"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.
Krista KM, White NA, Barrett JG, Furr MO, Buechner-Maxwell VA.To quantify peripheral blood neutrophil apoptosis in equine patients with acute abdominal disease (ie, colic) caused by strangulating or nonstrangulating intestinal lesions and compare these values with values for horses undergoing elective arthroscopic surgery. Methods: 20 client-owned adult horses. Methods: Peripheral blood was collected from horses immediately prior to and 24 hours after surgery for treatment of colic (n = 10) or elective arthroscopic surgery (10), and neutrophils were counted. Following isolation by means of a bilayer colloidal silica particle gradient and culture for 24 h...
North SE, Wakeley PR, Mayo N, Mayers J, Sawyer J.Infection with Streptococcus equi subspecies equi (S. equi) is endemic in the UK. A proportion of horses serve as long-term carriers and act as a reservoir of infection. Detection of these persistently infected horses is difficult using standard culture techniques owing to a lack of sensitivity and overgrowth by contaminating bacteria. In addition, differentiation of this causative bacterium from the closely related S. equi zooepidemicus has made the development of reliable and accurate diagnostic tests difficult. Objective: To develop and validate a sensitive and specific real-time PCR assay ...
Wylie CE, Shaw DJ, Fordyce FM, Lilly A, McGorum BC.Equine grass sickness (EGS) remains a frequently fatal disease of equids in Britain. Since previous investigations of signalment- and meteorology-related risk factors for EGS have yielded some conflicting data, further investigation is warranted. Objective: To identify signalment- and meteorology-related risk factors for EGS in Scotland. Methods: Retrospective time-matched case-control study. Methods: This study was undertaken using data for 455 EGS cases and 910 time-matched controls that were referred to the Royal (Dick) School of Veterinary Studies, and average UK Meteorological Office weat...
Miller C, Utter ML, Beech J.To determine effects of age and pituitary pars intermedia dysfunction (PPID) on corneal sensitivity in horses. Methods: 20 adult horses allocated into 3 groups (PPID group, old [> 15 years old] horses with PPID [n = 5]; old group, old [> 15 years old] horses without PPID [9]; and young group, young [≤ 10 years old] horses without PPID [6]). All horses with PPID had hirsutism and abnormal fat deposition or laminitis; none of the old or young horses had hirsutism, abnormal fat deposition, or laminitis. Methods: A Cochet-Bonnet aesthesiometer was used to measure the corneal touch threshold (CTT...
te Moller NC, Brommer H, Liukkonen J, Virén T, Timonen M, Puhakka PH, Jurvelin JS, van Weeren PR, Töyräs J.Arthroscopy enables direct inspection of the articular surface, but provides no information on deeper cartilage layers. Optical coherence tomography (OCT), based on measurement of reflection and backscattering of light, is a diagnostic technique used in cardiovascular surgery and ophthalmology. It provides cross-sectional images at resolutions comparable to that of low-power microscopy. The aim of this study was to determine if OCT is feasible for advanced clinical assessment of lesions in equine articular cartilage during diagnostic arthroscopy. Diagnostic arthroscopy of 36 metacarpophalangea...
Mullen KR, Schwark W, Divers TJ.To assess pharmacokinetics of pregabalin in horses after a single intragastric or IV dose. Methods: 5 healthy adult mares. Methods: Horses received 1 dose of pregabalin (approx 4 mg/kg) via nasogastric tube in a crossover-design study; after a 3-week washout period, the same dose was administered IV. Food was not withheld. Plasma pregabalin concentrations in samples obtained 0 to 36 hours after administration were measured by use of ultra-performance liquid chromatography with triple quadrupole tandem mass spectrometry. Pharmacokinetic variables were estimated by means of noncompartmental anal...
Inoue Y.Diagnostic techniques for oviductal obstruction in the mare are limited and development of a more reliable and direct method to assess oviductal patency is needed. Objective: To evaluate the feasibility of hysteroscopic selective hydrotubation of the equine oviduct via videoendoscopy in standing mares. Methods: Using a catheter inserted under endoscopic guidance into the uterotubal junctions of 10 mares, 5 ml of indigo carmine solution (4 mg/ml) was flushed into the oviduct. After introduction of the dye, peritoneal fluid was obtained via abdominocentesis. A colpotomy was also performed to all...
Dixon PM, Ceen S, Barnett T, O'Leary JM, Parkin TD, Barakzai S.Cheek teeth diastemata are a common cause of painful periodontal disease in horses, but there is limited objective information on their treatment. Objective: To assess the long-term response to diastema widening in clinically affected horses. Methods: Retrospective study. Methods: Medical records from cases of cheek teeth diastemata treated by diastema widening referred to the University of Edinburgh Equine Hospital from 2008 to 2011 were analysed. Results: During this period, 302 horses were diagnosed with clinically significant cheek teeth diastemata, of which 202, median age 11 years, with ...
Crijns CP, Martens A, Bergman HJ, van der Veen H, Duchateau L, van Bree HJ, Gielen IM.Computed tomography (CT) is increasingly accessible in equine referral hospitals. Objective: To document the level of agreement within and between radiography and CT in characterising equine distal limb fractures. Methods: Retrospective descriptive study. Methods: Images from horses that underwent radiographic and CT evaluation for suspected distal limb fractures were reviewed, including 27 horses and 3 negative controls. Using Cohen's kappa and weighted kappa analysis, the level of agreement among 4 observers for a predefined set of diagnostic characteristics for radiography and CT separately...
Menzies R.The oral examination is performed in equids to assess and monitor oral health status, provide diagnoses, and determine efficacy of treatments. While there is currently insufficient scientific material of adequate quality to enable evidence-based medicine in equine dentistry, this by no means negates the clinician's responsibility to provide oral health care in a scientific and ethical manner. To do so requires that the clinician be knowledgable and skilled in dentistry and general medicine, that each case upholds the principles of scientific method, and that data is gathered and appraised in a...
Galloway SS, Easley J.This article discusses the significant features and use of digital cameras, intraoral cameras, and oral endoscopes in equine dental practice. Although system features believed to be important have been listed, specific system recommendations have been omitted, since each veterinarian must individually determine the best system to meet practice clinical needs and budget. Veterinarians are encouraged to thoroughly research not only the camera/endoscope purchase but also the capabilities of the entire system, the compatibility of the system with different computer software programs, the reputatio...
Fielding CL, Meier CA, Magdesian KG, Pusterla N.Fecal shedding of Salmonella spp. was recently documented in 8% of endurance horses presented to equine referral centers for colic. Previous studies have documented fecal shedding of Salmonella spp. in as few as 0.8% of the general horse population, although horses with colic appear to be at higher risk. Fecal Salmonella spp. shedding before and after endurance horse competitions has not been evaluated. Fecal samples were collected from 204 horses during three separate 100 mile endurance competitions. Following incubation in selenite broth, 289 fecal samples were tested by real-time PCR analys...
Hellander-Edman A, Makdoumi K, Mortensen J, Ekesten B.Corneal ulcers are one of the most common eye problems in the horse and can cause varying degrees of visual impairment. Secondary infection and protease activity causing melting of the corneal stroma are always concerns in patients with corneal ulcers. Corneal collagen cross-linking (CXL), induced by illumination of the corneal stroma with ultraviolet light (UVA) after instillation of riboflavin (vitamin B2) eye drops, introduces crosslinks which stabilize melting corneas, and has been used to successfully treat infectious ulcerative keratitis in human patients. Therefore we decided to study i...
Na W, Kang B, Kim HI, Hong M, Park SJ, Jeoung HY, An DJ, Moon H, Kim JK, Song D.Equine influenza virus (EIV) causes a highly contagious respiratory disease in equids, with confirmed outbreaks in Europe, America, North Africa, and Asia. Although China, Mongolia, and Japan have reported equine influenza outbreaks, Korea has not. Since 2011, we have conducted a routine surveillance programme to detect EIV at domestic stud farms, and isolated H3N8 EIV from horses showing respiratory disease symptoms. Here, we characterized the genetic and biological properties of this novel Korean H3N8 EIV isolate. This H3N8 EIV isolate belongs to the Florida sublineage clade 1 of the America...
Beccati F, Gialletti R, Giontella A, Davanzo S, Di Meo A, Pepe M.The aim of this study was to identify differences in bone shape (height and width) of proximal sesamoid bones (PSB) in 2-year-old Thoroughbred racehorses in training. Dorsal 15° proximal-palmarodistal oblique images of each metacarpophalangeal joint were acquired before the horses started training and at 1 year after the start of exercise and racing. There were no changes in height and width of PSBs induced by training. There was a significant difference of height and width between medial and lateral PSBs. In both forelimbs, the medial PSB was significantly wider and shorter than the lateral...
Abutarbush SM.The objective of this observational study is to describe clinical, haematological and serum biochemical findings of horses affected with alfalfa dodder (Cuscuta campestris) toxicity. Twenty horses naturally exposed to alfalfa dodder toxicity were examined and information was collected on history and clinical signs. Physical examination was done on horses in the premises (n=20), and venous blood samples of 12 horses were submitted for haematology and serum biochemical examination for each horse. Abnormal clinical signs started around 36 hours after horses were fed the contaminated alfalfa. Abno...
Navas de Solis C, Slack J, Boston RC, Reef VB.To describe the prognosis and clinical, echocardiographic, and pathological features of hypertensive cardiomyopathy in horses. Methods: Retrospective case series. Methods: 5 horses with cardiac hypertrophy and systemic hypertension. Methods: Demographics, history, physical and cardiological examination findings, diagnosis, clinical progression, prognosis, and pathological findings were obtained from medical records. Results: The primary diagnosis was chronic laminitis in 3 horses and chronic renal failure in 2. Persistent tachycardia, hypertension, chronic laminitis, or a combination of these ...
Aurich C, Weber J, Nagel C, Merkl M, Jude R, Wostmann S, Ollech D, Baron U, Olek S, Jansen T.Early pregnancy loss is a major reason for low reproductive efficiency in the horse. In humans and mice, low numbers of regulatory T cells (Treg cells) are linked to miscarriage. The percentage of Treg cells in oestrous mares at the start of the breeding season was evaluated in relation to the outcome of subsequent pregnancy. For identification and quantification of Treg cells, a highly sensitive and specific qPCR assay targeting the Treg-specific demethylated region in the equine forkhead box transcription factor (FOXP3) gene was established. In a total of 108 mares, pregnancy was followed un...
Schuster RK, Sivakumar S.Equine habronematidosis has a global distribution and is caused by three spirurid species, Habronema muscae, Habronema microstoma and Draschia megastoma. A case of cutaneous habronematidosis in a stallion in a stable in Dubai, UAE gave occasion to investigate the parasite situation on the farm. Patent H. muscae infections were diagnosed in 18 out of 49 horses in a stable in Dubai, UAE with a xenodiagnostic test using houseflies as indicator host. All horses in the stable were treated with a single dose of moxidectin administered orally as 2% gel in a dosage of 0.4 mg/kg body weight and the eff...
Devine EP, KuKanich B, Beard WL.To determine the pharmacokinetics of morphine after IM administration in a clinical population of horses. Methods: Prospective clinical study. Methods: 77 horses. Methods: Morphine sulfate (0.1 mg/kg [0.045 mg/lb], IM) was administered to horses, and blood samples were obtained at predetermined time points. Plasma morphine concentrations were measured via liquid chromatography and mass spectrometry. In preliminary investigations, samples were obtained from 2 healthy horses at 12 time points (up to 12 hours after drug administration) and analyzed via 2-stage pharmacokinetic analysis. In the cli...
Belgrave RL, Dickey MM, Arheart KL, Cray C.To compare serum amyloid A (SAA) concentration, plasma fibrinogen concentration, total WBC count, and serum albumin-to-globulin concentration ratio (A:G ratio) in clinically normal (CN) and clinically abnormal (CA) horses. Methods: Prospective cohort study. Methods: 111 CN horses and 101 CA horses hospitalized at a specialty clinical practice. Methods: Shortly after admission, a blood sample (20 mL) was collected from each horse for a CBC, serum protein electrophoresis, and determination of plasma fibrinogen concentration; SAA concentration was assessed with a previously validated immunoturbid...
Steel CM, Pannirselvam RR, Anderson GA.The aims of this study were to determine the risk of septic arthritis after intra-articular medication (IAM) and to identify potential risk factors for this complication. Methods: A retrospective and prospective descriptive study of prevalence, and matched case-control study for risk factors. Results: Of 16,624 joints injected in 1103 horses at 6695 horse-visits, septic arthritis occurred as a complication in 13 joints (13 horses). The risk of septic arthritis following IAM was 7.8 cases per 10,000 injections or 1 case per 1279 injections. Veterinarian and type of corticosteroid were identifie...
Spelta CW, Axon JE, Begg A, Diallo IS, Carrick JB, Russell CM, Collins NM.Equine multinodular pulmonary fibrosis (EMPF) is a recently described form of interstitial pneumonia associated with the presence of equine herpesvirus type 5 (EHV-5). Since 2007, several case reports from America, Europe and the United Kingdom have further characterised the clinical presentation and laboratory findings of this disease. Methods: Three Thoroughbred broodmares were diagnosed with EMPF. Diagnosis was based on lung histopathology and positive identification of EHV-5 using PCR DNA amplification. There was multiple organ involvement in all three cases, including identification of EH...
Pereira GR, Lorenzo PL, Carneiro GF, Ball BA, Pegoraro LM, Pimentel CA, Liu IK.In horses, successful in vitro fertilization procedures are limited by our inability to consistently mature equine oocytes by in vitro methods. Growth hormone (GH) is an important regulator of female reproduction in mammals, playing an important role in ovarian function, follicular growth and steroidogenesis. The objectives of this research were to investigate: the effects of equine growth hormone (eGH) and insulin-like growth factor-I (IGF-I) on the in vitro maturation (IVM) of equine oocytes, and the effects of eGH in addition to estradiol (E2), gonadotropins (FSH and LH) and fetal calf seru...
Dezutti JE.Patients with eating disorders may have the most complex interdisciplinary treatment plans of any mental illness. Nurses need innovative evidence-based treatment interventions to assist their patients with eating disorders on their road to recovery. Although much has been written about equine-assisted psychotherapy (EAP) and equine-facilitated psychotherapy, the literature has not described a detailed session that can help nurses understand how this experiential treatment works and the impact it can have on the patient. A review of the literature on eating disorders and on the use of equine th...
Clarke L, Simon A, Ehrhart EJ, Mulick J, Charles B, Powers B, Duncan C.Mast cell tumors are uncommon in horses and typically have a benign clinical course, but there are occasional reports of more aggressive behavior. The objective of this study was to review histologic features and KIT expression patterns of 72 previously diagnosed equine cutaneous mast cell tumors to determine if either is associated with clinical outcomes. Biopsy specimens were reviewed using histologic criteria derived from grading schemes, and KIT antibody expression patterns used in canine tumors and surveys were sent to referring veterinarians for follow-up clinical data. Arabians were ove...
Troedsson MH, Liu IK, Crabo BG.After the deposition of semen in the mare's uterus, spermatozoa must be transported to the site of fertilization, be maintained in the female tract until ovulation occurs, and be prepared to fertilize the released ovum. Sperm motility, myometrial contractions, and a spontaneous post-mating uterine inflammation are important factors for the transport and survival of spermatozoa in the mare's reproductive tract. Fertilizable sperm are present in the oviduct within 4 h after insemination. At this time, the uterus is the site of a hostile inflammatory environment. Our data suggest that spermatozoa...
HOLLISTER AC, LONGSHORE WA, DEAN BH, STEVENS IM.For the most part, epidemiologic phenomena observed in the outbreak of encephalitis in 1952 accorded with patterns that had been apparent in previous years. Ninety-seven per cent of the 414 laboratory-confirmed cases of western equine and St. Louis encephalitis in humans occurred in the 20 Central Valley counties. The cases of western equine encephalomyelitis in horses were generally scattered over the state. In the Central Valley most of the cases in horses were in animals less than two years of age; elsewhere the incidence was higher in older horses.There were no laboratory-confirmed cases o...
Torfs SC, Maes AA, Delesalle CJ, Deprez P, Croubels SM.Serotonin is regularly measured in equine platelet-poor plasma in research settings. However, reported reference values vary between studies, partially because plasma serotonin concentrations are very low and a reliable and affordable detection method is lacking. A simple, rapid, and sensitive method for serotonin determination in equine platelet-poor plasma using liquid chromatography--tandem mass spectrometry (LC-MS/MS) was developed and validated. Results of a commercially available enzyme-linked immunosorbent assay (ELISA) were compared to the LC-MS/MS results, in order to validate a test ...
Hess IM, Massey PD, Walker B, Middleton DJ, Wright TM.Hendra virus infection is an emerging infectious disease that is not well understood. Most cases of Hendra virus infection have occurred in Queensland, with one case in a horse in NSW. Hendra virus infection has a high mortality rate in horses and humans and as cases could occur anywhere in Australia it is important to be ready for prompt action should an outbreak occur in NSW. This paper: reviews the current knowledge on Hendra virus infection including methods for preventing the disease; explains the animal health and human health response for an outbreak within NSW; and discusses possible f...
Rodrigues NL, Doré M, Doucet MY.To characterize the expression of the cyclooxygenase (COX)-1 and COX-2 isoforms in naturally occurring ulcers of the nonglandular portion of the stomach in horses. SPECIMEN POPULATION: 38 specimens from ulcerated stomachs and 10 specimens from healthy stomachs. Methods: Specimens were collected at an abbatoir; for each specimen of squamous gastric mucosa, 1 portion was fixed in neutral-buffered 10% formalin for immunohistochemical analysis and another was frozen at -70 degrees C for immunoblotting analysis. Immunoreactivity to 2 antibodies, MF241 (selective for COX-1) and MF243 (selective for ...
Lansade L, Neveux C, Levy F.Learning performance is influenced by emotional reactivity, low reactivity being generally beneficial. Previous experiments show that emotional reactivity can be modified after a period of social isolation. We hypothesized that eleven days of isolation would affect yearlings' emotional reactivity and improve their learning abilities. Twenty-five yearlings were divided into two groups: 12 were continuously isolated for 11 days (isolated) and 13 stayed together (control). During the period of isolation, all yearlings underwent two learning tasks: a habituation procedure in which a novel object w...
Gorgas D, Kircher P, Doherr MG, Ueltschi G, Lang J.Radiography is part of evaluating horses with poor performance and pelvic limb lameness; however, the radiographic appearance of the sacroiliac region is poorly described. The goal of the present study was to describe the use of a simple technique to obtain radiographs of the sacroiliac region in the anesthetized horse and to describe the radiographic appearance of this region. Seventy-nine horses underwent radiography of the pelvis under general anesthesia in dorsal recumbency. During a 5s exposure time the horse was actively ventilated to blur the abdominal viscera, which allowed assessment ...
Dabernat HJ, Delmas CF, Tainturier DJ, Lareng MB.The in vitro susceptibility of recent clinical isolates of Haemophilus equigenitalis to various antimicrobial agents was determined by the disk diffusion test and the World Health Organization-International Collaborative Study agar dilution procedure. Ampicillin and tetracycline were the most active drugs. All strains were susceptible to beta-lactam antibiotics, chloramphenicol, trimethoprim-sulfamethoxazole, nalidixic acid, nitrofurantoin (Furadantin), and bacitracin. All but two strains were resistant to streptomycin, whereas all strains were susceptible to the other aminocyclitol antibodies...
Kasapi MA, Gosline JM.The mechanical properties of fully hydrated equine hoof wall were examined at various loading rates in compact tension (CT) fracture, tensile and three-point bending dynamic tests to determine possible effects of hoof wall viscoelasticity on fracture toughness and tensile parameters. Four cross-head rates were used in CT tests: 1.7 x 10(-5), 1.7 x 10 (-3), 1.7 x 10(-2) and 2.5ms-1; four strain rates were used in tensile tests: 1.6 x 10(-3), 3.2 x 10(-2), 0.33 and 70s(-1). Speeds for the highest test rates were achieved using a large, custom-built impact pendulum. Bending test frequencies range...
Young SS, Tesarowski D, Viel L.The effect of measurement frequency on respiratory mechanics was investigated in six horses with reversible allergic airway disease. Total respiratory impedance was measured at 1.5, 2.0, 3.0, and 5.0 Hz by using the forced oscillation technique with the horses in remission, after acute antigenic challenge producing clinical heaves, and with heaves but after the administration of 2 mg fenoterol by inhalation. The slopes of the magnitude (magnitude of Zrs) and real part (R) of total respiratory impedance over the frequency range 1.5-3 Hz changed significantly after antigenic challenge and fenote...
Grahn BH, Cullen CL.This retrospective clinical study describes the clinical manifestations, light microscopic findings, and diagnosis and treatment of acute and chronic lens rupture in the horse. Rupture of the lens capsule in the horse usually results in a chronic, blinding inflammation (phacoclastic uveitis) unless prompt surgical and medical therapies are implemented. The clinical manifestations of acute lens capsule rupture included: cataract; intralenticular displacement of iridal pigment; lens cortical fragments attached to the perforated lens capsule, iris, and corneal endothelium; miosis; aqueous flare; ...
Grosenbaugh DA, Backus CS, Karaca K, Minke JM, Nordgren RM.A new recombinant West Nile virus (WNV) vaccine has been licensed for use in horses. Prior to the availability of the recombinant vaccine in 2004, the only equine WNV vaccine available on the market had been an inactivated vaccine. Since the recombinant vaccine only expresses selected viral genes, the question could be posed as to whether a single dose of the recombinant vaccine would be effective in producing an anamnestic serologic response in horses previously vaccinated with an inactivated WNV vaccine. In this study we demonstrate that vaccination of horses with a canarypox-vectored recomb...
Baxter GM.Low doses of endotoxin cause vasoconstriction and hypoperfusion of the digit, small intestine, and cecum in horses. To determine the potential cause of these vascular alterations, in vitro vascular responses of palmar digital arteries and veins were determined in 8 horses after intravenous (IV) infusion of 1 L 0.9% NaCl (control) and 0.1 microgram/kg Escherichia coli 055:B5 endotoxin in 1 L of 0.9% NaCl (endotoxin-treated). Vessels were surgically removed under general anesthesia, cut into 4-mm vascular rings, suspended in tissue baths, and attached to force displacement transducers for measur...
Hare JE, Viel L, Conlon PD, Marshall JS.To determine the capacity of pulmonary mast cells (PMC) to degranulate in response to various potential allergens and other secretagogues in horses with recurrent airway obstruction (heaves) and clinically normal horses before and after exposure to moldy hay. Methods: 5 horses with heaves and 5 clinically normal horses. Methods: Heaves was characterized as an increased clinical respiratory score and maximum change in transpulmonary pressure of > 20 cm H2O after exposure. Bronchoalveolar lavage was performed during each period. Washed and resuspended cells were exposed for 20 minutes at 37 C wi...
Arar S, Chan KH, Quinn BA, Waelchli RO, Hayes MA, Betteridge KJ, Monteiro MA.During the second and third weeks of pregnancy, the equine conceptus expands rapidly while it is enclosed within a glycan capsule. Around day 16 of gestation, the conceptus loses its mobility in the uterus by a process termed 'fixation', coinciding with various changes in the capsule. Here, we compared the structure of the carbohydrate moieties expressed by the capsule during pre- and post-fixation periods. The glycan structures were studied by chemical analyses in combination with mass spectrometry. Capsule material from conceptuses collected before fixation (days 13-16) was observed to carry...
Mills PC, Ng JC, Kramer H, Auer DE.Five clinically healthy Thoroughbred geldings were injected with Freund's adjuvant 3 times to induce a chronic inflammatory response. Blood was collected at various times before and after adjuvant administration. Clinical responses (rectal temperature and general demeanor) were also monitored. Adjuvant injection induced increases in rectal temperature and plasma fibrinogen concentration (maximum levels measured were mean +/- s.d. 39.7 +/- 0.5 degrees C and 8.2 +/- 0.3 g/l, respectively), indicative of an inflammatory response. A mild clinical depression was also observed in the horses for 24 h...
Pearson H, Pinsent PJ, Denny HR, Waterman A.The indications for laparotomy in 140 horses are analysed, with particular emphasis on the operative or autopsy findings in 82 cases of colic. In cases of exploratory laparotomy, the overall recovery rate was only 28 per cent but 48 of the 82 animals were considered to have inoperable lesions. The recovery rate and causes of death for each indication are briefly reviewed.
Jones RL.Equine clostridial enterocolitis is being recognized with increasing frequency. It has been identified in foals with diarrhea, antibiotic-associated enterocolitis, or nosocomial enterocolitis. The sporadic occurrence of clostridial enterocolitis, the variety of types of clostridia involved, and the difficulty of experimentally reproducing the disease suggest that it is a poorly defined multifactorial syndrome. The risk factors associated with susceptibility to colonization and progressive infection are largely based on anecdotal observations and extrapolation from human studies. Quantitative s...
Nanayakkara SN, Rahnama S, Harris PA, Anderson ST, de Laat MA, Bailey S, Sillence MN.Although it is well established that equine laminitis can be triggered by extreme hyperinsulinemia, the mechanism of insulin action is not known. High concentrations of insulin lead to separation of the weight-bearing apparatus from the hoof wall and are associated with an increased cycle of cell death and proliferation in the lamellae. Gene expression and immunohistochemistry studies have indicated that the lamellae are sparsely populated with insulin receptors, whereas IGF-1 receptors (IGF-1R) are abundant, suggesting that the action of insulin may be mediated by insulin binding to the IGF-1...
Zhao J, Negussie H, Laval K, Poelaert KC, Nauwynck HJ.Equine herpesvirus 1 (EHV-1) and equine arteritis virus (EAV) induce respiratory problems and abortion in horses and are considered as two serious threats to equine industry. Both EHV-1 and EAV misuse patrolling leukocytes in the upper respiratory tract to breach the basement membrane (BM) and to migrate to blood vessels. So far, the behavior and impact of a double infection in the respiratory mucosa of a horse are unknown. In the present study, the outcome of double infections with EHV-1 and the low virulent EAV strain 08P187 (superinfection with an interval of 12h or co-infection) were compa...
Feist JD, McCullough DR.A behavioural study of feral horses was conducted on the Pryor Mountain Wild Horse Range in the western United States. All 270 horses on the Range were identified individually. The sex ratio was nearly balanced. Foal to adult female ratio was 43-2:100. Morality was concentrated among foals and old horses. Horses were organized as forty-four harem groups each with a dominant stallion, one to two immature stallions, one to three immature mares, one to three adult mares and their yearling and foal offspring, and 23 bachelor groups of one to eight stallions. Harem groups were quite stable year-rou...
Ehrle A, Ressel L, Ricci E, Merle R, Singer ER.The equine interspinous ligament (ISL) consists of an oblique crossing arrangement of collagenous bundles which are thought to counteract the tensile and rotational forces of distraction between the spinous processes (SPs) in the caudal thoracic and cranial lumbar spine. The aim of this controlled histological study was to assess the structural anatomy and innervation of the ISL in horses with clinically significant overriding (dorsal) SPs (ORSPs) and to compare the findings with the ISL of normal horses. Samples of the ISL were obtained from 10 horses that underwent subtotal ostectomy for tre...
Swanstrom MD, Zarucco L, Stover SM, Hubbard M, Hawkins DA, Driessen B, Steffey EP.The superficial (SDF) and deep digital flexor (DDF) muscles are critical for equine forelimb locomotion. Knowledge of their mechanical properties will enhance our understanding of limb biomechanics. Muscle contractile properties derived from architectural-based algorithms may overestimate real forces and underestimate shortening capacity because of simplistic assumptions regarding muscle architecture. Therefore, passive and active (=total - passive) force-length properties of the SDF and DDF muscles were measured directly in vivo. Muscles from the right forelimbs of four Thoroughbred horses we...
Van Oirschot JT, Bruin G, de Boer-Luytze E, Smolders G.Foals that were born to mares vaccinated twice a year against influenza had moderate to high haemagglutination-inhibition antibody titers at 24 hours after birth. The foals were vaccinated at six and ten weeks of age, and again at three to five months after birth. Four months after the third vaccination no antibodies against A/H7N7 and A/H3N8 influenza viruses were detected in these foals. Thus, maternal antibodies probably prevented the development of antibodies against equine influenza virus after vaccination. Foals born to the same mares one year later were monitored to determine the rate o...
Carstanjen B, Duboeuf F, Detilleux J, Lepage OM.The purpose of this ex vivo study was to analyse two commonly established methods of mechanical bone property assessment for application in horses: Quantitative ultrasound (QUS), which depends on the bone's density and Young's modulus, and dual energy X-ray absorptiometry (DXA), which depends on the areal bone mineral density (BMD). The third metacarpal bone (MC III) of horses was selected as examination region for practical reasons. An interrelationship between QUS- and DXA-values was examined. Both MC III of eleven randomly selected equine cadavers were divided in nine regions of interest (R...
Durand JP, Simon F, Tolou H.West Nile virus (WNV) is a common arbovirosis, transmitted by mosquitoes mainly Culex. WNV is commonly responsible for equine epizootics and epidemics in humans in sub-Saharan Africa. It has been occasionally described in Southern Europe and in some Mediterranean countries. Since 1994, WNV clinical aspects seem to change with an increase of central neurological involvement and a higher mortality, especially among people older than 50 years. In 1999, WNV reached New York, being responsible for severe clinical manifestations. It spread all over North America in less than four years Four (only fo...
Sewgobind S, Johnson N, Mansfield KL.Japanese encephalitis (JE) is an infection that occurs predominantly in Asia and the Pacific Islands. It is transmitted by mosquito bites, with the main vector being Culex tritaeniorhynchus, and is maintained in enzootic cycles involving pigs, wild birds and mosquitoes. JE is caused by infection with Japanese encephalitis virus (JEV), a zoonotic pathogen that also causes disease in mammals such as pigs and horses. In humans, most symptoms are mild or flu-like but can progress to encephalitis. Pigs are considered amplification hosts, and sows may have gestational complications. Horses may exhib...
