Experimental methods in equine research encompass a variety of techniques and procedures used to investigate physiological, behavioral, and health-related aspects of horses. These methods are designed to collect data that can enhance the understanding of equine biology and inform veterinary practices. Common experimental approaches include controlled trials, observational studies, and laboratory-based experiments. Techniques may involve the use of non-invasive imaging, biochemical assays, and physiological monitoring to assess parameters such as metabolic function, locomotion, and disease progression. This page compiles peer-reviewed research studies and scholarly articles that explore the application, development, and evaluation of experimental methods in the study of equine science.
Pablo LS, Purohit RC, Teer PA, Newton JC, Hammond LS.Total strangulation obstruction of the caudal part of the jejunum was induced in 3 groups (each of 3 ponies) for 2, 4, and 6 hours. Coagulation tests which included blood platelet counts, prothrombin time, activated partial thromboplastin time, activated coagulation time, plasma fibrinogen level, and fibrin/fibrinogen degradation products assay were performed at specified time intervals for 1 week or until death of the experimental ponies. Another 3 ponies (sham-operated) were similarly treated, except that intestinal strangulation obstruction (ISO) was not induced. Necropsy was done on ponies...
Soma LR, Gallis DE, Davis WL, Cochran TA, Woodward CB.Phenylbutazone (PBZ) was administered (8.8 mg/kg of body weight) every 24 hours for 5 consecutive days, orally for the first 4 days and IV on day 5. The half-life (t 1/2) after this daily administration was 6.2 hours and the volume of distribution was 0.152 +/- 0.014 L/kg; the bioavailability after oral administration was 91.8 +/- 2.5%. The plasma concentration of PBZ at experimental hour (EH) 24 (24 hours after the 1st oral dose) was 1.7 +/- 0.39 micrograms/ml and increased to 4.2 +/- 0.29 micrograms/ml at EH 48 (24 hours after the 2nd oral dose). Values at EH 72, 96, and 120 (24 hours after ...
Becht JL, Page EH, Morter RL, Boon GD, Thacker HL.Serological evidence with or without clinical signs of neonatal isoerythrolysis was experimentally produced in 6 of 8 foals born to mares allo-immunized with washed erythrocytes from the stallion. Blood group antigens were determined in all mares, stallions and foals, and the incompatible antigenic factor(s) responsible for the disease were defined. In 5 of 8 foals born to alloimmunized mares, a single antigenic factor difference accounted for the erythrocyte incompatibility between mare and foal. The erythrocyte antigen suspected as the most responsible for isoerythrolysis observed was A1. Ag...
Toro M, León E, López R, Pallota F, Garcia JA, Ruíz A.Assays dealing with the therapeutic and prophylactic activity of isometamidium on experimental infections by Trypanosoma vivax and T. evansi were carried out. The drug was found to be highly effective against T. vivax infection in sheep and cattle in which periods of protection ranging from 118 to 195 days were achieved. No complete effects against infection by T. evansi were observed. The drug was well tolerated in sheep and cattle while side-effects were noted in treated mares. It was concluded that isometamidium could be used to prevent damage and economical losses caused by T. vivax in Ven...
Johnson JA, Prescott JF, Markham RJ.Six foals were inoculated intrabronchially with a suspension of Corynebacterium equi. Six weeks before this challenge, three foals were vaccinated with a C. equi bacterin. Three foals were unvaccinated controls. All foals developed a severe bronchopneumonia in the inoculated lung, indicating that vaccination was not protective. Three foals (two vaccinated, one control) were killed eight to nine days after infection. One control died on day 9 with lesions of disseminated intravascular coagulation. The remaining two foals (one vaccinated, one control) were killed on day 17. C. equi was cultured ...
Blanchard TL, Elmore RG, Youngquist RS, Loch WE, Hardin DK, Bierschwal CJ, Ganjam VK, Balke JM, Ellersieck MR, Dawson LJ, Miner WS.Fifty mature pony stallions were randomly assigned to one of five treatment groups: Group 1- controls (no treatment), Group 2 - 0.55 mg/kg stanozolol weekly for 13 treatments, Group 3 - 1.1 mg/kg stanozolol every 3 weeks for 5 treatments, Group 4 - 1.1 mg/kg boldenone undecylenate every 3 weeks for 5 treatments, and Group 5 - 0.55 mg/kg boldenone undecylenate weekly for 13 treatments. Scrotal widths (SW), combined testis weights (CTW), and daily sperm productions (DSP) were not different between Groups 1 and 2. Ponies in Group 5 had smaller SW (P<0.01), smaller CTW and decreased DSP compare...
van Leeuwen W, Noden PA, Dieleman SJ.Three experiments were conducted to test the abortifacient effects of PGF2 alpha analogues on mares during midgestation (average gestation length 141.5 days). The progesterone concentration was measured by radioimmunoassay. In experiment 1. five mares received an injection of PGF2 alpha analogue (fluprostenol: 500 micrograms intramuscularly) and a second injection either at 24, 48, of 72 h. Although the progesterone concentration decreased (P less than 0.05) an average of 44 per cent in 24 h, none of the pregnancies were terminated. In experiment 2, beginning at least 10 days after experiment ...
Johnson JA, Prescott JF, Markham RJ.The intragastric inoculation of a suspension of Corynebacterium equi on five consecutive days induced severe ulcerative colitis, typhlitis, and lymphadenitis of colonic and cecal nodes in two ponies necropsied three weeks after infection. No gross lesions were observed in two ponies necropsied ten days after infection. A single inoculum of equivalent size failed to induce gross lesions in four ponies killed at ten or 20 days after infection. Microscopic lesions consistent with early C. equi infection of Peyer's patches were seen in two of the ponies killed ten days after infection. Only one sm...
Roberts MC, Seawright AA.Colic was induced in horses and ponies following topical or intravenous (iv) administration of amitraz, a formamidine acaricide. The condition was characterised by rapid cessation of intestinal sounds, stasis, extensive impaction and tympany throughout the large colon. Three animals that were necropsied had a faecalith obstructing the proximal small colon aboral to marked colonic impaction. A reproducible and reversible impaction colic syndrome could be induced by an iv injection of 1 mg amitraz/kg body weight in solvent. There were immediate central nervous system and intestinal signs. Large ...
Harrington DD, Page EH.Acute vitamin D toxicosis was diagnosed in 2 horses fed a grain ration containing 1,102,311 IU of cholecalciferol (vitamin D3)/kg (500,000 IU/lb) for about 30 days. Horse 1 died acutely with extensive mineralization of cardiovascular and other soft tissues. Horse 2, which had severe clinical signs and clinicopathologic changes of toxicosis, was treated with nonsteroidal antiinflammatory drugs and recovered in about 6 months. In an experimental study, the toxicity of ergocalciferol (vitamin D2) and cholecalciferol was compared in 2 horses (No. 3 and 4) given the respective vitamins at a daily d...
The Journal of hygieneJune 1, 1983
Volume 90, Issue 3 385-395 doi: 10.1017/s0022172400029016
Mumford J, Wood JM, Scott AM, Folkers C, Schild GC.Forty ponies immunized with inactivated virus vaccine containing A/equine/Miami/63 (H3N8) virus and six unvaccinated, seronegative ponies were experimentally challenged with a representative of recent equine H3N8 virus isolates, A/equine/Newmarket/79. All unvaccinated ponies became infected as judged by virus excretion, febrile responses and antibody responses, but only two of the vaccinated ponies were fully protected. Pre-challenge antibody levels to A/Newmarket/79 virus detected by single radial haemolysis (SRH) correlated well with the degree of clinical protection but the levels required ...
Brown MP, Pool RR.Braided carbon fiber sutures were used to repair surgically transected or lacerated digital flexor tendons of 20 mature horses (10 experimental and 10 clinical cases). In addition, 4 experimental horses had tenectomies that were not surgically repaired; these served as controls for the horses with carbon-implanted tendons. Six of the 10 clinically affected horses were returned to their intended use; 2 were euthanatized because of complications and 2 were still recuperating. The experimental horses were euthanatized at 12 days and 1, 2, 4, 8, and 12 months. Tendon scars were structurally and fu...
Zamansky GB, Arundel C, Nagasawa H, Little JB.The growth of two human diploid skin fibroblast cell lines, originally grown in medium supplemented with foetal bovine serum and later adapted to medium supplemented with newborn bovine, bovine calf or horse serum, has been studied. Prolonged generation times increased cell volumes and decreased plating efficiencies were observed in cultures grown in newborn bovine, bovine calf or horse serum. In general, the deleterious effects were most severe as a result of growth in bovine calf or horse serum. In the light of the present findings, we believe investigators should exert great caution in swit...
Cho SN, Collins MT, Reif JS, McChesney AE.Attempts to infect horses with Legionella pneumophila were undertaken to determine pathogenicity and to evaluate the possibility that horses serve as a reservoir for the organism. A previous study showed that the prevalence of antibodies to L pneumophila in the equine population exceeded 30% of over 600 sera examined. Horses were infected experimentally with the Philadelphia 1 or Bloomington 2 strain of L pneumophila IV or by aerosolization. Signs of clinical illness were restricted to a transient febrile response. A transient decrease in circulating lymphocytes occurred 2 days after inoculati...
Thompson DL, Godke RA, Nett TM.Two hormonal treatments, chosen for their effectiveness in other seasonally breeding species, were tested in mares during the nonbreeding season to determine if they could induce ovarian activity and estrus during the winter. Of 15 functionally anestrous (anovulatory) mares, five received intravaginal, polyurethane sponges containing .75 g of melatonin on December 16; fresh sponges containing melatonin were inserted weekly until February 3. These mares also received daily injections of saline. Five other mares received daily im injections of 100 micrograms of thyrotropin-releasing hormone (TRH...
Biewener AA, Thomason J, Goodship A, Lanyon LE.Longitudinal stresses acting in the cranial and caudal cortices of the radius and the dorsal and palmar cortices of the metacarpus in the horse were determined using two independent methods simultaneously. One approach involved the use of rosette strain gauges to record in vivo bone strain; the other involved filming the position of the horse's forelimb as it passed over a force plate. Agreement between the two analyses was better for the radius than for the metacarpus. Both methods showed the radius to be loaded primarily in sagittal bending, acting to place the caudal cortex in compression a...
Wolter R, Durix A, Letourneau JC, Carcelen M, Henry N.One pony has been subjected to the intravenous injections of L-lactic acid. Two other ponies have been trained to intracaecal administration of L-lactic acid or sucrose. The obtained results show that: Intravenous injection of lactic acid increases the concentration of histamin and lactic acid, decreases the level of magnesium and reduces the pressure of carbon dioxide in the blood (the control animals and the treated animals) without the clinical symptoms of lactic acidosis. Intracaecal administration of lactic acid induces a high liberation of histamin in the caecum (the control animals and ...
Timoney PJ, Dillon PB, Geraghty VP, McArdle JF.Aspects of experimental transmission of the causal bacterium of contagious equine metritis (CEM) to albino Swiss mice were investigated. Whereas infection was established in the majority of female mice, the organism was recovered from only a limited number of male mice after challenge. No clinical evidence of infection was observed in the experimental mice. There was only one instance of presumptive venereal transmission of the CEM bacterium. One third of infected females conceived and had normal litters.
Campbell TM, Studdert MJ, Blackney MH.Some kinetic data on the inactivation of equine herpesvirus type 1 (EHV1) and equine rhinovirus type 1 (ERhV1) by betapropiolactone (BPL) and ultraviolet (UV) irradiation are reported. 0.25% BPL at 37 degrees C for 1 h reduced the titre of EHV1 by greater than 10(3 . 4) and of ERhV1 by greater than 10(4 . 1) TCID50/ml. UV irradiation (334 microW/cm2) produced similar reductions in titre after 2 min. These data were used as a basis for inactivating EHV1 and ERhV1 by the combined action of BPL and UV irradiation. Viruses were exposed to 0.1% BPL for 1 h at 4 degrees C with constant stirring, fol...
MacMillan AP, Baskerville A, Hambleton P, Corbel MJ.Five mares, one stallion and a colt foal were inoculated intraconjunctivally with Brucella abortus strain 544. No clinical signs of disease developed except mild pyrexia. Intermittent bacteraemia was detected in the mares but not in the stallion or foal. Antibodies to B abortus became detectable from the second week after inoculation. Titres in the serum agglutination and complement fixation tests declined substantially after six to eight weeks but reactions to the Coombs antiglobulin, 2-mercaptoethanol and immunodiffusion tests were maintained. No consistent changes in biochemical or haematol...
Ayliffe TR, Allen WE.PREVIOUS studies have shown that instillation of sodium benzylpenicillin into the uterine lumen of ponies in small volumes is followed by peak plasma concentrations of the antibiotic in 10to 15 mins (Allen 1978; Allen and Clarke 1978). However, the assumption that the circulating penicillin is absorbed only through the endometrium is questionable because Allen, Kessy and Noakes (1979) concluded that the intrauterine instillation of phenolsulphonphthalein was followed by absorption of the dye from the peritoneal cavity, after passage along the uterine tubes.
The present investigation was carri...
Cysewski SJ, Pier AC, Baetz AL, Cheville NF.Adult male Shetland ponies, two per dose level, were given aflatoxin daily at levels of 0.3, 0.15, or 0.075 mg/kg. Signs of toxicosis included inappetence, depression, tremors, and terminal prostration. Deaths occurred at 12 and 16 days (0.3 mg/kg), 25 and 32 days (0.15 mg/kg), and 36 and 39 days (0.075 mg/kg). Prothrombin time, sulfabromophthalein clearance time, total plasma bilirubin, and icteric index increased markedly before death. Elevations in plasma activity of aspartate amino transferase (AST) were observed 1 to 4 days after the start of aflatoxin administration in the high dose grou...
Malan FS, De Vos V, Reinecke RK, Pletcher JM.Infective larvae were harvested from a culture of eggs collected from adult Strongylus asini recovered from a free-ranging Burchell's zebra, Equus burchelli, in the Kruger National Park. Worm-free zebra, horse and donkey foals were successfully infested, but infestation failed in a mule foal. At slaughter, 117-125 days post-infestation, S. asini in their 4th moult were recovered from the liver and portal veins. This is the first report of successful experimental infestation of these hosts with S. asini.
Drudge JH, Lyons ET, Tolliver SC.In 1973-1974, 4 controlled tests were performed in pony foals (n = 17) raised parasite-free and experimentally infected with Strongyloides westeri. Administration of infective larvae by stomach tube in 1 test resulted in low-grade infections and tended to invalidate the test. Intraoral and percutaneous (intra-aural) administration of larvae resulted in suitable test infections for 1 and 2 tests, respectively. A paste formulation of dichlorvos at 36.3 mg/kg of body weight removal from 4 ponies. Treatment of 4 the dosage rate of 44 mg/kg was consistently effective (greater than 99% to 100%) for ...
Sod GA, Riggs LM, Mitchell CF, Martin GS, Gill MS.To compare the number of cycles to failure of 4.5 mm broad dynamic compression plates (DCP), 4.5 mm broad limited-contact dynamic compression plates (4.5-LC-DCP), and 5.5 mm broad limited-contact dynamic compression plates (5.5-LC-DCP) having a rough (denoted by a prefix R-) versus a standard smooth contact surface for the fixation of osteotomized equine 3rd metacarpal (MC3) bones. Methods: Experimental. Methods: Fifteen pairs of adult equine cadaveric MC3 bones. Methods: Fifteen pairs of equine MC3 were divided into 3 test groups (5 pairs each) for comparison of (1) R-DCP fixation with DCP fi...
Van Eenoo P, Deventer K, Delbeke FT.A sensitive, accurate and precise liquid chromatography/tandem mass spectrometry (LC/MS(2)) method was developed for the quantification of salmeterol in the urine of horses. The method consists of a liquid-liquid extraction with tert-butylmethyl ether and isopropanol at pH 12 after enzymatic hydrolysis. The extracts are analysed using an LC/MS system equipped with an electrospray ionisation (ESI) probe. Method validation showed excellent linearity, specificity, accuracy, precision and intra-laboratory repeatability and reproducibility. The limit of quantitative detection was 0.25 ng/mL and the...
Bodurov N, Filipov Zh.Comparative clinical and experimental investigations were carried out on 18 clinically normal horses. It was found that the single transfusion of in vitro UV-treated autogenous blood, following a previously described method, was tolerated well by horses and did not lead to any deviations from the normal indices. Under the effect of the treated blood there was an increase in the hemoglobin content, rise in the erythrocyte and leukocyte count with slightly expressed hyperleukocytosis and weak neutrophilia (simple regeneration of the blood). The sedimentation of erythrocytes also showed higher ra...
Crowson CL, Jann HW, Stein LE, Claypool LP, Moll HD, Blaik MA.To compare effects of the locking-loop suture pattern (LLP) and 3-loop pulley (3LP) suture pattern for tenorrhaphy on the intrinsic vasculature of the superficial digital flexor tendon (SDFT) of horses in vitro after surgery. Methods: 16 forelimbs obtained from 8 mature horses. Methods: Tenotomy and subsequent tenorrhaphy was performed in anesthetized horses. Following systemic administration of heparin, horses were euthanatized and the limbs were removed and placed under tension to load the flexor tendons. The intrinsic vasculature was then perfused with a mixture of barium sulfate and water....
Jacobs CC, O'Neil E, Prange T.To determine the ability of a commercial cryotherapy system (Game Ready Equine) to cool the metacarpal subcutaneous tissue and the superficial digital flexor tendon (SDFT) in horses. Methods: Experimental study. Methods: Six healthy adult horses. Methods: Thermocouples were implanted into the metacarpal subcutaneous tissues and the SDFT of six horses. Two treatments (cryotherapy or cryotherapy with 5-50 mmHg intermittent compression) were randomly assigned to forelimbs and performed for 20 minutes. Temperatures were compared to the target range of 10-19°C and between groups. Results: Only...
Barrett EJ, Munsterman AS, Hanson RR, Jackson RL.To compare in vitro strength and failure characteristics of a tendon implant against a 3 loop pulley suture pattern for equine superficial digital flexor tendon (SDFT) laceration repair. Methods: Experimental. Methods: Cadaveric equine forelimb SDFT (n = 16). Methods: One tendon of each of 8 pair of SDFT was randomly selected for repair with either the 3-loop pulley (3LP) suture pattern using 2 polydioxanone or with 4 stainless steel suture and anchor implants (SA). Ultimate load to failure, mode of failure, gap at failure, and load to 2 mm gap were obtained using a materials testing sys...
Caron JP, Eberhart SW, Nachreiner R.Articular cartilage explants from 3 horses were maintained in tissue culture to test the effects of a polysulfated glycosaminoglycan on proteoglycan biosynthesis. Cultures were exposed to concentrations of 0, 50, or 200 micrograms of the drug/ml for either 2 days or 6 days, and labeled with 35S, before measuring the content of sulfated proteoglycan in the culture media and in extracts of cartilage. In a second experiment, the explants were incubated with the isotope and subsequently exposed to the same concentrations of the polysulfated glycosaminoglycan for 4 days. Subsequently, the amount of...
Wagner IP, Hood DM.To evaluate the effect of prolonged water exposure on tissue mass and solutes of outer and inner layers of the stratum medium, sole, frog, and the stratum medium (SMZA) zona alba layer of horses' hooves. SPECIMEN POPULATION: 10 hooves from 10 horses without foot abnormalities. Methods: Hoof wall tissue specimens were obtained and immersed for 10 days in distilled deionized water. Serial changes in mass were recorded during the immersion period. Subsequently, osmolarity and Na+, K, Cl-, and protein concentrations of the immersion solution were quantified. Results: Fully cornified outer hoof wal...
Woodie JB, Ruggles AJ, Litsky AS.To evaluate 2 methods of midbody proximal sesamoid bone repair--fixation by a screw placed in lag fashion and circumferential wire fixation--by comparing yield load and the adjacent soft-tissue strain during monotonic loading. Methods: Experimental study. Methods: 10 paired equine cadaver forelimbs from race-trained horses. Methods: A transverse midbody osteotomy of the medial proximal sesamoid bone (PSB) was created. The osteotomy was repaired with a 4.5-mm cortex bone screw placed in lag fashion or a 1.25-mm circumferential wire. The limbs were instrumented with differential variable relucta...
Merritt AM, Xie H, Lester GD, Burrow JA, Lorenzo-Figueras M, Mahfoud Z.To evaluate the reliability of a method for inducing colic via small intestinal distention in horses and to examine the analgesic potential of bilateral electroacupuncture (EAP) at the Guan-yuan-shu (similar to BL21) acupoint. Methods: 5 healthy adult horses, each with a gastric cannula. Methods: A polyester balloon connected to an electronic barostat was introduced into the duodenum via the gastric cannula. At 2 specified intervals (before and after commencement of EAP), the balloon was inflated to a barostat-controlled pressure that induced signs of moderate colic. Each inflation was maintai...
Gracia-Calvo LA, Martín-Cuervo M, Jiménez J, Vieítez V, Argüelles D, Durán ME, Ezquerra J.To develop an experimental standing hand-assisted laparoscopic splenectomy (HALS) technique, report the associated peri-operative complications and document the short-term surgical outcomes. Results: Five healthy 300-470 kg horses that underwent standing HALS. Spleens of different weights (2.25-7.0 kg) were removed using this technique. The main complication during surgery was difficulty sectioning the gastrosplenic ligament. The postoperative complications included adhesions of the colon to the nephrosplenic ligament stump and incisional discharge in two horses. Conclusions: Standing HALS...
Thomas AL, Schramme MC, Lepage OM, Segard EM.An awareness of magnetic susceptibility artifacts is important for interpreting prepurchase and postoperative magnetic resonance imaging (MRI) studies in horses. These artifacts occur when a metallic or a paramagnetic substance creates a local magnetic field deformity. Aims of the current experimental study were to determine prevalence of these artifacts after arthroscopy in a sample of nonlame horses, and to describe effects of time and type of pulse sequence on low-field MRI signal intensity and detection of the artifacts. Ten, nonlame Standardbred horses were prospectively recruited. All ho...
Hallebeek JM, Beynen AC.In a Latin square design, six horses were fed hay and concentrates with isoenergetic amounts of either starch, cellulose or medium chain triacylglycerols (MCT). The dietary variables provided on average 22% of total dietary net energy. Plasma triacylglycerols and other variables of lipid metabolism were determined. The experimental periods lasted 21 days. Blood samples were taken just before the morning meal and three and six hours later. The diet rich in MCT significantly raised the plasma level of triacylglycerols when compared to either the starch- or cellulose-rich diet. The plasma concent...
Ingarden J, Dubiel A, Rauluszkiewicz S.This study investigated the effect of a beta blocker on parturition, fetal membrane retention and subsequent fertility in mares. The animals were divided into an experimental group (150 mares treated during second stage labour with propranolol [50 mg i.v.]) and a control group (180 mares with no treatment). Administration of propranolol was associated with a significant decrease in time of expulsion of fetal membranes, and an increase in both exhibition of foal heat and pregnancy rates at this heat.
Karasu GK, Krabbenborg R, Einspanier A, Vervuert I.This study aimed to investigate the effect of a second meal of a fibre- or starch-enriched compound feed on glycaemic and insulinaemic responses in healthy horses. In a cross-over design, horses were fed either a starch-enriched compound feed (SCF) or a fibre-enriched compound feed (FCF). On days of blood collection, test diets were fed in the morning (0800 h, first meal) and a second meal was fed 510 min after the first meal was finished (second meal). Significantly higher glycaemic and insulinaemic responses were associated with SCF compared with FCF. Feeding FCF for the second meal yiel...
The objective of this study was to test the efficacy of an equine pericardial patch for repairing full-thickness defects of the stomach wall. Methods: Circular defects, 1.5 cm in diameter, were created on the anterior wall of the stomach of 12 female New Zealand rabbits. The defects were repaired by an equine pericardial patch. After euthanasia at different time intervals (3 days to 8 weeks) a macroscopic evaluation of the abdominal cavity (including adhesion scoring), mechanical testing and a histological examination of the stomach were performed. Results: The animals survived the surgical pr...
Mathes RL, Dietrich UM, Krunkosky TM, Hurley DJ, Reber AJ.To establish a reproducible method for the culture of primary equine corneal epithelial cells, keratocytes, and endothelial cells and to describe each cell's morphologic characteristics, immunocytochemical staining properties and conditions required for cryopreservation. Methods: Corneas from eight horses recently euthanized for reasons unrelated to this study were collected aseptically and enzymatically separated into three individual layers for cell isolation. The cells were plated, grown in culture, and continued for several passages. Each cell type was characterized by morphology and immun...
Lloyd DR, Rose RJ, Duffield AM, Suann CJ.The combination of large doses of sodium bicarbonate and the potent narcotic, etorphine, has reportedly been given to racehorses in attempts to improve their performance and also to "mask" the presence of etorphine in urine samples. The increased urinary output and pH associated with sodium bicarbonate (approximately 500 g) administration may reduce the urinary concentration of etorphine, making it more difficult to detect. Our experiment was designed to examine the effects of this combination. Six Thoroughbred horses were used in a latin-square design with three horse pairs and three treatmen...
Hunt S, Kuo J, Aristizabal FA, Brown M, Patwardhan A, Hedman T.The mechanical properties of the soft palate can be associated with breathing abnormalities. Dorsal displacement of the soft palate (DDSP) is a naturally occurring equine soft palate disorder caused by displacement of the caudal edge of the soft palate. Snoring and a more serious, sometimes life-threatening, condition called obstructive sleep apnea (OSA) are forms of sleep-related breathing disorders in humans which may involve the soft palate. The goal of this study was to investigate the effect of injecting the protein crosslinker genipin into the soft palate to modify its mechanical propert...
Fitzgerald BP.The purpose of this experiment was to investigate whether N-methyl-D,L-aspartate stimulated gonadotropin secretion in mares and to determine the response in two experimental paradigms where gonadotropin secretion is low or elevated. In Experiment 1, conducted during the breeding season (summer), eight long-term ovariectomized mares were treated daily for 21 d with progesterone plus estradiol (n = 4) or oil vehicle. Beginning on Day 14, each mare received, in a randomized design on alternate days, an intravenous injection of either 0, 0.5, 1.0, or 5.0 mg/kg NMA. Treatment with NMA was not accom...
French DD, Klei TR, Taylor HW, Chapman MR.Twenty-one mixed-breed pony foals, reared and maintained under parasite-free conditions, were used to test the efficacy of ivermectin in oral drench and paste formulations (200 micrograms/kg) against 11-day-old migrating larvae of Parascaris equorum. Three replicates of 4 foals and 3 replicates of 3 foals were formed on the basis of age. Foals in replicates of 4 were randomly allocated to be indicators, or to receive vehicle (control) or ivermectin paste or ivermectin liquid. Foals in replicates of 3 were randomly allocated to receive vehicle or ivermectin paste or ivermectin liquid. The recov...
Rice DA, Rice JC.The time it takes audible sound to travel from the trachea to the pleura in five intact, excised horse lungs and one dog lung inflated with several gases was measured. Regression estimates of sound speed at total lung capacity (TLC) using straight line distance from the carina to the pleura are: helium, 775 +/- 60.5 m/s (means +/- 95% confidence limits); air, 282 +/- 23.5; carbon dioxide, 219 +/- 25.5; sulfur hexafluoride, 142 +/- 43.5. With the exception of sulfur hexafluoride, these speeds are 15%-20% less than the free-field speed of sound in each gas. Total airway length did not predict ti...
Guedes A, Aleman M, Davis E, Tearney C.To determine physiologic responses to apnea-induced severe hypoxemia in anesthetized horses. Methods: Prospective experimental study. Methods: Six university-owned horses with a median (range) body weight of 500 (220-510) kg and aged 13.5 (0.8-24.0) years scheduled for euthanasia. Methods: Xylazine-midazolam-ketamine-anesthetized horses breathing room air spontaneously were instrumented with a facial artery catheter for pressure measurement and blood sampling, and were made apneic with atlanto-occipital intrathecal lidocaine (4 mg kg ). Cardiopulmonary, biochemical and hematologic variable...
Adam CD.The formation and release under gravity of blood droplets from simulated weapon tips has been investigated experimentally and the results analysed and interpreted using established theoretical models for detached pendent drops. Droplets were produced from a series of conical nozzles, manufactured with a range of cone angles and including a set of un-bored conical tips, under conditions where the tip was either non-wetted or pre-wetted with blood. For the former, radius-limited case, detached droplet volumes were found to agree well with the predictions of both the pendent drop weight and drop ...
Hopper SA, Schneider RK, Ratzlaff MH, White KK, Johnson CH.To determine the ability of a full-limb transfixation pin cast to protect the distal portion of the equine forelimb from weight-bearing forces by measuring bone strain in vitro on cadaver limbs loaded in a mechanical testing machine. Methods: 6 forelimbs from 6 horses. Methods: Each limb was instrumented with 3 unidirectional metal foil electrical resistant strain gauges. Gauges were placed on the dorsal aspect of the distal portion of the radius and the mid-dorsal portion of the cortex of the third metacarpal bone and the first phalanx. Each limb was tested 3 times, once supported with a tran...
Velloso Alvarez A, Wooldridge AA, Fuller J, Shrader SM, Mansour M, Boone LH.No studies have evaluated the effect of culture in serum-free media (SF) vs. media supplemented with equine serum (ES) on co-culture of synovial membrane and cartilage tissue explants. The study objective was to evaluate the effects of equine serum supplementation on induced production of inflammatory and catabolic mediators from articular cartilage and synovial explants while in co-culture. Articular cartilage and synovial membrane explants were harvested from femoropatellar joints of five adult horses. Cartilage and synovial explants were harvested from the stifle of five horses, placed in c...
Wolter R, Durix A, Letourneau JC, Carcelen M, Henry N.One pony has been subjected to the intravenous injections of L-lactic acid. Two other ponies have been trained to intracaecal administration of L-lactic acid or sucrose. The obtained results show that: Intravenous injection of lactic acid increases the concentration of histamin and lactic acid, decreases the level of magnesium and reduces the pressure of carbon dioxide in the blood (the control animals and the treated animals) without the clinical symptoms of lactic acidosis. Intracaecal administration of lactic acid induces a high liberation of histamin in the caecum (the control animals and ...
Fayrer-Hosken R, Stanley A, Hill N, Heusner G, Christian M, De La Fuente R, Baumann C, Jones L.The cellular effects of tall fescue grass-associated toxic ergot alkaloids on stallion sperm and colt testicular tissue were evaluated. This was a continuation of an initial experiment where the effects of toxic ergot alkaloids on the stallion spermiogram were investigated. The only spermiogram parameter in exposed stallions that was affected by the toxic ergot alkaloids was a decreased gel-free volume of the ejaculate. This study examined the effect of toxic ergot alkaloids on chilling and freezing of the stallion sperm cells. The effect of toxic ergot alkaloids on chilled extended sperm cell...
Booth LC, Oxender WD, Douglas RH, Woodley SL.A gonadotropin-releasing hormone (GnRH) was injected in mares given prostaglandin F2 alpha (PGF2 alpha) to induce luteolysis in an attempt to sunchronize ovulation. Pretreatment with estradiol-17 beta (E2-17 beta) was used to determine whether or not estradiol would enhance the release of luteinizing hormone (LH) after treatment with GnRH. Twelve mares were used in a balanced Latin square crossover design. Mares were injected with PGF2 alpha, treatment A; PGF2 alpha mgnRH, treatment B; or PGF2 alpha me2-17 beta mgnRH, treatment C. The interval +/- SEM from PGF2 alpha injection to estrus was 3....
Casella S, Piccione D, Ielati S, Bocchino EG, Piccione G.The aim of this study was to assess the anion transport in equine erythrocytes through the measurement of the sulfate uptake operating from band 3 using different experimental temperatures and buffer solutions. Blood samples of six clinically healthy horses were collected via jugular vein puncture, and an emochrome-citometric examination was performed. The blood was divided into four aliquots and by centrifugation and aspiration the plasma and buffy coat were carefully discarded. The red blood cells were washed with an isosmotic medium and centrifuged. The obtained cell suspensions were incuba...
