Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Gutierrez-Nibeyro SD, White Ii NA, Werpy NM.Currently, there are limited data regarding the long-term outcome of horses with foot pain treated with corrective shoeing, rest and rehabilitation, and intrasynovial anti-inflammatory medication to target lesions detected with MRI. Objective: To report the long-term (≥12 months) outcome of horses with foot lesions following medical therapy. Objective: 1) There is no association between clinical parameters considered and a poor response to therapy. 2) Horses with a deep digital flexor tendinopathy are less likely to respond to medical therapy than horses without a deep digital flexor tendino...
Southwood LL, Gassert T, Lindborg S.Owners and veterinarians are often concerned about mortality of geriatric horses following colic surgery. Objective: To compare treatment, diagnosis and short-term survival for geriatric compared to mature nongeriatric horses with colic. Methods: Medical records of horses admitted with a presenting complaint of colic between 2000 and 2006 were reviewed. Geriatric horses were aged ≥16 years (n = 300) and subcategorised as age ≥20 years (n = 134). Mature nongeriatric horses were age 4-15 years (n = 300). Information obtained included medical (included horses subjected to euthanasia without s...
Ducharme NG, Cheetham J, Sanders I, Hermanson JW, Hackett RP, Soderholm LV, Mitchell LM.The success rate of prosthetic laryngoplasty is limited and may be associated with significant sequelae. Nerve muscle pedicle transplantation has been attempted but requires a year before function is restored. Objective: To determine the optimal parameters for functional electrical stimulation of the recurrent laryngeal nerve in horses. Methods: An experimental in vivo study was performed on 7 mature horses (2-21 years). A nerve cuff was placed on the distal end of the common trunk of the recurrent laryngeal nerve (RLN). In 6 horses the ipsilateral adductor branch of RLN was also transected. T...
Sinding MF, Berg LC.The aetiological factors behind impinged or overriding of dorsal spinous processes ('kissing spine syndrome', KSS) are not clearly understood. Back conformation, breed, age, training and gender may play important roles in this condition. Radiographic changes vary and abnormalities are seen in many clinically normal horses, but the conclusion of previous studies in mature horses is that interspinous spaces <4 mm are considered too narrow and potentially indicative of KSS. Objective: To evaluate whether narrowing of the interspinous space was present in a population of normal Warmblood foals....
Kearney CM, van Weeren PR, Cornelissen BP, den Boon P, Brama PA.The flexion test is used routinely as part of lameness and prepurchase examinations. However, little is known about the mechanisms that cause a positive response to a flexion test. Objective: To determine which anatomical regions play a role in a positive outcome of a flexion test of the distal aspect of a forelimb in a nonlame horse. Methods: Eight clinically sound Dutch Warmblood horses were subjected to a standardised flexion test (force 250 N, time 60 s) inducing a consistent lameness. To discriminate between different areas of the distal aspect of a forelimb, effects of various nerve bloc...
Parker RA, Bladon BM, Parkin TD, Fraser BS.Increased radio-isotope uptake (IRU) in the subchondral bone of the plantaro-lateral condyle of the third metatarsus (MTIII) is a commonly reported scintigraphic finding and potential cause of lameness in UK Thoroughbred racehorses in training and has not been fully documented. Objective: To characterise lameness attributable to IRU of the subchondral bone of MTIII, compare the scintigraphic findings of these horses with a normal population and evaluate the use of scintigraphy as an indicator of prognosis. Objective: IRU will be in significantly higher in horses with subchondral bone injury an...
Hubbell JA, Saville WJ, Bednarski RM.To determine the sedative, analgesic and anaesthetic drugs and techniques that are used by equine veterinarians. HYPOTHESIS OR OBJECTIVES: To provide equine veterinarians with information concerning veterinary use of anaesthetic techniques, a reflection of the collective experiences of the profession. Methods: A survey was conducted of those members of the American Association of Equine Practitioners (AAEP) with an electronic mail address on file with the organisation using proprietary, web-based software. The survey was comprised of 30 questions divided into 8 sections: nonsteroidal anti-infl...
Bardell D, Iff I, Mosing M.Anaesthesia of the maxillary nerve of the horse has been described using several approaches, but sparse data exist to evaluate the accuracy of these methods. Objective: This study compared 2 previously described approaches to the maxillary nerve to assess their relative accuracies. Methods: Thirty severed heads from horse cadavers were arranged to approximate the position of a live horse. Methylene blue (0.25 or 0.1 ml) was injected using a 19 gauge 90 mm spinal needle by one of 2 approaches, the method used being randomly allocated in each instance. Method ANG: angulated needle insertion on t...
Devisscher L, Schauvliege S, Dewulf J, Gasthuys F.To evaluate the effects of a constant rate infusion (CRI) of romifidine on the requirement of isoflurane, cardiovascular performance and recovery in anaesthetized horses undergoing arthroscopic surgery. Methods: Randomized blinded prospective clinical trial. Methods: Thirty horses scheduled for routine arthroscopy. Methods: After premedication (acepromazine 0.02 mg kg(-1), romifidine 80 microg kg(-1), methadone 0.1 mg kg(-1)) and induction (midazolam 0.06 mg kg(-1) ketamine 2.2 mg kg(-1)), anaesthesia was maintained with isoflurane in oxygen. Horses were assigned randomly to receive a CRI of s...
Olver CS, Webb TL, Long LJ, Scherman H, Prenni JE.Disease-specific biomarkers hold diagnostic promise in both human and veterinary medicine, but serum biomarkers in low concentrations may be masked by the presence of abundant proteins, mostly albumin and IgG. Methods to deplete albumin and IgG exist, but efficacy of these methods for depleting equine serum of these proteins has not been established. Objective: The aim of this study was to determine if albumin and IgG could be depleted from equine serum using several commercially available kits and procedures. Methods: One-dimensional gel electrophoresis followed by densitometry was used to de...
Tóth P, Horváth C, Ferencz V, Nagy K, Gligor N, Szenci O, Bodó G.In the first part of this methodological study eleven metacarpi of 9 skeletally normal horses were examined from 4 directions by dual energy x-ray absorptiometry (DXA). The differences between the dorsopalmar-palmarodorsal and lateromedial-mediolateral (opposite sites) bone mineral density (BMD) values were found to be nonsignificant. In the second part of the study the precision of the Norland XR-26 densitometer was tested by measuring 34 metacarpal bones and 34 proximal phalanges, each of them three times, from a single direction. The difference between the individual measurements of the fir...
Rezende ML, Boscan P, Stanley SD, Mama KR, Steffey EP.To characterize cardiovascular, respiratory and biochemical effects and recovery behavior associated with a 3-hour continuous infusion of a micellar microemulsion propofol formulation in horses. Methods: Prospective experimental trial. Methods: Six healthy adult horses, 9 +/- 2 years old and weighing 557 +/- 14 kg. Methods: All horses received xylazine (1 mg kg(-1), IV) 5 minutes prior to anesthetic induction. Each horse was anesthetized on two occasions with a 5% micellar microemulsion propofol formulation (2 mg kg(-1), IV); first as a single bolus (phase I) and then as a 3-hour continuous in...
Skedros JG, Kiser CJ, Mendenhall SD.Using circularly polarized light microscopy,we described a weighted-scoring method for quantifying regional distributions of six secondary osteon morphotypes(Skedros et al.: Bone 44 (2009) 392-403). This osteon morphotype score (MTS) strongly correlated with "tension" and "compression" cortices produced by habitual bending. In the present study, we hypothesized that the osteon MTS is superior to a relatively simpler method based on the percent prevalence (PP) of these osteon morphotypes. This was tested in proximal femoral diaphyses of adult chimpanzees and habitually bent bones: calcanei from...
Galvao AM, Ramilo DW, Skarzynski DJ, Lukasik K, Tramontano A, Mollo A, Mateus LM, Ferreira-Dias GM.Proapoptotic factor Fas ligand (FASL) and its cell surface receptor FAS are tumor necrosis factor superfamily members that trigger apoptosis in different cell types. However, their influence on luteal steroidogenesis is not clearly understood. The aim of the present work was to determine (i) the presence of the cytokine FASL and its receptor FAS in the mare's corpus luteum (CL) throughout the luteal phase, as well as (ii) the influence of FASL alone, or together with the cytokines tumor necrosis factor alpha (TNF) and interferon gamma (IFNG), on equine luteal cell production of luteotrophic an...
Lyons ET, Tolliver SC, Kuzmina TA, Collins SS.Critical tests were performed in 2009 and 2010 in four 2-year-old horses naturally infected with internal parasites. The horses were from a herd (Farm MC) where reduced activity of ivermectin and moxidectin on small strongyles was demonstrated previously from EPG (eggs/gram of feces) data in field tests. Also, in critical tests in horses from the same herd, ivermectin was less effective on immature small strongyles in the lumen of the large intestine than when the drug was first marketed. The main interest in the present critical tests was to determine the efficacy of moxidectin (400 μg/kg) o...
Vanschandevijl K, Nollet H, Vonck K, Raedt R, Boon P, Roost D, Martens A, Deprez P.The aim of this study was to assess the feasibility of implanting an existing vagus nerve stimulating (VNS) electrode around the recurrent laryngeal nerve. The stimulus response characteristics required to achieve abduction of the ipsilateral arytenoid by the VNS electrode in the normal horse could then be determined. The electrode was wound around the left recurrent laryngeal nerve at the cervical level and connected to a pulse generator. Stimulus response characteristics were obtained by measuring stimulated arytenoid displacement endoscopically in the standing, non-sedated horse. A full and...
Schöniger S, Valentine BA, Fernandez CJ, Summers BA.Schwannomas are uncommonly recognized in horses. This study describes cutaneous schwannomas in 22 horses aged 8 to 25 years: 12 male, 7 female, and 3 of unknown sex. The horses had solitary cutaneous masses: 9 on the head, 3 on the neck, and the others on the shoulder, hip, thorax, abdomen, rump, extremities, or tail. The location of 1 tumor was unknown. The dermal tumors were well demarcated and expansile. Twelve had a multinodular pattern, whereas 10 formed a single nodule. Antoni A areas were observed in all tumors, and 10 tumors contained Antoni B areas. In Antoni A areas, the densely pack...
Santos EM, Paula JF, Motta PM, Heinemann MB, Leite RC, Haddad JP, Del Puerto HL, Reis JK.We compared three different protocols for DNA extraction from horse peripheral blood mononuclear cells (PBMC) and lung fragments, determining average final DNA concentration, purity, percentage of PCR amplification using beta-actin, and cost. Thirty-four samples from PBMC, and 33 samples from lung fragments were submitted to DNA extraction by three different protocols. Protocol A consisted of a phenol-chloroform and isoamylic alcohol extraction, Protocol B used alkaline extraction with NaOH, and Protocol C used the DNAzol((R)) reagent kit. Protocol A was the best option for DNA extraction from...
Nielsen MK, Baptiste KE, Tolliver SC, Collins SS, Lyons ET.Increasing levels of anthelmintic resistance in equine nematodes have led to recommendations of more sustainable anthelmintic treatment protocols with emphasis on parasite surveillance and diagnosis, rather than prophylactic calendar-based treatments. This requires knowledge of the diagnostic test performance of techniques for counts of eggs per gram of feces (EPG) as well as methods for culturing, counting and identifying third stage (L(3)) strongyle larvae per gram of feces (LPG). For horses, such information does not exist in the published literature. The aim of this study was to examine th...
Paillot R, Darby AC, Robinson C, Wright NL, Steward KF, Anderson E, Webb K, Holden MT, Efstratiou A, Broughton K, Jolley KA, Priestnall SL....The acquisition of superantigen-encoding genes by Streptococcus pyogenes has been associated with increased morbidity and mortality in humans, and the gain of four superantigens by Streptococcus equi is linked to the evolution of this host-restricted pathogen from an ancestral strain of the opportunistic pathogen Streptococcus equi subsp. zooepidemicus. A recent study determined that the culture supernatants of several S. equi subsp. zooepidemicus strains possessed mitogenic activity but lacked known superantigen-encoding genes. Here, we report the identification and activities of three novel ...
Busschers E, Epstein KL, Holt DE, Parente EJ.To describe the surgical technique, complications, and outcome after use of extraluminal prostheses in 2 ponies with severe tracheal collapse. Methods: Clinical report. Methods: Ponies (n=2) with severe tracheal collapse. Methods: A ventral median approach was used to expose the trachea from the larynx to the manubrium. Extraluminal, high-density polyethylene, C-shaped prostheses were sutured to the dorsal tracheal membrane and tracheal rings to provide external tracheal support. Results: The surgical approach provided good tracheal access and placement of the rings was uncomplicated. Initial ...
Holcomb KE, Stull CL, Kass PH.Closure of US equine slaughter facilities in 2007 along with the concomitant economic recession have contributed to a sharp increase in the number of unwanted horses throughout the United States, with estimates totaling 100,000 horses per year. The objective of the study was to obtain comprehensive data regarding nonprofit organizations caring for unwanted horses, along with the characteristics and outcome of horses relinquished to these organizations. Nonprofit organizations that accept relinquished equines were contacted to participate in a 90-question survey. Responding organizations (144 o...
Atli MO, Kurar E, Kayis SA, Aslan S, Semacan A, Celik S, Guzeloglu A.The aim was to evaluate expression of genes involved in the biosynthesis of prostaglandins (PTG), Prostaglandin H Synthase-1 (PTGS1) and PTGS2, PGF synthase (PTGFS), and PGE synthase (PTGES), PGF receptor (PTGFR), PGE receptors (PTGER2 and PTGER4), prostaglandin transporter (SLCO2A1) and hydroxyprostaglandin dehydrogenase-15 (HPGD). Endometrial biopsies were obtained from mares on day of ovulation (d0, n=4), late diestrus (LD, n=4), early luteolysis (EL, n=4) and after luteolysis (AL, n=4) during the cycle. Stages of the cycle were confirmed by plasma progesterone concentrations measured daily...
Earing JE, Cassill BD, Hayes SH, Vanzant ES, Lawrence LM.The objective of this study was to determine if in vitro methodologies developed for the Ankom Daisy(II) incubator could produce accurate estimates of in vivo equine DM digestibility (DMD) and NDF digestibility (NDFD) when equine feces were used as the inoculum source. Four mature geldings were utilized in a 4 × 4 Latin square design experiment with a 2 × 2 factorial arrangement of dietary treatments (timothy hay, alfalfa hay, timothy hay plus oats, and alfalfa hay plus oats), in which the geldings were individually housed and fed. During each 5-d total fecal collection period, feces were co...
Malik P, Pálfi V, Bálint A.Equine herpesvirus-1 (EHV-1) is a major pathogen of horses with worldwide distribution that can cause various clinical signs ranged from mild respiratory disease to neurological symptoms. Comparison of neuropathogenic and non-neuropathogenic EHV-1 strains revealed that a single non-synonymous nucleotide substitution (A/G2254) in the ORF30 region is associated with the altered functions of the viral DNA polymerase and therefore the neuropathogenicity of EHV-1 virus strains. The aim of the present study was the development of a new differentiation method of this particular single nucleotide poly...
Reilly PT, Dean EK, Orsini JA.The goals of mechanical treatment during the acute phase of laminitis are to preserve the lamellar interface by reducing the forces that are compromising its integrity and to make the horse more comfortable. Early decision making is important in managing acute laminitis. This article helps the practitioner to identify some of the commonly used and accepted methods of protecting the laminitic foot. The materials available and the theories behind their use are also described. The laminitic foot needs to be understood before determining methods for its support. Most treatment options involve shif...
Geor RJ.Epidemiologic studies indicate that most laminitis cases occur in horses and ponies kept at pasture, hence the term 'pasture-associated laminitis'. Clinical cases of laminitis most often occur under conditions that favor accumulation of rapidly fermentable nonstructural carbohydrates (fructans, simple sugars, or starches) in pasture, and animals with an equine metabolic syndrome (EMS) phenotype (insulin resistance, abnormal insulin dynamics, +/- obesity) seem to be at highest risk for developing the condition. Although the mechanisms linking consumption of pasture forage with development of la...
Morrison S.Laminitis is a disease of the suspensory apparatus of the distal phalanx, which can advance to the chronic stage with varying degrees of structural failure. Because the disease may ultimately lead to mechanical failure of the digit, a foot management plan is required to effectively and mechanically treat these cases. Many laminitis cases can be successfully rehabilitated back to athletic soundness, light use, breeding, or pasture soundness, whereas others suffer from permanent instability and never enjoy an acceptable level of comfort. To understand how to minimize damage in the acute laminiti...
van der Holst W.Season was shown to markedly influence semen characteristics of stallions in Holland, including ejaculate volume, sperm motility, total number of spermatozoa/ejaculate and the percentage of spermatozoa showing morphological abnormalities. Maintenance of normal stallions in continuous light during the winter months and administration of a vitamin and mineral supplement to sub-fertile stallions before the start of the breeding season appeared to improve spermatogenesis significantly.
Welch RD, Watkins JP, DeBowes RM, Leipold HW.The effects of intra-articular administration of dimethylsulfoxide (DMSO) on chemically induced synovitis in the middle carpal joint of 6 weanling horses were evaluated. Following aseptic collection of synovial fluid, the middle carpal joint of each forelimb was injected with 50 mg of Na-monoiodoacetate to induce synovitis. Eight days after injection, synovial fluid was obtained and the right middle carpal joints were injected with 2 ml of 40% DMSO in lactated Ringer solution. The corresponding joints of the left limb (control) were injected with 2 ml of lactated Ringer solution. Sampling and ...
Davies HM, Watson KM.The aims of this study were to test whether longer third metacarpal (MC3) bones had thicker dorsal cortices in a group of racehorses that were exercising at similar maximum speeds, and to establish if horses with larger differences in length between their right and left MC3 bones showed larger differences in the dorsal cortical thickness between the two limbs. Methods: An observational study. Methods: Forty Thoroughbred racehorses aged between 2 and 6 years and in training at racing speed at two racing stables were used. Two sets of radiographs of each left and right metacarpus of each horse w...
Liu CC, Hsiao YC, Chu LJ, Wang PJ, Liu CH, Hsieh WC, Yu JS., also known as Taiwanese cobra, is one of the most prevalent venomous snakes in Taiwan. Clinically, freeze-dried neurotoxic antivenom (FNAV) produced from horses by Taiwan Centers for Disease Control (CDC) has been the only approved treatment for envenoming for the last few decades. During antivenom production, large numbers of mice are used in the in vivo assay to determine whether the neutralization potency of hyperimmunized equines is satisfactory for large-scale harvesting. However, this in vivo assay is extremely laborious, expensive, and significantly impairs animal welfare. In the pre...
Kollias-Baker C, Maxwell L, Stanley S, Boone T.Cocaine is a naturally occurring alkaloid that is commonly abused by human-beings for its psychostimulatory effects. Occasionally, very small concentrations (i.e. <100 ng/mL) of the primary cocaine metabolite, benzoylecgonine (BZE) have been detected in urine collected from horses competing in athletic events. In this study urine samples, collected from four horses following the administration of 2.5 and 20 mg of cocaine sublingually and 50 mg of cocaine intravenously, were analyzed for the presence of cocaine and/or its metabolites by enzyme-linked immunosorbent assay (ELISA) and gas chrom...
Collins JN, Galuppo LD, Thomas HL, Wisner ER, Hornof WJ.To provide a detailed description of the vascular anatomy of the distal portion of the forelimbs of horses by use of computed tomography angiography (CTA). Methods: 6 forelimbs of 5 horses and 1 forelimb from an equine cadaver; none of the horses had orthopedic or vascular disease. Methods: Horses were anesthetized and CTA was conducted on the dependent forelimb. A catheter was inserted in the median artery, and contrast medium was infused at a rate of 3 mL/s. A computed tomography (CT) scanner was used to obtain contiguous slices from the region of the proximal sesamoid bones to the toe. All ...
Cain JL, Norris JK, Ripley NE, Suri P, Finnerty CA, Gravatte HS, Nielsen MK.Parasitic nematodes, including large roundworms colloquially known as ascarids, affect the health and well-being of livestock animals worldwide. The equine ascarids, Parascaris spp., are important parasites of juvenile horses and the first ascarids to develop widespread anthelmintic resistance. The microbiota has been shown to be an important factor in the fitness of many organisms, including parasitic nematodes, where endosymbiotic Wolbachia have been exploited for treatment of filariasis in humans. Methods: This study used short-read 16S rRNA sequences and Illumina sequencing to characterize...
Derisoud E, Auclair-Ronzaud J, Rousseau-Ralliard D, Philau S, Aujean E, Durand A, Dahirel M, Charlier M, Boutinaud M, Wimel L, Chavatte-Palmer P.Nulliparity is associated with intra-uterine growth retardation and foal delayed catch-up growth. Older mares produce larger/taller foals than the precedents. Nursing at conception on foal growth had not been investigated yet. In any case, milk production conditions the foal's growth. This study aimed to determine effects of mare parity, age and nursing on subsequent lactation quantity and quality. Saddlebred mares and their foals (N = 43) run as a single herd over the same year were: young (6-7-year-old) primiparous, young multiparous, old (10-16-year-old) multiparous nursing at inseminatio...
Collins J, More SJ, Hanlon A, Duggan V.This report describes the progression in welfare standards for horses on a horse farm in the Republic of Ireland between 2007 and 2009. Visits to the farm were undertaken and information, in the form of written notes and digital recording of observations and examinations, was gathered in consultation with officials from the Gardaí (the Irish police), the Department of Agriculture, Fisheries and Food and the Irish Society for the Prevention of Cruelty to Animals. Further independent veterinary corroboration of clinical findings and laboratory support occurred following seizure of the horses. T...
Davis JL, Papich MG, Weingarten A.The purpose of this study was to determine the pharmacokinetics and physicochemical characteristics of orbifloxacin in the horse. Six healthy adult horses were administered oral and intravenous orbifloxacin at a dose of 2.5 mg/kg. Plasma samples were collected and analyzed by high-pressure liquid chromatography with ultraviolet detection. Plasma protein binding and lipophilicity were determined in vitro. Following i.v. administration, orbifloxacin had a terminal half-life (t1/2) of 5.08 h and a volume of distribution (V(d(SS))) of 1.58 L/kg. Following oral administration, the average maximum p...
Mostert HJ, Lund RJ, Guthrie AJ, Cilliers PJ.A theoretical integrative model was developed to determine the heat balance of horses working in a given environment. This model included the following parameters: metabolic heat gain, solar heat gain, evaporative heat loss due to sweating, respiratory tract heat loss, radiation from the body and heat gain or loss due to convection and conduction. The model developed in this study includes an unique approach for estimating heat loss via evaporation of sweat from the animal's skin surface. Previous studies modelling evaporative heat dissipation were based on the volume of sweat loss. While it i...
Añor S, Espadaler JM, Monreal L, Mayhew IG.The electrically induced blink reflex was studied electromyographically in 21 healthy adult, detomidine-sedated horses. Using surface electrodes, the supraorbital nerve was electrically stimulated at the supraorbital foramen. The responses were recorded from the ipsilateral and contralateral orbicularis oculi muscles with concentric needle electrodes inserted in the lateral aspect of the ventral eyelids. Ipsilateral and contralateral recordings were made on successive stimulations of the same side of the face, maintaining a constant stimulus intensity. The electromyographically recorded respon...
Lund RJ, Guthrie AJ.This study determined the maximal O2 uptake (VO2max) of Thoroughbred horses acclimatised to mild hypobaric conditions using a standard exercise test on a treadmill inclined at a 7% slope. The O2 uptake (VO2) versus speed relationship was linear below the exercise intensity required to attain VO2max. The VO2max of individual horses ranged from 143.5 to 172.6 ml/kg/min. The proportion of total variance for the VO2 versus speed relationship was greater than 0.992, and the coefficients of variation in repeated tests in individual horses ranged between 0.07 and 1.54%. The VO2 versus speed relations...
Webbon PM.The normal appearance of the superficial (SFT) and deep (DFT) digital flexor tendons was described and the difference between their histological structures was emphasised. Further differences were recognised between different sites from the same tendon and between tendons in the fore and hind limbs of the same animal. Both of the tendons underwent changes with age but although a number of alterations in the histological appearance were described, a particular change, involving a patchy loss of stainable nuclei, was found at the common site of SFT injuries. While this appearance has been seen i...
Morris DD, Moore JN.The formation of eicosanoids may be a primary route through which platelet activating factor (PAF) exerts its effects during endotoxemia. Since endotoxemia is a common cause of death in horses, a study was conducted to determine whether PAF could stimulate equine macrophage release of thromboxane A2 (TxA2) and prostacyclin (PGI2) and whether a PAF-receptor antagonist would alter macrophage eicosanoid synthesis. Equine peritoneal macrophages were cultured from clinically normal horses and exposed to various concentrations of PAF, the PAF-receptor antagonist SRI 63-441, endotoxin, or a combinati...
McDowell KJ, Adams MH, Franklin KM, Baker CB.A cDNA library was constructed from poly(A) RNA obtained from Day 14 nonbred equine endometrium. A cDNA probe for porcine retinol-binding protein (RBP) was used to screen the library, and a complete cDNA sequence (1133 bp, excluding the poly(A) tail) was obtained. Endometrial biopsies were obtained from cycling, nonbred mares at Days 0, 1, 4, 8, 10, 11, 13, and 15 and from pregnant mares at Days 11, 13, 15, and 17 after ovulation (n = 2 mares each day). Endometrial biopsies were also taken from 18 noncycling anestrous mares after the following treatments: C (vehicle control for 1 day, n = 3), ...
Evans MJ, Hamer JM, Gason LM, Irvine CH.Twelve acyclic mares of various ages (2-29 years) and parity (maiden-multiparous) were given oestradiol-17 beta i.m. (winter 1982) or progesterone i.m. (winter 1983) to induce changes in the endometrium consistent with oestrus and dioestrus, respectively. After hormone treatment, mares were inoculated intrauterine with 50 ml saline containing 5 X 10(5) Streptococcus zooepidemicus bacteria, 51Cr-labelled 15-micron microspheres, and 500 mg charcoal (Groups E + B and P + B) or microspheres and charcoal only (Groups EC and PC). At 5 h after inoculation uteri were flushed with 50 ml saline containi...
Reppas GP, McClintock SA, Canfield PJ, Watson GF.Mammary gland neoplasms in horses are uncommon and may initially be confused with mastitis. Masses from the mammary glands of two horses with chronic discharges were examined by cytology and histopathology. Both masses were diagnosed as papillary ductal adenocarcinomas with extensive intraductal and intralobular involvement and only focal infiltration of the adjacent stroma. Complementary immunohistochemical studies were made of both fresh and formalin-fixed tumour tissue, and attempts were made to assess the steroid receptor status of fresh tissue biochemically to assess the possibility of ho...
Azab W, El-Sheikh A, Abdel-Gawad A.Equine herpesvirus 4 (EHV-4) is an important pathogen that causes respiratory tract disease in horse populations worldwide. Glycoprotein G (gG) homologs have been identified in several alphaherpesviruses as minor non-essential membrane-anchored glycoproteins. In this study, EHV-4 gG deletion mutant has been generated by using bacterial artificial chromosome technology to investigate the role of gG in viral pathogenesis. Our findings reported here revealed no significant difference between parental EHV-4 and gG-negative strain in their replication cycle in cell culture. Furthermore, virus titer...
Hollanders B, Mougin A, N'Diaye F, Hentz E, Aude X, Girard A.A new two-step gradient technique has been used in the separation of the different classes of lipoproteins from the serum of cows, horses, dogs, pigs, rabbits and rats. Total lipoproteins were first isolated at d 1.21 then floated through a d 1.006 to d 1.21 gradient. Collection by mean of a gradient fractionator provided directly comparable lipoprotein profiles, allowed the determination of the exact density range of each lipoprotein class and the fraction by fraction analysis of composition. Cholesterol and apo AI recoveries were high. Horse, dog, rabbit and pig exhibited three distinct lipo...
Dirikolu L, Hughes C, Harkins D, Boyles J, Bosken J, Lehner F, Troppmann A, McDowell K, Tobin T, Sebastian MM, Harrison L, Crutchfield J, Baskin SI....The epidemiological association between black cherry trees and mare reproductive loss syndrome has focused attention on cyanide and environmental cyanogens. This article describes the toxicokinetics of cyanide in horses and the relationships between blood cyanide concentrations and potentially adverse responses to cyanide. To identify safe and humane blood concentration limits for cyanide experiments, mares were infused with increasing doses (1-12 mg/min) of sodium cyanide for 1 h. Infusion at 12 mg/min produced clinical signs of cyanide toxicity at 38 min; these signs included increased heart...
Moreno-Irusta A, Dominguez EM, Marín-Briggiler CI, Matamoros-Volante A, Lucchesi O, Tomes CN, Treviño CL, Buffone MG, Lascano R, Losinno L....Sperm chemotaxis may facilitate the finding of the oocyte. Only capacitated spermatozoa can orient their movement by chemotaxis, which as well as capacitation, is regulated in part by the cAMP-PKA pathway. Reactive oxygen species (ROS) are produced during sperm capacitation which is closely related to chemotaxis. Then, the ROS participation in the chemotactic signaling can be expected. Here we studied the role of ROS in the chemotaxis signaling of equine spermatozoa which produce high quantities of ROS because of their energy metabolism. The level of capacitated and chemotactic spermatozoa was...
Mari G, Barbara M, Eleonora I, Stefano B.Ovum pick-up (OPU) by transvaginal ultrasound guided aspiration (TUGA) is a procedure applied in equine-assisted reproduction programs such as oocyte transfer and in vitro embryo production. Despite a large number of studies reporting that it is a repeatable and safe technique, little information is available about the effect of repeated punctures on fertility of mares. Moreover, even if flushing follicles improves the oocyte recovery rate, to our knowledge the efficiency of flushing estrous and diestrous follicles has not been evaluated. The aims of the present study were (1) evaluate if repe...
Geyer H, Schulze J.The influence of dietary biotin in horses with brittle hoof horn and chipped hooves was investigated in a long-term study, which was performed over a period from one to six years. 97 horses received 5 mg of biotin per 100 to 150 kg of body weight, per os, daily; 11 horses were not supplemented with biotin and served as controls. The hooves of all horses were evaluated macroscopically every three to four months. Hoof horn specimens of the proximal wall were examined histologically and physically in 25 and 15 horses, respectively. The tensile strength of normal coronary horn was 60 N/mm2 or grea...
Cutmore CM, Snow DH, Newsholme EA.The effect of physical training on the in vitro activities of key enzymes that provide quantitative information on the maximum capacities of anaerobic and aerobic metabolism has been investigated in the gluteal muscle of the horse. Training had no effect on the activities of 6-phosphofructokinase or creatine kinase, suggesting that there was no effect on the capacity of anaerobic metabolism in this muscle. However, the activities of hexokinase and citrate synthase were increased, indicating that training increased the capacity of aerobic metabolism. For comparative purposes, muscle fibre compo...