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.
McKellar QA, Horspool LJ.Penicillin G was extensively (84.7 per cent) and amikacin moderately (14.4 per cent) degraded when incubated for one hour in a chloride buffer at pH 1.9 designed to mimic the equine gastric pH. Ampicillin and oxytetracycline were stable at pH 1.9. Penicillin and ampicillin were moderately stable (more than 90 per cent) when incubated in equine caecal liquor for three hours but were degraded by about 65 per cent after 24 hours. More than 80 per cent of the initial concentrations of amikacin and oxytetracycline were recovered after 24 hours' incubation in equine caecal liquor. The concentrations...
Douglas J, Clarke A.Equine demineralized bone matrix, particle size 2 to 4 mm, was implanted SC and IM in 4 foals and 4 adult horses. The implants were removed between 5 and 8 weeks after implantation. Bone formation was induced by SC and IM implantations in all animals. The implantation site had a marked effect on the amount of bone that developed, bone being formed earlier and in greater amounts when the matrix was implanted IM. The amount of bone formed increased with increasing time after matrix implantation at both sites. Demineralized bone matrix implantation also led to formation of small amounts of chondr...
Moore BR, Krakowka S, Robertson JT, Cummins JM.Cytologic examination of bronchoalveolar lavage fluid (BALF), including phenotypic analysis of lymphocytes, was performed on 32 Standardbreds with poor race performance and endoscopic examination findings characteristic of inflammatory airway disease (IAD). Nucleated cell counts in BALF from IAD-affected horses were higher than those in control horses; the cytologic profile of BALF in affected horses included mixed inflammation, characterized by mild neutrophilia, lymphocytosis, and monocytosis. Eosinophil and mast cell counts were not higher in the IAD-affected group, compared with those in t...
Moore RM, Muir WW, Bertone AL, Beard WL, Stromberg PC.Thirty horses were randomly assigned to 1 of 5 groups. All horses were anesthetized and subjected to ventral midline celiotomy, then the large colon was exteriorized and instrumented. Colonic arterial blood flow was reduced to 20% of baseline (BL) and was maintained for 3 hours. Colonic blood flow was then restored, and the colon was reperfused for an additional 3 hours. One of 5 drug solutions was administered via the jugular vein 30 minutes prior to colonic reperfusion: group 1, 0.9% NaCl; group 2, dimethyl sulfoxide: 1 g/kg of body weight; group 3, allopurinol: 25 mg/kg; group 4, 21-aminost...
Rossier Y, Divers TJ, Sweeney RW.The urinary GGT/urinary creatinine (uGGT/uCR) ratio was measured on Days 1, 3 and 10 in 4 adult, healthy horses; in 6 adult, healthy horses treated with gentamicin at recommended dosages and 9 adult horses treated for pleuropneumonia with gentamicin at recommended dosages. Plasma creatinine and gentamicin trough concentrations were measured on the same days. The uGGT/uCr ratio was higher in the normal horses (mean +/- s.d. 22.85 +/- 13.69) than previously reported normal values (10.5 +/- 6.8) (Adams and McClure 1985). Analysis of variance for repeated measures was used to compare the ratio in ...
Hardy J, Bertone AL, Muir WW.The effects of joint angle, fluid infusion, history-dependence, and time dependence on the pressure-volume (PV) relationships of normal equine midcarpal joints were determined. Horses (n = 24 and 48 midcarpal joints) were anesthetized and placed in dorsal recumbency, and the four midcarpal joint pouches were cannulated for intra-articular pressure (IAP) measurements and recording. Fluid (synovial fluid or saline) was infused or withdrawn through the dorsal joint capsule. The PV curves were sigmoid and best described by IAP = A x e(B x volume) - C, where B is the fractional change in pressure p...
Johnston GM, Taylor PM, Holmes MA, Wood JL.The Confidential Enquiry into Perioperative Equine Fatalities (CEPEF-1) is an observational multi-institutional prospective study of recovery outcome at 7 days post operatively, as called for by Steffey (1991). Data from 6,255 general anaesthetics (February 91-March 93) were submitted confidentially by 62 clinics. The outcomes of 333 cases which were subjected to euthanasia and which were not classified 'alive' or 'died' at 7 days, were excluded from the analysis. The remaining 5922 cases were analysed to identify risk ratios (RR) between survivors and nonsurvivors for a variety of factors. Th...
Godber LM, Walker RD, Stein GE, Hauptman JG, Derksen FJ.Once-daily administration of aminoglycosides may be a safe and effective therapeutic regimen, on the basis of the microbiologic and pharmacokinetic characteristics of these antibiotics. This study was designed to determine serum and tissue concentrations following i.v. administration of gentamicin, at dosages of 6.6 mg/kg of body weight, every 24 hours, and 2.2 mg/kg, every 8 hours, for 10 days in adult horses. Nephrotoxicosis from these dosage regimens also was compared, and microbiologic effects, including postantibiotic effects, were determined with various concentrations of gentamicin agai...
Del Campo MR, Donoso X, Parrish JJ, Ginther OJ.Equine oocytes (n = 537) were collected from slaughterhouse ovaries (n = 118 mares) by scraping the internal follicular wall. Preculture record was made of the appearance of oocyte investments (no cumulus, corona radiata only, compact cumulus, expanded cumulus), appearance of cytoplasm (homogeneous, condensed heterogeneous/fragmented), and nuclear maturation stages (germinal vesicle, germinal-vesicle breakdown, metaphase I, metaphase II, degenerated). There was no difference between follicles > 30 mm and follicles < or = 30 mm in the preculture frequency distribution among the 5 nuclear stages...
Heilkenbrinker T, Schubert TS, Oetjen J, Pózvári M, Frerking H.In this thesis the influence of pneumo-vagina on the microbiological colonization of the genital tract and their manifestation in cytological smears was examined. For mares with poor vulval conformation a comparison of the bacterial growth before and after plastic surgery of the vulva and vestibulum was carried out, as well as the registration of conception rates after operation and insemination. The biggest reduction of the bacterial content in the reproductive tract was found between vestibulum and cranial section of the vagina. The increased number of contaminant bacteria in the cranial sec...
Beech J, Fletcher JE, Tripolitis L, Lindborg S, Dawso T.The contractile activity, the threshold for calcium-induced calcium release in fractions of sarcoplasmic reticulum and the potassium concentration were determined in preparations of semimembranosus muscle from normal quarter horses and quarter horses with hyperkalaemic periodic paralysis before and after they were treated with phenytoin. Before the treatment there was no difference in caffeine contracture or electrically elicited twitch response between the two groups. For one week after the treatment, the time to peak tension of caffeine contractures was significantly (P < 0.005) reduced i...
Cannon SC, Hayward LJ, Beech J, Brown RH.1. Equine hyperkalemic periodic paralysis (E-HPP) is a dominantly inherited disorder of muscle that causes recurrent episodes of stiffness (myotonia) and weakness in association with elevated serum K+. Affected horses carry a mutant allele of the skeletal muscle isoform of the Na channel alpha-subunit. To understand how this mutation may cause the disease phenotype, the functional defect in Na channel behavior was defined physiologically by recording unitary currents from cell-attached patches on normal and affected equine myotubes. 2. The presence of the mutation was confirmed in our cell lin...
Raidal SL.Pleuropneumonia is a clinically important equine disease, predisposed by a number of identifiable factors. Successful management is largely dependent on early identification and prompt initiation of appropriate treatment strategies. Rapid resolution of the disease process is associated with appropriate treatment commenced within 48 h of the causative insult. Lower airway contamination by oropharyngeal organisms and subsequent extension into the pulmonary parenchyma results in respiratory dysfunction and systemic toxaemia. Acute disease is associated with the isolation of facultatively anaerobi...
Sticker LS, Thompson DL, Fernandez JM, Bunting LD, DePew CL.Sixteen light horse mares were fed diets of bermudagrass hay and a corn/cottonseed hull-based supplement formulated to contain either 100% (control) or 50% (restricted) of the protein and(or) energy requirements for maintenance in a 2 x 2 factorial arrangement of treatments. Plasma IGF-I, prolactin, cortisol, triiodothyronine, and thyroxine were monitored for 33 d. On the 27th d, frequent blood samples were drawn throughout the day for the measurement of growth hormone (GH), and on the 29th d, an epinephrine challenge and an i.v. glucose tolerance test (IVGTT) were performed in the morning and...
Moore RM, Couto CG, Muir WW, Moore BR, Kociba GJ.Twenty-four horses were randomly allocated to 3 groups. All horses underwent a ventral midline celiotomy, and the large colon was exteriorized and instrumented. Group-1 horses served as sham-operated controls, group-2 horses underwent 6 hours of colonic ischemia, and group-3 horses were subjected to 3 hours of ischemia and 3 hours of reperfusion. Baseline blood samples were collected, then low-flow colonic ischemia was induced in horses of groups 2 and 3 by reducing colonic arterial blood flow to 20% of baseline. All horses were monitored for 6 hours. Citrated systemic venous (SV) blood sample...
Day TK, Gaynor JS, Muir WW, Bednarski RM, Mason DE.One hundred sixty horses were anesthetized with xylazine, guaifenesin, thiamylal, and halothane for elective soft tissue and orthopedic procedures. Horses were randomly assigned to one of four groups. Group 1 (n = 40): Horses positioned in lateral (LRG1; n = 20) or dorsal (DRG1; n = 20) recumbency breathed spontaneously throughout anesthesia. Group 2 (n = 40): Intermittent positive pressure ventilation (IPPV) was instituted throughout anesthesia in horses positioned in lateral (LRG2; n = 20) or dorsal (DRG2; n = 20) recumbency. Group 3 (n = 40): Horses positioned in lateral (LRG3; n = 20) or d...
Dabareiner RM, Snyder JR, White NA, Pascoe JR, Harmon FA, Gardner I, Woliner MJ, Pinney D, Sullins KE.Microvascular permeability of the jejunum of clinically normal equids and microvascular permeability associated with 60 minutes of ischemia (25% baseline blood flow) and subsequent reperfusion were investigated. Eight adult horses were randomly allotted to 2 equal groups: normal and ischemic/reperfusion injury. Lymphatic flow rates, mesenteric blood flow, and lymph and plasma protein concentrations were determined at 15-minute intervals throughout the study. Microvascular permeability was determined by estimates of the osmotic reflection coefficient, which was determined when the ratio of lymp...
Todd FG, Stermitz FR, Schultheis P, Knight AP, Traub-Dargatz J.Horses in a few, localized northern Colorado pastures exhibited weight loss and colic. At post mortem, intestinal fibrosis and vascular sclerosis of the small intestine was identified. The pastures where the affected horses grazed were overrun by field bindweed (Convolvulus arvensis). Bindweed from the pasture was found to contain the tropane alkaloids tropine, pseudotropine, and tropinone and the pyrrolidine alkaloids cuscohygrine and hygrine. Laboratory mice readily ate C. arvensis and exhibited a variety of abnormal clinical signs depending on the amount eaten. Similar alkaloids have been f...
Price JS, Jackson B, Eastell R, Goodship AE, Blumsohn A, Wright I, Stoneham S, Lanyon LE, Russell RG.Biochemical markers of bone metabolism were analysed in serum samples obtained from 60 horses with no history of orthopaedic disease (age 3 months-20 years). Serum levels of the carboxyterminal propeptide of type I procollagen (PICP), a marker of bone formation and the pyridinoline cross linked telopeptide domain of type I collagen (ICTP), a putative marker of bone resorption, were measured by radioimmunoassay (RIA). Serum levels of the bone specific isoenzyme of alkaline phosphatase (BALP), another marker of bone formation, were measured by a wheatgerm agglutinin affinity (WGA) method. Total ...
Gawor JJ.The digestive tracts of 50 working horses from private farms in Poland were examined. Thirty-seven nematode species, two tapeworm species and one species of botfly were recovered. The most prevalent small strongyle species were Cyathostomum catinatum, Cylicocyclus nassatus, Cylicostephanus goldi, Cylicostephanus longibursatus, Cyathostomum coronatum, Cylicostephanus calicatus, Cylicocyclus leptostomus and Cylicostephanus minutus. Thirteen cyathostome species showed a site preference in the ventral colon, five in the dorsal colon and three in the caecum. One species, Cylicocyclus triramosus, wa...
Lichtenstein DL, Rushlow KE, Cook RF, Raabe ML, Swardson CJ, Kociba GJ, Issel CJ, Montelaro RC.As an important enzyme in DNA synthesis, dUTPase is present in a wide variety of organisms and viruses and has been identified as a component of the equine infectious anemia virus (EIAV) pol gene. The role of EIAV dUTPase, designated DU, in virus replication in vitro and in vivo was investigated with a recently described infectious molecular clone of EIAV. A deletion mutant that was deficient in dUTPase activity was constructed, and its replication kinetics was examined in fetal equine kidney (FEK) cells and primary equine bone marrow macrophage (EBMM) cells. In FEK cells, which are permissive...
Moore RM, Muir WW, Granger DN.Restoration of blood flow after a period of intestinal ischemia is necessary to maintain cell function and viability; however, the reintroduction of oxygen can initiate a cascade of events that exacerbates tissue injury. Intestinal I-R injury is manifested as increased microvascular and mucosal permeability, and mucosal necrosis. Reperfusion injury begins with the accumulation of hypoxanthine from ATP metabolism and the conversion of XDH to XO during ischemia. Upon reperfusion, the XO catalyzes the conversion of hypoxanthine to superoxide radicals in the presence of oxygen. Superoxide radicals...
Zientara S, Sailleau C, Moulay S, Wade-Evans A, Cruciere C.The development of a coupled reverse transcriptase-polymerase chain reaction assay (RT-PCR) is described for the detection of African horse sickness virus (AHSV) double-stranded RNA. Genome segments 7 and 10 were chosen as target templates for primers selected for use in the RT-PCR. Using these AHSV-specific primers all 9 serotypes were detectable. The sensitivity and specificity of the RT-PCR results were compared to those obtained by competition ELISA.
Zhao Y, Holden VR, Smith RH, O'Callaghan DJ.The UL3 protein of equine herpesvirus 1 (EHV-1) KyA strain is a homolog of the ICP27 alpha regulatory protein of herpes simplex virus type 1 (HSV-1) and the ORF 4 protein of varicella-zoster virus. To characterize the regulatory function of the UL3 gene product, a UL3 gene expression vector (pSVUL3) and a vector expressing a truncated version of the UL3 gene (pSVUL3P) were generated. These effector plasmids, in combination with an EHV-1 immediate-early (IE) gene expression vector (pSVIE) and chimeric EHV-1 promoter-chloramphenicol acetyltransferase (CAT) reporter constructs, were used in trans...
Koupai-Abyazani MR, Yu N, Esaw B, Laviolette B.Urine and serum samples collected from four standard-bred mares after 30-mg intraarticular administrations of triamcinolone acetonide were analyzed using combined high-performance liquid chromatography-atmospheric pressure ionization mass spectrometry. Maximum triamcinolone acetonide concentrations of 32.3, 14.8, 24.3, and 29.4 ng/mL in the urine and 2.7, 1.9, 2.3, and 2.5 ng/mL in the serum samples were observed. The peak concentrations of the drug were detected approximately 22 h (urine) and 12 h (serum) after administration. The drug elimination profiles for both urine and serum are present...
Kim W, Kawcak CE, McIlwraith CW, Firth EC, Broom ND.To describe and measure histologic features of midcarpal joint cartilage defects in Thoroughbreds and evaluate the influence of early conditioning exercise on defect development. Methods: 24 midcarpal joints from twelve 18-month-old Thoroughbreds. Methods: Midcarpal joints from 12 horses (6 exercised spontaneously at pasture only and 6 given additional conditioning exercise beginning at a mean age of 3 weeks were evaluated. Gross cartilage defects were assessed histologically. Third and radial carpal bones were categorized with regard to the presence or absence of calcified cartilage (CC) abno...
Karakka Kal AK, Perwad Z, K Karatt T, Nalakath J, Subhahar M.Recently, an increased tendency to use various metals has been observed in the sports competition fields. Many of these metals and their organic complexes reportedly have good pharmacologic, therapeutic and performance-enhancement uses; they are banned or recommended as controlled medications in competitive sports. The objective of this research was to determine the concentration of pharmacologically relevant metals in urine samples collected from racehorses at various sport events, develop a method and assess the concentrations of above metals using inductively coupled plasma mass spectrometr...
To evaluate the effect of four recumbent body positions on intraocular pressure (IOP) in anesthetized normal horses. Methods: Ten nonglaucomatous adult horses. Methods: Intraocular pressure was measured with a rebound tonometer in both eyes of standing sedated horses (baseline), then under general anesthesia during four randomized recumbent body positions, including Trendelenburg (Tr; 15-degree head down), reverse Trendelenburg (RTr; 15-degree head up), dorsal, and lateral; only the superior eye was measured in lateral positions. The mean of 3 IOP readings was taken at each position, allowing ...
Stolz I, Tillmann V, Anneken V, Froboese I.Scientific investigation and documentation of equine-assisted therapy has increased over the past several years. Yet there are no standardized and validated tools for evidence-based measurement of processes and outcomes to assess equine-assisted interventions. Objective: The objective of this cross-sectional survey study was to develop a standardized assessment tool for the effective measurement of equine-assisted therapy based on the common language of the International Classification of Functioning, Disability and Health (ICF) framework of the World Health Organization (WHO). Methods: Cross-...
Matthews JB, Dowdall SM, Baudena MA, Klei TR, Kaplan RM, von Samson-Himmelstjerna G, Drögemüller M, Schnieder T.This collection of articles provides an in depth account of five presentations delivered during the Symposium on Equine Cyathostomins held at the 19th International Conference of the World Association for the Advancement of Veterinary Parasitology (WAAVP), New Orleans, Louisiana,10–14 August 2003. The symposium was organized and chaired by Ray M. Kaplan and Jacqui B. Matthews and focused on new developments in two major areas of current importance: the immunobiology of cyathostomin–horse interactions and anthelmintic resistance.
Caloni F, Spotti M, Villa R, Mariani C, Montana M, Pompa G.An investigation was undertaken to demonstrate whether therapeutic treatment with ACTH raises hydrocortisone (cortisol) levels in horse urine above the limit (1000 ng/ml) established by the International Conference of Racing Authorities with the aim of controlling the abuse of cortisol and ACTH in equine sports. ACTH (200 iu) was administered i.m. to 3 Thoroughbred horses; urine and blood samples were collected at intervals afterwards and analysed by an immunoenzymatic system (ELISA) and HPLC-MS. To ascertain post exercise cortisol levels in untreated horses, 101 urine and 103 serum samples we...
Vanderwagen LC, Pearson JL, Franti CE, Tamm EL, Riemann HP, Behymer DE.As a result of the continuing threat of Venezuelan equine encephalomyelitis (VEE), a study was made to determine if revaccination against VEE (TC-83 vaccine) was feasible and if revaccination could be incorporated into other routine vaccination practices. Of the horses given annual vaccination with bivalent western equine encephalomyelitis (WEE) and eastern equine encephalomyelitis (EEE) vaccine, 57% retained detectable serum-neutralizing (SN) antiboyd titers for VEE 18 months after the initial VEE vaccination was given. Of horses with no record of WEE-EEE vacinnation, 100% retained detectable...
Patterson-Kane JC, Sanchez LC, MacKay RJ, Sundberg JP, Homer BL.A 4-year-old Quarter Horse gelding was presented with a history of weight loss of 6 months duration, along with extensive ventral subcutaneous edema. Clinicopathologic findings included a markedly low serum total protein (2.9 g/dl) and a low packed cell volume (24%). The mucosal surface of the distal jejunum and entire ileum were carpeted with numerous polypoid, papillary, and glandular masses comprised of pseudostratified tall columnar cells and large numbers of interspersed goblet cells. Neoplastic change was diffuse throughout the mucosa of each mass, but abrupt demarcation occurred between...
Suárez-Bonnet A, Espinosa de los Monteros A, Herráez P, Rodríguez F, Andrada M, Caballero MJ.A 4-year-old female Appaloosa horse was referred to the Department of Comparative Pathology, Veterinary Faculty, with a history of colic and acute respiratory distress. At necropsy, gross lesions consisted of extensive firm, multinodular, hemorrhagic foci in fat tissues with yellow-brown discoloration. The most affected areas were peritoneal fat and perirenal, epicardial, and subcutaneous adipose tissues. Other findings were hepatic lipidosis and multiple 1-1.5 cm hemorrhagic foci scattered in both lungs. Histopathological examination revealed severe degeneration and necrosis of adipose tissue...
Draper ACE, Cahalan SD, Goodwin D, Perkins J, Piercy RJ.Equine recurrent laryngeal neuropathy (RLN) is a naturally occurring model of length-dependent axonopathy characterized by asymmetrical degeneration of recurrent laryngeal nerve axons (RLn). Distal RLn degeneration is marked, but it is unclear whether degeneration extends to include cell bodies (consistent with a neuronopathy). With examiners blinded to RLN severity, brainstem location, and side, we examined correlations between RLN severity (assessed using left distal RLn myelinated axon count) and histopathological features (including chromatolysis and glial responses) in the nucleus ambiguu...
Wilson PJ, Clark KA.To determine whether postexposure rabies prophylaxis (PEP) in domestic animals, as mandated by the state of Texas, has continued to be effective and to evaluate PEP and preexposure rabies vaccination failures from 1995 through 1999. Methods: Retrospective study. Methods: 830 unvaccinated domestic animals (621 dogs, 78 horses, 71 cats, and 60 cattle) that received PEP and 4 animals (3 dogs and 1 horse) that had preexposure rabies vaccination failure. Methods: Zoonotic incident case reports from 1995 through 1999 were reviewed for information regarding unvaccinated domestic animals that received...
Putt W, Fisher RA.In this paper we describe seven enzymes, NP, GOTM, PGM2, alpha FUC, PEP A, ADA and MPI which are found in the white cells of horses, including 39 British crossbred ponies and 16 crossbred horses, 30 Mongolian ponies and 10 Icelandic ponies. Two of these enzymes--alpha FUC and MPI--were polymorphic in all the populations of horses studied and could prove useful as additional markers in the paternity testing of horses. PEP A and GOTM were also polymorphic in two of the populations studied and could be used as further markers in these populations.
Anzai T, Timoney JE, Kuwamoto Y, Wada R, Oikawa M, Higuchi T.To develop polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis for molecular typing of strains of Streptococcus zooepidemicus and to use the new typing method to analyze a collection of isolates from the respiratory tract of Thoroughbreds. Methods: 10 strains of S zooepidemicus, 65 isolates from the respiratory tract of 9 yearlings following long distance transportation, and 89 isolates from tracheal aspirates of 20 foals with pneumonia. Methods: Phenotypic variations in the SzP protein were detected by western immunoblot analysis. Using PCR-RFLP analysis, ge...
Luque I, Fernández-Garayzábal JF, Blume V, Maldonado A, Astorga R, Tarradas C.The anti-microbial susceptibility and genetic diversity of 65 strains of Streptococcus equi ssp. zooepidemicus (Sez) isolated from mares presenting clinical signs of endometritis was determined by disk agar diffusion and pulsed field gel electrophoresis (PFGE) methods, respectively. Overall, Sez isolates were susceptible to beta-lactams, enrofloxacin, trimethoprim-sulfamethoxazole and gentamicin. These anti-microbials could be recommended as empiric anti-microbial therapy in cases of endometritis caused by Sez. Pulsed field gel electrophoresis typing revealed a great genetic diversity (56 diff...
Nelson BB, Ragle CA, Barrett MF, Hendrickson DA.An 18-year-old Paint stallion (horse 1) and a 17-year-old Morgan gelding (horse 2) were evaluated because of an acute onset of severe unilateral forelimb lameness. Results: Both horses were unable to bear weight on the affected forelimb and had a dropped elbow appearance. Radial nerve paralysis, triceps myopathy, and fractures of the humerus and ulna were ruled out. The caudal aspect of the affected antebrachium of each horse was very firm to palpation and became firmer when weight was shifted onto the limb. Ultrasonographic examination revealed swelling and suspected intramuscular hemorrhage ...
Schröder J, Swan GE.Ivermectin, described as 22,23-dihydroavermectin B1, was the compound chosen from the avermectin group of compounds for development as an antiparasitic agent in horses. A review of the literature indicates that parenteral administration in horses at 200 microgram/kg body mass is highly effective against the strongyles Strongylus vulgaris, Strongylus edentatus and triodontophorus spp., and adult and immature cyathostomes, including strains resistant to benzimidazole anthelmintics. Other nematodes controlled in horses include Oxyuris equi, Parascaris equorum, Trichostrongylus axei, and Habronema...
Mahony C, Rantanen NW, DeMichael JA, Kincaid B.Spontaneous echocardiographic contrast is the term used by ultrasonographers to describe particulate material visible in intracardiac blood by ultrasound. The purpose of the present study was to determine the prevalence of spontaneous contrast in a farm population of Thoroughbreds and in the farm's racehorses. The results showed that spontaneous echocardiographic contrast is common in Thoroughbreds, and that the prevalence of contrast is affected by age, male gender, racing and pregnancy. The amount of right-sided cardiac contrast was quantitated by videodensitometry and was increased in horse...
Eiler H, Goble D, Oliver J.The plasma concentration of hydrocortisone was determined in mares given either cosyntropin (100 IU, given IV) or corticotropin (200 IU, given IM). Plasma hydrocortisone concentrations of the mares treated with cosyntropin increased by 46%, 57% and 80% at 30, 60, and 120 minutes, respectively, when compared with base-line values; these values returned to base line at 240 minutes. In mares treated with corticotropin, mean plasma hydrocortisone concentrations increased by 42%, 143%, 101% and 155% at 30, 60, 120, and 240 minutes, respectively, when compared with base-line values. Differences in t...
Oliveira SN, Segabinazzi LGTM, Canuto L, Lisboa FP, Medrado FE, Dell'Aqua JA, Aguiar AJA, Papa FO.The goal of this study was to compare the efficiency of histrelin acetate (GnRH analog) and human chorionic gonadotropin (hCG) to hasten ovulation in Brazilian Northeastern jennies (Equus africanus asinus). Thirty cycles of ten jennies were randomly assigned in one of the three groups: G0 (control group), saline; G1, 250 μg of histrelin acetate; G2, 2500 IU of hCG. Jennies were evaluated by transrectal palpation and ultrasonography, and had the administration of an ovulation-inducing agent when a follicle measuring between 29 and 32 mm of diameter was diagnosed. Jennies were monitored every...
Bailey SR, Andrews MJ, Elliott J, Cunningham FM.Altered platelet responsiveness has been demonstrated in human atopic dermatitis. This study has compared the in vitro function of platelets from normal ponies and those with the allergic skin disease, sweet itch. Methods: Ponies with a clinical history of sweet itch and normal ponies were used as blood donors. Methods: PAF and ADP-induced platelet aggregation was measured and TxB2 production quantitated at the time of maximal aggregation; 12-HETE was additionally measured in some samples. Agonist-induced release of 3[H]5-HT was also studied. Results: Although both PAF and ADP caused equine pl...
Soma LR, Uboh CE, Guan F, Birks EK, Teleis DC, Rudy JA, Tsang DS, Watson AO.To determine pharmacokinetics and excretion of phenytoin in horses. Methods: 6 adult horses. Methods: Using a crossover design, phenytoin was administered (8.8 mg/kg of body weight, IV and PO) to 6 horses to determine bioavailability (F). Phenytoin also was administered orally twice daily for 5 days to those same 6 horses to determine steady-state concentrations and excretion patterns. Blood and urine samples were collected for analysis. Results: Mean (+/- SD) elimination half-life following a single IV or PO administration was 12.6+/-2.8 and 13.9+/-6.3 hours, respectively, and was 11.2+/-4.0 ...
Bayly WM, Slocombe RF.Effects of respiratory tract obstructions on ventilatory mechanics in horses exercising at high speeds were tested with a fibreglass replica of the airways (nares to mainstem bronchi) of an adult horse. Segmental pressures were recorded at six sites along the model at four different unidirectional flows (1300-4100 litre min-1), and the respective resistances (R) to airflow were calculated. The external nares and the larynx made the greatest contributions to the total resistance (RTOT) when no obstruction was present. Modifying the model to simulate severe pharyngeal lymphoid hyperplasia (PLH) ...
Erkert RS, Macallister CG, Campbell G, Payton ME, Shawley R, Clarke CR.Local anesthesia and tissue inflammation associated with lidocaine infiltration and lidocaine/prilocaine topical anesthetic cream for episioplasty in mares were compared. Twenty-two mares were randomly assigned to lidocaine or lidocaine/prilocaine topical anesthetic cream treatment groups. Perineum and vulva were cleaned, 8-12 g (approximately 1 g/cm per side of vulva) of topical anesthetic cream was applied, and the area was covered by plastic wrap 30 min prior to beginning procedure. Alternately, lidocaine was injected (1 mL) every centimeter just prior to the procedure. Episioplasty was con...
