"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.
Arrighi S.Occurrence of a solitary cilium was an unexpected discovery while studying the ultrastructure of epididymal epithelium in equidae. Primary cilia were detected in epididymal basal cells of all individuals of the equines studied - horses, donkey and mules - independently from age and tract of the duct, emerging from the basal cell surface and insinuating into the intercellular spaces. More rarely solitary cilia occurred also at the luminal surface of the principal cells. The ciliary apparatus was constituted by a structurally typical basal body continuous with the finger-like ciliary shaft exten...
Soykan E, Oge H.This study was carried out between March 2004- April 2005 to determine the prevalance of liver trematode infections of equids in different cities of Turkey. Methods: A total of 117 equids (72 horses, 39 donkeys and 6 mules) in Ankara were examined for liver parasites after the slaugthering process. On the other hand, a total of 620 feces of horses in Bursa, Gemlik, Malatya, Eskişehir and Ankara provinces were detected for determining liver trematodes in live equines. The fecal samples of horses were examined for liver fluke infection by Benedect's sedimentation methods. Results: Of these 117 ...
Seabaugh KA, Goodrich LR, Morley PS, Bohn A, Rao S, Hendrickson DA.To determine the effect of unilateral laparoscopic cryptorchidectomy and removal of the descended testis on peritoneal fluid values, and to compare effect between 2 methods for cryptorchid testis vessel hemostasis. Methods: Randomized clinical study. Methods: Stallions (n = 10) with unilateral abdominal cryptorchid testis. Methods: During standing laparoscopic cryptorchidectomy, blood vessels within the mesorchium of the cryptorchid testis were either sealed and transected with the LigaSure Atlas™ or 2 ligating loops were placed proximal to the testis and the tissue transected with laparosco...
Greve L, Dyson S.Common causes of poor performance in horses include factors related to the horse, the rider and/or the saddle, and their interrelationships remain challenging to determine. Horse-related factors (such as thoracolumbar region pain and/or lameness), rider-related factors (such as crookedness, inability to ride in rhythm with the horse, inability to work the horse in a correct frame to improve core strength and muscular support of the thoracolumbar spine of the horse), and saddle-related factors (such as poor fit causing focal areas of increased pressure) may all contribute to poor performance to...
Meng Q, Lin Y, Ma J, Ma Y, Zhao L, Li S, Yang K, Zhou J, Shen R, Zhang X, Shao Y.Data from successful attenuated lentiviral vaccine studies indicate that fully mature Env-specific antibodies characterized by high titer, high avidity, and the predominant recognition of conformational epitopes are associated with protective efficacy. Although vaccination with a DNA prime/recombinant vaccinia-vectored vaccine boost strategy has been found to be effective in some trials with non-human primate/simian/human immunodeficiency virus (SHIV) models, it remains unclear whether this vaccination strategy could elicit mature equine infectious anemia virus (EIAV) Env-specific antibodies, ...
Fukushi H, Yamaguchi T, Yamada S.Equine herpesvirus type 9 (EHV-9), which we isolated from a case of epizootic encephalitis in a herd of Thomson's gazelles (Gazella thomsoni) in 1993, has been known to cause fatal encephalitis in Thomson's gazelle, giraffe, and polar bear in natural infections. Our previous report indicated that EHV-9 was similar to the equine pathogen equine herpesvirus type 1 (EHV-1), which mainly causes abortion, respiratory infection, and equine herpesvirus myeloencephalopathy. We determined the genome sequence of EHV-9. The genome has a length of 148,371 bp and all 80 of the open reading frames (ORFs) fo...
Chagnaud BP, Simmers J, Straka H.In guiding adaptive behavior, efference copy signals or corollary discharge are traditionally considered to serve as predictors of self-generated sensory inputs and by interfering with their central processing are able to counter unwanted consequences of an animal's own actions. Here, in a speculative reflection on this issue, we consider a different functional role for such intrinsic predictive signaling, namely in stabilizing gaze during locomotion where resultant changes in head orientation in space require online compensatory eye movements in order to prevent retinal image slip. The direct...
Fazio E, Medica P, Cravana C, Aveni F, Ferlazzo A.In order to evaluate the effects of short transportation on β-endorphin, adrenocorticotropic hormone (ACTH) and cortisol changes, 12 healthy stallions of Equidae (Equus asinus and Equus caballus) were studied before and after transportation of 50 km. Blood samples were collected 1 week before transportation in basal conditions, immediately before loading and after transportation and unloading, on their arrival at the breeding station. Compared to basal and before values, donkeys showed an increase in circulating ACTH (P < 0.001) and cortisol (P < 0.0005) levels after transportation and ...
Nielsen BD, Vick MM, Dennis PM.Iron overload disorder afflicts captive rhinoceros but has not been documented in the wild. The specific cause for the disorder has not been identified but is likely associated with diet and management. Compared with wild counterparts, captive rhinoceros eat diets containing more iron, have greater fat stores, and exercise less. It has been suggested that the problem may be linked to development of insulin resistance in the captive population. Given that controlled experiments with sufficient numbers of rhinoceros are logistically not possible, an equine model was used to look for a relationsh...
Yadav SC, Kumar R, Manuja A, Goyal L, Gupta AK.In present communication, we report an outbreak of Trypanosoma evansi in equine herd n = 30 (horse and mules) which, were reared in fly proof stables as well as in open paddock maintained under semi-intensive system of management, and its effective control using trypanocidal drug. The infection was monitored by antibody ELISA up to 180 days post-treatment (PT). A total of 8 out of 14 equines (57.14 %) which were maintained only in open paddocks were found positive with T. evansi infection parasitologically. The infected animals were treated with quinapyramine methyl sulphate and chloride c...
Divers TJ, Grice AL, Mohammed HO, Glaser AL, Wagner B.Changes in ELISA serology are frequently used to determine antibiotic treatment success for Lyme disease in horses. This concept was based upon a previous report showing a marked decline in ELISA values in experimentally infected and antibiotic-treated ponies. Changes in Lyme serology following antibiotic treatment in naturally infected horses have not been reported. The objective of this study was to compare Borrelia ELISA antibody concentrations in naturally exposed horses both before and following antibiotic treatment for Lyme disease. A retrospective study was performed comparing oxytetrac...
Lichter-Peled A, Polani S, Stanyon R, Rocchi M, Kahila Bar-Gal G.Juvenile idiopathic epilepsy (JIE) in Arabian foals resembles benign-familial neonatal convulsion (BFNC) syndrome, a rare idiopathic epilepsy of new-born humans. BFNC syndrome exhibits genetic heterogeneity, as has been hypothesised to occur in Arabian foals, and is known to be caused by mutations in the voltage-gated potassium channel subunit KCNQ2 and KCNQ3 genes. The close phenotypic characteristics of both Arabian foals and children suggest these epileptic syndromes are caused by the same genetic disorder. In horses, the KCNQ2 and KCNQ3 genes are located on the terminal region of chromosom...
van der Ree M, Wijnberg I.Epilepsy in the horse is diagnosed based on clinical signs, but diagnosing can be difficult if a grand mal is not present. The future prospects of the horse and potentially the safety of the owner depend on an accurate diagnosis. This review presents information on epilepsy and focuses on the diagnostic potential of (Ambulatory) electroencephalography ((A) EEG). An epileptic seizure is a brain disorder, which expresses itself as a recurrent episode of involuntary abnormal behaviour. The aetiology can originate from inside or outside the brain or is idiopathic. Besides those categories, seizure...
Mc Nally TP, Slone DE, Hughes FE, Lynch TM.To describe a tenosynoviotomy technique for treatment of sepsis of the digital flexor tendon sheath (DFTS) in horses and report long-term outcome. Methods: Case series. Methods: Horses (n = 9). Methods: Horses were positioned in lateral recumbency with the affected limb uppermost. A linear incision was made just lateral to the mesotenon beginning 5 cm proximal to the apices of the proximal sesamoid bones, extending 2 cm distal to the bifurcation of the superficial digital flexor tendon (SDFT). The incision was continued through the skin, subcutaneous tissue, palmar/plantar annular ligament, an...
Tydén E, Morrison DA, Engström A, Nielsen MK, Eydal M, Höglund J.The large roundworm of horses, Parascaris equorum is considered ubiquitous in breeding operations, and is regarded as a most important helminth pathogen of foals. Over the past decade, this parasite has been reported increasingly resistant to anthelmintic drugs worldwide. This paper reports analysis of the population genetic structure of P. equorum. Adult parasites (n=194) collected from Sweden, Norway, Iceland, Germany, Brazil and the USA were investigated by amplified restriction fragment length polymorphism (AFLP) analysis. The genetic variation was low (Hj=0.12-0.4), for the global populat...
Henselek Y, Fischer J, Schloegl C.The ability to understand the relation between quantities has been documented in a wide range of species. Such quantity discrimination competences are commonly demonstrated by a choice of the larger quantity or numerosity in a two-choice task. However, despite their overall success, many subjects commit a surprisingly large number of errors even in simple discriminations such as 1 vs. 3. Recently, it had been suggested that this is a result of the testing procedure. When monkeys could choose between different quantities of edible rewards, they showed low-level success. If, however, they chose ...
Issel CJ, Scicluna MT, Cook SJ, Cook RF, Caprioli A, Ricci I, Rosone F, Craigo JK, Montelaro RC, Autorino GL.Serological diagnosis of equine infectious anaemia virus (EIAV) infections has depended mainly on the agar gel immunodiffusion test (AGIDT). This study documents the presence of EIAV genetic sequences in a number of persistently infected horses and mules whose serums were interpreted as negative/equivocal on AGIDT, but positive on more than one ELISA test and in immunoblot tests. Strategies designed to take advantage of the combined strengths of the ELISA and AGIDT are shown effective in a national surveillance program for EIA in Italy where 17 per cent (25/149) of the equids considered to be ...
Beschta RL, Donahue DL, DellaSala DA, Rhodes JJ, Karr JR, O'Brien MH, Fleischner TL, Deacon Williams C.Climate change affects public land ecosystems and services throughout the American West and these effects are projected to intensify. Even if greenhouse gas emissions are reduced, adaptation strategies for public lands are needed to reduce anthropogenic stressors of terrestrial and aquatic ecosystems and to help native species and ecosystems survive in an altered environment. Historical and contemporary livestock production-the most widespread and long-running commercial use of public lands-can alter vegetation, soils, hydrology, and wildlife species composition and abundances in ways that exa...
Votion DM.Atypical myopathy (AM) is a frequently fatal seasonal pasture myopathy that emerges in Europe. Outbreaks are of an acute and unexpected nature and practitioners should be prepared to handle these critically ill patients. This review retraces the history of AM and describes results of epidemiological investigations that were conducted to raise hypotheses concerning the etiology of this devastating disease as well as to be able to suggest potential preventive measures. Also, clinical studies have contributed to a better definition and recognition of the syndrome, whereas elucidation of the patho...
Hinden S, Klukowska-Rötzler J, Janda J, Marti EI, Gerber V, Roosje PJ.Recurrent urticaria (RU) is a common skin disease of horses, but little is known about its pathogenesis. Objective: The aim of this study was to characterize the inflammatory cell infiltrate and cytokine expression pattern in the skin of horses with RU. Methods: Biopsies of lesional and nonlesional skin of horses with RU (n = 8) and of skin from healthy control horses (n = 8) were evaluated. Methods: The inflammatory cell infiltrate was analysed by routine histology. Immunohistochemistry was used to identify T cells (CD3), B ells (CD79), macrophages (MAC387) and mast cells (tryptase). E...
Hurcombe SD, Mudge MC, Daniels JB.To document whether presumptive bacterial translocation (PBT) occurs in horses with small intestinal strangulation (SIS). Methods: Prospective clinical cohort study. Methods: University tertiary care facility. Methods: Thirty-six adult horses with SIS (clinical cases) and 10 adult horses without gastrointestinal disease (control cases). Methods: Sterile collection and bacterial culture of samples from peripheral venous blood, mesenteric venous blood, mesenteric lymphatic tissue, and intestinal aspirates from horses with SIS and control horses without gastrointestinal disease. Results: Five of ...
Verwoerd DW.In the early colonial history of South Africa, horses played an important role, both in general transportation and in military operations. Frequent epidemics of African horsesickness (AHS) in the 18th century therefore severely affected the economy. The first scientific research on the disease was carried out by Alexander Edington (1892), the first government bacteriologist of the Cape Colony, who resolved the existing confusion that reigned and established its identity as a separate disease. Bluetongue (BT) was described for the first time by Duncan Hutcheon in 1880, although it was probably ...
Ramos RT, Silva A, Carneiro AR, Pinto AC, Soares Sde C, Santos AR, Almeida SS, Guimarães LC, Aburjaile FF, Barbosa EG, Dorella FA, Rocha FS....The bacterium Corynebacterium pseudotuberculosis is of major veterinary importance because it affects livestock, particularly sheep, goats, and horses, in several countries, including Australia, Brazil, the United States, and Canada, resulting in significant economic losses. In the present study, we describe the complete genome of the Corynebacterium pseudotuberculosis Cp316 strain, biovar equi, isolated from the abscess of a North American horse.
Thomsen LN, Berg LC, Markussen B, Thomsen PD.Cervical synovial folds have been suggested as a potential cause of neck pain in humans. Little is known about the extent and characteristics of cervical synovial folds in horses. Objective: The objective of this explorative study was to determine the frequency of synovial folds in equine cervical articular process joints and to provide a characterisation of the size and morphology of the synovial folds. Methods: Equine cervical articular process joints from 6 horses were included in the study, ranging from cervical vertebra 2 (C2) to cervical vertebra 7 (C7) bilaterally. The articular process...
Andersen UV, Howe DK, Olsen SN, Nielsen MK.Parasites infecting horses are ubiquitous and clinically important across the world. The major parasitic threats to equine health are cyathostomins, Parascaris equorum, Anoplocephala perfoliata, and Strongylus vulgaris. Increasing levels of anthelmintic resistance reported world wide in equine parasites have led to recommendations of constructing sustainable parasite control programmes based on systematic surveillance of parasite levels. Regulations at the European Union level now make anthelmintics available on prescription-only basis and disallow prophylactic treatment. This emphasizes the n...
Wauters J, Pille F, Martens A, Franck T, Serteyn D, Gasthuys F, Meyer E.Equine joint infection is a life-threatening disorder, and confirmation of the diagnosis can be difficult. Synovial fluid biomarkers may assist the discrimination between infectious and noninfectious joint disease. Objective: This study investigates whether the immunological detection of total and enzymatically active myeloperoxidase (MPO) assists the diagnosis of joint infection in horses. Methods: The following 4 sample groups were included: healthy; osteochondritis dissecans (OCD); traumatic synovitis; and culture-confirmed infected joints. Synovial fluid was analysed for total MPO by a hor...
Biggi M, Dyson S.The distribution of lesions detected using magnetic resonance imaging (MRI) of hind feet has not been reported. Objective: To evaluate type and distribution of lesions detected using MRI in hind feet of lame horses and to compare the findings with those reported in front feet; to document follow-up information. Methods: Horses were selected if hindlimb lameness was abolished by plantar nerve blocks performed at the base of the proximal sesamoid bones. Magnetic resonance images were acquired using either a low-field or a high-field magnet, and all images were evaluated retrospectively by both a...
Knych HK, Corado CR, McKemie DS, Steffey EP.Both the potential analgesic effect and the conflicting reports describing tramadol disposition in the horse warrant further study of the pharmacokinetics of tramadol in this species. Objective: To describe the pharmacokinetics of tramadol and its metabolites, O-desmethyltramadol and N-desmethyltramadol, following i.v. administration of 3 doses to the horse. Methods: Nine adult horses received a single i.v. dose of 0.5, 1.5 and 3 mg/kg bwt tramadol. Blood samples were collected prior to and at various times up to 72 h post administration. Plasma samples were analysed using liquid chromatograph...
Stewart DR, Nevins B, Hadas E, Vandlen R.Relaxin, a polypeptide hormone normally associated with pregnancy, has been purified from many species, and the sequence determined for a growing number. Equine relaxin has been previously purified by acetone extraction, gel filtration, and ion exchange chromatographies. In an attempt to develop a more rapid and efficient method for relaxin purification, the use of affinity chromatography coupled with HPLC was explored. Monoclonal antibodies were raised against highly purified equine relaxin; large quantities of antibody were obtained by ascites production and attached to a solid phase support...
Milner PI, Sidwell S, Talbot AM, Clegg PD.Primary lesions of the deep digital flexor tendon (DDFT) within the digit are an important cause of lameness diagnosed using magnetic resonance imaging (MRI) but appearance of these lesions over time has not been documented. Objective: To determine whether the magnetic resonance (MR) appearance of different primary DDFT lesions alter over a 6 month period and whether lesion type is a determinant of these changes. Methods: Cases included had lameness attributable to a primary lesion involving the DDFT in the digit diagnosed on MRI. Lesions were typed into parasagittal, dorsal border and core le...
Li FI, Spence RJ, de Laat MA, Harris PA, Sonntag J, Menzies-Gow NJ, Durham AE, Bailey SR, Sillence MN.High concentrations of adrenocorticotropic hormone (ACTH) are used as an indicator of pituitary pars intermedia dysfunction (PPID), but other factors that may influence ACTH need to be understood, if diagnostic reference ranges for ACTH are to be used with confidence. Insulin dysregulation (ID) could be one such factor, as insulin affects pituitary hormones in other species. Objective: To test the hypothesis that a relationship exists between high insulin and high ACTH in aged (>15-year-old) animals with no clinical signs of PPID. Methods: A cohort study. Methods: Thirteen horses and eleven p...
Fiala SM, Pimentel CA, Mattos AL, Gregory RM, Mattos RC.Our objective was to determine whether the concentration of cooled sperm inseminated influenced sperm transport and intensity of the uterine inflammatory reaction 2, 4 and 24h after insemination. Experimental subjects were 189 estrous mares with a dominant follicle > or =35 mm in diameter and no bacterial growth or neutrophils detected in uterine smears. Each mare was randomly assigned to receive one of the following intrauterine treatments (volume, 20 mL): insemination with 5x10(6) mL(-1) or 25x10(6) mL(-1) or 50x10(6) mL(-1) sperm diluted in 3 mL seminal plasma (SP) and 17 mL skim milk; s...
Scholes SF, Holliman A, May PD, Holmes MA.Fell pony foals developed a syndrome of anaemia, immunodeficiency and peripheral ganglionopathy. They became ill in the second or third week, and died in the second or third month of life. Clinical and pathological investigations revealed severe anaemia associated with small numbers of late erythroid precursors in bone marrow, small thymi, an absence of secondary lymphoid follicles, a lack of plasma cells and neuronal chromatolysis involving trigeminal, cranial mesenteric and dorsal root ganglia. Some of the foals had cryptosporidial enteritis and adenoviral bronchopneumonia and pancreatitis. ...
Klein C, Scoggin KE, Troedsson MH.Establishment of pregnancy is critically dependent upon a precisely orchestrated embryo-maternal interaction leading to a receptive uterine environment. The up-regulation of the interferon-stimulated protein 15 kDa (ISG15) during pregnancy has been described in various species and has been hypothesized to be part of the molecular repertoire that makes the uterus receptive to conceptus development. In the current study, the expression of ISG15 and enzymes involved in ISG15ylation was examined at the mRNA and protein level in equine endometrium at Day 14 of the luteal phase and at Day 14 and 50 ...
Lampe V, Dierks C, Komm K, Distl O.In this study we present a newly detected QTL associated with osteochondrosis in Hanoverian warmblood horses on equine chromosome 18 (ECA18). We developed a highly polymorphic and evenly distributed marker set on ECA18 employing the horse genome assembly EquCab2. The marker set included 11 newly developed microsatellites. Average polymorphism information content was 62.1% at an average spacing of 3 Mb. For genotyping of this marker set comprising a total of 27 highly polymorphic microsatellites, we used the same 14 paternal half-sib families as in the previous whole genome scan. The chromosome...
O'Connor S, Hitchens PL, Fortington LV.The most recent report on hospital-treated horse-riding injuries in Victoria was published 20 years ago. Since then, injury countermeasures and new technology have aimed to make horse riding safer for participants. This study provides an update of horse-riding injuries that required hospital treatment in Victoria and examines changes in injury patterns compared with the earlier study. Methods: Horse-riding injuries that required hospital treatment (hospital admission (HA) or emergency department (ED) presentations) were extracted from routinely collected data from public and private hospitals ...
Liu S, Jiang S, Dong XG, Cui R, Ling Y, Zhao C.The Debao pony is a well-known dwarf horse breed in China. High-mobility group AT-hook 2 (HMGA2) gene is regarded as one of the important candidate genes regulating body height in horses. The aim of this study was to study the association between mutations in HMGA2 gene and withers height in Debao ponies. The polymorphisms in all exons and partial introns of the HMGA2 gene were screened with sequencing across 180 Debao ponies. And the association between the DNA variants and withers height was analyzed. Seven genetic variants were identified in HMGA2 gene, including six novel variants. Among t...
Cummings E, James ER.Of 664 horses reported to have originated in southeastern and midwestern United States, 341 (51.4%) were positive for Onchocerca cervicalis cutaneous microfilariasis. The highest prevalence of 68.8% was recorded for horses from Virginia. Horses with the highest concentrations of microfilariae (as high as 19,770 microfilariae/mg in 1 horse) were from the Southeast (Georgia, Florida, Tennessee, and Alabama). For horses from South Carolina, the prevalence of infection was 57.1%; from the Midwest (Kentucky, Illinois, Ohio, and Indiana), 54.4%; from North Carolina, 45.5%; from Pennsylvania, 7.7%; a...
McKeever KH, Hinchcliff KW, Kociba GJ, Reed SM, Muir WW.Changes in clotting time (CT) and fibrinolytic activity (FA) were evaluated in 6 mature, female horses during exercise. Two trials were performed on consecutive days, using a randomized crossover design. Each mare was assigned to either an exercise trial or a control trial on the first day, and to the alternate trial 24 hours later. Mares exercised for 20 minutes on a treadmill at an elevation of 2 degrees and a velocity of 5 m/s. Venous blood samples were collected immediately before exercise, at 4, 8, 12, 16 and 20 minutes during exercise, and 15 minutes after cessation of exercise. Blood wa...
Comer JA, Irby WS, Kavanaugh DM.Hosts of Lutzomyia shannoni Dyar, a suspected biological vector of the New Jersey serotype of vesicular stomatitis (VSNJ) virus, were determined using an indirect enzyme-linked immunosorbent assay (ELISA) of 333 blood-fed female sandflies collected from their diurnal resting shelters on Ossabaw Island, Georgia, U.S.A. Sandflies had fed primarily on white-tailed deer (Odocoileus virginianus) (81%) and to a lesser extent on feral swine (Sus scrofa) (16%), two species of host infected annually with VSNJ. Other hosts were raccoons (Procyon lotor) and horses (Equus caballus) or donkeys (E. asinus),...
Tenter AM, Otte MJ, Gonzalez CA, Abuabara Y.Eighty-two equine sera from 13 farms in northern Colombia were examined for antibodies to Babesia caballi and B. equi using the complement fixation (CF) and the indirect fluorescent antibody (IFA) test. Seroreactors to both piroplasms were present on all farms. The IFA test indicated a prevalence of 90% for B. caballi and 94% for B. equi. The CF test detected antibodies to B. caballi in 41% and to B. equi in 65% of the animals. The prevalence of seroreactors in different age groups revealed a significant decline in CF antibodies to B. caballi in animals older than three years. IFA titres for b...
Sutherland IH.Following the development of a unique claim structure encompassing both nematode and arthropod species, ivermectin was first introduced as a veterinary parasiticide in 1981. For cattle(c), sheep(s), horses(h) and pigs(p) injectable(c,s,p), oral(c,s,h) and topical(c) products are available delivering ivermectin at 200 to 500 micrograms/kg. Efficacy extends to nematodes of the gastrointestinal and respiratory tracts, conjunctival sac and soft tissues. Among the arthropod parasites claims have been established for the biting fly Haematobia irritans(c), the screw-worm Chrysomyia bezziana(c), larva...
Portier K, Crouzier D, Guichardant M, Prost M, Debouzy JC, Kirschvink N, Fellmann N, Lekeux P, Coudert J.To evaluate whether a period of hyperoxia or after a period of hypoxia produced changes attributable to reactive oxygen species in anaesthetized horses. Methods: Prospective randomized experimental study. Methods: Six healthy (ASA I) geldings, aged 4.5-9.5 years and weighing 510-640 kg(-1). Methods: After 30 minutes breathing air as carrier gas for isoflurane, horses were assigned randomly to breathe air as carrier gas (CG0.21) or oxygen as carrier gas (CG1.00) for a further 90 minutes. After an interval of 1 month each horse was re-anaesthetized with the other carrier gas for the 90 minute te...
Lillich JD, Bertone AL, Schmall LM, Ruggles AJ, Sams RA.OBJECTIVE--To document plasma, urine, and synovial fluid disposition of 2 common intra-articularly administered steroid preparations, methylprednisolone acetate (MPA) and isoflupredone acetate (IPA). DESIGN--Descriptive investigation. SAMPLE POPULATION--100 mg of MPA or 4 mg of IPA was administered to 2 groups of 4 healthy sound radiographically normal female horses. PROCEDURE--Blood samples were collected at time 0 (before) and 2, 4, 6, 8, 10, 12, 24, 36, 48, 72, and 96 hours after administration of the designated steroid. Complete urine collection for measurement of designated steroid was ac...
McClure SR, Koenig R, Hawkins PA.To evaluate the effectiveness of a novel trimethoprim-sulfadiazine oral suspension for the treatment of naturally acquired Streptococcus equi subsp zooepidemicus infection in horses. Methods: Randomized, controlled field trial. Methods: 180 horses with S equi subsp zooepidemicus infection. Methods: Horses with lower respiratory tract infections caused by S equi subsp zooepidemicus were treated with a new formulation of combined trimethoprim-sulfadiazine oral suspension at a dosage of 24 mg/kg (10.9 mg/lb) twice daily for 10 days (treatment group) or with an equivalent volume of saline (0.9% Na...
Oliver-Espinosa O.Chronic diarrhea in the horse is defined as diarrhea present for more than several days with little if any improvement. The diagnosis and treatment of horses with chronic diarrhea usually present a great challenge to the clinician. There are many limitations to treatment of these patients given the limited numbers in which a final diagnosis can be achieved. The lack of knowledge of the alterations of horse microbiota during chronic diarrhea and the multiplicity of causes also make treatment challenging. A poor prognosis is often attached to chronic diarrhea, particularly in cases with neoplasi...
Moens Y, Lanz F, Doherr MG, Schatzmann U.To study the analgesic potency of the alpha2-agonist romifidine in the horse using both an electrical current and a mechanical pressure model for nociceptive threshold testing. In addition, a comparison was made with doses of detomidine and xylazine that produce equivalent degrees of sedation. Methods: Randomized, placebo-controlled, blinded cross-over study. Methods: Six adult Swiss warmblood horses, one mare and five geldings, weighing from 530 to 650 kg and aged 6-15 years. Methods: Nociceptive thresholds were measured using an electrical stimulus applied to the coronary band and using a pn...
Davies Morel MC, O'Sullivan JA.Ovarian activity was monitored in 2181 oestrous cycles from 1136 thoroughbred brood mares to accurately determine overall ovulation rate, the relative distribution of ovulations between left and right ovary, whether mare age had an effect on these parameters and whether ovulation pattern in one cycle affected the pattern within the next. Ultrasonic scanning was used in preference to rectal palpation and slaughterhouse material due to its greater accuracy. Mare's ages ranged from 3 to 22 years. The results obtained indicated a similar incidence of ovulation occurring on the right (49.5% of all ...
Yamashita K, Muir WW, Tsubakishita S, Abrahamsen E, Lerch P, Izumisawa Y, Kotani T.To evaluate effects of infusion of guaifenesin, ketamine, and medetomidine in combination with inhalation of sevoflurane versus inhalation of sevoflurane alone for anesthesia of horses. Methods: Randomized clinical trial. Methods: 40 horses. Methods: Horses were premedicated with xylazine and anesthetized with diazepam and ketamine. Anesthesia was maintained by infusion of guaifenesin, ketamine, and medetomidine and inhalation of sevoflurane (20 horses) or by inhalation of sevoflurane (20 horses). A surgical plane of anesthesia was maintained by controlling the inhaled concentration of sevoflu...
Bannai H, Nemoto M, Tsujimura K, Yamanaka T, Maeda K, Kondo T.To increase the sensitivity of an enzyme-linked immunosorbent assay (ELISA) for equine herpesvirus type 4 (EHV-4) that uses a 12-mer peptide of glycoprotein G (gG4-12-mer: MKNNPIYSEGSL) [4], we used a longer peptide consisting of a 24-mer repeat sequence (gG4-24-mer: MKNNPIYSEGSLMLNVQHDDSIHT) as an antigen. Sera of horses experimentally infected with EHV-4 reacted much more strongly to the gG4-24-mer peptide than to the gG4-12-mer peptide. We used peptide ELISAs to test paired sera from horses naturally infected with EHV-4 (n=40). gG4-24-mer ELISA detected 37 positive samples (92.5%), whereas ...
Holve DL.To determine the effect of sedation with detomidine on intraocular pressure (IOP) in standing horses and whether topical ocular application of anesthetic alters this effect. Methods: Clinical trial. Methods: 15 clinically normal horses. Methods: Horses were assigned to group 1 (n = 7) or 2 (8). Intraocular pressure measurements were obtained at baseline (before sedation) and 10 minutes after IV administration of detomidine (0.02 mg/kg [0.009 mg/lb]). Group 1 horses had an additional IOP measurement at 20 minutes after sedation. For group 2 horses, topical ocular anesthetic was administered 10 ...
Soraci A, Benoit E, Jaussaud P, Lees P, Delatour P.Carprofen (CPF) enantiomers and their glucuronide conjugates (GLUC) were measured in plasma and bile of horses after IV administration of the racemic compound (0.7 mg/kg of body weight). The CPF was detectable in plasma for up to 72 hours after dosing, whereas GLUC appeared early (time for maximal plasma concentration, 1 hour) and was measurable transiently at low concentration (maximal plasma concentration, 0.5 microgram/ml). The enantiospecific plasma profiles indicated a clear predominance of R-CPF, whereas the stereoselectivity of the glucuronides favored S-GLUC. At 1, 2, and 12 hours afte...
Goetz TE, Manohar M, Hassan AS, Baker GJ.The present study was carried out to examine whether nasal strip application would improve the exercise-induced arterial hypoxemia and hypercapnia, diminish anaerobic metabolism, and modify the incidence of exercise-induced pulmonary hemorrhage (EIPH) in horses. Two sets of experiments, control and nasal strip experiments, were carried out on seven healthy, sound, exercise-trained Thoroughbred horses in random order, 7 days apart. Simultaneous measurements of core temperature, arterial and mixed venous blood gases/pH, and blood lactate and ammonia concentrations were made at rest, during subma...
DiMaio Knych HK, Arthur RM, Taylor A, Moeller BC, Stanley SD.Dantrolene is a skeletal muscle relaxant used commonly in performance horses to prevent exertional rhabdomyolysis. The goal of the study reported here was to begin to characterize cytochrome P450-mediated metabolism of dantrolene in the horse and describe the pharmacokinetics of the compound, formulated as a capsule or a compounded paste formulation, following oral administration. Dantrolene is rapidly metabolized to 5-hydroxydantrolene both in vivo and in vitro. Preliminary work with equine liver microsomes suggest that two enzymes are responsible for the metabolism of dantrolene, as evidence...
Mondo E, Rinnovati R, Spadari A, Giacometti F, Serraino A, Savini F, Piva S.Respiratory diseases are the second most common cause of illnesses in horses, their etiology can be viral, bacterial, immune-mediated, or mechanical (Racklyeft and Love DN, Aust Vet J 78:549-59, 2000; Austin et al., J Am Vet Med Assoc 207:325-328, 1995; Arroyo et al., J Vet Intern Med 31:894-900, 2017). Klebsiella variicola is a Gram-negative bacterium that was initially identified as an endophyte in soil and plants such as bananas, rice, sugar cane and maize but recent studies have identified this microorganism as an emerging pathogen in humans (Rodríguez-Medina et al., Emerg Microbes Infec...
