pH monitoring in humans, was adapted to measure intragastric pH in adult horses. Objective: To (1) determine the feasibility of wireless intragastric pH measurement in foals; (2) determine capsule attachment duration; and (3) describe the intragastric pH profiles recorded. Methods: Eight healthy foals aged 24-98 days. Methods: Prospective interventional study. Capsules were attached to the glandular g...
Auvinen JRE, Kritchevsky JE, Reinhart JM, Gochenauer AE, Jannasch AS, Han-Hallett Y.Manipulation of forms of rectally administered metronidazole to improve bioavailability in horses has not been reported. Objective: Evaluate the pharmacokinetics of 3 rectal metronidazole preparations compared to nasogastric (NG) administration. Methods: Seven healthy horses. Methods: Phase 1A was a randomized, 3-way crossover, single-dose pharmacokinetic study, and Phases 1B and 2 were non-randomized, single-dose follow-up studies. Metronidazole (20 mg/kg) was administered NG and rectally in water (RW20), as a rectal gel (RG), and in dimethyl sulfoxide (DMSO). Metronidazole (80 mg/kg) was a...
Viviani P, Ragno VM, Parker S, Montgomery JB.Endocrine disorders in horses, such as pituitary pars intermedia dysfunction and equine metabolic syndrome, rely on hormone testing for diagnosis, but seasonal and regional variabilities highlight the need for locally generated data. Objective: To characterize monthly blood concentrations of ACTH and insulin over 1 year in healthy horses in Saskatchewan. A secondary objective was to assess the association between these outcomes and the following factors: sex, age, breed, pregnancy status, level of exercise, body condition score, and cresty neck score. Methods: Sixty-eight clinically healthy, c...
Semik-Gurgul E, Ocłoń E, Zubel-Łojek J, Pędziwiatr R, Pawlina-Tyszko K.Sarcoids are locally invasive skin tumors in equids, associated with bovine papillomavirus. Objective: Address potential applications of cannabidiol (CBD) in veterinary medicine. We evaluated the response of equine sarcoid cells to CBD in vitro, focusing on viability, invasiveness, and matrix remodeling. Methods: Three primary sarcoid cell lines. Methods: Cells were treated with CBD (20, 6.75, 2.25, 0.75 μM) and incubated for 6, 24, 48, 72 hours. Cell viability, cytotoxicity, and apoptosis were assessed using the ApoTox-Glo Assay. Based on these results, further analyses were performed for ...
Massie S, Léguillette R, Jones JH, Guigand C, Sides RH, Jones KB, Warlick LM, Thueson EL, Troudt TA, Bayly WM.Maximal intensity exercise in equine athletes induces pulmonary capillary stress failure and exercise-induced pulmonary hemorrhage (EIPH) secondary to excessive transmural pressure (Ptm). Furosemide decreases EIPH severity and pulmonary arterial (PAP) and pulmonary wedge (PAW) pressures. Objective: Assess the effects of furosemide on Ptm and EIPH during supramaximal exercise. Methods: Six fit retired Thoroughbreds with consistent EIPH Grade ≥ 2. Methods: Horses performed a controlled crossover design protocol, completing standardized treadmill tests (120%V̇O2max) before and 4 h after int...
Migliorisi A.The goal of this article is to provide the equine practitioners with a framework for a diagnostic algorithm for the patient presented with possible seizures/epilepsy. Using a comparative approach, a review of companion animal and human research is provided with the intention of expanding our current knowledge on seizure/epilepsy, as well as diagnostic and treatment strategies for equine patients.
McCosh KK, Selberg KT, Platt LA, Seabaugh KA.To compare effusion scores obtained via ultrasound (US) and computed tomography (CT) in equine cervical articular process joints (CAPJs). Unassigned: Cadaveric cervical specimens (skull through C7) from 6 horses were used. One specimen was used to establish maximal joint distension volume. In the main study phase, 50 CAPJs were randomly assigned to receive 0, 2, or 4 mL of positive contrast solution. The CAPJs were imaged via US and CT before and after injection. Effusion was subjectively graded on a scale of 0 to 4 for both modalities. Statistical analyses compared pre- and post-injection eff...
Mendes RP, Gonzaga MS, Matheus MM, Bittar MJ, Doria RGS, Corrêa RR.Developmental and eruption abnormalities are common and can result in progressive dental diseases. Ectopic eruption of the affected tooth may be the result of these processes. This study aims to report the occurrence of a permanent mandibular tooth in a horizontal position, with retention of the corresponding deciduous tooth, in a miniature horse. A 2-year-old female miniature horse was admitted to the veterinary hospital with a hard swelling on the left mandibular ramus, which had been growing continuously for three months. After a complete evaluation, it was concluded that the swelling was t...
Rinnovati R, Meistro F, Ralletti MV, D'Angelo P, Spadari A, Zingariello E, Pollera C, Stancampiano L.In horses, surgical site infections (SSIs) are multifactorial complications influenced by patient-related, procedural, and environmental factors. While perioperative contamination has been extensively studied in the operating theater, the anesthetic induction and recovery environment has received limited attention. The aim of this study was to characterize bacterial contamination within an equine anesthetic induction and recovery stall and to evaluate its spatial and temporal distribution. Environmental samples were collected from four predefined locations within the stall at three time points...
Keller J, Hassenstein MJ, Jung K, Geburek F.Ground reaction forces are accepted as gold standard for objective assessment of weightbearing lameness but measurements at the hoof are limited to experimental devices. This study aimed to evaluate whether innovative instrumented hoof boots (IHBs) could detect and monitor lameness in horses during diagnostic anaesthesia. Twenty-six horses referred for lameness examination (15 front limbs, 17 hindlimbs) were equipped with IHBs and body mounted inertial sensors. Data were collected simultaneously before and after diagnostic anaesthesia until objectively considered positive. Recorded IHB data i...
Ledbetter EC, Knickelbein KE, Irby NL, Schmidt C.To describe the clinical and in vivo confocal microscopy (IVCM) characteristics of horses with corneal stromal invasive squamous cell carcinoma (CSI-SCC). Methods: Retrospective study of 7 horses with histopathologically confirmed unilateral CSI-SCC. Methods: Horses with corneal CSI-SCC were examined by laser scanning IVCM. Signalment, clinical findings, and histopathology results were compared with IVCM findings. Results: Clinical ocular lesions in all horses included a heavily vascularized, opaque, gray or tan, anterior or midstromal opacity invading the cornea from the limbus. The corneal ...
Hendrikx AL, Vendrig JC, Gehring R, van den Boom R, van Alphen J, Vernooij JCM, Teske E, Roelfsema E.To determine the effect of repeated IV administration of dexamethasone (0.06 mg/kg, q 24 h, twice) on WBC parameters in healthy adult horses. Unassigned: This prospective, longitudinal study was conducted from October 7 through November 5, 2024. Five warmblood mares received an IV dexamethasone sodium phosphate injection (DMI) at 0 and 24 hours and an IV injection with 0.9% sodium chloride solution at 48 and 72 hours. Blood samples were collected at 0, 6, 12, 24, 30, 36, 48, 72, 96, and 168 hours, and WBC parameters were evaluated using linear mixed-effects models. Unassigned: Leukocyte count,...
Çortu A, Çınar H.Rectal examination is routine in equine reproduction but may trigger acute stress affecting welfare and safety. Intraocular pressure (IOP) responds rapidly to autonomic changes and may capture short-lived stress responses. Objective: To evaluate whether rectal examination acutely affects IOP and behavioral responses in mares, and whether reactions differ by reproductive status. Methods: Twenty Rahvan mares (10 pregnant, 30-40 days' gestation; 10 non-pregnant; 4-7 years) underwent transrectal examination without sedation. IOP was measured bilaterally at six time points: 2 min pre-exam (T1), dur...
Pereira Lopes A, Emanuel da Silva R, Sousa Santos L, de Morais Nobre ML, de Araujo Sousa PS, Almeida Rocha J, Veras Quelemes P, de Araujo-Nobre AR....The aim of this study was to investigate the antibacterial, antibiofilm and modulating activities of trans-trans-farnesol (tt-farnesol) on two strains of Streptococcus equi subsp. equi and two strains of S. equi subsp. zooepidemicus, pathogenic or commensal bacteria of horses. Tt-farnesol showed bactericidal activity against all tested strains, with a minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) between 8 and 4 μg/mL. The sesquiterpene caused significant damage to the bacterial membrane, and its antibacterial activity did not appear to depend on oxidat...
Skierbiszewska K, Turek B, Jasiński T, Kaczorowski M, Kozłowska N, Higuchi J, Domino M.Bone grafting in equine medicine offers a promising contribution to treating orthopaedic developmental diseases and chondral, osteochondral and segmental bone defects. Among grafts, synthetic bone substitutes-alloplastics-show favourable biological properties addressing numerous limitations presented by autografts, xenografts and allografts. Objective: To compile and disseminate clinical data and research findings from existing publications on the use of alloplastics in horses. Methods: Systematic review. Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-analysis 202...
Dillmann JB, Dos Santos TS, Dos Santos RC, Monteiro SG.Equine cutaneous pythiosis, caused by Pythium insidiosum, is a severe disease in tropical and subtropical regions, often leading to progressive granulomatous lesions with poor response to conventional therapies. Standard treatment includes surgical excision and immunotherapy, but recurrence is common, particularly in distal limb lesions. Maggot Debridement Therapy (MDT) with disinfected Lucilia cuprina larvae provides selective debridement, microbial control, and stimulation of granulation, representing a potential adjunctive option. This report describes the successful use of MDT combined wit...
Lenarz J, Smit IH, Rhodin M, Lischer C, Fugazzola MC.Intramuscular vaccination is a routine component of equine medicine, but local muscle soreness may transiently affect gait symmetry. Objective data on vaccination-associated gait changes in horses are lacking. Objective: To investigate whether intramuscular vaccination induces measurable gait asymmetries depending on injection site, to inform recommendations on vaccination site selection and short-term exercise management. Methods: In this prospective, randomised, blinded, placebo-controlled study, eighteen clinically sound Warmblood horses were enrolled and received an intramuscular vaccinati...
Rosa MCB, Campos MEST, Albuquerque AS, Braz MS, Mapele RO, de Oliveira MCG, Toma HS, Ferraz PFP, Pereira RN, Raymundo DL.Skin wounds in horses, particularly in the distal extremities, often heal slowly due to mechanical stress, compromised perfusion, and excessive fibroplasia. This study evaluated the effects of topical Croton lechleri (CL) cream, alone or in combination with nitroglycerin, on the healing of skin wounds in the metatarsal region of horses. Six mares received six standardized wounds in each region and were treated with: saline solution, nitroglycerin (0.1 or 1 mg/mL), CL (1 or 10 µg/mL), or CL + nitroglycerin (10 µg/mL + 1 mg/mL). Wound contraction, histology, and bacterial culture were evaluate...
Chan ZYS, Ho W, Slobodova A, Parkes RSV, Forbes B, Pfau T.To investigate associations between contralateral (left-right) hoof width asymmetry and vertical movement asymmetry in racing Thoroughbreds. We hypothesized that forehoof differences would be associated with poll and withers movement asymmetry and hind hoof differences with pelvis movement asymmetry. Unassigned: This observational cross-sectional study included 169 Thoroughbred racehorses recently retired from clockwise racing and assessed the day of scheduled farriery work. Contralateral hoof width differences were quantified and movement asymmetry during trot measured using inertial sensors ...
Andrade AC, Fonseca SMC, Silva Filho GB, Melo ET, Santos JRP, Frota MLSL, Duarte JMBS, Evêncio-Neto J, Brito LB, Lima TS, Wicpolt NS, Riet-Correa F....We report an outbreak of Crotalaria juncea intoxication in horses exhibiting progressive weight loss and respiratory distress in northeastern Brazil. Necropsy revealed firm, non-collapsed lungs with extensive interstitial fibrosis, bronchiolar epithelial hyperplasia with club cells proliferation, and marked pulmonary arterial remodeling. Hepatic lesions consisted primarily of centrilobular necrosis, probably resulting from hypoxic injury related to anemia and prolonged agonic death. Pasture inspection identified significant invasion by shrubs of C. juncea in various phenological stages.
Granello ME, Young JM, Cleff DB, Banks EBM, Trumble TN.To describe characteristics of postoperative peritoneal fluid following exploratory laparotomy for naturally-occurring gastrointestinal lesions in horses. Methods: Prospective, observational cohort study. Methods: A total of 26 client-owned horses that underwent exploratory laparotomy for naturally-occurring gastrointestinal lesions. Methods: Abdominocentesis was performed pre- or intraoperatively, and at three time points postoperatively (24, 72, and 168 h). Peritoneal lactate, total protein (TP), total nucleated cell count (TNCC), cytology, and systemic lactate were performed at each time ...
Imai S, Sato R, Fujiwara R, Terui S, Kimura A, Ichijo T, Kasashima Y, Miyazaki T.A 15-year-old Thoroughbred gelding was presented for examination due to chronic corneal opacity in the right eye, which had been noted for several years. An ophthalmic evaluation revealed dense, irregular corneal opacity; an absence of the direct pupillary light reflex; and a positive dazzle reflex. Fluorescein staining was negative and cytology of a corneal conjunctival swab identified nucleated squamous epithelial cells, but no inflammatory cells. Slit-lamp examination failed to visualize intraocular structure, and the lesion was deemed to be chronic and irreversible. An obstacle-avoidance t...
An SJ, Sohn Y, Forbes E, Ryu SH.Osteochondritis dissecans (OCD) is a common developmental orthopedic condition in Thoroughbred racehorses and although arthroscopic surgery is widely used for treatment, its long-term effects on race performance remain unclear. This retrospective study evaluated the effect of OCD surgery on race performance, compared the predictive power of pedigree and management variables and applied interpretable machine learning methods for forecasting race performance outcomes. Data were collected from 75 Thoroughbreds that underwent OCD surgery between 2015 and 2017 and 257 maternal siblings without reco...
Cifuentes V, Zuluaga-Cabrera AM, Vargas-Muñoz LJ, Estrada-Gómez S.Albumin is one of the most abundant and physiologically important blood protein in horses due to its ability to regulate vascular volume and transport blood metabolites or drugs. Despite the importance of this protein, in Colombia there is no previous reference of the use of equine albumin in horses as a pharmacological therapy and there is no available any pharmaceutical preparation of this protein to be administrated in horses. This study aims to evaluate for first time the preliminary clinical response of healthy adult Colombian Creole horses after the intravenous administration of an equin...
Shroff K, Underwood C, Stefanovski D, Hopster K, Slack J.To determine transthoracic impedance (TTI) in adult horses using an exponential biphasic defibrillator and investigate patient and technique factors influencing TTI. Unassigned: A randomized crossover design with 2 phases was used. Phase 1: TTI was measured in dorsal and lateral recumbency, with and without manual pressure on the electrodes in deceased horses immediately following euthanasia. Phase 2: TTI was measured in dorsal recumbency during inspiration and expiration using anesthetized live horses sourced from 2 terminal studies. Mixed-effects linear regression modeling was performed to a...
Mazzucco L, Marcatili M, Withers J, Cantatore F.Superficial digital flexor tendinopathy is a common cause of forelimb lameness in Thoroughbred racehorses and sports horses; however, this condition is rarely observed in the hindlimb. A 16-year-old Irish sports horse gelding was presented with bilateral swelling in the plantar metatarsal region and severe bilateral hindlimb lameness visible at the walk. The lameness occurred after the cross-country phase of an eventing competition. The clinical suspicion of superficial digital flexor tendon (SDFT) injury was confirmed after ultrasonographic examination, which revealed an extensive core lesion...
Bryan A, Shapir N, Sadowsky MJ.Nonselected and natural populations of Escherichia coli from 12 animal sources and humans were examined for the presence and types of 14 tetracycline resistance determinants. Of 1,263 unique E. coli isolates from humans, pigs, chickens, turkeys, sheep, cows, goats, cats, dogs, horses, geese, ducks, and deer, 31% were highly resistant to tetracycline. More than 78, 47, and 41% of the E. coli isolates from pigs, chickens, and turkeys were resistant or highly resistant to tetracycline, respectively. Tetracycline MICs for 61, 29, and 29% of E. coli isolates from pig, chickens, and turkeys, respect...
Moran CJ, Ramesh A, Brama PA, O'Byrne JM, O'Brien FJ, Levingstone TJ.Much research is currently ongoing into new therapies for cartilage defect repair with new biomaterials frequently appearing which purport to have significant regenerative capacity. These biomaterials may be classified as medical devices, and as such must undergo rigorous testing before they are implanted in humans. A large part of this testing involves in vitro trials and biomechanical testing. However, in order to bridge the gap between the lab and the clinic, in vivo preclinical trials are required, and usually demanded by regulatory approval bodies. This review examines the in vivo models ...
Gabriels RL, Pan Z, Dechant B, Agnew JA, Brim N, Mesibov G.This study expands previous equine-assisted intervention research by evaluating the effectiveness of therapeutic horseback riding (THR) on self-regulation, socialization, communication, adaptive, and motor behaviors in children with autism spectrum disorder (ASD). Methods: Participants with ASD (aged 6-16 years; N = 127) were stratified by nonverbal IQ standard scores (≤85 or >85) and randomized to 1 of 2 groups for 10 weeks: THR intervention or a barn activity (BA) control group without horses that used similar methods. The fidelity of the THR intervention was monitored. Participants ...
Barlough JE, Madigan JE, DeRock E, Bigornia L.A nested polymerase chain reaction for detecting Ehrlichia equi in horses and ticks (Ixodes pacificus) was developed. A major second-round PCR product of 928 bp could be readily visualized in ethidium bromide-stained agarose minigels. An internal probe was used to verify the identity of the amplified product by non-radioactive (digoxigenin-based) Southern blotting; additional confirmation was provided by DNA sequence analysis. A dilution study testing the sensitivity of the PCR indicated that DNA derived from 3 infected neutrophils was sufficient to generate a PCR signal. The specificity of t...
Nugent J, Birch-Machin I, Smith KC, Mumford JA, Swann Z, Newton JR, Bowden RJ, Allen GP, Davis-Poynter N.Equid herpesvirus 1 (EHV-1) can cause a wide spectrum of diseases ranging from inapparent respiratory infection to the induction of abortion and, in extreme cases, neurological disease resulting in paralysis and ultimately death. It has been suggested that distinct strains of EHV-1 that differ in pathogenic capacity circulate in the field. In order to investigate this hypothesis, it was necessary to identify genetic markers that allow subgroups of related strains to be identified. We have determined all of the genetic differences between a neuropathogenic strain (Ab4) and a nonneuropathogenic ...
van Kasteren PB, Bailey-Elkin BA, James TW, Ninaber DK, Beugeling C, Khajehpour M, Snijder EJ, Mark BL, Kikkert M.Protein ubiquitination regulates important innate immune responses. The discovery of viruses encoding deubiquitinating enzymes (DUBs) suggests they remove ubiquitin to evade ubiquitin-dependent antiviral responses; however, this has never been conclusively demonstrated in virus-infected cells. Arteriviruses are economically important positive-stranded RNA viruses that encode an ovarian tumor (OTU) domain DUB known as papain-like protease 2 (PLP2). This enzyme is essential for arterivirus replication by cleaving a site within the viral replicase polyproteins and also removes ubiquitin from cell...
Weese JS.Methicillin-resistant Staphylococcus aureus (MRSA) is a critically important human pathogen that is also an emerging concern in veterinary medicine and animal agriculture. It is present in a wide range of animal species, including dogs, cats, rabbits, horses, cattle, pigs, poultry, and exotic species, both as a cause of infection and in healthy carriers. Identification of MRSA in various species and in food has led to concerns about the roles of animals, both pets and livestock, in the epidemiology of MRSA infection and colonization in humans. There is evidence of the role of food animals in h...
Hauck SM, Dietter J, Kramer RL, Hofmaier F, Zipplies JK, Amann B, Feuchtinger A, Deeg CA, Ueffing M.Autoimmune uveitis is a blinding disease presenting with autoantibodies against eye-specific proteins as well as autoagressive T cells invading and attacking the immune-privileged target tissue retina. The molecular events enabling T cells to invade and attack the tissue have remained elusive. Changes in membrane protein expression patterns between diseased and healthy stages are especially interesting because initiating events of disease will most likely occur at membranes. Since disease progression is accompanied with a break-down of the blood-retinal barrier, serum-derived proteins mask the...
Bunning ML, Bowen RA, Cropp CB, Sullivan KG, Davis BS, Komar N, Godsey MS, Baker D, Hettler DL, Holmes DA, Biggerstaff BJ, Mitchell CJ.A total of 12 horses of different breeds and ages were infected with West Nile virus (WNV) via the bites of infected Aedes albopictus mosquitoes. Half the horses were infected with a viral isolate from the brain of a horse (BC787), and half were infected with an isolate from crow brain (NY99-6625); both were NY99 isolates. Postinfection, uninfected female Ae. albopictus fed on eight of the infected horses. In the first trial, Nt antibody titers reached >1:320, 1:20, 1:160, and 1:80 for horses 1 to 4, respectively. In the second trial, the seven horses with subclinical infections developed Nt a...
Komar N, Clark GG.West Nile virus (Flavivirus: Flaviviridae; WNV) has spread rapidly throughout the Caribbean Basin since its initial detection there in 2001. This report summarizes our current knowledge of WNV transmission in tropical America. Methods: We reviewed the published literature and consulted with key public health officials to obtain unpublished data. Results: West Nile virus infections first appeared in human residents of the Cayman Islands and the Florida Keys in 2001, and in apparently healthy Jamaican birds sampled early in 2002. Serologic evidence of WNV infection in 2002 was detected in horses...
Patel JR, Heldens J.This review concentrates on the epidemiology, latency and pathogenesis of, and the approaches taken to control infection of horses by equine herpesvirus types 1 (EHV-1) and 4 (EHV-4). Although both viruses may cause febrile rhinopneumonitis, EHV-1 is the main cause of abortions, paresis and neonatal foal deaths. The lesion central to these three conditions is necrotising vasculitis and thrombosis resulting from lytic infection of endothelial cells lining blood capillaries. The initiation of infection in these lesions is likely to be by reactivated EHV-1 from latently infected leukocytes. Howev...
Timoney JF.Streptococci pathogenic for the horse include S. equi (S. equi subsp. equi), S. zooepidemicus (S. equi subsp. zooepidemicus), S. dysgalactiae subsp. equisimilis and S. pneumoniae capsule Type III. S. equi is a clonal descendent or biovar of an ancestral S. zooepidemicus strain with which it shares greater than 98% DNA homology and therefore expresses many of the same proteins and virulence factors. Rapid progress has been made in identification of virulence factors and proteins uniquely expressed by S. equi. Most of these are expressed either on the bacterial surface or are secreted. Notable e...
Schnabel LV, Lynch ME, van der Meulen MC, Yeager AE, Kornatowski MA, Nixon AJ.Tendinitis remains a catastrophic injury among athletes. Mesenchymal stem cells (MSCs) have recently been investigated for use in the treatment of tendinitis. Previous work has demonstrated the value of insulin-like growth factor-I (IGF-I) to stimulate cellular proliferation and tendon fiber deposition in the core lesion of tendinitis. This study examined the effects of MSCs, as well as IGF-I gene-enhanced MSCs (AdIGF-MSCs) on tendon healing in vivo. Collagenase-induced bilateral tendinitis lesions were created in equine flexor digitorum superficialis tendons (SDFT). Tendons were treated with ...
Cai W, Ryan U, Xiao L, Feng Y.Giardia duodenalis is a common intestinal parasite in various hosts, with the disease giardiasis being a zoonosis. The use of molecular typing tools has improved our understanding of the distribution and zoonotic potential of G. duodenalis genotypes in different animals. The present review summarizes recent data on the distribution of G. duodenalis genotypes in humans and animals in different areas. The dominance of G. duodenalis assemblages A and B in humans and common occurrence of host-adapted assemblages in most domesticated animals suggests that zoonotic giardiasis is probably less common...
Guy JS, Breslin JJ, Breuhaus B, Vivrette S, Smith LG.A coronavirus was isolated from feces of a diarrheic foal and serially propagated in human rectal adenocarcinoma (HRT-18) cells. Antigenic and genomic characterizations of the virus (isolate NC99) were based on serological comparison with other avian and mammalian coronaviruses and sequence analysis of the nucleocapsid (N) protein gene. Indirect fluorescent-antibody assay procedures and virus neutralization assays demonstrated a close antigenic relationship with bovine coronavirus (BCV) and porcine hemagglutinating encephalomyelitis virus (mammalian group 2 coronaviruses). Using previously des...
Wilke MM, Nydam DV, Nixon AJ.Mesenchymal stem cells (MSCs) provide an important source of pluripotent cells for musculoskeletal tissue repair. This study examined the impact of MSC implantation on cartilage healing characteristics in a large animal model. Twelve full-thickness 15-mm cartilage lesions in the femoropatellar articulations of six young mature horses were repaired by injection of a self-polymerizing autogenous fibrin vehicle containing mesenchymal stem cells, or autogenous fibrin alone in control joints. Arthroscopic second look and defect biopsy was obtained at 30 days, and all animals were euthanized 8 month...
Marklund L, Moller MJ, Sandberg K, Andersson L.The melanocyte-stimulating hormone receptor gene (MC1R) is the major candidate gene for the chestnut coat color in horses since it is assumed to be controlled by an allele at the extension locus. MC1R sequences were PCR amplified from chestnut (e/e) and non-chestnut (E/-) horses. A single-strand conformation polymorphism was found that showed a complete association to the chestnut coat color among 144 horses representing 12 breeds. Sequence analysis revealed a single missense mutation (83Ser-->Phe) in the MC1R allele associated with the chestnut color. The substitution occurs in the second ...
Steelman SM, Chowdhary BP, Dowd S, Suchodolski J, Janečka JE.The nutrition and health of horses is closely tied to their gastrointestinal microflora. Gut bacteria break down plant structural carbohydrates and produce volatile fatty acids, which are a major source of energy for horses. Bacterial communities are also essential for maintaining gut homeostasis and have been hypothesized to contribute to various diseases including laminitis. We performed pyrosequencing of 16S rRNA bacterial genes isolated from fecal material to characterize hindgut bacterial communities in healthy horses and those with chronic laminitis. Results: Fecal samples were collected...
Leclere M, Lavoie-Lamoureux A, Lavoie JP.Animal models have been developed to investigate specific components of asthmatic airway inflammation, hyper-responsiveness or remodelling. However, all of these aspects are rarely observed in the same animal. Heaves is a naturally occurring disease of horses that combines these features. It is characterized by stable dust-induced inflammation, bronchospasm and remodelling. The evaluation of horses during well-controlled natural antigen exposure and avoidance in experimental settings allows the study of disease mechanisms in the asymptomatic and symptomatic stages, an approach rarely feasible ...
Rogers GN, Pritchett TJ, Lane JL, Paulson JC.Human and animal (avian and equine) influenza A virus isolates of the H3 serotype exhibit marked differences in their ability to bind specific sialyloligosaccharide sequences that serve as cell surface receptor determinants (G. Rogers and J. Paulson, 1983, Virology 127, 361-373). Whereas human isolates of this subtype strongly agglutinate enzymatically modified human erythrocytes containing the terminal SA alpha 2,6Gal sequence, avian and equine isolates preferentially agglutinate erythrocytes bearing the SA alpha 2, 3Gal sequence. As shown in this report, a glycoprotein found in horse serum, ...
Dick LK, Bernhard AE, Brodeur TJ, Santo Domingo JW, Simpson JM, Walters SP, Field KG.The purpose of this study was to examine host distribution patterns among fecal bacteria in the order Bacteroidales, with the goal of using endemic sequences as markers for fecal source identification in aquatic environments. We analyzed Bacteroidales 16S rRNA gene sequences from the feces of eight hosts: human, bovine, pig, horse, dog, cat, gull, and elk. Recovered sequences did not match database sequences, indicating high levels of uncultivated diversity. The analysis revealed both endemic and cosmopolitan distributions among the eight hosts. Ruminant, pig, and horse sequences tended to for...
Garmashova N, Atasheva S, Kang W, Weaver SC, Frolova E, Frolov I.The encephalitogenic New World alphaviruses, including Venezuelan (VEEV), eastern (EEEV), and western equine encephalitis viruses, constitute a continuing public health threat in the United States. They circulate in Central, South, and North America and have the ability to cause fatal disease in humans and in horses and other domestic animals. We recently demonstrated that these viruses have developed the ability to interfere with cellular transcription and use it as a means of downregulating a cellular antiviral response. The results of the present study suggest that the N-terminal, approxima...
Campo MS.Tumorigenesis due to papillomavirus (PV) infection was first demonstrated in rabbits and cattle early last century. Despite the evidence obtained in animals, the role of viruses in human cancer was dismissed as irrelevant. It took a paradigm shift in the late 1970s for some viruses to be recognised as 'tumour viruses' in humans, and in 1995, more than 60 years after Rous's first demonstration of CRPV oncogenicity, WHO officially declared that 'HPV-16 and HPV-18 are carcinogenic to humans'. Experimental studies with animal PVs have been a determining factor in this decision. Animal PVs have bee...
McCarthy HE, Bara JJ, Brakspear K, Singhrao SK, Archer CW.A chondrocyte progenitor population isolated from the surface zone of articular cartilage presents a promising cell source for cell-based cartilage repair. In this study, equine articular cartilage progenitor cells (ACPCs) and equine bone marrow-derived stromal cells (BMSCs) were compared as potential cell sources for repair. Clonally derived BMSCs and ACPCs demonstrated expression of the cell fate selector gene, Notch-1, and the putative stem cell markers STRO-1, CD90 and CD166. Chondrogenic induction revealed positive labelling for collagen type II and aggrecan. Collagen type X was not detec...
Baldacchino F, Desquesnes M, Mihok S, Foil LD, Duvallet G, Jittapalapong S.Tabanids are nuisance pests for people and livestock because of their painful and irritating bite, persistent biting behavior, and blood ingestion. About 4400 tabanid species have been described; they are seasonally present in all kinds of landscapes, latitudes, and altitudes. High populations have a significant economic impact on outdoor activities, tourism, and livestock production. Tabanids are also vectors of animal disease agents, including viruses, bacteria and parasites. However, tabanids have received little attention in comparison with other hematophagous Diptera. Here, we highlight t...
Wong K, van der Weyden L, Schott CR, Foote A, Constantino-Casas F, Smith S, Dobson JM, Murchison EP, Wu H, Yeh I, Fullen DR, Joseph N, Bastian BC....Mucosal melanoma is a rare and poorly characterized subtype of human melanoma. Here we perform a cross-species analysis by sequencing tumor-germline pairs from 46 primary human muscosal, 65 primary canine oral and 28 primary equine melanoma cases from mucosal sites. Analysis of these data reveals recurrently mutated driver genes shared between species such as NRAS, FAT4, PTPRJ, TP53 and PTEN, and pathogenic germline alleles of BRCA1, BRCA2 and TP53. We identify a UV mutation signature in a small number of samples, including human cases from the lip and nasal mucosa. A cross-species comparative...
Love S, Murphy D, Mellor D.Cyathostomes are now the principle parasitic pathogen of the horse: a remarkable transformation during the last 25 years from virtual obscurity to focus of attention in equine parasitology. This rise to prominence coincides with the marked decrease in prevalence of large strongyle infections as a result of widespread use of modern anthelmintic compounds. On the basis that strongyle-associated diseases continue to commonly occur in the absence of these large strongyle species, clinical attention has turned to the pathogenicity of cyathostomes. Although many horses harbour burdens of tens of tho...
