Equine diseases encompass a wide range of health conditions that can affect horses, including infectious diseases, metabolic disorders, and genetic conditions. These diseases can impact the overall health, performance, and well-being of horses. Common equine diseases include equine influenza, equine herpesvirus, laminitis, and equine metabolic syndrome. Diagnosis and management of these diseases often require a combination of clinical evaluation, laboratory testing, and appropriate treatment strategies. This page gathers peer-reviewed research studies and scholarly articles that explore the etiology, pathophysiology, diagnosis, and treatment options for various equine diseases, providing valuable insights for veterinarians and researchers in the field.
Wijnberg ID, Franssen H, Jansen GH, Back W, van der Kolk JH.Electromyographic needle examination (EMG), including the semiautomatic quantitative analysis of motor unit action potential (MUAP), is an important diagnostic tool for myopathy in humans. The diagnostic possibilities of this technique have not been fully explored in horses; however, recent studies have shown that MUAP analysis can be performed in conscious horses. To determine the diagnostic possibilities of EMG in horses, we compared the EMG results of the subclavian muscle, the triceps, and the lateral vastus muscle in 6 equine patients thought to have myogenic disorders with those in 7 nor...
Li X, Tremoleda JL, Allen WR.The effects of repeated passage in vitro of fetal fibroblast cells (FFC) and adult fibroblast cells (AFC) on nuclear remodelling and first embryonic division when used to reconstruct horse oocytes, and the reasons for the developmental block in progression to the two-cell stage were investigated. A total of 463 metaphase II oocytes produced 427 fibroblast-cytoplasm couplets after nuclear transfer, which finally resulted in 319 reconstructed oocytes. With increasing numbers of passages, the rates of nuclear remodelling decreased in both types of donor cell; about half of the fused donor cell nu...
Bailey SR, Baillon ML, Rycroft AN, Harris PA, Elliott J.Acute laminitis has been associated with the overgrowth of gram-positive bacteria within the equine hindgut, causing the release of factor(s) leading to ischemia-reperfusion of the digits. The products of fermentation which trigger acute laminitis are, as yet, unknown; however, vasoactive amines are possible candidates. The objectives of this study were to use an in vitro model of carbohydrate overload to study the change in populations of cecal streptococci and lactobacilli and to establish whether certain species of these bacteria were capable of producing vasoactive amines from amino acids....
Wagner HM, Balasuriya UB, James MacLachlan N.In an effort to further characterize the humoral immune response of horses to equine arteritis virus (EAV), direct and competitive enzyme-linked immunosorbent assays (c-ELISAs) were developed using monoclonal and polyclonal anti-sera to structural (G(L), N and M) and non-structural (nsp1) viral proteins. A nsp1-specific monoclonal antibody was produced to facilitate development of a c-ELISA to this protein. Data obtained using the various c-ELISAs confirm that the M protein is a major target of the antibody response of horses to EAV. However, none of the c-ELISAs that were developed were as se...
Chowdhary BP, Raudsepp T, Kata SR, Goh G, Millon LV, Allan V, Piumi F, Guérin G, Swinburne J, Binns M, Lear TL, Mickelson J, Murray J, Antczak DF....A first-generation radiation hybrid (RH) map of the equine (Equus caballus) genome was assembled using 92 horse x hamster hybrid cell lines and 730 equine markers. The map is the first comprehensive framework map of the horse that (1) incorporates type I as well as type II markers, (2) integrates synteny, cytogenetic, and meiotic maps into a consensus map, and (3) provides the most detailed genome-wide information to date on the organization and comparative status of the equine genome. The 730 loci (258 type I and 472 type II) included in the final map are clustered in 101 RH groups distribute...
Bartmann CP, Schiemann V.Diagnostic and operative hysteroscopy have offered an advance in equine fertility diagnostic and equine fertility surgery. A distension of the uterine cavity and an establishment of a continuous intrauterine pressure are basic requirements for complete visualisation of intrauterine structures and safe and efficient surgical procedures. Superelevated pressure and resorption of distension media may result in fatal complications. Intrauterine pressure was monitored in 28 healthy di- or anestrus mares during hysteroscopy via a transcervically inserted catheter. Mares were sedated with xylazine and...
Peters M, Graf G, Pohlenz J.A 14-year-old standardbred mare with clinically suspected acute bronchitis was killed because of rapidly progressing central nervous disturbances. Necropsy revealed systemic granulomatous inflammation and vasculitis involving the lungs, thoracic lymph nodes, ribs, and liver. In the cerebrum there was a severe subacute bilateral encephalitis and malacia predominately affecting the white matter, and vasculitis with perivascular infiltration of lymphocytes, macrophages, and giant cells. A causative infectious agent could not be detected by Ziehl-Neelsen, Grocott, or Giemsa stains, by periodic aci...
Hunter RP.Inflammation is a process consisting of a complex of cytological and chemical reactions which occur in and around affected blood vessels and adjacent tissues in response to an injury caused by a physical, chemical or biological insult. Much work has been performed in the past several years investigating inducible nitric oxide synthase (NOS, EC 1.14.13.39) and nitric oxide in inflammation. This has resulted in a rapid increase in knowledge about iNOS and nitric oxide. Nitric oxide formation from inducible NOS is regulated by numerous inflammatory mediators, often with contradictory effects, dep...
Matthee S, Dreyer FH, Hoffmann WA, van Niekerk FE.Fifty-one per cent of 110 questionnaires, designed for obtaining information on helminth control practices and management on Thoroughbred stud farms in South Africa, were completed by farmers during 2000. The number of horses per farm included in the questionnaire survey ranged from 15 to 410. Foals, yearlings and adult horses were treated with anthelmintics at a mean of 7.3 +/- 3.0, 6.6 +/- 2.7 and 5.3 +/- 2.3 times per year, respectively. An average of 3.4 different drugs were used annually, with ivermectin being used bymost farmers during 1997-2000. On 43% of farms the weights of horses wer...
Hill AE, Carpenter TE, Gardner IA, Stover SM.To evaluate a Markov-chain model for the development of forelimb injuries in Thoroughbreds and to use the model to determine effects of reducing sprint distance on incidence of metacarpal condylar fracture (CDY) and severe suspensory apparatus injury (SSAI). Methods: Weekly exercise and injury data for 122 Thoroughbreds during racing or training. Methods: Weekly data were used to construct a Markov-chain model with 5 states (uninjured [UNINJ], palpable suspensory apparatus injury [PSAII, SSAI, CDY, and lost to follow-up [LOST]). Transition probabilities between UNINJ and PSAI were estimated as...
Brown NA, Pandy MG, Buford WL, Kawcak CE, McIlwraith CW.To determine whether muscle moment arms at the carpal and metacarpophalangeal joints can be modeled as fixed-radius pulleys for the range of motion associated with the stance phase of the gait in equine forelimbs. Methods: 4 cadaveric forelimbs from 2 healthy Thoroughbreds. Methods: Thin wire cables were sutured at the musculotendinous junction of 9 forelimb muscles. The cables passed through eyelets at each muscle's origin, wrapped around single-turn potentiometers, and were loaded. Tendon excursions, measured as the changes in lengths of the cables, were recorded during manual rotation of th...
van Schie HT, Bakker EM, Jonker AM, van Weeren PR.To describe a method of computerized ultrasonographic tissue characterization that includes structures below the size limits of resolution in equine superficial digital flexor tendons. Methods: 2 damaged and 2 structurally normal superficial digital flexor tendons. Methods: Transverse ultrasonographic images were collected along the tendon long axis. Stability of echo pattern was quantified by means of variation in gray levels of each pixel in contiguous images and expressed as correlation, entropy, and waviness ratios. Results: Normal young and normal old tissues were characterized by high co...
Lillich JD, Rakestraw PC, Roussel AJ, Finley MR, Ganta S, Freeman LC.To determine whether ether-a-go-go (ERG) potassium channels are expressed in equine gastrointestinal smooth muscle, whether ERG channel antagonists affect jejunal muscle contraction in vitro, and whether plasma cisapride concentrations in horses administered treatment for postoperative ileus (POI) are consistent with ERG channels as drug targets. Methods: Samples of intestinal smooth muscle obtained from 8 horses free of gastrointestinal tract disease and plasma samples obtained from 3 horses administered cisapride for treatment of POI. Methods: Membranes were prepared from the seromuscular la...
Westcott DG, King DP, Drew TW, Nowotny N, Kindermann J, Hannant D, Belák S, Paton DJ.Routine detection of equine arteritis virus (EAV) can be achieved by virus isolation (VI) in cell culture, or by the amplification of viral genome by molecular methods. To simplify molecular diagnosis, a number of different Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) and RT-nested PCR (RT-nPCR) assays were compared, and a one-tube method was developed and optimised utilizing a fluorogenic probe (TaqMan). An artificial RNA template (Mimic) and associated probe were also constructed to provide in-tube validation of the RT-PCR system. To assess the utility of the RT-PCR TaqMan assay,...
Weiss DJ, Moritz A.Previous studies have suggested an association between equine immune-mediated hemolytic anemia and clostridial infections or neck abscesses. Objective: The purpose of this report was to describe and characterize the hematologic abnormalities in a horse with Clostridium-associated immune-mediated hemolytic anemia. We also retrospectively evaluated hematologic abnormalities in 8 horses with clostridial myositis or subcutaneous emphysema. Methods: A 7-year-old Foreign Warm-Blood gelding was evaluated for anemia and a cervical abscess. CBCs and reticulocyte counts were obtained using an Advia 120 ...
Turell MJ, O'Guinn ML, Parker MD.Specific mutations associated with attenuation of Venezuelan equine encephalitis (VEE) virus in rodent models were identified during efforts to develop an improved VEE vaccine. Analogous mutations were produced in full-length cDNA clones of the Cba 87 strain of western equine encephalitis (WEE) virus by site-directed mutagenesis in an attempt to develop an improved WEE vaccine. Isogenic viral strains with these mutations were recovered after transfection of baby hamster kidney cells with infectious RNA. We evaluated two of these strains (WE2102 and WE2130) for their ability to replicate in and...
Seltenhammer MH, Simhofer H, Scherzer S, Zechner R, Curik I, Sölkner J, Brandt SM, Jansen B, Pehamberger H, Eisenmenger E.Equine melanomas occur most commonly in grey horses at age 5 years or more. Generally, benign and malignant melanomas are distinguished by microscopy, but a more distinct classification would be helpful. Objective: The objectives of this study were to gain further evidence concerning the occurrence of melanotic tumours, and to evaluate the impact of heredity on melanoma development. Methods: A clinical study was conducted on a defined population of 296 grey horses of Lipizzaner breed. Individuals were classified according to their stage of disease using a 0-5 scale. Heritability was estimated ...
Bailey SR, Wheeler-Jones C, Elliott J.5-hydroxytryptamine (5-HT; serotonin) is a potent vasoconstrictor of equine digital blood vessels and has been implicated in the pathogenesis of acute laminitis. Objective: The aims of this study were firstly to examine whether cells of the digital blood vessel wall exhibited an active uptake mechanism for 5-HT and to characterise its efficiency; and secondly, to study the potential inhibitory effect on this process of other amines, produced in the equine caecum. Methods: Confluent monolayers of equine digital vein endothelial cells (EDVEC) and equine digital vein smooth muscle cells (EDVSMC) ...
McGorum BC, Wilson R, Pirie RS, Mayhew IG, Kaur H, Aruoma OI.The aetiopathogenesis of equine grass sickness (EGS) is unknown. The role of free radical-mediated neuronal damage has not previously been investigated in this condition. Objective: To investigate the potential contribution of oxidative damage and antioxidant status to neurodegeneration in EGS. Methods: Systemic levels of surrogate biomarkers were determined in 10 horses with acute EGS and in 2 control populations; 10 healthy horses co-grazing with the 10 EGS horses at the onset of clinical disease, and 10 healthy mares grazing where EGS has not been reported. Results: EGS horses had alteratio...
Viitanen MJ, Wilson AM, McGuigan HR, Rogers KD, May SA.Increased joint pressure has been implicated in the progression of osteoarthritis. Objective: That intra-articular pressure in the distal interphalangeal joint (DIP) is significantly higher in legs loaded with heel up (HU), low heel (TU), lateral side up (LU) and medial side up (MU) imbalance compared to the balanced position. Methods: Twelve elbow down limbs were compressed in a hydraulic loading jig and DIP pressure measured. Results: Elevating the heels by 5 degrees significantly increased DIP pressure. After 5 ml of contrast was injected into the joint, heel elevation caused a greater incr...
Milenkovic D, Chaffaux S, Taourit S, Guérin G.Epidermolysis bullosa (EB) is a heterogeneous group of inherited diseases characterised by skin blistering and fragility. In humans, one of the most severe forms of EB known as Herlitz-junctional EB (H-JEB), is caused by mutations in the laminin 5 genes. EB has been described in several species, like cattle, sheep, dogs, cats and horses where the mutation, a cytosine insertion in exon 10 of the LAMC2 gene, was very recently identified in Belgian horses as the mutation responsible for JEB. In this study, the same mutation was found to be totally associated with the JEB phenotype in two French d...
De Cock HE, Labelle P, Magdesian KG.The clinical, gross morphological, histological and immunohistochemical characteristics of an ameloblastic carcinoma in a 30-year-old Quarter Horse mare are reported. This tumour was fast growing, locally invasive and destructive. Histologically, it showed an infiltrative pattern of large islands, broad sheets and, at the periphery, small cords of moderately pleomorphic round, oval to spindle-shaped cells. Immunohistochemical evaluation revealed positive labelling for vimentin, cytokeratin 5/6 and cytokeratin 14. In the oral cavity of human beings, this immunolabelling pattern is unique for th...
Harman J, Ward M.Equine Cushing's syndrome, a relatively common and complex condition, is difficult to treat with conventional medicine. Cushing's syndrome involves a hyperplasia or adenoma of the anterior pituitary gland. Biochemical alterations include increased endogenous cortisol, insulin resistance, elevated adrenocorticotrophic hormone, and decreased thyroid hormone levels. Symptoms include hirsutism with no loss of the winter coat in summer, refractory laminitis, weight problems (over- or underweight), polyuria/polydipsia (Pu/Pd), frequent infections, lowered immunity to intestinal parasites, decreased ...
Steffey EP, Woliner MJ, Puschner B, Galey FD.To quantitate the effects of desflurane and mode of ventilation on cardiovascular and respiratory functions and identify changes in selected clinicopathologic variables and serum fluoride values associated with desflurane anesthesia in horses. Methods: 6 healthy adult horses. Methods: Horses were anesthetized on 2 occasions: first, to determine the minimum alveolar concentration (MAC) of desflurane in O2 and second, to characterize cardiopulmonary and clinicopathologic responses to 1X, 1.5X, and 1.75X desflurane MAC during both controlled and spontaneous ventilation. Results: Mean +/- SEM MAC ...
Retamal C, Urzúa J, Lorca C, López ML, Alves EW.The present paper reports modifications in the electrophoretic and cytochemical characteristics of mature and immature stallion spermatozoa. Some sperm surface glycoproteins (36, 32, 29, 21, 20, 18 kDa) detected in cauda epididymidis spermatozoa, were either absent or present in a very low relative concentration in immature sperm cells. A major 14 kDa protein band, observed in sperm extracts obtained from ductus efferentes, progressively decreased along the epididymal ductus. The nature and distribution of carbohydrate residues on the sperm membrane, during epididymal maturation, was also stud...
Ramina A, Dalla Valle L, De Mas S, Tisato E, Zuin A, Renier M, Cuteri V, Valente C, Cancellotti FM.The reverse transcriptase polymerase chain reaction (RT-PCR) assay was used to detect Equine Arteritis Virus (EAV) in the semen of 88 horses and 2 donkeys, with neutralising antibodies against EAV, on the basis of the amplification of a 279 bp long fragment located in the viral polymerase gene. The RT-PCR assay revealed the virus at 4 TCID50/ml in cell culture and showed a greater sensitivity (54.4%) than cell culture isolation (33.3%). Moreover, the two samples of donkey semen were found positive. The cDNAs obtained from 14 samples of horse and 2 of donkey semen were sequenced. Comparing the ...
Traversa D.Cyathostomes (Nematoda, Cyathostominae) cause colic, decreased performance and growth, peripheral edema, and dysorexia in equids. Also, the synchronous emergence of cyathostome larvae encysted in the colon and cecal wall causes larval cyathostominosis, which is characterized by protein-depriving enteropathy, chronic diarrhea, edema, weight loss, colitis, and may be fatal. In the past few decades, drug resistance in cyathostomes has become widespread, especially for benzimidazoles. Resistance to tetrahydropyrimidines is still confined to a few areas, and the recent reports of reduced efficacy i...
Boger BL, Manfredi JM, Yob C, Weber PSD, Jacobs CC.Diagnosis of equine septic arthritis is not straightforward, and increasing time between onset, diagnosis, and treatment can have serious consequences for quality of life. Defensins are used in diagnosis of human joint infection. The presence of beta defensins (BDs) in equine synovial fluid and their utility as a biomarker of sepsis has not been investigated; therefore, our objectives were to (1) compare in vitro gene expression of lipopolysaccharide (LPS)-stimulated equine neutrophils to unstimulated neutrophils and (2) compare BD protein expression from normal, aseptically inflamed, and sept...
Freeman DE, Schaeffer DJ.Although experimental studies have demonstrated differences in performance between methods for handsewn jejunojejunostomy in horses, information on clinical results after different methods of anastomosis are rare. Objective: A continuous Lembert pattern wrapped in a carboxymethylcellulose and hyaluronate membrane would perform better than an interrupted Lembert pattern for jejunojejunostomy in horses. Methods: Data was reviewed on 32 horses that underwent jejunojejunostomy from 1993-2002. Kaplan-Meier analyses and rates for post operative colic and death were used to compare outcomes after an ...
Douthit TL, Bormann JM, Gradert KC, Lomas LW, DeWitt SF, Kouba JM.This experiment was conducted to evaluate if consumption of endophyte-infected fescue alters digital circulation in the distal thoracic limb of the horse and to assess if soundness of the hooves of horses is affected by consumption of endophyte-infected fescue. Twelve American Quarter Horses (mean initial BW 459 ± 31 kg), 6 mares and 6 geldings, were used in this 90-d study that comprised high-endophyte (E+) and low-endophyte (E-) treatment groups. Fescue seed was integrated into the E+ diet at a rate sufficient to bring total ergovaline to 200 μg/kg, and endophyte-free fescue seed was incor...
Manso-Díaz G, García-Real MI, Casteleyn C, San-Román F, Taeymans O.Noncontrast magnetic resonance angiography (MRA) is widely used in human and small animal medicine. However, this technique has not yet been described in the horse, and compared to other angiographic techniques MRA could be more cost efficient and potentially safer. Objective: The aim of this study was to provide a comprehensive anatomical reference of the normal equine head vasculature using a noncontrast MRA technique, on both low- and high-field MRI. Methods: Five healthy adult horses were examined, 4 with a low-field magnet (0.23T) and the remaining one with a high-field magnet (1.5T). The...
Vanderwall DK, Woods GL, Freeman DA, Weber JA, Rock RW, Tester DF.The objectives of this study were: 1) to document age-related ovulation failure in mares and 2) to contrast the number of ovarian follicles, occurrence of ovulations, and postovulatory concentrations of progesterone in aged versus young mares. In Experiment 1, 4 of 10 aged (25- to 33-years-old) mares were anovulatory between July 1 and September 1, 1989. In Experiment 2, two of 25 aged (20- to 30-years-old) and none of 21 young (3- to 12-years-old) mares were anovulatory between February 1 and June 30, 1990. The average (+/- SEM) day of the first ovulation was later (P<0.05) for aged versus...
Singer E, Garcia T, Stover S.The biomechanical circumstances that promote sagittal fracture of the equine proximal phalanx (P1) are poorly understood. In order to improve our understanding of equine metacarpophalangeal joint (MCPJ) biomechanics and potential aetiologies of sagittal P1 fractures, the study objectives were to quantify P1 bone strains, collateromotion and axial rotation during MCPJ extension under controlled loading circumstances. Unilateral limbs from six cadavers were instrumented with bone reference markers for measurement of P1 movement relative to third metacarpal bone positions during axial limb loadin...
Kuzmina TA, Tolliver SC, Lyons ET.Three species of cyathostomes--Cylicocyclus ashworthi, Cylicostephanus bidentatus, and Cylicostephanus hybridus were identified recently in horses in Kentucky. General characteristics and distinguishing description of these species are presented. Distribution of these species and their role in the horse strongylid community are discussed. The importance of examining the entire contents of the large intestine or alternatively a high number of specimens in order to recover and identify species residing in low numbers is stressed.
Rose BV, Cabrera-Sharp V, Firth MJ, Barrelet FE, Bate S, Cameron IJ, Crabtree JR, Crowhurst J, McGladdery AJ, Neal H, Pynn J, Pynn OD, Smith C....Early pregnancy loss occurs in 6-10% of equine pregnancies making it the main cause of reproductive wastage. Despite this, reasons for the losses are known in only 16% of cases. Lack of viable conceptus material has inhibited investigations of many potential genetic and pathological causes. We present a method for isolating and culturing placental cells from failed early equine pregnancies. Trophoblast cells from 18/30 (60%) failed equine pregnancies of gestational ages 14-65 days were successfully cultured in three different media, with the greatest growth achieved for cells cultured in Amnio...
Kelmer G, Martin-Jimenez T, Saxton AM, Catasus C, Elliot SB, Lakritz J.There are no reported studies evaluating the use of erythromycin for regional limb perfusion (RLP) in horses. Our hypothesis was that using the cephalic and saphenous veins for RLP will enable delivery of therapeutic concentrations of erythromycin to the distal limb. Nineteen healthy horses participated in the study. The cephalic, saphenous or palmar digital (PD) vein was used to perfuse the limb with erythromycin. Synovial samples were collected from the metacarpo/metatarso-phalangeal (MCP/MTP) joint and blood samples were collected from the jugular vein. Maximum concentration (C(max)) of ery...
Gutekunst DE, Malmquist WA, Becvar CS.Antiserums prepared in specific pathogen free (SPF) ponies were used in direct and indirect immunofluorescence, immunodiffusion, complement fixation and serum neutralization procedures to study the interrelationships of the three types of equine herpes viruses (EHV-1, EHV-2, and EHV-3). Equine cell cultures infected with each type virus fluoresced when stained with homologous conjugated antiserum. In reciprocal tests EHV-1 and EHV-3 cross-fluoresced, but EHV-2 did not cross-fluoresce. Non-infected cell cultures did not fluoresce when stained with the 3 conjugates. EHV-1 and EHV-3 cross-fluores...
Haven ML, Dave K, Burrow JA, Merritt AM, Harris D, Zhang D, Hickey GJ.The antisecretory activity of omeprazole on gastric acid when administered i.v., intragastrically or per os, was evaluated in 2 female and 3 castrated male horses. Each horse had been prepared with a chronic indwelling gastric cannula. A single i.v. administration of omeprazole (1.5 mg/kg bwt) was effective in abolishing basal and pentagastrin (PG)-stimulated acid secretion. Once daily, nasogastric administration of omeprazole in acid-stable granules for 5 days inhibited acid secretion in a dose-dependent manner: 57% (1.5 mg/kg bwt) and 98% (5.0 mg/kg bwt) reduction of PG-stimulated acid secre...
Wyse CA, Murphy DM, Preston T, Morrison DJ, Love S.The aim of this study was to assess the feasibility of applying the 13C-octanoic acid breath test for assessment of gastric emptying in ponies by investigating the pattern of 13C enrichment in breath following the administration of a test meal +/- 13C-octanoic acid. After a 14 h fast, the ponies received either no meal (Test I) or a standardised test meal labelled with 0 mg (Test II), 125 mg (Test III), 250 mg (Test IV) or 500 mg (Test V) 13C-octanoic acid. For each test (I-V), exhaled breath samples were collected in duplicate at 1 h and immediately before ingestion of the test meal and at fr...
Conrado FO, Beatty SSK.Fluid analysis is an important part of the diagnostic work-up of equine patients presenting with disorders of the nervous system, musculoskeletal system, and abdominal cavity. Proper specimen handling and processing are paramount for complete and accurate interpretation of fluid samples. Normal cerebrospinal fluid is a low-cellularity, low-protein fluid requiring specific sample handling to ensure accurate results. Joint and abdominal fluid analyses are completed in practice or submitted for analysis to a reference laboratory. This article discusses fluid sample handling and processing conside...
Scacchia M, Molini U, Marruchella G, Maseke A, Bortone G, Cosseddu GM, Monacoo F, Savini G, Pini A.African horse sickness (AHS) is a vector‑borne viral disease of equids, endemic in Sub‑Saharan Africa. This article reports the clinic‑pathological and laboratory findings observed in the framework of passive surveillance during the AHS outbreaks which occurred in Namibia between 2006 and 2013. This study was conducted in the framework of the collaboration among the Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise (Teramo, Italy), the Namibian Ministry of Agriculture Water and Forestry, and the Namibian National Veterinary Association. A total of 92 horses were investigate...
Olchowy TW, Ames TR, Molitor TW.Antibody titer to Ehrlichia risticii was determined, in 2,549 equine serum samples, using an indirect fluorescent antibody assay. During 1986, samples were obtained from the Minnesota State-Federal Equine Infectious Anemia Diagnostic Laboratory, the Minnesota Racing Laboratory, from horses admitted to the University of Minnesota Veterinary Teaching Hospital, and as a result of field investigations of horses with acute diarrhea. Results of the study revealed antibody prevalence of 33, 24, 47, and 25% for the respective groups. There was no statistical association between seropositive status and...
Weiss DJ, Geor R, Smith CM, McClay CB.Echinocytes have been incriminated in the pathogenesis of exertional diseases in horses. To evaluate the hypothesis that echinocytes are dehydrated erythrocytes, we decreased blood sodium and potassium concentrations in 4 horses by administering furosemide (1.0 mg/kg of body weight, q 12 h) for 2 days and we monitored CBC, serum and erythrocyte sodium and potassium concentrations, and echinocyte numbers. Serum sodium concentration decreased progressively over the 48 hours of furosemide administration, then returned to near baseline concentration at 168 hours. A statistically significant decrea...
Gibb Z, Morris LH, Maxwell WM, Grupen CG.Cryopreserved, sex-sorted stallion sperm has been shown to have poor fertility. During this study, the effects of cryoprotectant (glycerol [GLY] and dimethyl formamide [DMF]), cryoprotectant equilibration time (0, 30, 60, 90, or 120 minutes), and cryoprotectant concentration (2%, 3%, or 4% vol/vol) on stored sex-sorted and stored nonsorted stallion sperm were evaluated. Total motility, viability, and DNA integrity (determined using sperm chromatin structure assay) of sperm were assessed after thawing. Equilibration for 90 minutes improved total motility (33.8%) compared with 0 (28.5%) or 120 m...
Tachibana Y, Sakurai T, Bai H, Shiota K, Nambo Y, Nagaoka K, Imakawa K.Extensive studies have been conducted to characterize the unique phenomena of equine pregnancy. Most studies have focused on embryo transmigration when the embryo is covered with a mucin-like glycoprotein capsule and on the characterization of the chorionic girdle and chorionic gonadotropin (CG) secretion. However, the events preceding and following capsule disappearance have not been well studied. In this study, the mRNA expression in conceptus membranes at days 19, 21, and 25 (day 0 = day of ovulation) was analyzed by RNA-seq (SOLiD3), and transcript levels on these three days and day 13...
Finding EJT, Lawson C, Elliott J, Harris PA, Menzies-Gow NJ.Microvesicles are small (up to 1 μm) vesicles found in plasma and other bodily fluids. They are recognised as part of the normal system of inter-cellular communication but altered numbers are also used as biomarkers of disease. Microvesicles have not been studied in detail in the horse but may be relevant to diseases such as laminitis. Identification of equine cell specific microvesicles was performed by developing a panel of cross reactive antibodies to use in flow cytometry to detect microvesicles of platelet, leucocyte and endothelial origin in plasma from healthy ponies and those predis...
Winter MD.The usefulness of magnetic resonance (MR) imaging in the diagnosis of equine lameness is unquestionable. As with most imaging modalities, advances in technology happen quickly, and the information that can be obtained can seem limitless. An understanding of MR sequences, expected signal intensity of normal tissues, and the role of multiplanar imaging is the foundation for interpreting MR images. The rapid development of new techniques and sequences and the potential for biochemical changes to be indirectly assessed using MR spectroscopy offer possibilities for the continued development of this...
Estell KE, Knych HK, Patel T, Edman JM, Magdesian KG.To the authors' knowledge, there have been no studies evaluating the pharmacokinetics of chloramphenicol administered orally to horses at the currently recommended dose of 50 mg/kg PO q6 h for multiple days. The published antimicrobial susceptibility breakpoint is 8.0 ug/mL; it is unknown if this concentration is achievable at the recommended dose rate in horses. The aim of this prospective multi-dose pharmacokinetic study was to perform pharmacokinetic analysis of chloramphenicol after multiple doses. The authors hypothesize that the antimicrobial susceptibility breakpoint will not be reached...
Moloney E, Kavanagh KS, Buckley TC, Cooney JC.Streptococcus equi ssp. equi is the causative agent of 'Strangles' in horses. This is a debilitating condition leading to economic loss, yard closures and cancellation of equestrian events. There are multiple genotypes of S. equi ssp. equi which can cause disease, but to date there has been no systematic study of strains which are prevalent in Ireland. This study identified and classified Streptococcus equi ssp. equi strains isolated from within the Irish equine industry. Results: Two hundred veterinary isolates were subjected to SLST (single locus sequence typing) based on an internal sequenc...
Trachsel DS, Stage HJ, Rausch S, Trappe S, Söllig K, Sponder G, Merle R, Aschenbach JR, Gehlen H.Physiological particularities of the equine heart justify the development of an in vitro model suitable for investigations of the species-specific equine cardiac electrophysiology. Adipose tissue-derived stromal/stem cells (ASCs) could be a promising starting point from which to develop such a cardiomyocyte (CM)-like cell model. Therefore, we compared abdominal, retrobulbar, and subcutaneous adipose tissue as sources for the isolation of ASCs applying two isolation methods: the collagenase digestion and direct explant culture. Abdominal adipose tissue was most suitable for the isolation of ASC...
Bayless RL, Sheats MK, Jones SL.Neutrophils play a major role in many equine conditions, including equine asthma, laminitis, and intestinal ischemia and reperfusion injury, and therefore represent an attractive target for innovative therapeutic approaches. Novel strategies for reducing neutrophilic inflammation include modulation of neutrophil functions and lifespan. Withaferin A (WFA) is a phytochemical with well-established and anti-inflammatory properties, but its direct effects on neutrophils are largely unknown. We hypothesized that WFA would inhibit adhesion, migration, and respiratory burst by equine neutrophils and...
Choi YH, Penedo MC, Daftari P, Velez IC, Hinrichs K.Preimplantation genetic diagnosis has great potential in the horse, but information on evaluation of equine embryo biopsy samples is limited. Blastocysts were biopsied using a Piezo drill and methods for whole-genome amplification (WGA) investigated. Results for 33 genetic loci were then compared between biopsy samples from in vitro-produced (IVP) and in vivo-recovered (VIV) blastocysts. Under the experimental conditions described, WGA using the Qiagen Repli-g Midi kit was more accurate than that using the Illustra Genomiphi V2 kit (98.2% vs 25.8%, respectively). Using WGA with the Qiagen kit,...
