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.
Maliye S, Voute L, Lund D, Marshall JF.In order for changes in lameness to be accurately and repeatably detected and recorded during diagnostic investigations, an objective measure of lameness is required. Objective: To ascertain whether an inertial sensor-based system can distinguish between a positive and negative response to diagnostic anaesthesia of the foot and objectively assess the effect of a positive response on the trot. Methods: Restrospective clinical study. Methods: Data obtained during lameness investigations undertaken between August 2011 and December 2012 in which either a palmar digital or abaxial sesamoid nerve bl...
Hunter BG, Schlipf JW, Cebra C.The transverse facial venous sinus (TFVS) can be used for blood collection in horses, but information on the validity of blood values from this site is limited. Objective: To determine if packed cell volume (PCV), total solids (TS) and blood lactate concentrations in blood drawn simultaneously from a TFVS and jugular vein of critically ill horses are correlated and determine the effect of serial TFVS sampling on the same parameters in healthy horses. Methods: Prospective observational study. Methods: Critically ill horses had simultaneous blood samples drawn from a TFVS and jugular vein. Blood...
Crowley J, Po E, Celi P, Muscatello G.Oxidative stress (OS) is most simply defined as an imbalance between oxidants and antioxidants. Oxidative stress has been suggested to play roles in various equine respiratory diseases and the significance of OS in the pathogenesis of Rhodococcus equi pneumonia is unknown. Objective: To measure and relate biomarkers of OS to lesions consistent with R. equi pneumonia. Methods: Case-control study. Methods: Various OS biomarkers were measured from blood and exhaled breath condensate (EBC) samples collected from 26 foals between 1 and 2 months of age (n = 12 cases and n = 14 controls) on 2 Thoro...
Bolfa P, Nolf M, Cadoré JL, Catoi C, Archer F, Dolmazon C, Mornex JF, Leroux C.EIA (Equine Infectious Anemia) is a blood-borne disease primarily transmitted by haematophagous insects or needle punctures. Other routes of transmission have been poorly explored. We evaluated the potential of EIAV (Equine Infectious Anemia Virus) to induce pulmonary lesions in naturally infected equids. Lungs from 77 EIAV seropositive horses have been collected in Romania and France. Three types of lesions have been scored on paraffin-embedded lungs: lymphocyte infiltration, bronchiolar inflammation, and thickness of the alveolar septa. Expression of the p26 EIAV capsid (CA) protein has been...
Ruple-Czerniak AA, Aceto HW, Bender JB, Paradis MR, Shaw SP, Van Metre DC, Weese JS, Wilson DA, Wilson J, Morley PS.Methods that can be used to estimate rates of healthcare-associated infections and other nosocomial events have not been well established for use in equine hospitals. Traditional laboratory-based surveillance is expensive and cannot be applied in all of these settings. Objective: To evaluate the use of a syndromic surveillance system for estimating rates of occurrence of healthcare-associated infections among hospitalised equine cases. Methods: Multicentre, prospective longitudinal study. Methods: This study included weaned equids (n = 297) that were admitted for gastrointestinal disorders at ...
Galvin P, Gildea S, Arkins S, Walsh C, Cullinane A.Antibodies against equine influenza virus (EIV) are traditionally quantified by haemagglutination inhibition (HI) or single radial haemolysis (SRH). Objective: To evaluate an ELISA for the detection of antibodies against influenza nucleoprotein in the diagnosis and surveillance of equine influenza (EI). Methods: The ELISA was compared with the SRH and HI tests. Serial serum samples from 203 naturally and 14 experimentally infected horses, from 60 weanlings following primary vaccination with five different vaccines (two whole inactivated vaccines, two ISCOM-based subunit vaccines and a recombin...
Barstow A, Pfau T, Bolt DM, Smith RK, Weller R.The ability to recognize lameness in the horse is an important skill for veterinary graduates; however, opportunities to develop this skill at the undergraduate level are limited. Computer-aided learning programs (CALs) have been successful in supplementing practical skills teaching. The aim of this study was to design and validate a CAL for the teaching of equine lameness recognition (CAL1). A control CAL was designed to simulate learning by experience (CAL2). Student volunteers were randomly assigned to either CAL and tested to establish their current ability to recognize lameness. Retesting...
Bertin FR, Pader KS, Lescun TB, Sojka-Kritchevsky JE.To evaluate the effect of ovariectomy on insulin sensitivity in horses and determine whether the effects of suppression of the hypothalamo-pituitary-adrenal axis differ before and after ovariectomy. Methods: 6 healthy mares. Methods: The horses underwent an IV glucose tolerance test (IVGTT), an insulin sensitivity test, and a dexamethasone suppression test before and 5 weeks after ovariectomy. Body weight, serum cortisol and plasma ACTH concentrations, serum insulin-to-blood glucose concentration ratios, and changes in blood glucose concentration with time after injection of glucose or insulin...
Gildea S, Fitzpatrick DA, Cullinane A.Outbreaks of equine influenza (EI) in endemic populations cause disruption and economic loss. Objective: To identify (i) factors involved in the spread of EI (ii) virus strains responsible for outbreaks (iii) single radial haemolysis (SRH) antibody levels correlating with protection against current virus strains (iv) evidence of vaccination breakdown. Methods: RT-PCR, virus isolation and SRH were carried out on nasopharyngeal swabs and blood samples collected from horses, ponies and donkeys on affected premises. Data relating to 629 samples from 135 equidae were analysed. Conclusions: Outbreak...
Hudson NP, Pearson GT, Mayhew IG, Proudman CJ, Burden FA, Fintl C.Intestinal motility disorders are an important problem in horses and donkeys and this study was carried out in order to evaluate the enteric neurons in animals with and without intestinal disease. Surplus intestinal tissue samples were collected from 28 horses undergoing exploratory laparotomy for colic. In addition, surplus intestinal samples from 17 control horses were collected immediately following humane destruction for clinical conditions not relating to the intestinal tract. Similar samples were also collected during routine post-mortem examinations from 12 aged donkeys; six animals wer...
Pérez-Écija A, Estepa JC, Barranco I, Rodríguez-Gómez IM, Mendoza FJ, Gómez-Laguna J.Verrucous hemangiomas are a rare specific variant of equine skin tumors not well described in the literature. An 8-year-old gelding presented a unilateral lesion on the pastern. Macroscopically, the mass showed a warty and verrucous surface with focal ulcerations. The histology showed a dermal proliferation of endothelial-layered capillaries and venules separated by a delicate stroma of scant fibroblasts and collagen deposition, with pseudoepitheliomatous hyperplasia (exuberant reactive irregular epithelial hyperplasia with tongue-like projections extending into the dermis, mimicking downgrowt...
Rashmir-Raven A.Hereditary equine regional dermal asthenia is a form of Ehlers-Danlos syndrome, and has an autosomal recessive mode of inheritance. Affected horses are typically born normal and develop lesions within the first 2 years of life. The most common symptoms of the disease include stretchy, loose skin that feels doughy or mushy. More severely affected horses experience spontaneous skin sloughing and extensive lacerations, hematomas, and seromas from minor trauma. Affected horses have a higher than expected incidence of corneal ulcers. DNA testing can normal, establish carrier and affected status. Pa...
Bergvall KE.Sarcoids are the most common skin tumors seen in horses worldwide. The pathogenesis of sarcoids is multifactorial, including an association with bovine papillomavirus types 1 and 2 and a genetic susceptibility to tumor development. Clinical manifestations vary and include occult, verrucous, nodular, fibroblastic, mixed, and malignant (malevolent) types. The tumor is nonmetastasizing but can become very aggressive locally. Multiple tumors are common. All clinical types can be present in the same horse. No treatment protocol is universally effective. The tumor has a high risk of recurrence. Recu...
Yu AA.Equine Pastern Dermatitis (EPD) is not a single disease, but a cutaneous reaction pattern of the horse. EPD should be considered a syndrome, rather than a diagnosis. Uncovering the underlying etiology prior to treatment is key to minimizing treatment failures and frustration. To achieve a positive therapeutic outcome, treating the predisposing and perpetuating factors is just as important as addressing the primary cause of EPD. This article reviews clinical signs, differential diagnoses, diagnosis, and treatment of EPD.
Rosenkrantz W.Pemphigus foliaceus is the most common autoimmune skin disease in horses and is associated with the production of autoantibodies directed against surface proteins of the keratinocyte. Pemphigus vulgaris is a rare autoimmune skin disease in horses. Systemic lupus erythematosus and cutaneous lupus erythematosus are recognized in horses and both are rare. Bullous pemphigoid is a rare autoimmune disease in horses caused by immunologic attack of the basement membrane zone by autoantibodies. Erythema muliforme is an immunologic reaction in the skin in which keratinocyte cell death is the prominent c...
Wang L, Pawlak EA, Johnson PJ, Belknap JK, Alfandari D, Black SJ.Matrix metalloproteinases (MMP) are hypothesized to degrade structurally important components of the laminar extracellular matrix (ECM) in horses with laminitis. Objective: To compare levels of expression of stromelysin-1 (MMP-3), collagenases (MMP-1, -13), and membrane type-MMPs (MMP-14, -15, -16), and the distribution of their ECM substrates, in laminae of healthy horses and horses with carbohydrate overload laminitis. Methods: Twenty-five adult horses. Methods: Gene and protein expression were determined in extracts of laminae using real-time quantitative polymerase chain reaction and Weste...
Sykes BW, Sykes KM, Hallowell GD.Studies on omeprazole have reported that doses as low as 0.7 mg/kg bwt per os are potent suppressors of acid production. Yet, to date, no studies have compared treatment efficacy of different doses in clinical cases of equine gastric ulceration. Furthermore, no studies have been performed to compare the healing response of the squamous and glandular mucosa to acid suppression therapy. Objective: To compare: 1) the efficacy of 2 doses of omeprazole in the treatment of primary squamous and glandular gastric ulceration; and 2) the healing response of primary squamous and glandular gastric ulcer...
Riesenberg A, Feßler AT, Erol E, Prenger-Berninghoff E, Stamm I, Böse R, Heusinger A, Klarmann D, Werckenthin C, Schwarz S.The aim of this study was to determine the MICs of 32 antimicrobial agents for 200 isolates of Rhodococcus equi of animal origin by applying a recently described broth microdilution protocol, and to investigate isolates with distinctly elevated rifampicin MICs for the genetic basis of rifampicin resistance. Methods: The study included 200 R. equi isolates, including 160 isolates from horses and 40 isolates from other animal sources, from the USA and Europe. MIC testing of 32 antimicrobial agents or combinations thereof followed a recently published protocol. A novel PCR protocol for the joint ...
Mackinnon MC, Southwood LL, Burke MJ, Palmer JE.To document causes of colic in equine neonates, evaluate clinical features of neonates managed medically versus surgically, determine short- and long-term survival rates for neonates with specific medical and surgical lesions, and assess ability of patients to achieve intended use. Methods: Retrospective case series. Methods: 137 client-owned equine neonates (< 30 days old) with a history of colic or signs of colic within 1 hour after hospital admission examined between 2000 and 2010. Methods: Signalment, history, results of physical examination, laboratory data, ancillary diagnostic tests, de...
Sherlock CE, Eggleston RB.To determine the clinical signs, treatment, and prognosis for horses with impaction of the cranial aspect of the base of the cecum (cecal cupula). Methods: Retrospective observational case series. Methods: 7 horses with colic attributed to cecal cupula impaction. Methods: Medical records were reviewed and horses that underwent exploratory celiotomy from 2000 through 2010 were identified. Horses with cecal cupula impaction and without other abdominal problems to which colic could be attributed were selected for inclusion in the study. Information regarding history, clinical findings, diagnostic...
Fernandez-Fuente M, Martin-Duque P, Vassaux G, Brown SC, Muntoni F, Terracciano CM, Piercy RJ.Several human and animal myopathies, such as malignant hyperthermia (MH), central core disease and equine recurrent exertional rhabdomyolysis (RER) are confirmed or thought to be associated with dysfunction of skeletal muscle calcium regulation. For some patients in whom the genetic cause is unknown, or when mutational analysis reveals genetic variants with unclear pathogenicity, defects are further studied through use of muscle histopathology and in vitro contraction tests, the latter in particular, when assessing responses to ryanodine receptor agonists, such as caffeine. However, since musc...
Waller AS, Robinson C.The host-restricted bacterium Streptococcus equi is the causative agent of equine strangles, the most frequently diagnosed infectious disease of horses worldwide. The disease is characterized by abscessation of the lymph nodes of the head and neck, leading to significant welfare and economic cost. S. equi is believed to have evolved from an ancestral strain of Streptococcus zooepidemicus, an opportunistic pathogen of horses and other animals. Comparison of the genome of S. equi strain 4047 with those of S. zooepidemicus identified examples of gene loss due to mutation and deletion, and gene ga...
Lin YZ, Yang F, Zhang SQ, Sun LK, Wang XF, Du C, Zhou JH.Equine lentivirus receptor 1 (ELR1) has been identified as the sole receptor for equine infectious anemia virus (EIAV) and is a member of the tumor necrosis factor receptor (TNFR) superfamily. In addition to the previously described membrane-associated form of ELR1, two other major alternative splicing variant mRNAs were identified in equine monocyte-derived macrophages (eMDMs). One major spliced species (ELR1-IN) contained an insertion of 153 nt, which resulted in a premature stop codon situated 561 nt upstream of the predicted membrane spanning domain. The other major species (ELR1-DE) has a...
Rosa R, Costa EA, Marques RE, Oliveira TS, Furtini R, Bomfim MR, Teixeira MM, Paixão TA, Santos RL.St. Louis encephalitis virus (SLEV) is a causative agent of encephalitis in humans in the Western hemisphere. SLEV is a positive-sense RNA virus that belongs to the Flavivirus genus, which includes West Nile encephalitis virus, Japanese encephalitis virus, Dengue virus and other medically important viruses. Recently, we isolated a SLEV strain from the brain of a horse with neurological signs in the countryside of Minas Gerais, Brazil. The SLEV isolation was confirmed by reverse-transcription RT-PCR and sequencing of the E protein gene. Virus identity was also confirmed by indirect immunofluore...
Badial PR, Oliveira-Filho JP, Winand NJ, Borges AS.Hereditary equine regional dermal asthenia (HERDA) is a genetic disorder that occurs in the American Quarter horse (AQH) and is caused by a c.115G>A missense mutation in the peptidylprolyl isomerase B (PPIB) gene. Using a quantitative real-time PCR high resolution melting analysis genotyping assay for the PPIB mutation, the estimated HERDA allele and carrier frequencies in a sample of Brazilian AQHs were 2.9% and 5.8%, respectively.
Velineni S, Breathnach CC, Timoney JF.Streptococcus zooepidemicus (Sz) is a tonsillar commensal of healthy horses but with potential to opportunistically invade the lower respiratory tract. Sz is genetically variable and recombinogenic based on analysis of gene sequences including szp, szm and MLST data. Although a variety of serovars of the protective SzP are commonly harbored in the tonsils of the same horse, lower respiratory infections usually involve a single clone. Nevertheless, isolation of specific clones from epizootics of respiratory disease has been recently reported in horses and dogs in N. America, Europe and Asia. In...
Tarr CJ, Thompson PN, Guthrie AJ, Harper CK.The carrier prevalence of severe combined immunodeficiency (SCID), lavender foal syndrome (LFS) and cerebellar abiotrophy (CA) in Arabian foals in South Africa was determined in order to quantify the potential impact of these conditions locally. Furthermore, the carrier prevalence of SCID prior to and following the introduction of a genetic test was compared to evaluate the effect of testing in the population. Objective: To estimate the carrier prevalence of SCID, LFS and CA in registered purebred Arabians born in South Africa in the 2004/5 and 2009/10 foaling seasons and compare the changes i...
Bühler M, Fürst A, Lewis FI, Kummer M, Ohlerth S.Computed tomographic (CT) studies evaluating the relevance of individual CT features of apical infection in maxillary cheek teeth are lacking. Objective: To study the prevalence and relationship of single CT features in horses with and without clinical evidence of apical infection in maxillary cheek teeth. Methods: Retrospective case-control study. Methods: Multislice CT scans of the head of 49 horses were evaluated retrospectively. Changes of the infundibulum, pulp, root, lamina dura, periodontal space and alveolar bone in maxillary cheek teeth were recorded. Results: Single CT changes were m...
Nagy A, Murray JK, Dyson SJ.There is limited information on risk factors for elimination from endurance rides. Objective: To assess risk factors for elimination for lameness and metabolic reasons from Fédération Equestre Internationale (FEI) endurance rides of 80-160 km distance. Methods: Unmatched case-control. Methods: Venue-, horse- and rider-related data were collected from the FEI website. Data on weather conditions and terrain were collected at the venue. Univariable and multivariable logistic regression analyses were used to assess risk factors for elimination for lameness and metabolic reasons, respectively. Re...
Hilla D, Distl O.The main objective of this study is to estimate genetic parameters for osteochondrosis (OC) and osteochondrosis dissecans (OCD) in fetlock, hock and stifle joints as well as for palmar or plantar osteochondral fragments (POFs) and dorsodistal osteochondral fragments (DOFs) in fetlock joints. For this purpose, the results of a standardized radiographic examination of 7396 Hanoverian Warmblood horses were used. Heritabilities and genetic correlations were estimated using residual maximum likelihood (REML) under a linear animal model. Heritability estimates for OC at the different joints were at ...
Burnheim K, Hughes KJ, Evans DL, Raidal SL.Respiratory problems are common in horses, and are often diagnosed as a cause of poor athletic performance. Reliable, accurate and sensitive spirometric tests of airway function in resting horses would assist with the diagnosis of limitations to breathing and facilitate investigations of the effects of various treatments on breathing capacity. The evaluation of respiratory function in horses is challenging and suitable procedures are not widely available to equine practitioners. The determination of relative flow or flow-time measures is used in paediatric patients where compliance may limit c...
Sánchez-Vizcaíno JM.African horse sickness (AHS) is an infectious but no-contagious viral disease of equidae with high mortality in horses. The disease is caused by an arthropod-borne double-stranded RNA virus within the genus Orbivirus of the family Reoviridae transmitted by at least two species of Culicoides. Nine different serotypes have been described. The nine serotypes of AHS have been described in eastern and southern Africa. Only AHS serotypes 9 and 4 have been found in West Africa from where they occasionally spread into countries surrounding the Mediterranean. Examples of outbreaks that have occurred ou...
Schoenbaum MA, Hall SM, Glock RD, Grant K, Jenny AL, Schiefer TJ, Sciglibaglio P, Whitlock RH.A USDA Early Response Team investigated deaths of several horses and a mule in northern Arizona at the request of local animal health officials. Thirteen animals (12 horses and 1 mule) housed at 5 facilities in a 7.4 square mile area died between August 1998 and January 1999. Clinical signs consisted of muscular weakness that rapidly progressed to lateral recumbency. Ten animals had paresis of the tongue, throat, or lips. Affected animals appeared alert and were interested in eating and drinking, even while recumbent. All 13 animals were euthanatized. Clostridium botulinum type C was isolated ...
Ostrowska J, Lindström L, Tóth T, Hansson K, Uhlhorn M, Ley CJ.Computed tomography (CT) is commonly used to investigate equine paranasal sinus disease, however, only limited information is available in the literature about the detailed CT appearance of equine paranasal sinus cysts. Objective: To investigate if paranasal sinus cysts have specific characteristics in CT images that allow differentiation from other sinus diseases. Methods: Retrospective observational study. Methods: Evaluation and comparison of CT studies of eight horses with surgically and/or histopathologically confirmed paranasal sinus cysts and 10 horses with other confirmed paranasal sin...
de Pádua BR, Dias RA, Fioravanti MCS, Borsanelli AC.Equine infectious anemia (EIA) is an infectious disease affecting equine in most countries and represents a notifiable disease with compulsory euthanasia of positive animals. The present study aimed to determine the prevalence of EIAV infected equines in herds of the state of Goiás (Central Brazil) and to evaluate the risk factors associated with the occurrence of the disease. Blood samples were collected from 1170 equids from 332 randomly selected farms divided into three different strata according to their herd characteristics. Also, an epidemiological questionnaire was applied during the v...
Ueno T, Nambo Y, Tajima Y, Umemura T.Broad ligament haemorrhage in peripartum mares is a life-threatening disease and there are few reports on the aetiology and pathogenesis of broad ligament haematoma. Objective: To obtain information regarding the sites for the early diagnosis and pathogenesis of broad ligament haematoma of mares. Methods: Thirty-one mares that died of broad ligament haematoma peripartum were examined pathologically for bleeding sites. The arterial distribution of 5 young mares with several parities served as negative controls. Results: Age and/or multiparity were the predisposing factors for the disease. Arter...
Brinsko SP.Genital neoplasms in the male horse are relatively uncommon. Squamous cell carcinomas and squamous papillomas are the most commonly diagnosed neoplasms of the penis and prepuce. Geldings appear to be overrepresented for these types of neoplasms, and accumulation of smegma may be a contributing factor. Early diagnosis and treatment are essential for salvaging these organs before lesions become excessively large and invasive or are allowed to metastasize. Newer treatment modalities such as 5-fluorouracil appear to be promising alternatives to surgical excision. Although generally considered to b...
Valentine BA, McDonough SP, Chang YF, Vonderchek AJ.Polysaccharide storage myopathy is an equine neuromuscular disorder characterized by accumulation of glycogen-related polysaccharide inclusions within skeletal muscle fibers. The pathologic criteria for diagnosis of this disorder are somewhat controversial; however, periodic acid-Schiff-positive, amylase-resistant inclusions are considered pathognomonic. Although these inclusions are most often found in affected horses related to the Quarter Horse, draft horse, and Warmblood breeds, this report describes these characteristic inclusions in muscle of five horses from nonrelated breeds (two Morga...
Hines R, Sorensen BR, Shea MA, Maury W.Binding of the transcription factor PU.1 to its DNA binding motif regulates the expression of a number of B-cell- and myeloid-specific genes. The long terminal repeat (LTR) of macrophage-tropic strains of equine infectious anemia virus (EIAV) contains three PU.1 binding sites, namely an invariant promoter-proximal site as well as two upstream sites. We have previously shown that these sites are important for EIAV LTR activity in primary macrophages (W. Maury, J. Virol. 68:6270-6279, 1994). Since the sequences present in these three binding motifs are not identical, we sought to determine the r...
Dieckmann SM, Hoelzle K, Dieckmann MP, Straube I, Hofmann-Lehmann R, Hoelzle LE.Hemotrophic mycoplasmas (HM) are small, cell wall-less bacteria and infections are known for a wide range of animals. One possible indication of equine HM infection was given in 1978, when a 'haemobartonellosis' outbreak was diagnosed in Nigerian horses by microscopy. However the first molecular proof of HM in horses was not reported until 2010, when a fragment of about 900 bp of the 16S rRNA of the equine HM was obtained. This sequence was used for the development of a SYBR green I real-time PCR assay specific for equine HM. The lower detection limit of the PCR was ten 16S rDNA copy numbers p...
Byam-Cook KL, Singer ER.Despite the possibility that sound horses may have radiographic signs consistent with osteoarthritis of the small tarsal joints (OA-STJ), a diagnosis of 'bone spavin' as a cause of lameness is often made based only on radiographic examination. Objective: To determine whether severity of radiographic change and response to treatment are correlated with the duration and degree of lameness and the response to intraarticular anaesthesia in horses with OA-STJ. Methods: A retrospective study of all horses that showed a positive response to intra-articular anaesthesia of the STJ was performed. Detail...
Hu Y, Jia Q, Liu J, Sun W, Bao Z, Che C, Wu G, Fan B, Jarhen , Ran D.Equid alphaherpesvirus 1 (EHV-1) is prevalent in China, and causes notable economic damage to the equine industry. However, there is no information regarding the molecular characteristics and pathogenicity of the Chinese strains. Therefore, an EHV-1 strain, named YM2019, was isolated from the lung tissue of an aborted horse fetus in Xinjiang, China, and its genome and pathogenicity were analyzed. The full genome of the isolate was 150,267 base pairs in length, with 56.7% G + C content. Genetic and phylogenetic analysis showed that strain YM2019 (GenBank: MT063054) belonged to the ORF30 N75...
Durham AE, Kemp-Symonds J.Serology is commonly used as a means of identifying horses that might be chronic and silent carriers of S. equi but its sensitivity is rarely examined. Objective: The study was designed to investigate the sensitivity of serological testing for antibodies against S. equi antigens A and C to detect guttural pouch carriers of S. equi. Methods: Retrospective clinical study. Methods: As part of routine surveillance and quarantine procedures horses arriving at a welfare charity quarantine unit were subject to both microbiological sampling of guttural pouches and also serological testing for antibo...
Eysker M, Boersema JH, Kooyman FN.Two groups of three yearling Shetland ponies were used in 1988 to study the epidemiological significance of inhibited development of the Cyathostomine nematodes. In Group 1, acquisition of infections was prevented throughout the grazing season whereas in Group 2 strongylid infections were acquired from the beginning of July until the end of September. Worm counts showed that the Cyathostomine nematode populations of Group 1 ponies mainly consisted of adult worms and those of Group 2 ponies of inhibited early third stage larvae (L3). These results indicate that a large proportion of Cyathostomi...
Khan A, Hallowell GD, Underwood C, van Eps AW.Rectal fluid administration may offer a simple, safe and inexpensive alternative to intravenous or nasogastric fluid therapy in equine clinical cases. Objective: To evaluate the tolerance and effects of rectally administered fluid and compare the measurements of haemodilution and intravascular volume with those during nasogastric and intravenous fluid administration. Methods: Randomised controlled experimental trial. Methods: Six clinically normal Standardbred geldings were used in a 4-way crossover study: each received three different fluid treatments (intravenous, nasogastric and rectal) at ...
Fielding CL, Pusterla N, Magdesian KG, Higgins JC, Meier CA.To characterize signalment, clinical and laboratory findings, treatment, and outcome in horses with rattlesnake envenomation in northern California. Methods: Retrospective case series. Methods: 58 client-owned horses evaluated for rattlesnake envenomation at 2 referral hospitals from 1992 to 2009. Methods: Records of horses with rattlesnake envenomation were reviewed, and data concerning signalment, clinical and laboratory findings, treatment, and outcome were collected. In addition, a rattlesnake-bite severity score (RBSS) was assigned to each horse. Variables were compared between horses tha...
Souto EPF, Maia LA, Neto EGM, Kommers GD, Junior FG, Riet-Correa F, Galiza GJN, Dantas AFM.The epidemiologic, clinical, pathologic, microbiological and immunohistochemical findings of pythiosis in equidae in northeastern Brazil are described. From January 1985 to December 2020 the Laboratory of Animal Pathology of the Federal University of Campina Grande received 1,331 tissue samples of equidae, 202 (15.17%) of which were diagnosed as pythiosis. Equidae of both sexes with ages varying from 4 months to 25 years were affected. Most animals were mixed breed (79.7%) and reared in an extensive system (73.26%). The disease occurred throughout the year but the highest incidence (70.29%) wa...
Hoffman DW, Colvin RA, Garcia-Blanco MA, White SW.A 25-nucleotide RNA with the sequence of the trans-activation response (TAR) element of equine infectious anemia virus (EIAV) was analyzed by biochemical methods and by one- and two-dimensional NMR spectroscopy. NMR, nuclease probing, and polyacrylamide gel migration rates show that the RNA consists of an A-helical stem capped by two non-Watson-Crick U-G base pairs and a compact four-nucleotide loop. The loop is stabilized by base stacking, with loop nucleotides C12 and C15 stacked upon U11 and G16, respectively. Near the 5' end of the molecule, the stem contains a bulge at nucleotide C2, most...
Davis TZ, Stegelmeier BL, Hall JO.Horses are very susceptible to chronic selenosis if grazed on seleniferous forages for a prolonged period. In this study, mane and tail samples from horses that exhibited classical hoof lesions of chronic selenosis were analyzed by inductively coupled plasma mass spectrometry for selenium (Se) content. The horses had grazed for 6 months, from approximately May 15 until November 15, each year for three grazing seasons in a pasture containing seleniferous forages and water sources with elevated Se concentrations. The segmented hair samples showed a cyclic pattern in Se concentrations in the mane...
Tscheschlok L, Venner M, Howard J.Failure of transfer of passive immunity (FTPI) in foals is associated with a risk of infection and death. The current diagnostic gold standard is quantification of immunoglobulins using radial immunodiffusion (IgG-RID). Routine diagnosis is often performed using semi-quantitative tests. Concentrations of serum electrophoretic gamma globulins (EGG) and total globulins may be useful to assess FTPI, but few studies have investigated their use. Objective: To assess agreement between IgG-RID and EGG and evaluate the accuracy of total globulin concentration to diagnose FTPI based on both IgG-RID and...
Shrestha M, Solé M, Ducro BJ, Sundquist M, Thomas R, Schurink A, Eriksson S, Lindgren G.Equine insect bite hypersensitivity (IBH) is a pruritic skin allergy caused primarily by biting midges, Culicoides spp. IBH susceptibility has polygenic inheritance and occurs at high frequencies in several horse breeds worldwide, causing increased costs and reduced welfare of affected horses. The aim of this study was to identify and validate single nucleotide polymorphisms (SNPs) associated with equine IBH susceptibility. After quality control, 33,523 SNPs were included in a Bayesian genome-wide association study on 177 affected and 178 unaffected Icelandic horses. We report associated regio...
Yin X, Lin Y, Cai W, Wei P, Wang X.Equine infectious anemia virus (EIAV) is an important animal model for understanding the relationship between viral persistence and the host immune response during lentiviral infections. Comparison and analysis of the codon usage model between EIAV and its hosts is important for the comprehension of viral evolution. In our study, the codon usage pattern of EIAV was analyzed from the available 29 full-length EIAV genomes through multivariate statistical methods. Results: Effective number of codons (ENC) suggests that the codon usage among EIAV strains is slightly biased. The ENC-plot analysis d...
Lichtenstein DL, Craigo JK, Leroux C, Rushlow KE, Cook RF, Cook SJ, Issel CJ, Montelaro RC.The long terminal repeat (LTR) is reported to be one of the most variable portions of the equine infectious anemia virus (EIAV) genome. To date, however, no information is available on the effects of observed sequence variations on viral replication properties, despite a widespread assumption of the biological importance of EIAV LTR variation. EIAV LTR sequence variability is confined mostly to a small portion of the enhancer within the U3 segment of the LTR. Analysis of published EIAV LTR sequences revealed six different types of LTR based on the pattern of putative transcription factor motif...
Prieto D, Benedito S, Rodrigo J, Martínez-Murillo R, García-Sacristán A.The distribution and density of neuropeptide Y (NPY)-immunoreactive nerve fibres and cells were determined in the urinary bladder of the horse by using the peroxidase-antiperoxidase (PAP) immunohistochemical method. Numerous undulating NPY-immunoreactive nerve fibres were found throughout the vesical wall, sometimes forming nerve bundles which ramified repeatedly as they coursed through the connective tissue septa to give rise to smaller bundles or single fibres which projected into the muscle fascicles forming muscular nerve plexuses, mainly in the bladder base. In the submucosa of this regio...
La Perle KM, Piercy RJ, Long JF, Blomme EA.Multisystemic, eosinophilic, epitheliotropic disease and intestinal lymphosarcoma were diagnosed in a Paso Fino mare that presented with anorexia and weight loss. The stomach, ileum, cecum, colon, pancreas, and lungs were infiltrated by large numbers of eosinophils forming prominent eosinophilic granulomas, as well as lymphocytes and plasma cells. Two jejunal masses composed of solid sheets of neoplastic lymphocytes were present. In contrast to the regions of inflammation, the infiltrates in these masses did not contain plasma cells, eosinophils, and eosinophilic granulomas. Immunohistochemica...
Perelygin AA, Zharkikh AA, Astakhova NM, Lear TL, Brinton MA.Chemokine receptors (CCRs) play an essential role in the initiation of an innate immune host response. Several of these receptors have been shown to modulate the outcome of viral infections. The recent availability of complete genome sequences from a number of species provides a unique opportunity to analyze the evolution of the CCR genes. A phylogenetic analysis revealed that the CCR2 gene evolved in concert with the paralogous CCR5 gene, but not with another paralogous gene, CCR3, in the opossum, platypus, rabbit, guinea pig, cat, and rodent lineages. In addition, evidence of concerted evolu...
Arble JB, Mattoon JS, Drost WT, Weisbrode SE, Wassenaar PA, Pan X, Hunt RJ, Belknap JK.Equine laminitis is a severely debilitating disease. There is a poor understanding of the underlying pathophysiology, and traditional imaging modalities have limited diagnostic capacity. High field strength magnetic resonance (MR) imaging allows direct visualization of the laminae, which other modalities do not. This would prove useful both in assessment of clinical patients and in further investigation into the pathophysiology of the disease. The objective of this study was to characterize the anatomic changes within the equine foot associated with the initial active stage of laminitis. Image...
Boyle AG, Boston RC, O'Shea K, Young S, Rankin SC.Streptococcus equi is the etiologic agent of a highly infectious upper respiratory disease of horses known as strangles. Bacterial culture methods and polymerase chain reaction (PCR) of nasopharyngeal washes and guttural pouch lavages are used routinely to test clinical and carrier animals for the presence of S. equi but no definitive or gold standard test method has been shown to be optimal. We hypothesized that (i) a flocked swab submerged in ten-fold serial dilution suspensions of S. equi prepared in 0.9% NaCl would detect more colony forming units (CFU) than a rayon swab when used to inocu...
Van Eps AW, Pollitt CC.The histopathology of laminitis during its transition from the acute to the chronic phase has not been previously documented. Studying hoof lamellar tissues 7 days after induction of laminitis may provide insight into the intractable nature of the chronic phase of the disease. Objective: To induce laminitis and investigate hoof wall lamellar tissues 7 days after dosing. Methods: Laminitis was induced using oligofructose in 6 normal Standardbred horses. The dorsal hoof lamellar tissues of these and 12 normal horses were processed and examined by light microscopy. Serial sections of a lamellar t...
Wolf D, Hermosilla C, Taubert A.Whilst anthelminthic resistance of small strongyles is well documented, anthelmintic failures against infections with Oxyuris equi have scarcely been published so far. We describe two cases of equine oxyurosis and the anthelminthic failure of macrocyclic lactones (moxidectin, ivermectin) resulting in persistent O. equi infections with continuous egg shedding. The horses were kept in two different herds in the federal state of Hessia, Germany. Herd A kept two geldings: an 8-year-old Welsh-Cob-Mix and a 7-year-old Haflinger. Herd B was composed of four animals: 2 Connemara-mares, 31 and 19 years...
