"Horses" is a broad topic that encompasses various aspects of equine biology, behavior, and management. This category includes studies on the anatomy, physiology, and genetics of horses, as well as their behavior, nutrition, and care. Research in this area may also cover the historical and cultural significance of horses, their roles in agriculture, sport, and therapy, and the challenges associated with their conservation and welfare. The page aggregates peer-reviewed research articles and scholarly studies that explore the multifaceted relationships between humans and horses, examining both scientific and socio-economic perspectives.
Burk SV, Dangoudoubiyam S, Brewster-Barnes T, Howe DK, Carter CN, Bryant UK, Rossano MG.Parascaris equorum is an intestinal nematode of foals and young horses that can produce mild to severe pathology. Current diagnosis is limited to detection of patent infections, when parasite eggs are identified during fecal examinations. This study examined the use of larval P. equorum excretory-secretory (ES) products in a western blot test for diagnosis of prepatent equine P. equorum infection. Sera from adult mares negative for patent P. equorum infections, foals prior to consuming colostrum, and P. equorum infected foals were used as controls in this study. Study samples included sera fro...
Lemieux H, Boemer F, van Galen G, Serteyn D, Amory H, Baise E, Cassart D, van Loon G, Marcillaud-Pitel C, Votion DM.Equine atypical myopathy in Europe is a fatal rhabdomyolysis syndrome that results from the ingestion of hypoglycin A contained in seeds and seedlings of Acer pseudoplatanus (sycamore maple). Acylcarnitine concentrations in serum and muscle OXPHOS capacity were determined in 15 atypical myopathy cases. All but one acylcarnitine were out of reference range and mitochondrial respiratory capacity was severely decreased up to 49% as compared to 10 healthy controls. The hallmark of atypical myopathy thus consists of a severe alteration in the energy metabolism including a severe impairment in muscl...
Pfau T, Daly K, Davison J, Bould A, Housby N, Weller R.Military working horses perform a high proportion of work on road surfaces and are shod frequently to deal with high attrition rates. The authors investigate the influence of shoeing on movement symmetry as an indirect indicator of mechanical differences affecting force production between contralateral limbs. In this quantitative observational study, inertial sensor gait analysis was performed in 23 Irish sport type horses (4-21 years, 1.58-1.85 m) in full ceremonial work at the King's Troop, Royal Horse Artillery. Changes in two movement symmetry measures (SI: symmetry index; MinDiff: dif...
van der Kolk JH, Fouché N, Gross JJ, Gerber V, Bruckmaier RM.In this review, we address the function of the hypothalamus-pituitary-adrenocortical (HPA) axis with special emphasis on the comparison between the bovine and equine species. The pars intermedia of the pituitary gland is particularly well developed in horses and cattle. However, its function is not well appreciated in cattle yet. The Wulzen's cone of the adenohypophysis is a special feature of ruminants. Total basal cortisol concentration is much higher in horses than that in cows with similar free cortisol fractions. Corticotropin-releasing factor (CRF) concentrations in equine pituitary veno...
González-Fernández ML, Pérez-Castrillo S, Sánchez-Lázaro JA, Prieto-Fernández JG, López-González ME, Lobato-Pérez S, Colaço BJ, Olivera ER....OBJECTIVE To assess the ability to regenerate an equine meniscus by use of a collagen repair patch (scaffold) seeded with mesenchymal stem cells (MSCs) derived from bone marrow (BM) or adipose tissue (AT). SAMPLE 6 female Hispano-Breton horses between 4 and 7 years of age; MSCs from BM and AT were obtained for the in vitro experiment, and the horses were subsequently used for the in vivo experiment. PROCEDURES Similarities and differences between MSCs derived from BM or AT were investigated in vitro by use of cell culture. In vivo assessment involved use of a meniscus defect and implantation o...
Tuska P, Tóth B, Vásárhelyi G, Hangody L, Papp M, Bodó G.The purpose of this study was to evaluate changes in biomarker and synovial parameters following autologous osteochondral transplantation (AOT) in the equine stifle joint, to test the hypothesis whether synovial parameters would show significant differences at selected time points following the surgery (at days 3, 14, 60 and 180) compared to baseline level (at day 0). Surgical intervention was performed in both stifles of nine horses (n = 18). The joints were randomly assigned to operated and sham-operated groups. Grafts 8.5 mm in diameter were harvested from the femoropatellar (FP) joint unde...
Dorrego-Keiter E, Tóth J, Dikker L, Sielhorst J, Schusser GF.In the ongoing discussion regarding the aetiopathogenesis of equine recurrent uveitis (ERU) it was the aim of the present study to elucidate the relationship of leptospira infection and ERU. In a population of 225 horses leptospira were examined in vitreous humor by culture and leptospira antibody were detected in vitreous humor and serum samples. Preoperative serum samples were collected from 221/225 ERU patients of different age, gender and breed. Undiluted vitreous humor was aseptically taken from 198/225 patients that underwent pars plana vitrectomy at the beginning of surgery and from 27/...
Carmalt JL, Duke-Novakovski T, Schott HC, van der Kolk JH.OBJECTIVE To determine effects of anesthesia on plasma concentrations and pulsatility of ACTH in samples obtained from the cavernous sinus and jugular vein of horses. ANIMALS 6 clinically normal adult horses. PROCEDURES Catheters were placed in a jugular vein and into the cavernous sinus via a superficial facial vein. The following morning (day 1), cavernous sinus blood samples were collected every 5 minutes for 1 hour (collection of first sample = time 0) and jugular venous blood samples were collected at 0, 30, and 60 minutes. On day 2, horses were sedated with xylazine hydrochloride and ane...
Ghosh M, Cho HW, Park JW, Choi JY, Chung YH, Sharma N, Singh AK, Kim NE, Mongre RK, Huynh D, Jiao ZJ, Do KT, Lee HK, Song KD, Cho BW, Jeong D.The athletic abilities of the horse serve as a valuable model to understand the physiology and molecular mechanisms of adaptive responses to exercise. We analyzed differentially expressed genes in triceps brachii muscle tissues collected from Eonjena Taeyang and Jigusang Seryeok Thoroughbred horses and their co-expression networks in a large-scale RNA-sequence dataset comparing expression before and after exercise. High-quality horse transcriptome data were generated, with over 22 million 90-bp pair-end reads. By comparing the annotations, we found that MYH3, MPZ, and PDE8B genes in Eonjena Ta...
Scholz FM, Burrows AK, Muse R.Sublingual immunotherapy (SLIT) offers an alternative mode of allergen delivery to subcutaneous immunotherapy (SCIT) with the aim of inducing immunological tolerance. Currently, there are no published reports regarding the efficacy or safety of SLIT in horses. Objective: To describe the first case of several adverse events occurring in a horse subsequent to the repeat administration of SLIT. Methods: A seven-year-old, warmblood mare with a confirmed diagnosis of equine hypersensitivity dermatitis (EHD). Results: Immunotherapy was recommended for management of EHD. Due to the temperament of the...
Pikalo J, Sattler T, Eichinger M, Loitsch A, Sun H, Schmoll F, Schusser GF.Aim of the study was to detect antibodies and potential risk factors for an infec- tion with Leptospira in horses in Middle Germany. Serum samples of 314 horses were examined retrospectively by microscopic agglutination test for the presence of antibodies against eight Leptospira serovars. In total, 17.2% (n = 54) of the horses were positive for one or more of the serovars analyzed. The most prevalent serovar was lcterohaemorrhagiae (11.1%), followed by serovar Bratislava (9.6 %) and Grippotyphosa (1.9%). Mares showed a significantly higher occurrence of antibodies (p < 0.05) than geldings ...
McKenzie EC, Esser MM, McNitt SE, Payton ME.OBJECTIVE To compare the effects of equivalent volumes of equine plasma and 6% hydroxyethyl starch (600/0.75) solution (hetastarch) administered IV on plasma colloid osmotic pressure (pCOP) and commonly monitored clinicopathologic variables in horses. ANIMALS 6 healthy mares. PROCEDURES In a randomized, crossover study, horses were administered hetastarch or plasma (both 10 mL/kg, IV) 18 months apart. The pCOP and variables of interest were measured before (baseline), immediately after, and at intervals up to 96 or 120 hours after infusion. Prothrombin and activated partial thromboplastin time...
Kaido M, Kilborne AH, Sizemore JL, Reisbig NA, Aarnes TK, Bertone AL.OBJECTIVE To analyze the effects of vertical force peak (VFP) of repition within trials and between trial sessions in horses with naturally occurring appendicular lameness. ANIMALS 20 lame horses acclimated to trotting over a force plate. PROCEDURES Kinetic gait data were collected by use of a force plate regarding affected and contralateral limbs of lame horses that completed 5 valid repetitions in each of 5 sessions performed at 0, 3, 6, 12, and 24 hours, constituting 1 trial/horse. Data were compared within and among repetitions and sessions, and factors influencing VFP values were identifi...
Bazzano M, Giudice E, Rizzo M, Congiu F, Zumbo A, Arfuso F, Di Pietro S, Bruschetta D, Piccione G.The aim of this study was to investigate whether a combined global positioning system (GPS)/heart rate (HR) monitoring system is a valuable tool to assess, step by step, the physiological response of HR and its relationship with speed in healthy horses competing in an official show jumping class. Six mares performing a standardised warm-up and jumping course were monitored using a HR/GPS device. Venous blood lactate (BL), assessed before and after exercise, showed a significant increase (P = 0.0004) following the physical effort. One-way analysis of variance (ANOVA) showed significant changes ...
Durward-Akhurst SA, Finno CJ, Barnes N, Shivers J, Guo LT, Shelton GD, Valberg SJ.Major histocompatibility complex (MHC) I and II expression is not normally detected on sarcolemma, but is detected with lymphocytic infiltrates in immune-mediated myositis (IMM) of humans and dogs and in dysferlin-deficient muscular dystrophy. Objective: To determine if sarcolemmal MHC is expressed in active IMM in horses, if MHC expression is associated with lymphocytic subtype, and if dysferlin is expressed in IMM. Methods: Twenty-one IMM horses of Quarter Horse-related breeds, 3 healthy and 6 disease controls (3 pasture myopathy, 3 amylase-resistant polysaccharide storage myopathy [PSSM]). ...
Dobesova O, Bezdekova B.Thirty-eight guttural pouch lavages from 19 clinically healthy horses were collected transendoscopically. Cytological examination and bacteriological culture of the samples were carried out. All 38 lavages assessed for cytology contained less than five per cent neutrophils and could be termed as cytologically 'normal'. In none of the lavages did the neutrophil count vary between five and 25 per cent or exceed 25 per cent, which are the borderlines for being termed 'reactive' or 'pathological', respectively. Epithelial cells were the most commonly represented cell type in all lavages. Bacteriol...
Nemery E, Gabriel A, Piret J, Antoine N.In athletic horses, diseases leading to lameness are of great importance due to the loss of performance and the resultant economic concerns. Although stifle lesions are frequent in the hindlimb, due to the large size and complexity of the joint, and although meniscal tears have been identified as the most common soft tissue injuries in this joint, little is known about the mechanism that causes the painful sensation and thus the lameness. The aim of our study was to highlight any peripheral fibres involved in meniscal nociception in five macroscopically sound cranial horns of the equine medial...
Soroko M, Howell K, Dudek K, Henklewski R, Zielińska P.A previous thermographic study of racehorses identified 13 regions of interest (ROIs) for monitoring the impact of training. However, that investigation did not consider the influence of breed, age, gender or training intensity level on the temperature of ROIs. The present study adopted a multivariate analysis approach to determine whether the aforementioned factors, along with ambient temperature, significantly influenced ROI temperature in the key body regions. Thermography measurements were obtained from 53 racehorses of three breeds. Horses were in regular training for over 10 months, havi...
Simeonova GP, Krastev SZ, Simeonov RS.The pathogenic mechanism of equine recurrent uveitis (ERU) is still poorly defined and many variations between experimental animal models and spontaneous disease exist. Objective: The aim of our study was to investigate if Th17 cell-mediated response plays role in the pathogenesis of the used experimental model in horses and to reveal its pathological findings. Methods: Experimental uveitis was induced in 6 healthy horses. The concentrations of retinal autoantigen CRALBP and IL-17 were measured using ELISA in aqueous humor and vitreous body of the 12 inflamed eyes as well as in 12 control non-...
Ribeiro MJ, Rosa MH, Bruhn FR, Garcia Ade M, Rocha CM, Guimarães AM.The present study used the indirect fluorescent antibody test (IFAT) to determine the seroprevalence of Sarcocystis neurona, Toxoplasma gondii and Neospora spp., and evaluated the variables associated with these infections among 506 apparently healthy horses, reared in the south of the state of Minas Gerais, Brazil. This study was conducted between April 2012 and October 2013. Among the horses, the true prevalence of S. neurona was 26% (95% CI: 22.0-30.4%), T. gondii 19.9% (95% CI: 15.5-24.8%) and Neospora spp. 23.9% (95% CI: 19.9-28.1%); and among the farms, 88.3% (95% CI: 74.4-91.6%), 71.6% ...
Edmonds RE, Garvican ER, Smith RK, Dudhia J.To provide evidence to support recommendations regarding the co-administration of drugs with mesenchymal stem cell (MSC) therapy. Objective: To determine the influence of sedatives, local anaesthetic and corticosteroids on MSC viability and proliferation, in comparison to somatic cells derived from tendon (TDCs). Methods: In vitro cell culture. Methods: MSCs (n = 3) and TDCs (n = 2) were cultured in media containing a clinically relevant dose range of xylazine, romifidine, detomidine and butorphanol, mepivacaine, methylprednisolone, or triamcinolone acetonide. Cell viability in suspension cult...
Suzuki T, Kobayashi H, Kawasaki Y, Okazuka K, Hatano K, Fujiwara S, Oh I, Ohmine K, Kanda Y.Anti-thymocyte globulin (ATG) is a key drug in immunosuppressive therapy for patients with aplastic anemia. The mainstay of ATG therapy had been a horse ATG (hATG) formulation, Lymphoglobulin or ATGAM, but Lymphoglobulin was recently discontinued, and Thymoglobulin, a rabbit ATG (rATG) formulation, is currently used as the first-line drug in many countries, including Japan. However, a recent randomized clinical trial reported significantly unfavorable outcomes associated with the use of rATG regimens. We retrospectively analyzed clinical outcomes of adult patients with moderate to severe aplas...
Ferreira EP, Vidotto O, Almeida JC, Ribeiro LP, Borges MV, Pequeno WH, Stipp DT, de Oliveira CJ, Biondo AW, Vieira TS, Vieira RF.Theileriosis is a worldwide protozoal tick-borne disease caused by Theileria equi, which may produce a variety of clinical signs and turn infected horses into lifetime carriers. This study has aimed to perform a serological and molecular detection of T. equi and associated factors in sports horses from six areas of northeastern Brazil. In overall, 59.6% horses were positive by indirect immunofluorescence assay and 50.4% by polymerase chain reaction. No significant association was found when presence of ticks, age, gender, anemia or total plasma proteins was analyzed with seropositivity and mol...
Mosing M, Waldmann AD, MacFarlane P, Iff S, Auer U, Bohm SH, Bettschart-Wolfensberger R, Bardell D.This study evaluated the breathing pattern and distribution of ventilation in horses prior to and following recovery from general anaesthesia using electrical impedance tomography (EIT). Six horses were anaesthetised for 6 hours in dorsal recumbency. Arterial blood gas and EIT measurements were performed 24 hours before (baseline) and 1, 2, 3, 4, 5 and 6 hours after horses stood following anaesthesia. At each time point 4 representative spontaneous breaths were analysed. The percentage of the total breath length during which impedance remained greater than 50% of the maximum inspiratory impeda...
Amat JP, Vergne T, Tapprest J, Ferry B, Hans A, Hendrikx P, Dufour B, Leblond A.Equine viral arteritis (EVA) may have serious economic impact on the equine industry. For this reason, it is monitored in many countries, especially in breeding stock, to avoid its spread during breeding activities. In France, surveillance is mainly based on serological tests, since mares are not vaccinated, but difficulties in interpreting certain series of results may impair the estimation of the number of outbreaks. In this study, we propose specific rules for identifying seroconversion in order to estimate the number of outbreaks that were detected by the breeding stock surveillance compon...
Braid LR, Hu WG, Davies JE, Nagata LP.: Mesenchymal stromal cells (MSCs) are being exploited as gene delivery vectors for various disease and injury therapies. We provide proof-of-concept that engineered MSCs can provide a useful, effective platform for protection against infectious disease. Venezuelan equine encephalitis virus (VEEV) is a mosquito-borne pathogen affecting humans and equines and can be used in bio-warfare. No licensed vaccine or antiviral agent currently exists to combat VEEV infection in humans. Direct antibody administration (passive immunity) is an effective, but short-lived, method of providing immediate prote...
Scott ML, John EE, Bellone RR, Ching JC, Loewen ME, Sandmeyer LS, Grahn BH, Forsyth GW.Congenital stationary night-blindness (CSNB) is a recessive autosomal defect in low-light vision in Appaloosa and other horse breeds. This condition has been mapped by linkage analysis to a gene coding for the Transient Receptor Potential cation channel Member 1 (TRPM1). TRPM1 is normally expressed in the ON-bipolar cells of the inner nuclear layer of the retina. Down-regulation of TRPM1 expression in CSNB results from a transposon-like insertion in intron 1 of the TRPM1 gene. Stop transcription signals in this transposon significantly reduce TRPM1 primary transcript levels in CSNB horses. Thi...
Miyakoshi D, Senba H, Shikichi M, Maeda M, Shibata R, Misumi K.This study aimed to evaluate the influence of radiographic abnormalities of 2-year-old Thoroughbred horses that were listed at in-training sales in Japan, on whether they started to race or not at 2-3 years of age. Radiographs of 850 2-year-old Thoroughbreds in the in-training sales repository from 2007 to 2010 were reviewed, and 26 categories of radiographic abnormalities were found. Forty-three horses (5.1%, 43/850) did not start a race at 2-3 years of age. In accordance with the racing results for this age category, as determined by Fisher's exact test and multiple logistic regression analy...
Gorucu S, Murphy DJ, Kassab C.The purpose of this study was to investigate characteristics associated with farm equipment and horse and buggy roadway crashes in relation to person, incident, and injury characteristics to identify appropriate points for injury incident prevention. Information on crashes occurring on public roads during the years 2010-2013 was obtained from the Pennsylvania Department of Transportation (PennDOT) and analyzed. There were 344 farm equipment and 246 horse and buggy crashes during the 4-year study period. These crashes involved 666 and 504 vehicles and 780 and 838 people, respectively. In incide...
McCarthy HE, French NP, Edwards GB, Poxton IR, Kelly DF, Payne-Johnson CE, Miller K, Proudman CJ.Equine grass sickness is a high mortality disease which, despite many years of investigation, is of unknown aetiology. Recent findings indicating that the disease is associated with Clostridium botulinum require support from an epidemiological study that recognises and controls for potential confounders, e.g. age, time of year and premises. Objective: EGS is associated with low antibody levels to C. botulinum antigens. Methods: A matched case-control study was conducted. Data were collected from 66 histologically confirmed cases of EGS and 132 premises-matched control horses. The probability o...
Winther L, Honoré Hansen S, Baptiste KE, Friis C.Doxycycline concentrations, following two types of oral administration to horses, in pulmonary epithelial lining fluid (PELF) were examined and compared to plasma concentrations. The oral bioavailability was estimated from plasma concentrations achieved after an intravenous study in two horses. Doxycycline (10 mg/kg) was administered either intragastric or as topdressing to nonfasted horses. Blood samples were collected for drug analysis, before and 11 times after administration during 24 h. PELF samples were collected by a tampon device four times after drug administration and analysed for do...
Pfau T, Daly K, Davison J, Bould A, Housby N, Weller R.Military working horses perform a high proportion of work on road surfaces and are shod frequently to deal with high attrition rates. The authors investigate the influence of shoeing on movement symmetry as an indirect indicator of mechanical differences affecting force production between contralateral limbs. In this quantitative observational study, inertial sensor gait analysis was performed in 23 Irish sport type horses (4-21 years, 1.58-1.85 m) in full ceremonial work at the King's Troop, Royal Horse Artillery. Changes in two movement symmetry measures (SI: symmetry index; MinDiff: dif...
Barrandeguy M, Vissani A, Lezica FP, Salamone J, Heguy A, Becerra L, Olguin Perglione C, Thiry E.The temporary disruption of reproductive activities due to equine coital exanthema (ECE), caused by equid herpesvirus 3 (EHV-3), at thoroughbred breeding facilities and embryo transfer centres, has an appreciable economic impact. The aim of the present study was to estimate the prevalence of excretion of EHV-3 in mares without clinical symptoms under field conditions and the re-excretion patterns of the virus in two seropositive (presumably latently infected) mares maintained in isolation for 11 mo. The EHV-3 virus was detected in perineal-vaginal swabs by real time PCR in 14 (6%) of 220 thoro...
Munday JS, Orbell G, Fairley RA, Hardcastle M, Vaatstra B.Equine sarcoids are common mesenchymal neoplasms of horses that are caused by cross-species infection by . While bovine papillomavirus (BPV) 1 and 2 are the most common causes, there are differences between countries regarding which of these BPV types cause the majority of sarcoids. Additionally, no causative PV can be detected in a subset of sarcoids, suggesting that other PV types could be rarer causes of these neoplasms. In the present study, consensus PCR primers and PCR primers specific for the five types currently known to cause mesenchymal neoplasia (BPV1, BPV2, BPV13, BPV14, and Ovis ...
Lavoie JP, Spensley MS, Smith BP, Mihalyi J.The uptake of colostral IgG and IgM, their serum half-lives, and the rates of endogenous synthesis of IgG and IgM were evaluated in 6 newborn foals fed bovine colostrum (principals) and 6 foals allowed to suckle their dams (controls). The principal foals were fed 400 ml of bovine colostrum (IgG, 10,000 mg/dl and IgM, 200 mg/dl) at 2-hour intervals, from 2 to 20 hours after foaling (total dose, 4 L). Serum IgG and IgM concentrations were determined by single radial immunodiffusion from birth to 98 days of age. At foaling, principal foals had no detectable serum equine IgG, but 1 control foal ha...
Hwang I, Jung EM, Yang H, Choi KC, Jeung EB.Calcium transporter genes, such as transient receptor potential cation channel subfamily V members 5/6 (TRPV5/6), Na(+)/Ca(2+) exchanger 1 (NCX1), and plasma membrane calcium-transporting ATPase 1b (PMCA1b), are essential for maintaining homeostasis and metabolizing Ca(2+) ions. The TRPV5 and TRPV6 proteins play an important role in Ca(2+ )absorption, and NCX1 and PMCA1b are both critical for intracellular calcium homeostasis. In this study, the tissue-specific mRNA and protein expression of these calcium transporter genes in the duodenum, kidney and heart of the horse (Equus caballus) was exa...
Reinemeyer CR, Prado JC, Nichols EC, Marchiondo AA.The expanding prevalence of Parascaris equorum populations that are resistant to macrocyclic lactone (ML) anthelmintics makes it desirable to identify dewormers which remain effective. The objective was to evaluate the efficacy of pyrantel pamoate in 14 suckling foals that had been infected orally with approximately 600 larvated eggs of a P. equorum isolate selected for ML resistance (ML-R). Seventy days after inoculation, foals were weaned, housed individually, and fecal samples were examined frequently to detect the onset of patency. Between 73 and 80 days post-inoculation, all 14 foals deve...
McGorum BC, Dixon PM.Local transendoscopic endobronchial antigen challenge, which has proved to be a valuable clinical and research technique in the study of human pulmonary hypersensitivity, was evaluated in control and asymptomatic COPD--affected horses. Transendoscopic endobronchial challenges with phosphate-buffered saline (PBS), Micropolyspora faeni extract at 60 and 600 micrograms/ml and mouldy hay extract elicited neutrophilic airway inflammatory responses in control (N = 5-7) and asymptomatic COPD-affected (N = 5-7) horses, as determined by cytological examinations of bronchoalveolar lavage fluid (BALF) ha...
Crabill MR, Schumacher J.Periodontitis, infundibular necrosis, and periapical infection are dental diseases commonly affecting adult horses. Routine dental examinations and care may help to prevent these diseases. Further investigation of the treatment of horses with these diseases using local antimicrobial therapy, restorative dentistry, and endodontic therapy is needed. An understanding of the pathogenesis of these diseases aids in diagnosis and treatment. Gingival hyperplasia and odontogenic tumors are uncommon but should remain in a list of differential diagnoses when examining a horse with pertinent clinical sign...
Satué K, Marcilla M, Medica P, Ferlazzo A, Fazio E.Androgens modulate maternal ovarian activity, embryo implantation and correct placental development. The objective of this study was to establish reference values for testosterone (T), androstenedione (A4) and dehydroepiandrosterone (DHEA) concentrations in pregnant mares. A total of 30 healthy Spanish Purebred mares with an age range of 9.33 ± 3.31 years, were studied during the 11 months of gestation. T, A4 and DHEA concentrations were determined using EIA validated specifically for equines. T increased in the 2nd and 3rd month (P < 0.05), showing a plateau between the 4th and 6th m...
Peters J, Eggers K, Oswald S, Block W, Lütjohann D, Lämmer M, Venner M, Siegmund W.Pulmonary penetration of clarithromycin (CLR) in epithelial lining fluid (ELF) and bronchoalveolar lavage cells (BALCs) can be influenced by CYP3A4, by P-glycoprotein, and, according to our hypothesis, by a member of the organic anion-transporting protein (OATP) family, for which rifampicin (RIF) is inhibiting in single doses but inducing after long-term coadministration. To assess the partial inhibitory effect, we measured absorption and pulmonary distribution of CLR after short-term (2.5-day) coadministration of RIF, after which up-regulation is not expected. The drug interaction study was p...
Baggot JD, Short CR.Differences between neonatal and adult animals in their response to drugs can usually be attributed to altered disposition (ie, distribution, metabolism and excretion) processes during the neonatal period. These alterations affect the plasma concentrations as well as the concentrations of drug attained at the receptor site. Some characteristics of the neonatal period include greater absorption from the gastrointestinal tract, lower extent of plasma protein binding, increased apparent volume of distribution of drugs that distribute in extracellular fluid or total body water, increased permeabil...
Axmann S, Hummel K, Nöbauer K, Razzazi-Fazeli E, Zitterl-Eglseer K.Devil's claw is used for the treatment of inflammatory symptoms and degenerative disorders in horses since many years, but without the substantive pharmacokinetic data. The pharmacokinetic parameters of harpagoside, the main active constituent of Harpagophytum procumbens DC ex Meisn., were evaluated in equine plasma after administration of Harpagophytum extract FB 8858 in an open, single-dose, two-treatment, two-period, randomized cross-over design. Six horses received a single dose of Harpagophytum extract, corresponding to 5 mg/kg BM harpagoside, and after 7 days washout period, 10 mg/kg ...
Crook TC, Cruickshank SE, McGowan CM, Stubbs N, Wilson AM, Hodson-Tole E, Payne RC.Selective breeding for performance has resulted in distinct breeds of horse, such as the Quarter Horse (bred for acceleration) and the Arab (bred for endurance). Rapid acceleration, seen during Quarter Horse racing, requires fast powerful muscular contraction and the generation of large joint torques, particularly by the hind limb muscles. This study compared hind limb moment arm lengths in the Quarter Horse and Arab. We hypothesized that Quarter Horse hind limb extensor muscles would have longer moment arms when compared to the Arab, conferring a greater potential for torque generation at the...
Verhaar N, Breves G, Hewicker-Trautwein M, Pfarrer C, Rohn K, Burmester M, Schnepel N, Neudeck S, Twele L, Kästner S.Ischaemic postconditioning (IPoC) has been shown to ameliorate ischaemia reperfusion injury in different species and tissues. Objective: To assess the feasibility of IPoC in equine small intestinal ischaemia and to assess its effect on histomorphology, electrophysiology and paracellular permeability. Methods: Randomised in vivo experiment. Methods: Experimental jejunal ischaemia was induced for 90 min in horses under general anaesthesia. In the control group (C; n = 7), the jejunum was reperfused without further intervention. In the postconditioning group (IPoC; n = 7), reocclusion was im...
Pérez-Manrique L, León-Pérez K, Zamora-Sánchez E, Davies S, Ober C, Wilson B, McGreevy P.Restrictive nosebands are used in equestrian sports to hold the bit in place and reduce mouth-opening, a response that can attract penalties in some sports and is thought to reduce the rider's control of the horse. Sustained pressure from such tightly fitted (restrictive) nosebands denies normal behaviour and thus, causes frustration and distress that can jeopardise horse welfare. It also may push the cheek against the molar teeth, compress soft tissues including blood vessels and nerves, and possibly induce chronic changes to underlying bone. This study of mature cavalry horses (n = 144) was ...
Nimmo Wilkie JS, Yager JA, Nation PN, Clark EG, Townsend HG, Baird JD.A generalized, chronic, progressive, exfoliative dermatitis in five horses is described. Histologically, the lesion is characterized by a superficial and deep perivascular dermatitis which is eosinophil-rich with a marked lymphocytic and plasmacytic component, accompanied by marked acanthosis and hyperkeratosis. More severe cases progress to a lichenoid pattern with the same cellular composition with focal eosinophilic spongiosis and eosinophilic subcorneal pustules. Clinically, the disease is associated with chronic, severe weight loss and is fulminating. The skin lesions are accompanied by l...
Bischofberger AS, Brauer T, Gugelchuk G, Klohnen A.Incisional complications are a major post operative challenge following ventral midline exploratory celiotomy for abdominal pain in horses. They lead to discomfort, prolonged hospitalisation, longer recovery times and increased cost; therefore, investigation of preventative procedures are warranted. Objective: To determine the clinical effect of antibacterial (triclosan) coated 2-0 polyglactin 910 suture material on the likelihood of incisional infections when used for closure of subcutaneous tissue following ventral midline celiotomies in horses. Methods: One hundred horses undergoing explora...
McKellar QA, Gokbulut C, Muzandu K, Benchaoui H.The present study was designed to describe the pharmacokinetics and fecal excretion of fenbendazole (FBZ) and fenbendazole sulphoxide (FBZSO) and their metabolites in horses, to investigate the effects which concurrent feeding has on the absorption and pharmacokinetics of FBZ, and to determine the effect of coadministration of the metabolic inhibitor piperonyl-butoxide on the in vivo pharmacokinetics and in vitro liver microsomal metabolism of sulfide and sulfoxide benzimidazoles. The effect of piperonyl-butoxide on the enantiomeric genesis of the sulfoxide moiety was also investigated. Follow...
Monreal L, Sabaté D, Segura D, Mayós I, Homedes J.The objective was to compare the gastrointestinal and general toxicity of suxibuzone (SBZ) to that of phenylbutazone (PBZ) when administered orally in horses. Fifteen healthy horses were allocated to three treatment groups. One group received a high dose of PBZ for two weeks; the second group was given an equimolecular dosage of SBZ; and a third group received placebo. Horses were daily monitored, and blood samples were collected before and during the study. On day 18, complete post-mortem examinations were performed. One horse treated with PBZ showed clinical signs of NSAID toxicosis. Small o...
Haas DJ, Dorneles EM, Spier SJ, Carroll SP, Edman J, Azevedo VA, Heinemann MB, Lage AP.Corynebacterium pseudotuberculosis biovar Equi is an important pathogen of horses. It is increasing in frequency in the United States, and is responsible for various clinical forms of infection, including external abscesses, internal abscesses of the abdominal or thoracic cavities, and ulcerative lymphangitis. The host/pathogen factors dictating the form or severity of infection are currently unknown. Our recent investigations have shown that genotyping C. pseudotuberculosis isolates using enterobacterial repetitive intergenic consensus (ERIC)-PCR is useful for understanding the evolutionary g...
Porcellato I, Mecocci S, Mechelli L, Cappelli K, Brachelente C, Pepe M, Orlandi M, Gialletti R, Passeri B, Ferrari A, Modesto P, Ghelardi A....Penile squamous cell carcinomas (SCCs) are common tumors in older horses, with poor prognosis mostly due to local invasion and recurrence. These tumors are thought to be mainly caused by papillomavirus type 2 (EcPV-2). The aim of this study is to characterize the tumor immune environment (TIME) in equine penile tumors. Equine penile epithelial tumors (17 epSCCs; 2 carcinomas , CIS; 1 papilloma, P) were retrospectively selected; immune infiltrate was assessed by histology and immunohistochemistry; RT-qPCR tested the expression of selected chemokines and EcPV-2 DNA and RNA. The results confirme...
Tavassoli M, Dalir-Naghadeh B, Esmaeili-Sani S.Fecal samples for detection of gastrointestinal parasites were collected from 221 working horses from September 2002 to May 2003 from 14 villages in Urmia, North West of Iran. Fecal samples of 46 horses (20.8%) were negative for parasite eggs or oocysts. One hundred and seventy five positive horses (48.9%) were infected with a single parasite type and 49 (22.2%) and 18 (8.1%) of horses had multiple infections with two and three parasites, respectively. The highest prevalence and intensity rate belonged to small strongyles. The overall prevalence of intestinal parasites eggs and oocyst in the p...
Bründler P, Frey CF, Gottstein B, Nussbaumer P, Neuhaus S, Gerber V.An association between equine recurrent airway obstruction (RAO) and increased resistance to intestinal parasites has been demonstrated in descendants of an RAO-affected stallion. It was hypothesised that members of another high-incidence RAO family (F) and unrelated RAO-affected Warmblood horses (UA) would shed fewer strongylid eggs than unrelated RAO-unaffected pasture mates (PM) under the same environmental conditions. Faecal worm egg counts were performed on faecal samples (63 F, 86 UA, 149 PM) and classified into three categories: 0, 1-100 and >100 eggs per gram. While results for F di...
Fotschki J, Wróblewska B, Fotschki B, Kalicki B, Rigby N, Mackie A.Horse milk is a valuable raw material and a very attractive alternative for scientific research to address the issue of cow milk (CM) allergy due to its protein profile. A decrease in immunoreactive properties can be achieved by thermal, enzymatic, and hydrolytic processing. Therefore, the aim of this study was to explore the possibility of reducing the immunoreactivity of horse milk proteins by microbial transglutaminase (TG) polymerization. To determine how TG linking alters immunoreactivity under simulated digestion of the examined milk, analyses were performed before, during, and after dig...
Kirkland PD, Delbridge G.An important consideration in the selection of a vaccine during the Australian equine influenza (EI) outbreak in 2007 was the ability to differentiate between infected and vaccinated animals (DIVA). A blocking enzyme-linked immunosorbent assay (bELISA) targeted for the nucleoprotein of influenza A viruses was developed to differentiate between naturally infected horses and horses vaccinated with the ProteqFlu® vaccine, which only induces a response to viral haemagglutinin. This bELISA assay met the DIVA requirements and was used extensively during the EI control and eradication programs and '...
Mair TS, Hillyer MH, Taylor FG, Pearson GR.Specificity of the oral glucose tolerance test (OGTT) for the diagnosis of small intestinal malabsorption in the horse was assessed by comparing the results of OGTT with the results of a histopathological examination of the small intestine in 42 adult horses affected by chronic weight loss. The horses were assigned to three groups on the basis of the results of the test. Five horses were considered to have a normal OGTT absorption result (Group 1); all the horses had a histologically normal small intestine. Twenty-five horses had a partial malabsorption result (Group 2) seven of which had norm...
