Disease diagnosis in horses involves the identification and characterization of illnesses through various diagnostic methods and tools. This process is essential for effective veterinary care and management of equine health. Techniques used in diagnosing diseases in horses include clinical examinations, laboratory tests, imaging modalities such as ultrasonography and radiography, and molecular diagnostics. Blood tests are frequently utilized to assess parameters such as complete blood count and biochemical profiles, which can indicate underlying health issues. Additionally, advancements in genetic testing and biomarker identification have enhanced the ability to detect specific diseases early. This page aggregates peer-reviewed research studies and scholarly articles that explore diagnostic methodologies, their applications, and their impact on equine health management.
Lin ST, Bolas NM, Sargan DR, Restif O, Peter VG, Pokora R, Patrick H, Foote AK, Murray RC.Dorsoproximal osteochondral defects commonly affect the proximal phalanx, but information about diagnosis on computed tomography (CT) and magnetic resonance imaging (MRI) is limited. Objective: To assess CT and MRI diagnoses of osteochondral defects, describe the lesions and compare sensitivity and specificity of the modalities using macroscopic pathology as gold standard. Methods: Cross-sectional study. Methods: Thirty-five equine cadaver limbs underwent standing cone-beam CT (CBCT), fan-beam CT (FBCT), low-field MRI and pathological examination. CT and MR images were examined for proximal ph...
May-Davis S, Dzingle D, Saber E, Blades Eckelbarger P.This study examined the anomalous variations of the ventral process of C6 in modern E. ferus caballus. The aim was to provide an incremental grading protocol measuring the absence of the caudal ventral tubercle (CVT) in this ventral process. The findings revealed the most prevalent absent CVT (aCVT) was left unilateral (n = 35), with bilateral (n = 29) and right unilateral (n = 12). Grading was determined in equal increments of absence 1/4, 2/4, 3/4, with 4/4 representing a complete aCVT in 56/76, with a significance of p = 0.0013. This also applied to bilateral specimens. In those C6 osseous ...
Boyle AG, O'Shea K, Stefanovski D, Rankin SC.There is debate around the clinical significance of Streptococcus equi subsp. equi detection in low numbers using quantitative real-time PCR (qPCR). Propidium monoazide (PMA) qPCR has been used to differentiate DNA from viable and nonviable bacterial cells. The aim of this study was to evaluate the ability of PMA eqbE SEQ2190 triplex qPCR to differentiate DNA from viable and nonviable S. equi in positive and suspect positive clinical specimens. Fifty-seven stored (frozen and refrigerated) positive (36) or suspect positive (21) clinical specimens (determined via SeeI qPCR as the gold standard) ...
Luff J, Weingart S, May S, Murphy B.The aetiology of oral squamous cell carcinoma (SCC) in horses is unknown, but papillomavirus infection as well as chronic periodontal disease are suspected to play a pathogenic role. In humans, some oropharyngeal cancers develop in association with human papillomaviruses. Equus caballus papillomavirus 2 (EcPV2) is suspected to play a causal role in the development of equine genital SCC. Given that association, we hypothesized that EcPV2 is associated with the development of oral SCC in horses. We performed standard polymerase chain reaction (PCR) and in-situ hybridization (ISH) for EcPV2 on 31...
Bello K, Lorch G, Kim K, Toribio RE, Yan L, Xie Z, Hill K, Phelps M.Additional efficacious immunomodulatory treatment is needed for the management of immune-mediated disease in horses. Mycophenolate mofetil (MMF) is an immunosuppressive drug that warrants assessment as a viable therapeutic agent for horses. Objective: To evaluate the pharmacokinetics (PK) of multiple-day oral dosing of MMF in healthy horses and to determine the tolerability of this dosing regimen. Methods: Six healthy Standardbred mares. Methods: Horses received MMF 10 mg/kg PO q12h for 7 days in the fed state. Serial sampling was performed over 12 hours on Days 1 and 7 with trough sampl...
Scala E, van Galen G, Skärlina EM, Durie I.Pyelonephritis is a serious condition that is rarely described in horses. In contrast, urinary tract infections are common in humans and small animals, and multi-drug-resistant urinary infections are an emerging threat. In this report, we describe a horse with unilateral pyelonephritis caused by extended-spectrum beta-lactamase-producing bacteria belonging to the Enterobacter cloacae complex. [Correction added on 9 August 2023, after first online publication: The preceding sentence was corrected.] An 11-year-old Swedish warmblood gelding was diagnosed with a cystolith and a cystotomy through a...
Etemadi F, Tabatabaei Naeini A, Aminlari M.Minerals play vital roles in physiologic processes. Calcium, phosphorus and magnesium are common minerals. Secretion, absorption and homeostasis of these minerals are affected by associations between the active vitamin D and parathyroid hormone (PTH). The aim of this study was to assess concentrations of vitamin D, PTH and minerals, such as calcium, phosphorus and magnesium in horse sera, as well as associations of these values with lameness in horses. In the references, the reasons for lameness can be deficiency and imbalance of minerals, and clinical observations also confirm this and there ...
Flota-Burgos GJ, Rosado-Aguilar JA, Rojas-Becerril R, Rodríguez-Vivas RI, Trinidad-Martínez I.Gastrointestinal nematodes (GIN) are a major impediment to breeding and exploitation of horses. Traditional control of GIN has generated resistance to main anthelmintics, including ivermectin. An analysis of five ranches with a history of IVM use was done to determine the efficacy and resistance of GIN to IVM treatment in horses from the Mexican southeast. Predesigned questionnaires were applied to collect information on previous treatment protocols. The fecal egg count reduction test (FECRT) was applied to determine resistance. Before IVM application, a McMaster test was used to diagnose GIN ...
Legere RM, Allegro AR, Affram Y, Silveira BPD, Fridley JL, Wells KM, Oezguen N, Burghardt RC, Wright GA, Pollet J, Bordin AI, Figueiredo P....To examine the susceptibility of cultured primary equine bronchial epithelial cells (EBECs) to a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudovirus relative to human bronchial epithelial cells (HBECs). Methods: Primary EBEC cultures established from healthy adult horses and commercially sourced human bronchial epithelial cells (HBECs) were used as a positive control. Methods: Angiotensin-converting enzyme 2 (ACE2) expression by EBECs was demonstrated using immunofluorescence, western immunoblot, and flow cytometry. EBECs were transduced with a lentivirus pseudotyped with ...
Sewgobind S, McCracken F, Schilling M.West Nile virus (WNV) is a positive-sense single-stranded RNA virus belonging to the Flaviviridae family and is maintained in an enzootic cycle between avian hosts and mosquito vectors. Humans, horses and other mammals are susceptible to infection but are dead-end hosts due to a low viraemia. The disease can manifest itself in a variety of clinical signs and symptoms in people and horses from mild fever to severe encephalitis and morbidity. There are no vaccines licensed for human protection, but parts of Europe, North America, Africa and Australia have vaccines commercially available for hors...
Barrett MF, Goorchenko GE, Frisbie DD.Damage to the soft tissue structures of the digit is a common source of equine lameness. While magnetic resonance imaging (MRI) allows for the most complete diagnostic imaging of the equine digit, ultrasound is more readily available and less expensive. This prospective diagnostic accuracy study compares ultrasound to MRI for the diagnosis of injuries visible with ultrasound within the digit, including the deep digital flexor tendon (DDFT), collateral sesamoidean ligament (CSL), and navicular bursa. Clinical patients underwent an MRI of the digit and a blinded ultrasound of the digit between t...
Pearson GB, Papa B, Mosaddegh A, Cooper H, Aprea M, Pigott J, Altier C, Cazer CL, Reesink HL.To investigate (1) variables associated with the likelihood of obtaining a positive culture, (2) commonly isolated microorganisms, and (3) antimicrobial resistance patterns of isolates from horses with presumptive synovial sepsis. Methods: Synovial fluid, synovium, and bone samples from equine cases with presumptive synovial sepsis submitted to the Cornell University Animal Health Diagnostic Center from 2000 to 2020 for microbial culture and antimicrobial sensitivity testing. Methods: Univariable and multivariable analyses were performed to determine the effect of variables on the likelihood o...
Roberts JH, Zhang J, David F, McLean A, Blumenshine K, Müller-Alander E, Halper J.Degenerative Suspensory Ligament Desmitis (DSLD) negatively impacts connective tissues in horses, which often leads to progressive chronic pain and lameness. DSLD has been shown to be a systemic disorder that affects multiple body systems, including tendons, sclerae, and the aorta. Currently, the diagnosis is confirmed by post mortem histological examination of a tendon or suspensory ligament. Histology reveals inappropriate accumulations of proteoglycans in the tendons and other tissues in DSLD-affected horses. Unfortunately, there is no reliable method to diagnose DSLD in living horses. Rece...
Gonzálvez M, Franco JJ, Barbero-Moyano J, Caballero-Gómez J, Ruano MJ, Martínez R, Cano-Terriza D, García-Bocanegra I.The largest epidemic of West Nile virus (WNV) reported ever in Spain in both humans and equines occurred in 2020, affecting 77 humans and 139 equine herds. Here, we aimed to monitor the outbreaks detected in equid herds in Andalusia (southern Spain), the Spanish region where 89.9% of the outbreaks were reported, and to evaluate the virus circulation and risk factor associated with WNV exposure in the affected herds. The first WNV case was detected in mid-July 2020, the number of outbreaks peaked in mid-August and the last one was confirmed on 26th October 2020. WNV lineage 1 was detected in 12...
Reed RA, Krikorian AM, Reynolds RM, Holmes BT, Branning MM, Lemons MB, Barletta M, Quandt JE, Burns CC, Dantino SC, Sakai DM.Equine pain scoring may be affected by the residual effect of anesthetic drugs. Unassigned: To compare pain scores in the hours immediately following anesthetic recovery to baseline pre-anesthetic scores in equine patients undergoing surgical and non-surgical procedures. Unassigned: Clinical observational study. Unassigned: Fifty adult horses undergoing anesthesia for surgical or non-surgical procedures were enrolled. Horses underwent pain scoring using the Composite Pain Score (CPS) and Equine Utrecht University Scale for Facial Assessment of Pain (EQUUS-FAP) prior to anesthesia (T0) and foll...
Dallarosa P, Monteiro ER, Borenstein APS, Valle SF.Packed cell volume (PCV) is important for assessing a patient's health status. Some blood gas analyzers measure hematocrit, and the agreement with PCV varies among different analyzers. Objective: We aimed to determine the agreement between PCV measured by microcentrifugation and hematocrit measured by the Cobas b121 blood gas analyzer in dogs, cats, and horses. Methods: Whole blood samples for PCV and blood gas analysis were collected in lithium-heparin syringes and analyzed within 10 min of collection. Agreement and association between the PCV and Cobas b121 generated hematocrit were assess...
Costa LRR, Swiderski C, Palm C, Aleman M.To investigate if hepatitis A virus cell receptor 1/kidney injury molecule 1 (HAVCR1/KIM1) in urine is detectable concurrently with increases in serum creatinine concentrations in horses receiving a recommended dose of phenylbutazone (PBZ) for 7 days. Methods: Preliminary study. Methods: Ten clinically healthy horses with normal physical examination and laboratory work were randomly assigned to PBZ or placebo groups (5 each). The PBZ group received PBZ at 4.4 mg/kg mixed with corn syrup orally every 12 hours. The placebo group received corn syrup orally every 12 hours. Both groups were tre...
Castro-Mesa AF, Resende Faleiros R, Martínez-Aranzales JR.The transmural ultrasound allows for the definition of the normal appearance of the hoof tissues and internal structures. Determining such measurements and proportions could contribute to evaluations of the normal spatial distal phalanx-hoof relationship. The objective was to describe the hoof's dermis and epidermis measurements using the transmural technique, in comparison with DR and anatomical sections. Sixty-two healthy hooves without digital radiographic abnormalities, made up of 30 anatomical pieces (phase 1) and 32 alive horse hooves (phase 2), and 16 sagittal sections of the first ones...
Elder E, Wong D, Johnson K, Robertson H, Marner M, Dembek K.Bacterial sepsis is the leading cause of death in foals and is associated with hypothalamic-pituitary-adrenocortical axis (HPAA) dysfunction. HPAA function can be evaluated by an arginine-vasopressin (AVP) stimulation test. Objective: Administration of AVP will stimulate a dose-dependent rise in systemic adrenocorticotropin-releasing hormone (ACTH) and cortisol in neonatal foals. There will be no response seen in corticotropin-releasing hormone (CRH) and baseline AVP will be within reference interval. Methods: Twelve neonatal foals, <72 hours old. Methods: HPAA function was assessed in foals...
Fürstenau J, Richter MT, Erickson NA, Große R, Müller KE, Nobach D, Herden C, Rubbenstroth D, Mundhenk L.Borna disease is a progressive meningoencephalitis caused by spillover of the Borna disease virus 1 (BoDV-1) to horses and sheep and has gained attention due to its zoonotic potential. New World camelids are also highly susceptible to the disease; however, a comprehensive description of the pathological lesions and viral distribution is lacking for these hosts. Here, the authors describe the distribution and severity of inflammatory lesions in alpacas ( = 6) naturally affected by this disease in comparison to horses ( = 8) as known spillover hosts. In addition, the tissue and cellular distribu...
Fikri F, Hendrawan D, Wicaksono AP, Purnomo A, Khairani S, Chhetri S, Maslamama ST, Purnama MTE.Colic is among the common health issues in equine health management. Gastrointestinal (GI) disorders are the most frequent causes of colic, but dysfunction of other organs and systems inside the abdominal cavity may also contribute. Therefore, it is crucial to identify risk factors for colic of specific etiologies. This study aimed to examine the incidence, risk factors, and best therapeutic management practices for horses with colic. Unassigned: A cohort of 256 horses living in Lamongan, East Java, Indonesia, was randomly recruited based on reports of colic symptoms by owners. Diagnosis and t...
Li L, Maboni G, Lack A, Gomez DE.Nontuberculous mycobacteria (NTM) infections are increasing in human and veterinary medicine. Although horses were initially thought to be resistant to NTM infection, reports of horses suffering from gastrointestinal, respiratory, and reproductive diseases associated with NTM have increased in the last few decades. The aim of this literature review is to summarize the mycobacteria species found in horses, describe clinical manifestations, diagnostic and treatment approaches, and public health concerns of NTM infection in horses. Clinical manifestations of NTM in horses include pulmonary diseas...
Pimenta J, Pires I, Prada J, Cotovio M.Melanocytic tumors are an important neoplastic disease in human and veterinary medicine, presenting large differences regarding tumor behavior between species. In horses, these tumors present a prolonged benign behavior, with rare invasiveness and metastases. In humans and small animals, invasion and metastasis have been associated with an Epithelial-Mesenchymal Transition, where the loss of E-cadherin expression plays a key role in tumor progression. This process and the role of E-cadherin have not yet been evaluated in equine melanocytic tumors. This study aimed to assess the immunolabeling ...
Gurgul A, Jasielczuk I, Szmatoła T, Sawicki S, Semik-Gurgul E, Długosz B, Bugno-Poniewierska M.Nanopore sequencing is a third-generation biopolymer sequencing technique that relies on monitoring the changes in an electrical current that occur as nucleic acids are passed through a protein nanopore. Increasing quality of reads generated by nanopore sequencing systems encourages their application in genome-wide polymorphism detection and genotyping. In this study, we employed nanopore sequencing to identify genome-wide polymorphisms in the horse genome. To reduce the size and complexity of genome fragments for sequencing in a simple and cost-efficient manner, we amplified random DNA fragme...
McCue PM, Bisiau C, Divine C, May E.Congential amastia, a medical condition in which mammary tissue fails to develop, was detected in a 3-year-old Quarter Horse mare. The dam of the mare was also afflicted with amastia, suggesting that the condition was due to an inherited genetic mutation as noted in other species. In addition, on presentation the mare had a purulent vaginal discharge secondary to a pyometra.
Schinköthe J, Gerlach K, Ulrich RG, Brehm W.A 12-y-old Shetland Pony was presented with a mucus-secreting fistula in the right paralumbar fossa. Surgery was performed to unravel the origin of the fistula. The horse died under anesthesia and was forwarded to autopsy. The right kidney was markedly atrophic and fibrotic, consistent with unilateral end-stage kidney. The right ureter was markedly thickened, but with luminal continuity leading into the urinary bladder where a partial obstruction caused by nodular para-ureteral fat necrosis was evident. The lumen of the cutaneous fistula was continuous with the right ureter; therefore, we diag...
de Melo UP, Ferreira C.Oral and dental diseases are common in horses, as evidenced by the results of incidence studies of dental diseases carried out on abattoir specimens or sports horses. Thus, periodic dental examinations in horses are essential to ensure the maintenance of dental health and proper use of ingested food. A retrospective study of the dental records of 416 Quarter Horses (256 males, 160 females), distributed in the western region of the Rio Grande do Norte, Brazil, was conducted. Horses were examined between July 2012 and August 2022. The variables collected were age, sex, type of diet, dental alter...
Talbot SE, Tallon R, Dunkel B.Gastric impactions (GI) have been identified as primary lesions (lone GI; LGI) or associated with other intestinal lesions (concurrent GI; CGI). Anecdotally, CGI resolve more rapidly with a better prognosis than LGI. Objective: To determine clinical, laboratory, and ultrasonographic findings, and short- and long-term survival in horses with GI. We hypothesized that LGI carries a worse prognosis than CGI. Methods: Seventy-one horses from 2 referral hospitals (2007-2022). Methods: Retrospective cohort study. Gastric impactions were defined as feed extending to the margo plicatus after ≥24 h...
Telford EA, Watson MS, Aird HC, Perry J, Davison AJ.The complete DNA sequence of equine herpesvirus 2 (EHV-2) strain 86/67 was determined. The genome is 184,427 bp in size and has a base composition of 57.5% G + C. Unusually for a herpesvirus, about a third of the sequence distributed in several large blocks appears not to encode proteins. The 79 open reading frames that were identified as probably polypeptide-coding are predicted to encode 77 distinct proteins. Amino acid sequence comparisons confirmed that EHV-2 is a gamma-herpesvirus that is genetically collinear with herpesvirus saimiri (HVS; a gamma 2-herpesvirus) and Epstein-Barr virus (E...
Criado-Fornelio A, Martinez-Marcos A, Buling-Saraña A, Barba-Carretero JC.Molecular epizootiology of piroplasmids (Babesia spp., Theileria spp.) and Hepatozoon canis was studied in mammals from southern Europe (mainly from Spain, but also from Portugal and France). Partial amplification and sequencing of the 18s rRNA gene was used for molecular diagnosis. In some particular cases (B. ovis and B. bovis) the complete 18s rRNA gene was sequenced. Blood samples were taken from domestic animals showing clinical symptoms: 10 dogs, 10 horses, 10 cows, 9 sheep and 1 goat. In addition, DNA samples were isolated from blood of 12 healthy dogs and from spleen of 10 wild red fox...
McCracken MJ, Kramer J, Keegan KG, Lopes M, Wilson DA, Reed SK, LaCarrubba A, Rasch M.Subjective evaluation of mild lameness has been shown to have poor interobserver reliability. Traditional methods of objective lameness evaluation require specialised conditions and equipment. Wireless inertial sensor systems have been developed to allow for simple, rapid, objective lameness detection in horses trotted over ground. Objective: The purpose of this study was to compare the sensitivities of an inertial sensor system and subjective evaluation performed by experienced equine practitioners at detecting lameness in horses. We hypothesised that the inertial sensor system would identify...
Hardefeldt LY, Gilkerson JR, Billman-Jacobe H, Stevenson MA, Thursky K, Bailey KE, Browning GF.Antimicrobial stewardship (AMS) programs are yet to be widely implemented in veterinary practice and medical programs are unlikely to be directly applicable to veterinary settings. Objective: To gain an in-depth understanding of the factors that influence effective AMS in veterinary practices in Australia. Methods: A concurrent explanatory mixed methods design was used. The quantitative phase of the study consisted of an online questionnaire to assess veterinarians' attitudes to antimicrobial resistance (AMR) and antimicrobial use in animals, and the extent to which AMS currently is implemente...
de Laat MA, McGowan CM, Sillence MN, Pollitt CC.Hyperinsulinaemia is known to induce laminitis experimentally in healthy ponies with no history of the condition. Horses are more insulin sensitive than ponies and whether prolonged hyperinsulinaemia and euglycaemia would have a similar laminitogenic effect requires study. Objective: To determine if laminitis results when the prolonged euglycaemic hyperinsulinaemic clamp technique (p-EHC) is applied to clinically normal Standardbred horses, and to monitor hoof wall temperature seeking an association between vascular activity and laminitis development. Methods: Eight young, clinically normal St...
Azlaf R, Dakkak A.The objectives of this epidemiological study on cystic echinococcosis (CE) in Morocco (2001-2004) were to update the prevalence of CE in different animal species living in the most important areas of the country and to collect protoscoleces and germinal layers for genetic research purposes. The post mortem inspection concerned 2948 sheep, 2337 goats, 618 cattle, 482 camels and 455 equines (325 horses, 60 mules and 70 donkeys) in five different regions: the Rif (Mediterranean coast and high mountains of the Rif), the Loukkos (Atlantic northwest plain), the center (Rabat and Casablanca regions),...
Puffer BA, Watkins SC, Montelaro RC.We have identified an interaction between the equine infectious anemia virus (EIAV) late assembly domain and the cellular AP-2 clathrin-associated adapter protein complex. A YXXL motif within the EIAV Gag late assembly domain was previously characterized as a sequence critical for release of assembling virions. We now show that this YXXL sequence interacts in vitro with the AP-50 subunit of the AP-2 complex, while the functionally interchangeable late assembly domains carried by the Rous sarcoma virus p2b protein and human immunodeficiency virus type 1 p6 protein, which utilize PPPY and PTAPP ...
Frisbie DD, Al-Sobayil F, Billinghurst RC, Kawcak CE, McIlwraith CW.To discriminate between changes in biomarkers with exercise compared to changes in biomarkers with osteoarthritis (OA) in exercising horses. Methods: Sixteen, 2-year-old horses were randomly assigned either to an exercise-alone (n=8) or OA-affected (also exercised) (n=8) group. All horses had both mid-carpal joints arthroscoped and OA induced in one mid-carpal joint in the OA-affected joints of OA-affected horses. Two weeks after surgery all horses commenced a strenuous exercise program on a high-speed treadmill. Clinical outcomes and synovial fluid and serum biomarkers, were evaluated weekly....
Schnabel LV, Pezzanite LM, Antczak DF, Felippe MJ, Fortier LA.The horse is a valuable species to assess the effect of allogeneic mesenchymal stromal cells (MSCs) in regenerative treatments. No studies to date have examined recipient response to major histocompatibility complex (MHC)-mismatched equine MSCs. The purposes of this study were to immunophenotype MSCs from horses of known MHC haplotype and to compare the immunogenicity of MSCs with differing MHC class II expression. Methods: MSCs and peripheral blood leukocytes (PBLs) were obtained from Thoroughbred horses (n=10) of known MHC haplotype (ELA-A2, -A3, and -A9 homozygotes). MSCs were cultured thro...
Weese JS, Holcombe SJ, Embertson RM, Kurtz KA, Roessner HA, Jalali M, Wismer SE.Disruptions in the gastrointestinal microbiota may trigger development of post partum colic. Objective: To determine the effects of the periparturient period on the faecal microbiome and identify associations between the faecal microbiota and post partum colic. Methods: Longitudinal case-control study. Methods: Pre- and post partum faecal samples were collected from mares on 3 farms in central Kentucky. Next generation sequencing of the V4 region of the 16S rRNA gene was performed on samples from 13 mares that developed colic, 13 mares that did not display colic and 5 nonpregnant controls. Res...
Guo Y, Wang M, Kawaoka Y, Gorman O, Ito T, Saito T, Webster RG.In March 1989 a severe outbreak of respiratory disease occurred in horses in the Jilin and Heilongjiang provinces of Northeast China that caused up to 20% mortality in some herds. An influenza virus of the H3N8 subtype was isolated from the infected animals and was antigenically and molecularly distinguishable from the equine 2 (H3N8) viruses currently circulating in the world. The reference strain A/Equine/Jilin/1/89 (H3N8) was most closely related to avian H3N8 influenza viruses. Sequence comparisons of the entire hemagglutinin (HA), nucleoprotein (NP), neuraminidase (NA), matrix (M), and NS...
Leroux C, Cadoré JL, Montelaro RC.Equine Infectious Anemia Virus (EIAV) is a lentivirus, of the Retrovirus family, with an almost worldwide distribution, infecting equids. It causes a persistent infection characterized by recurring febrile episodes associating viremia, fever, thrombocytopenia, and wasting symptoms. The disease is experimentally reproducible by inoculation of Shetland ponies or horses with EIAV pathogenic strains. Among lentiviruses, EIAV is unique in that, despite a rapid virus replication and antigenic variation, most animals progress from a chronic stage characterized by recurring peaks of viremia and fever ...
Asanovich KM, Bakken JS, Madigan JE, Aguero-Rosenfeld M, Wormser GP, Dumler JS.The agent of human granulocytic ehrlichiosis (HGE), Ehrlichia phagocytophila, and Ehrlichia equi are very similar. HGE is of variable severity. Genetic and antigenic differences among 3 human isolates (Webster, Spooner, and NY-8) and 1 horse isolate (MRK) were evaluated. The 16S rRNA gene sequences were identical in all human isolates. By use of 5 homologous antisera from these 3 humans and 1 horse and an additional 5 antisera in heterologous reactions, the immunodominant antigens of each isolate were noted to differ in molecular size: 43 kDa in the Webster (Wisconsin) isolate, 46 kDa in the S...
Durham AE, Frank N, McGowan CM, Menzies-Gow NJ, Roelfsema E, Vervuert I, Feige K, Fey K.Equine metabolic syndrome (EMS) is a widely recognized collection of risk factors for endocrinopathic laminitis. The most important of these risk factors is insulin dysregulation (ID). Clinicians and horse owners must recognize the presence of these risk factors so that they can be targeted and controlled to reduce the risk of laminitis attacks. Diagnosis of EMS is based partly on the horse's history and clinical examination findings, and partly on laboratory testing. Several choices of test exist which examine different facets of ID and other related metabolic disturbances. EMS is controlled ...
Edson D, Field H, McMichael L, Vidgen M, Goldspink L, Broos A, Melville D, Kristoffersen J, de Jong C, McLaughlin A, Davis R, Kung N, Jordan D....Pteropid bats or flying-foxes (Chiroptera: Pteropodidae) are the natural host of Hendra virus (HeV) which sporadically causes fatal disease in horses and humans in eastern Australia. While there is strong evidence that urine is an important infectious medium that likely drives bat to bat transmission and bat to horse transmission, there is uncertainty about the relative importance of alternative routes of excretion such as nasal and oral secretions, and faeces. Identifying the potential routes of HeV excretion in flying-foxes is important to effectively mitigate equine exposure risk at the bat...
Costa MC, Weese JS.The equine intestinal tract contains a complex microbial population (microbiota) that plays an important role in health and disease. Despite the undeniable importance of a 'normal' microbiota, understanding of the composition and function of this population is currently limited. As methods to characterize the microbiota and its genetic makeup (the microbiome) have evolved, the composition and complexity of this population are starting to be revealed. As is befitting a hindgut fermenter, members of the Firmicutes phylum appear to predominate, yet there are significant populations of numerous ot...
Pezzanite LM, Fortier LA, Antczak DF, Cassano JM, Brosnahan MM, Miller D, Schnabel LV.This study tested the hypothesis that Major Histocompatibility Complex (MHC) incompatible equine mesenchymal stromal cells (MSCs) would induce cytotoxic antibodies to donor MHC antigens in recipient horses after intradermal injection. No studies to date have explored recipient antibody responses to allogeneic donor MSC transplantation in the horse. This information is critical because the horse is a valuable species for assessing the safety and efficacy of MSC treatment prior to human clinical application. Methods: Six MHC heterozygote horses were identified as non-ELA-A2 haplotype by microsat...
Ehlers B, Borchers K, Grund C, Frölich K, Ludwig H, Buhk HJ.A consensus primer PCR approach was used to (i) investigate the presence of herpesviruses in wild and zoo equids (zebra, wild ass, tapir) and to (ii) study the genetic relationship of the herpesvirus of pigeons (columbid herpesvirus 1) to other herpesvirus species. The PCR assay, based on degenerate primers targeting highly conserved regions of the DNA polymerase gene of herpesviruses, was modified by using a mixture of degenerate and deoxyinosine-substituted primers. The applicability of the modification was validated by amplification of published DNA polymerase genes of 16 herpesvirus specie...
Castillo-Olivares J, Wood J.West Nile virus (WNV) is a flavivirus closely related to Japanese encephalitis and St. Louis encephalitis viruses that is primarily maintained in nature by transmission cycles between mosquitoes and birds. Occasionally, WNV infects and causes disease in other vertebrates, including humans and horses. West Nile virus has re-emerged as an important pathogen as several recent outbreaks of encephalomyelitis have been reported from different parts of Europe in addition to the large epidemic that has swept across North America. This review summarises the main features of WNV infection in the horse, ...
Metallinos DL, Bowling AT, Rine J.Lethal White Foal Syndrome is a disease associated with horse breeds that register white coat spotting patterns. Breedings between particular spotted horses, generally described as frame overo, produce some foals that, in contrast to their parents, are all white or nearly all white and die shortly after birth of severe intestinal blockage. These foals have aganglionosis characterized by a lack of submucosal and myenteric ganglia from the distal small intestine to the large intestine, similar to human Hirschsprung Disease. Some sporadic and familial cases of Hirschsprung Disease are due to muta...
De Cock AW, Mendoza L, Padhye AA, Ajello L, Kaufman L.Pythium insidiosum sp. nov., the etiologic agent of pythiosis, a cosmopolitan disease of horses, cattle, and dogs, is described and illustrated.
Thorpe CT, Udeze CP, Birch HL, Clegg PD, Screen HR.Age-related tendinopathy is common in both humans and horses; the initiation and progression of which is similar between species. The majority of tendon injuries occur to high-strain energy storing tendons, such as the human Achilles tendon and equine superficial digital flexor (SDFT). By contrast, the low-strain positional human anterior tibialis tendon and equine common digital extensor (CDET) are rarely injured. It has previously been established that greater extension occurs at the fascicular interface in the SDFT than in the CDET; this may facilitate the large strains experienced during l...
Turton JF, Baklan H, Siu LK, Kaufmann ME, Pitt TL.A multiplex PCR using targets within the serotype-specific region of the capsular polysaccharide synthesis gene cluster of serotypes K1, K2 and K5 was evaluated using the 77 reference serotype strains of Klebsiella, and a panel of clinical isolates subjected previously to conventional serotyping. The PCR was highly specific for these serotypes, which are those most associated with virulence in humans and horses. PCR confirmed that isolates of the K5 serotype had cross-reacted with antiserum for other serotypes, particularly for K7. K5 isolates received by our laboratory were almost exclusively...
Arrigo NC, Adams AP, Weaver SC.The eastern equine encephalitis (EEE) complex consists of four distinct genetic lineages: one that circulates in North America (NA EEEV) and the Caribbean and three that circulate in Central and South America (SA EEEV). Differences in their geographic, pathogenic, and epidemiologic profiles prompted evaluation of their genetic diversity and evolutionary histories. The structural polyprotein open reading frames of all available SA EEEV and recent NA EEEV isolates were sequenced and used in evolutionary and phylogenetic analyses. The nucleotide substitution rate per year for SA EEEV (1.2 x 10(-4...
Labruna MB, Kasai N, Ferreira F, Faccini JL, Gennari SM.Natural tick infestations were assessed every 14 days on horses over a 2-year period. Amblyomma cajennense adult ticks were counted individually, without detachment from the horses. Larvae and nymphs of A. cajennense were collected using a rubber scraper that scratched engorged immature ticks from the host. Adult females of Anocentor nitens larger than 4mm length were counted on the horses. Blood samples were also obtained from the horses every 14 days and macroclimatic data were obtained for the study period. Infestations of A. cajennense demonstrated distinct peaks of activity for each of th...
Treiber KH, Kronfeld DS, Hess TM, Byrd BM, Splan RK, Staniar WB.To evaluate genetic and metabolic predispositions and nutritional risk factors for development of pasture-associated laminitis in ponies. Methods: Observational cohort study. Methods: 160 ponies. Methods: A previous diagnosis of laminitis was used to differentiate 54 ponies (PL group) from 106 nonlaminitic ponies (NL group). Pedigree analysis was used to determine a mode of inheritance for ponies with a previous diagnosis of laminitis. In early March, ponies were weighed and scored for body condition and basal venous blood samples were obtained. Plasma was analyzed for glucose, insulin, trigly...
Rossdale PD, Hopes R, Digby NJ, offord K.An epidemiological study of wastage among racehorses was conducted in 1982 and 1983 among six stables, five of which were in Newmarket. The basis of the survey was the inability of horses to take part in cantering exercise as a result of injury or disease. The greatest number of days lost to training was caused by lameness (67.6 per cent) and respiratory problems (20.5 per cent). Conditions of the foot (19 pe cent), muscle (18 per cent), carpus (14 per cent), fetlock joints (14 per cent), tendons (10 per cent) and sore shins (9 per cent) were the major reasons for training days being lost in 1...
Pirie RS.Recurrent airway obstruction is a widely recognised airway disorder, characterised by hypersensitivity-mediated neutrophilic airway inflammation and lower airway obstruction in a subpopulation of horses when exposed to suboptimal environments high in airborne organic dust. Over the past decade, numerous studies have further advanced our understanding of different aspects of the disease. These include clarification of the important inhaled airborne agents responsible for disease induction, improving our understanding of the underlying genetic basis of disease susceptibility and unveiling the fu...
