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.
Sekerel BE, Aliyeva G.Recent advancements in molecular diagnostics have unveiled a multitude of allergen molecules (AMs) associated with animal sensitizations, revealing significant cross- and co-sensitization patterns among these seemingly distinct allergens. Methods: We investigated the sensitization profiles of 120 children, sensitized to at least one of the 14 AMs from cat, dog, or horse using the Alex test, employing correlations and hierarchical clusters to explore relationship between sensitizations. Results: Sensitizations to Fel d 1, Can f 4/5, and Equ c 4 differ from other cat, dog, and horse AM sensitiza...
Dubuc J, Schneider MJ, Dubuc V, Richard H, Pinsard M, Bancelin S, Legare F, Girard C, Laverty S.Investigate meniscal extracellular matrix degradation. Equine menisci ( = 34 from 17 horses) were studied. Site-matched sections were cut and scored from three regions (ROIs; = 102) and stained for histology, proteoglycan (safranin O and fast green), aggrecan, and collagen cleavage (NITEGE, DIPEN, and C1,2C antibodies, respectively). Picrosirius red and second harmonic generation microscopy were performed to investigate collagen ultrastructure. A total of 42 ROIs met the inclusion criteria and were included in the final analysis. The median (range) ROI histological score was 3 (0-9), providin...
Elisabeth Müller C.A study comprising 74 colic and 74 control horses admitted to an animal hospital was performed. Faecal samples were collected and analysed for dry matter concentration, particle size distribution using wet-sieving, and sand presence through a sand sedimentation test. Data on horse breed, age, gender and basic feeding variables was collected and analysed using χ-tests. Faecal dry matter concentration, particle size distribution and sand score was compared between colic and non-colic horses, and between horses with different colic types, using one-way ANOVA. Results showed that colic and non-co...
Omyla K, Conley A, Varner D, Dini P.Persistent stallion-like behavior is a common sign of cryptorchidism in supposed geldings. The presence of testicular tissue can be evaluated by analyzing hormones such as testosterone and anti-Müllerian hormone (AMH). Here, we used hormonal analysis to investigate relationships between the likely presence of testicular tissue and stallion-like behavior in samples submitted from presumptive geldings (n = 1,202), retrospectively. Most geldings with stallion-like behaviors had serum concentrations of testosterone (851/1,056; 80.6 %) and AMH (682/877; 77.8 %) below the laboratory reference range...
Easton-Jones CA.Primary immune mediated hemolytic anemia (IMHA) and thrombocytopenia (IMTP) are rare in horses with the conditions more commonly occurring secondary to underlying disease. Several case reports have suggested a link between neoplasia and immune-mediated destruction of platelets and red blood cells. Diagnostic investigations should therefore focus on identifying possible underlying causes such as infections and neoplasia. Immunosuppressive therapy with corticosteroids and azathioprine is the mainstay of treatment but should be used cautiously in cases where underlying infection has not been excl...
Dyson S, Zheng S, Aleman M.Detailed descriptions of clinical signs associated with radiological findings of the caudal cervical vertebral column are not available. Objective: Describe the clinical features associated with neck pain or stiffness, neck-related thoracic limb lameness, proprioceptive ataxia consistent with a cervicothoracic spinal cord or nerve lesion, and their frequency of occurrence compared with control horses. Methods: A total of 223 Warmblood horses. Methods: Case-control study. Controls and cases were recruited prospectively. All horses underwent predetermined lameness and neurologic examinations. Th...
Munday JS, Knight CG, Bodaan CJ, Codaccioni C, Hardcastle MR.Penile squamous cell carcinomas (SCCs) are common, potentially life-threatening neoplasms of horses. They are well-recognized to be caused by Equus caballus papillomavirus (EcPV) type 2, although EcPV2 cannot be detected in all cases. A 23-year-old standardbred gelding developed multiple penile in situ and invasive SCCs that contained histological evidence of PV infection. By using both consensus and specific PCR primers, these lesions were found to contain EcPV7 DNA, but not DNA from EcPV2 or any other PV type. To determine how frequently EcPV7 is present in equine penile SCCs, specific prime...
Pandit PS, Smith WA, Finno CJ, Aleman M, Conrad PA, Packham A, Plancarte M, Woolard K, Marsh A, Pusterla N.Equine protozoal myeloencephalitis (EPM) is a challenging disease to diagnose in horses with neurological signs. To optimize contemporary diagnostic testing, including the use of serum:CSF antibody ratios, the SarcoFluor antibody test for Sarcocystis neurona requires revalidation. The SarcoFluor, a previously validated immunofluorescent antibody test (IFAT) for the detection of antibodies specific to S. neurona in serum and cerebrospinal fluid (CSF) of naturally infected horses was analyzed using recent data and considering a serum:CSF antibody ratio threshold. Utilization of serum and CSF pho...
Wells B.Beth Wells, equine grass sickness project lead at the Moredun Research Institute, encourages vets to report any equine grass sickness cases they encounter and explains how case reports and samples are being used to support research into this complex disease.
Brodesser DM, Kummer S, Eichberger JA, Schlangen K, Corteggio A, Borzacchiello G, Bertram CA, Brandt S, Pratscher B.The ability of human melanoma cells to switch from an epithelial to a mesenchymal phenotype contributes to the metastatic potential of disease. Metalloproteinases (MPs) are crucially involved in this process by promoting the detachment of tumor cells from the primary lesion and their migration to the vasculature. In gray horse melanoma, epithelial-mesenchymal transition (EMT) is poorly understood, prompting us to address MP expression in lesions versus intact skin by transcriptome analyses and the immunofluorescence staining (IF) of gray horse tumor tissue and primary melanoma cells. RNAseq re...
Silva GF, Ribeiro TE, Cunha R, Salas PB, Guimarães T, Ribeiro MR, Barros G, Carvalho F, Mesquita JR, Amorim I.Although relatively uncommon, lymphoma is the most prevalent haematopoietic neoplasia in horses, and multicentric lymphoma remains the most common presentation of the disease. The pathogenesis of equine lymphoma is still poorly understood and the diagnosis is usually confirmed at an advanced stage of the disease, compromising the prognosis. This study investigated the clinical, pathological, and molecular features of a case of equine multicentric lymphoma. Unassigned: An apparently healthy 5-year-old crossbreed mare hospitalized at the Centre of Animal Reproduction of Vairão, Portugal, sudden...
Marsella R.Autoimmune dermatopathies are not common in horses. These autoimmune diseases can be idiopathic or triggered by an antigen such as drugs, vaccines, or neoplasia. The most common one is pemphigus foliaceus, which manifests as a pustular, crusting eruption. Other more common pustular diseases should be ruled out before considering pemphigus. Vasculitis is relatively common in horses and can be triggered by a variety of antigenic stimulations. Systemic lupus and true idiopathic autoimmune vasculitis are very rare in horses. Every effort should be made to reach a final diagnosis, as the prognosis ...
Knickelbein KE, Lassaline ME.Immune-mediated ocular inflammation is a common clinical diagnosis reached for horses with keratitis and uveitis. This diagnosis is made as a diagnosis of exclusion following a thorough effort to rule out an underlying cause for the inflammation, most importantly infectious and neoplastic disease. Practically, response to ophthalmic and systemic anti-inflammatory or immunomodulatory medications is used to support a diagnosis of immune-mediated ocular inflammation; however, such medications are often contraindicated in the face of infection or neoplasia. This article will summarize our current ...
Tong P, Pan J, Dang Y, Yang E, Jia C, Duan R, Tian S, Palidan N, Kuang L, Wang C, Lu G, Xie J.Equine herpesvirus type 1 (EHV-1) is commonly associated with horse abortion. Currently, there are no reported cases of abortion resulting from EHV-1 infection in donkeys. This was the first survey-based study of Chinese donkeys. The presence of EHV-1 was identified by PCR. This survey was conducted in Chabuchar County, North Xinjiang, China, in 2020. A donkey EHV-1 strain (Chabuchar/2020) was successfully isolated in MDBK cells. Seventy-two of 100 donkey sera were able to neutralize the isolated EHV-1. Moreover, the ORF33 sequence of the donkey-origin EHV-1 Chabuchar/2020 strain showed high l...
Venter A, Vorster I, Nkosi NF, Sibeko-Matjila KP, Bhoora RV.Babesia caballi is an intra-erythrocytic parasite causing equine piroplasmosis. Three B. caballi genotypes (A, B, and C) have been identified based on the 18 S rRNA and rhoptry-associated protein (rap-1) gene sequences. These variant parasite genotypes compromise the diagnostic utility of the WOAH-recommended serological assays in declaring horses free of equine piroplasmosis. Although a gene encoding a spherical body protein 4 (sbp4) has recently been identified as a potential antigen for the serological detection of B. caballi, the ability of this antigen to detect the different geographic...
Farber B, Urion R, Hostnik ET.A 16-year-old pony gelding presented with epistaxis and a head tilt. Referral skull radiographs suggested an ethmoid hematoma. Concurrent neurologic abnormalities prompted contrast-enhanced CT of the head and cranial neck, revealing numerous hyperattenuating masses throughout the brain and paranasal sinuses, along with a large osteolytic mass in the second cervical vertebra. The vertebral mass extended into the vertebral canal, causing focal extradural compressive myelopathy. These findings were inconsistent with ethmoid hematoma and metastatic hemangiosarcoma or malignant melanoma were priori...
Rasmussen N, Karlsen P, Otten ND, Fjeldborg J, Hansen S.Bronchoalveolar lavage (BAL) cytology results from 1 lung might not be representative of both lungs. Objective: To determine whether the lung site sampled would influence the horse's BAL cytology profile, and if a pooled BAL sample would be superior with regard to BAL cytology diagnosis in a cohort of healthy and subclinical asthmatic warmblood horses. Methods: Fifty-nine horses in 2021 and 70 horses in 2022, the follow-up included 53 of the same in each year. Methods: A cross-sectional study with follow-up included BAL cytology samples from individual lungs and from pooled BAL samples. The BA...
Mullen KR, Felippe MJB.Equine common variable immunodeficiency (CVID) is a rare, late-onset, nonfamilial humoral deficiency characterized by B-cell depletion and/or dysfunction resulting in inadequate antibody production and predisposition to recurrent infections. Serum immunoglobulin concentration and peripheral blood lymphocyte immunophenotyping are required to diagnose and characterize CVID in horses. Early recognition of the disease by the equine practitioner is paramount to managing the quality of life for these patients, for whom specific treatment is not yet available and long-term prognosis remains poor. An ...
Bozorgmanesh R.Immune-mediated vasculopathies occur secondary to infection or another noninfectious stimulus. Potential triggers include heterologous antigens including viruses, injected proteins and drugs; or auto-antigens including immunoglobulins or other endogenous proteins. Although these conditions are rare in horses, immune-mediated vasculopathies can cause considerable morbidity, with variable clinical signs depending on severity and organ system affected. Examples include purpura hemorrhagica, systemic lupus erythematosus, drug-induced vasculitis, paraneoplastic vasculitis, and idiopathic immune-med...
Ramos-Vázquez JR, Sánchez-Montes S, Esparza-González SC, Romero-Salas D, Pardio-Sedas V, Estrada-Coates AT, Alva-Trujillo M, Ballados-González GG....Leptospirosis is an infectious disease with a worldwide distribution, which represents a major challenge in animal production across developing countries, mainly in tropical areas. Horses are particularly susceptible to the disease, presenting manifestations ranging from subclinical to the development of uveitis that compromises the visual health of the animals. In recent years, serological studies have been carried out in equid populations from America, demonstrating high exposure. For this reason, the aim of this study was to demonstrate microbiologically and molecularly the presence of the ...
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-...
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...
Pan Y, Su X, Liu Y, Fan P, Li X, Ying Y, Ping J.In point-of-care diagnostics, the continuous monitoring of sweat constituents provides a window into individual's physiological state. For species like horses, with abundant sweat glands, sweat composition can serve as an early health indicator. Considering the salience of such metrics in the domain of high-value animal breeding, a sophisticated wearable sensor patch tailored is introduced for the dynamic assessment of equine sweat, offering insights into pH, potassium ion (K), and temperature profiles during episodes of heat stress and under normal physiological conditions. The device integra...
Young AE, Finno CJ.Equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy (eNAD/EDM) is an inherited neurodegenerative disease associated with vitamin E deficiency in the first year of life. It is the second most common cause of spinal ataxia in horses euthanized for neurologic disease. Equine NAD/EDM is characterized by neurologic signs including a symmetric proprioceptive ataxia (> grade 2/5) and a wide-base stance at rest. There are currently no antemortem tests for eNAD/EDM in any breed. Conclusive diagnosis requires postmortem histologic evaluation of the brainstem and spinal cord at necropsy....
Smarsh DN, Kenny LB, Spindler M, Poh KC, Machtinger ET.There is limited data on current knowledge of Pennsylvania horse caretakers on tick-borne diseases (TBDs), tick identification, and tick management practices. This study aimed to determine tick knowledge, concern, and management among Pennsylvania equine caretakers using an online survey. Descriptive statistics and one-way ANOVA tests were used to analyze data. The survey received 894 responses (539 completed) from Pennsylvania equine owners and caretakers. The largest proportion of respondents cared for 3-5 horses (31%), followed by 2 horses (27%). Veterinarian-confirmed diagnosis rates of tw...
Hamond C, Adam EN, Stone NE, LeCount K, Anderson T, Putz EJ, Camp P, Hicks J, Stuber T, van der Linden H, Bayles DO, Sahl JW, Schlater LK, Wagner DM....Equine leptospirosis can result in abortion, stillbirth, neonatal death, placentitis, and uveitis. Horses can also act as subclinical reservoir hosts of infection, which are characterized as asymptomatic carriers that persistently excrete leptospires and transmit disease. In this study, PCR and culture were used to assess urinary shedding of pathogenic Leptospira from 37 asymptomatic mares. Three asymptomatic mares, designated as H2, H8, and H9, were PCR-positive for lipL32, a gene specific for pathogenic species of Leptospira. One asymptomatic mare, H9, was culture-positive, and the recovered...
Ducrocq M, Kamus L, Richard H, Beauchamp G, Janvier V, Laverty S.Stifle osteoarthritis (OA) lesions are most common in the medial femorotibial (MFT) compartment. Their characterisation and mapping will inform equine veterinarians towards an accurate diagnosis of OA. Objective: Investigate and map micro-CT (μCT) changes in the hyaline articular cartilage (HAC) in the medial femoral condyle (MFC) and medial tibial plateau (MTP). Methods: Ex vivo cadaveric. Methods: Stifles (n = 7 OA and 17 control [CO]) were retrieved from a tissue bank. The MFC and MFT were imaged with μCT. Regions of interest (ROIs) were cranial (MFCcr; MTPcr) and caudal (MFCca; MTPca...
Leemans B, Gadella BM, Stout TA, De Schauwer C, Nelis H, Hoogewijs M, Van Soom A.In contrast to man and many other mammalian species, conventional in vitro fertilization (IVF) with horse gametes is not reliably successful. The apparent inability of stallion spermatozoa to penetrate the zona pellucida in vitro is most likely due to incomplete activation of spermatozoa (capacitation) because of inadequate capacitating or fertilizing media. In vivo, the oviduct and its secretions provide a microenvironment that does reliably support and regulate interaction between the gametes. This review focuses on equine sperm-oviduct interaction. Equine sperm-oviduct binding appears to be...
Knollinger AM, La Croix NC, Barrett PM, Miller PE.To compare intraocular pressure (IOP) measurements obtained with a rebound tonometer in dogs and horses with values obtained by means of applanation tonometry and direct manometry. Methods: Prospective study. Methods: 100 dogs and 35 horses with clinically normal eyes, 10 enucleated eyes from 5 dogs, and 6 enucleated eyes from 3 horses. Methods: In the enucleated eyes, IOP measured by means of direct manometry was sequentially increased from 5 to 80 mm Hg, and IOP was measured with the rebound tonometer. In the dogs and horses, results of rebound tonometry were compared with results of applana...
Ball JM, Rushlow KE, Issel CJ, Montelaro RC.We describe here a detailed analysis of the antigenic determinants of the surface unit glycoprotein (gp90) of equine infectious anemia virus (EIAV), using a comprehensive panel of synthetic peptides in enzyme-linked immunosorbent assays with immune serum from naturally and experimentally infected horses and with a panel of gp90-specific neutralizing and nonneutralizing monoclonal antibodies. The results of these studies identify immunoreactive segments throughout the conserved and variable domains of gp90 but localize immunodominant (100% reactivity) determinants to the amino and carboxyl term...
Perkins GA, Lamb S, Erb HN, Schanbacher B, Nydam DV, Divers TJ.Plasma ACTH levels have been variable in horses with a positive clinical response for therapy for equine Cushing's Disease (ECD). Therefore, our purpose was to determine the value of monitoring plasma adrenocorticotropin (ACTH) levels during treatment of equine Cushing's disease (ECD) with either cyproheptadine (n = 32) or pergolide (n = 10). First, we validated the chemiluminescent ACTH assay (specificity, precision, accuracy, intra-assay and interassay variations) and tested methods of handling the whole blood from the time of collection to when the ACTH was assayed. The sensitivity and spec...
Kutasi O, Bakonyi T, Lecollinet S, Biksi I, Ferenczi E, Bahuon C, Sardi S, Zientara S, Szenci O.The spread of lineage 2 West Nile virus (WNV) from sub-Saharan regions to Europe and the unpredictable change in pathogenicity indicate a potential public and veterinary health threat and requires scientific awareness. Objective: To describe the results of clinical and virological investigations of the 1st outbreak of a genetic lineage 2 WNV encephalomyelitis in horses. Methods: Seventeen horses with neurologic signs. Methods: Information regarding signalment, clinical signs, and outcome was obtained for each animal. Serology was performed in 15 cases, clinicopathological examination in 7 case...
Tomlinson JE, Tennant BC, Struzyna A, Mrad D, Browne N, Whelchel D, Johnson PJ, Jamieson C, Löhr CV, Bildfell R, McKenzie EC, Laverack M, Renshaw RW....A novel equine parvovirus (EqPV-H) was recently discovered in the equine liver with Theiler's disease. Objective: To determine the prevalence of EqPV-H infection in naturally occurring Theiler's disease cases and in-contact horses in the absence of historical equine biologic product administration. Methods: Ten cases of Theiler's disease from 6 separate properties were included in the study, based on the criteria of acute onset of clinical signs of liver failure with laboratory or histopathologic findings characteristic of Theiler's disease and no history of receiving an equine biologic produc...
Nemoto M, Oue Y, Morita Y, Kanno T, Kinoshita Y, Niwa H, Ueno T, Katayama Y, Bannai H, Tsujimura K, Yamanaka T, Kondo T.Recently, outbreaks associated with equine coronavirus (ECoV) have occurred in Japan and the United States. While ECoV is likely to be pathogenic to horses, it has not been shown that experimental inoculation of horses with ECoV produces clinical signs of disease. In this study, we inoculated three Japanese draft horses with an ECoV-positive diarrheic fecal sample to confirm infection after inoculation and to investigate the clinical course and virus shedding patterns of ECoV. Virus neutralization tests showed that all three horses became infected with ECoV. Two of the three horses developed c...
Nielsen MK, Peterson DS, Monrad J, Thamsborg SM, Olsen SN, Kaplan RM.Strongylus vulgaris is an important strongyle nematode with high pathogenic potential infecting horses world-wide. Several decades of intensive anthelmintic use has virtually eliminated clinical disease caused by S. vulgaris, but has also caused high levels of anthelmintic resistance in equine small strongyle (cyathostomin) nematodes. Recommendations aimed at limiting the development of anthelmintic resistance by reducing treatment intensity raises a simultaneous demand for reliable and accurate diagnostic tools for detecting important parasitic pathogens. Presently, the only means available t...
Christoffersen M, Woodward E, Bojesen AM, Jacobsen S, Petersen MR, Troedsson MH, Lehn-Jensen H.The objective of the study was to evaluate the gene expression of inflammatory cytokines (interleukin [IL]-1β, IL-6, IL-8, IL-10, tumor necrosis factor [TNF]-α, IL-1 receptor antagonist [ra] and serum amyloid A (SAA) in endometrial tissue and circulating leukocytes in response to uterine inoculation of 105 colony forming units (CFU) Escherichia coli in mares. Before inoculation, mares were classified as resistant or susceptible to persistent endometritis based on their uterine inflammatory response to infusion of 109 killed spermatozoa and histological assessment of the endometrial quality. ...
Reesink HL, Watts AE, Mohammed HO, Jay GD, Nixon AJ.The goals of this study were (1) to quantify proteoglycan 4 (PRG4) gene expression; (2) to assess lubricin immunostaining; and (3) to measure synovial fluid lubricin concentrations in clinical and experimental models of equine carpal osteoarthritis (OA). Lubricin synovial fluid concentrations and cartilage and synovial membrane PRG4 expression were analyzed in research horses undergoing experimental OA induction (n = 8) and in equine clinical patients with carpal OA (n = 58). Lubricin concentrations were measured using a custom sandwich enzyme-linked immunosorbent assay, and PRG4 expressio...
Chang MH, Kim KH, Kim HS, Jun HJ, Kim DH, Jang JH, Kim K, Jung CW.Immunosuppressive therapy (IST) with antithymocyte globulin (ATG) plus cyclosporine (CSA) is standard therapy in patients with severe aplastic anemia (SAA) who do not have an available HLA-matched sibling donor. Methods: The current study aimed to determine the predictive factors for response to IST in patients with SAA and to identify prognostic factors following IST. A total of 62 patients diagnosed with SAA who received IST with either rabbit ATG (n = 33) or horse ATG (n = 29) plus CSA between October 1994 and December 2007 were included. Results: With a median follow-up duration of 60.5 mo...
Newton JR, Wood JL, Dunn KA, DeBrauwere MN, Chanter N.During an outbreak of strangles on a farm with approximately 1500 horses, the spread of Streptococcus equi infection was monitored by repeated nasopharyngeal swabbing and culture. In order to control the infection and prevent new introductions of strangles on to the premises, a system of quarantine and swabbing of cases and all incoming animals was instituted. Long-term carriage of the organism was detected in four clinically healthy convalescent animals, and in two of 350 new ponies; it persisted for between seven and 39 months, but it was detected only intermittently by the culture of swabs ...
Kolodziejek J, Dürrwald R, Herzog S, Ehrensperger F, Lussy H, Nowotny N.The aim of this study was to gain more detailed insights into the genetic evolution and variability of Borna disease virus (BDV). Phylogenetic analyses were performed on field viruses originating from naturally infected animals, the BDV vaccine strain 'Dessau', four widely used laboratory strains and the novel BDV subtype No/98. Four regions of the BDV genome were analysed: the complete p40, p10 and p24 genes and the 5'-untranslated region of the X/P transcript. BDV isolates from the same geographical area exhibited a clearly higher degree of identity to each other than to BDV isolates from ot...
Hulínská D, Langrová K, Pejcoch M, Pavlásek I.The aim of this study was to detect Anaplasma phagocytophilum in wild and domesticated animals and to identify the phylogenetic relationships of different strains of this bacterium. We adapted six published conventional methods targeting 16S fragments for real-time polymerase chain reaction. Initial screening of samples from 419 animals found 37 Anaplasma positives, later confirmed with several different primers and a TaqMan probe. We also performed DNA quantification and melting curve analysis. The nucleic acid of Anaplasma sp. was detected in a higher percentage of cases in members of the de...
Chan J, Doyle B, Branley J, Sheppeard V, Gabor M, Viney K, Quinn H, Janover O, McCready M, Heller J.In November 2014, New South Wales Health was notified of a cluster of respiratory illness in a veterinary school. Active case finding identified another case at a local equine stud. All cases had exposure to the equine fetal membranes of Mare A. This tissue subsequently tested positive for Chlamydia psittaci using quantitative real-time polymerase chain reaction. We conducted a cohort study of the university and stud farm staff to determine risk factors for disease. Nine people were exposed to the fetal membranes of Mare A. Of these, five cases of psittacosis were identified. Two required hosp...
Equine trypanosomosis is a complex of infectious diseases called dourine, nagana and surra. It is caused by several species of the genus Trypanosoma that are transmitted cyclically by tsetse flies, mechanically by other haematophagous flies, or sexually. Trypanosoma congolense (subgenus Nannomonas) and T. vivax (subgenus Dutonella) are genetically and morphologically distinct from T. brucei, T. equiperdum and T. evansi (subgenus Trypanozoon). It remains controversial whether the three latter taxa should be considered distinct species. Recent outbreaks of surra and dourine in Europe illustrate ...
Stewart HL, Southwood LL, Indugu N, Vecchiarelli B, Engiles JB, Pitta D.The faecal microbiota is emerging as potentially important in intestinal disease. More research is needed to characterise the faecal microbiota from horses with colic. Objective: To compare the relative abundance of bacterial populations comprising the faecal microbiota in horses presenting for colic compared with an elective surgical procedure. Methods: Prospective observational clinical study. Methods: Admission faecal samples were collected from horses presenting for colic and elective surgical procedures. Faecal samples were extracted for genomic DNA, PCR- amplified, sequenced and analysed...
Reed SM, Furr M, Howe DK, Johnson AL, MacKay RJ, Morrow JK, Pusterla N, Witonsky S.Equine protozoal myeloencephalitis (EPM) remains an important neurologic disease of horses. There are no pathognomonic clinical signs for the disease. Affected horses can have focal or multifocal central nervous system (CNS) disease. EPM can be difficult to diagnose antemortem. It is caused by either of 2 parasites, Sarcocystis neurona and Neospora hughesi, with much less known about N. hughesi. Although risk factors such as transport stress and breed and age correlations have been identified, biologic factors such as genetic predispositions of individual animals, and parasite-specific factors...
Campbell AJ, Gasser RB, Chilton NB.In the current study, molecular techniques were evaluated for the species identification of individual strongyle eggs. Adult worms of Strongylus edentatus, S. equinus and S. vulgaris were collected at necropsy from horses from Australia and the U.S.A. Genomic DNA was isolated and a ribosomal transcribed spacer (ITS-2) amplified and sequenced using polymerase chain reaction (PCR) techniques. The length of the ITS-2 sequence of S. edentatus, S. equinus and S. vulgaris ranged between 217 and 235 nucleotides. Extensive sequence analysis demonstrated a low degree (0-0.9%) of intraspecific variation...
Goodship AE, Birch HL, Wilson AM.Injury of the collagenous structures comprising tendons and ligaments, either from acute trauma or from repetitive strain lesions, results in protracted periods of disability. The resolution of such injuries often fails to restore the normal morphologic and functional characteristics of the structure and, therefore, either compromises the future performance of the individual or predisposes to an increased risk of recurrent injury.
Wagner PD, Gillespie JR, Landgren GL, Fedde MR, Jones BW, DeBowes RM, Pieschl RL, Erickson HH.Arterial hypoxemia has been reported in horses during heavy exercise, but its mechanism has not been determined. With the use of the multiple inert gas elimination technique, we studied five horses, each on two separate occasions, to determine the physiological basis of the hypoxemia that developed during horizontal treadmill exercise at speeds of 4, 10, 12, and 13-14 m/s. Mean, blood temperature-corrected, arterial PO2 fell from 89.4 Torr at rest to 80.7 and 72.1 Torr at 12 and 13-14 m/s, respectively, whereas corresponding PaCO2 values were 40.3, 40.3, and 39.2 Torr. Alveolar-arterial PO2 di...
Maury W.In vivo, equine infectious anemia virus (EIAV) replicates in tissues rich in macrophages, and it is widely believed that the tissue macrophage is the principal, if not sole, cell within the host that replicates virus. No viral replication has been detected in circulating peripheral blood monocytes. However, proviral DNA can be detected in these cells, and monocytes may serve as a reservoir for the virus. In this study, an in vitro model was developed to clarify the role of monocyte maturation in regulating EIAV expression. Freshly isolated, nonadherent equine peripheral blood monocytes were in...
Carpenter S, Evans LH, Sevoian M, Chesebro B.Equine infectious anemia virus was isolated from peripheral blood leukocytes collected during two early febrile cycles of an experimentally infected horse. RNase T1-resistant oligonucleotide fingerprint analyses indicated that the nucleotide sequences of the isolates differed by approximately 0.25% and that the differences appeared randomly distributed throughout the genome. Serum collected in the interval between virus isolations was able to distinguish the isolates by membrane immunofluorescence on live cells. However, no neutralizing antibody was detected in the interval between virus isola...
Qablan MA, Oborník M, Petrželková KJ, Sloboda M, Shudiefat MF, Hořín P, Lukeš J, Modrý D.Microscopic diagnosis of equine piroplasmoses, caused by Theileria equi and Babesia caballi, is hindered by low parasitaemia during the latent phase of the infections. However, this constraint can be overcome by the application of PCR followed by sequencing. Out of 288 animals examined, the piroplasmid DNA was detected in 78 (27·1%). Multiplex PCR indicated that T. equi (18·8%) was more prevalent than B. caballi (7·3%), while mixed infections were conspicuously absent. Sequences of 69 PCR amplicons obtained by the 'catch-all' PCR were in concordance with those amplified by the multiplex str...
Hoopes JT, Stark CJ, Kim HA, Sussman DJ, Donovan DM, Nelson DC.Streptococcus equi is the causative agent of the purulent infection equine strangles. This disease is transmitted through shedding of live bacteria from nasal secretions and abscess drainage or by contact with surfaces contaminated by the bacteria. Disinfectants are effective against S. equi, but inactivation by environmental factors, damage to equipment, and toxicity are of great concern. Bacteriophage-encoded lysins (cell wall hydrolases) have been investigated as therapeutic agents due to their ability to lyse susceptible gram-positive organisms. Here, we investigate the use of one lysin, P...
O'Meara B, Bladon B, Parkin TD, Fraser B, Lischer CJ.There is limited information regarding the number of races and the period for evaluation of outcome which is critical for assessment of SDF tendonitis treatments. Objective: To evaluate the re-injury rate and racing performance of Thoroughbred racehorses that sustain SDF tendonitis in relation to matched controls in terms of number of races post treatment and maximum racing performance ratings before and after injury. Methods: Clinical records and racing histories of 401 racehorses with a first occurrence of SDF tendonitis diagnosed by ultrasonography. Controls were of the same age, sex and we...
Klaus C, Hörügel U, Hoffmann B, Beer M.During a routine examination of 130 horse sera from 13 herds in Thuringia one TBEV antibody positive serum - with a very high titre - could be detected. The horse had been bought from a holding in Bavaria, and was reported to have clinical signs that may have been caused by a TBEV infection. To identify the source of the suspected TBEV infection, ticks from the surroundings of the barn in Thuringia as well as horse sera and ticks from two herds in Bavaria were examined. In the holding in Bavaria, where the horse was kept before, two out of ten horse sera were found to be TBEV antibody positive...
Clutterbuck AL, Smith JR, Allaway D, Harris P, Liddell S, Mobasheri A.This study employed a targeted high-throughput proteomic approach to identify the major proteins present in the secretome of articular cartilage. Explants from equine metacarpophalangeal joints were incubated alone or with interleukin-1beta (IL-1β, 10ng/ml), with or without carprofen, a non-steroidal anti-inflammatory drug, for six days. After tryptic digestion of culture medium supernatants, resulting peptides were separated by HPLC and detected in a Bruker amaZon ion trap instrument. The five most abundant peptides in each MS scan were fragmented and the fragmentation patterns compared to m...
Nielsen MK, Reinemeyer CR, Donecker JM, Leathwick DM, Marchiondo AA, Kaplan RM.Anthelmintic resistance is becoming increasingly prevalent among equine nematode parasites. The first reports documenting resistance were published in the 1960s, just a short time after introduction of the first modern anthelmintics phenothiazine and thiabendazole. Several factors are known to influence development of resistance, but evidence specific to equine parasites is limited. Most current knowledge and applications have been extrapolated from research with trichostrongylid parasites of sheep. The number of cyathostomin species co-infecting horses adds to the complexity of investigating ...
Schoster A, Staempfli HR, Guardabassi LG, Jalali M, Weese JS.Diarrhea in foals affects up to 60% of foals during the first six months of life. The effect of diarrhea on the fecal bacterial microbiota in foals has not been investigated. Little is known on the fecal bacterial microbial richness and diversity of foals at a young age. The objective was to compare the fecal bacterial microbiota of healthy foals to foals with diarrhea at two and four weeks of life. Methods: Fecal samples were collected from foals (n = 20) at 1-14 (T1) and 15-28 (T2) days of age and analyzed using high throughput sequencing. Differences in relative abundance of bacterial tax...
