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.
Chang Y, Novosol V, McDonough SP, Chang CF, Jacobson RH, Divers T, Quimby FW, Shin S, Lein DH.Eight 1-year-old ponies were vaccinated with recombinant OspA (ospA gene derived from B. burgdorferi B31) with adjuvant (aluminium hydroxide). Four ponies were used as non-vaccinated controls with adjuvant. One hundred and twelve days after the first vaccination, the vaccinated and non-vaccinated ponies were challenged by exposure to B. burgdorferi-infected adults tick (Ixodes scapularis) collected from Westchester County, New York (tick infection rate >/=60%). Protection from infection was evaluated by culture for B. burgdorferi from three monthly skin biopsies taken near the site of tick bit...
Pusterla N, Pusterla JB, Braun U, Lutz H.Four cows and four horses were infected experimentally with Ehrlichia phagocytophila, the cause of tickborne fever in ruminants, and with human granulocytic ehrlichia-like agent, a recently discovered species that infects people, horses and dogs in the USA and Europe. They were infected in either order, 30 days apart, to investigate serological cross-reactivity within the Ephagocytophila genogroup. The course of infection was assessed by routine clinical, haematological, serological and polymerase chain reaction (PCR) examinations. Two of the cows infected with Ephagocytophila and two of the h...
Chapman MR, Kearney MT, Klei TR.With the increased interest in equine cyathostomes it has become apparent that some evaluations of methods currently used to count the various larval stages which occur in the mucosa would be beneficial. Experiments were conducted to investigate the effects of fixation and storage of mucosal tissues at -20 C on the accuracy of counting these larvae. The accuracy of counting developing larvae within the mucosa by transmural illumination (TMI) and by artificial digestion (DIG) of the mucosa was also compared. The data indicate that fixation of digested mucosa in PBS-buffered 5% or 10% formalin d...
Hammond SA, Raabe ML, Issel CJ, Montelaro RC.We previously demonstrated in trials of a variety of experimental vaccines to equine infectious anemia virus (EIAV) a remarkable spectrum of efficacy ranging from sterilizing protection to severe enhancement of virus replication and disease, depending on the immunization strategy used. This range of vaccine efficacy observed in vivo offers a unique opportunity for evaluating potential in vitro immune correlates of protection and enhancement. We describe here a comprehensive analysis and comparison of EIAV envelope-specific antibody responses elicited by attenuated, inactivated whole virus and ...
Ruitenberg KM, Walker C, Wellington JE, Love DN, Whalley JM.The potential of DNA-mediated immunisation to protect against equine herpesvirus 1 (EHV-1) disease was assessed in a murine model of EHV-1 respiratory infection. Intramuscular injection with DNA encoding the EHV-1 envelope glycoprotein D (gD) in a mammalian expression vector induced a specific antibody response detectable by two weeks and maintained through 23 weeks post injection. Immune responses were proportional to the dose of DNA and a second injection markedly enhanced the antibody response. EHV-1 gD DNA-injected mice developed neutralising antibodies, and a predominance of IgG2a antibod...
Doherty TJ, Andrews FM, Provenza MK, Frazier DL.The effect of sedation on gastric emptying was evaluated in six ponies by monitoring serum concentrations of acetaminophen (AP) after intragastric administration. Methods: Prospective randomized experimental study. Methods: Six adult ponies, 135 to 275 kg. Methods: Fifteen minutes after the intravenous administration of xylazine (1 mg/kg), butorphanol (0.05 mg/kg), acepromazine (0.05 mg/kg) or saline, ponies were given AP (20 mg/kg in 350 mL water) by stomach tube. Blood for AP analysis was collected at baseline and 15, 30, 45, 75, 90, 105, and 120 minutes after AP administration. The time (Tm...
Lopez MJ, Wilson DG, Vanderby R, Markel MD.To compare the mechanical properties of two stabilization methods for ostectomized equine third metacarpi (MC3): (1) an interlocking nail system and (2) two dynamic compression plates. Animal or Sample Population-Ten pairs of adult equine forelimbs intact from the midradius distally. Methods: Ten pairs of equine MC3 were divided into two test groups (five pairs each): caudocranial four-point bending and torsion. Interlocking nails (6 hole, 13-mm diameter, 230-mm length) were placed in one randomly selected bone from each pair. Two dynamic compression plates one dorsally (12 hole, 4.5-mm broad)...
Johnson CB, Bloomfield M, Taylor PM.To investigate the effects of ketamine on the electroencephalogram (EEG) of the horse. Methods: Prospective experimental study. Methods: Eight Welsh mountain pony geldings weighing between 280 and 330 kg, 5 to 9 years old. Methods: During halothane anesthesia at an end-tidal halothane concentration between 0.75 and 0.85%, the EEG frequency power spectrum and the auditory evoked potential were recorded while an infusion of ketamine was given. Ketamine 200 mg was infused over 5 minutes in 8 ponies. The effects of ketamine on the EEG were recorded continuously during the infusion and for a furthe...
Loubière L, Tiraby M, Cazaux C, Brisson E, Grisoni M, Zhao-Emonet J, Tiraby G, Klatzmann D.The herpes simplex virus type 1 thymidine kinase suicide gene (HSV1tk) together with ganciclovir (GCV) have been successfully used for in vivo treatment of various experimental tumors, and many clinical trials using this system have been launched. With the aim to improve this therapeutic system, we compared the potential efficacy of different herpes virus derived thymidine kinases (HSV1, varicella-zoster virus, equine herpes virus type-4 and Epstein-Barr virus) as suicide genes in association with the nucleoside analogs acyclovir, ganciclovir and bromovinyldeoxyur- idine. Using various murine ...
McGreevy PD, Nicol CJ.The results of an experimental study of the motivational consequences of short-term prevention of crib-biting are reported here. Eight test horses wore a cribbing collar for 24 h. This was effective in preventing crib-biting in 6 subjects. Using analysis of co-variance that accounted for baseline differences in crib-biting rate, test horses showed significantly more crib-biting than control horses on the first day after prevention (P < 0.05). There was also a highly significant increase in the crib-biting rate of test horses on the first day after prevention in comparison with their baselin...
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.
Wilson SM, Gallagher M, Rakhit S, Remsbury AL, Ko WH.Uridine triphosphate (UTP) evoked inhibition of adrenaline-evoked cAMP accumulation in cultured equine epithelial cells (EC50, 1.8 +/- 0.2 microM) and this effect was mimicked by 5-Br-UTP (EC50, 6.6 +/- 1.8 microM) and uridine diphosphate (UDP; EC50, 96 +/- 26 microM). This inhibitory action of UTP was abolished by pre-treating cells with pertussis toxin (10 ng ml-1, 24 h). UTP (EC50, 2.3 +/- 0.3 microM) and 5-Br-UTP (EC50, 29.4 +/- 9.4 microM) also increased intracellular free calcium ([Ca2+]i) whilst UDP did not; the two effects are thus differentially sensitive to these pyrimidine nucleotid...
Turell MJ.Experimental studies were undertaken to evaluate the vector competence of selected mosquito species [Aedes taeniorhynchus (Wiedemann), Culex declarator Dyar and Knab, and Mansonia titillans (Walker)] from northwestern Venezuela for the epizootic (IC) strain of Venezuelan equine encephalitis (VEE) virus that was responsible for the 1995 outbreak of VEE in this area. Ae. taeniorhynchus was highly susceptible to infection (94% of 35), and 89% had a disseminated infection. Virus-exposed Ae. taeniorhynchus that refed on susceptible hamsters readily transmitted virus, confirming that this species wa...
Gastal EL, Gastal MO, Ginther OJ.A two-follicle model was used to study the nature of selection of the dominant follicle in mares by ablating neither or one of the two follicles on the day the larger follicle reached >/= 20 mm (Day 0). The larger follicle became the dominant follicle in all mares in which both follicles (n = 8) or only the larger follicle (n = 10) was retained. When only the smaller follicle (n = 9) was retained, it became dominant and ovulated in six mares and became atretic in three mares; the difference in diameter between the two follicles on Day 0 was less (p < 0.01) in mares in which the retained ...
Pringle J, Roberts C, Kohl M, Lekeux P.The effects of epidermal pigmentation and hair covering on the relative transparency of various animal tissues to near infrared (NIR) light were examined, and the pathlengths of NIR light through tissues at four wavelengths in the NIR range were subsequently determined. Black hair covering and black or dark-coloured hooves prevented NIR light from penetration sufficient for conduction of pathlength or NIR spectroscopy measurements. Non-pigmented hair covering of the head did not appear to be a barrier to successful NIR light transmission. Tissues sufficiently transparent to NIR light had the d...
Rees WA, Harkins JD, Lu M, Holland RE, Lehner AF, Tobin T, Chambers TM.To determine pharmacokinetics of single and multiple doses of rimantadine hydrochloride in horses and to evaluate prophylactic efficacy of rimantadine in influenza virus-infected horses. Methods: 5 clinically normal horses and 8 horses seronegative to influenza A. Methods: Horses were given rimantadine (7 mg/kg of body weight, i.v., once; 15 mg/kg, p.o., once; 30 mg/kg, p.o., once; and 30 mg/kg, p.o., q 12 h for 4 days) to determine disposition kinetics. Efficacy in induced infections was determined in horses seronegative to influenza virus A2. Rimantadine was administered (30 mg/kg, p.o., q 1...
Dejardin LM, Arnoczky SP, Cloud GL.During impact, equine hooves undergo viscoelastic deformations which may result in potentially harmful strains. Previous hoof strain studies using strain gauges have been inconclusive due to arbitrary gauge placement. Photoelastic stress analysis (PSA) is a full-field technique which visually displays strains over entire loaded surfaces. This in vitro study identifies normal hoof strain patterns using PSA. Custom-made photoelastic plastic sheets were applied to the hoof surface. The hooves were axially loaded (225 kg) under level and varus/valgus conditions. Strain patterns were video-recorded...
Valiev AG, Valieva TA, Valeeva GR, Speranskiĭ VV, Levachev MM.The influence of essential fatty acids of mare's milk fat on the immunocompetent system and nonspecific resistance of male rats weighing 135-145 g was investigated after 6 weeks of feeding. Rats were fed with isocaloric purified diets containing 15% of test fat (in control--combination of lard and sunflower oil) which provide the ratio of omega-6/omega-3 fatty acids equal to 0.76. An increase of immune responsiveness and nonspecific resistance in the group fed with the diet with mare's milk fat on day 6 after a single immunization of the animals with 5% sheep erythrocyte suspension was noted.
Lindsay DS, Dubey JP.Equine protozoal myeloencephalitis (EPM) is a neurologic syndrome in horses from the Americas and is usually caused by infection with the apicomplexan parasite, Sarcocystis neurona. The activities of pyrimethamine, trimethoprim, sulfachloropyridazine, sulfadiazine, sulfadimethoxine, sulfamethoxazole, sulfamethazine, and sulfathiazole were examined against developing S. neurona merozoites in bovine turbinate cell cultures. A microtiter plate host cell lesion based assay was used to determine the effects of agents on developing merozoites. A cell culture flask assay was used to determine if sele...
Hess S, Gulati R, Peluso JJ.The present studies showed that sequential treatment with equine CG (eCG) and hCG not only induced an increase in ovarian weight, but also caused an estimated 4.6-fold increase in the number of ovarian surface epithelial cells. In addition, eCG-hCG treatment increased ovarian hepatocyte growth factor (HGF) messenger RNA levels. These studies also demonstrated that rat primary ovarian surface epithelial cells as well as a cell line derived from rat ovarian surface epithelium (i.e. ROSE-179 cells) do not express the LH (hCG) receptor. Both of these cells express c-Met, the receptor for HGF. To a...
Scott WM, Fowler JD, Matte G, Allen AL, Wilkinson AA, Bailey JV, Fretz PB.To investigate neutrophil accumulation after ischemia and reperfusion (IR) in microvascular tissue flaps in horses. Methods: Randomized controlled experiment. Methods: A total of 8 horses between 1 and 10 years of age, 4 of each sex. Methods: Control and experimental myocutaneous island flaps based on the superficial branch of the deep circumflex iliac vessels were dissected on each horse. Atraumatic vascular clamps were applied to the pedicle of the experimental flap for 90 minutes and then removed to allow reperfusion. Based on the assumption that rapid infiltration of neutrophils into affec...
Beluche LA, Bertone AL, Anderson DE, Kohn CW, Weisbrode SE.To determine whether enrofloxacin has detrimental, dose-dependent effects on equine articular cartilage in vitro. Methods: Cartilage explants were developed from 6 healthy horses between 0 and 96 months old. Methods: Patellar cartilage explants were incubated in 5 concentrations of enrofloxacin (2 microg/ml, 10 microg/ml, 1,000 microg/ml, 10,000 microg/ml, and 50,000 microg/ml) for 72 hours. Proteoglycan synthesis (Na35SO4 incorporation for 24 hours), proteoglycan degradation (Na35SO4 release for 72 hours), endogenous proteoglycan content (dimethylmethlene blue assay), and total protein conten...
Kästner SB, Haines DM, Archer J, Townsend HG.Twenty-four Quarter Horse and Quarter Horse-cross yearlings were experimentally infected with influenza A virus (Influenza A/equine/Saskatoon/90 [H3N8]) by nebulisation. In a double blind controlled trial the horses were randomly assigned to 3 groups of 8 animals. Group 1 received a placebo, (carrier syrup), Group 2 the labelled dose and Group 3 twice the labelled dose of clenbuterol hydrochloride. All treatments were given per os b.i.d. for 10 days and started on the day of infection. The horses were monitored for clinical signs of influenza infection for 14 days. Bronchoalveolar lavages were...
Grieder FB, Vogel SN.To investigate the role of type I interferon (IFN) and its regulatory transacting proteins, interferon regulatory factors (IRF-1 and IRF-2), in early protection against infection with virulent Venezuelan equine encephalitis virus (VEE), we utilized mice with targeted mutations in the IFN-alpha/beta receptor, IRF-1, or IRF-2 genes. IFN-alpha/beta-receptor knockout mice are highly susceptible to peripheral infection with virulent or attenuated VEE, resulting in their death within 24 and 48 h, respectively. Treatment of normal macrophages with anti-IFN-alpha/beta antibody prior to and during infe...
Cheramie HS, Pleasant RS, Robertson JL, Moll HD, Carrig CB, Freeman DE, Jensen ME.To evaluate an occlusion technique for the internal carotid artery of horses using an intravascular, detachable, self-sealing, latex balloon distally and ligatures proximally. Methods: Experimental study. Methods: Six healthy adult horses. Methods: In each horse, the left internal carotid artery was occluded by placement of an intravascular, detachable, self-sealing, latex balloon distally and two ligatures proximally. Radiographs were taken on days 2, 5, 10, and 30 after surgery to evaluate balloon inflation and position. Endoscopic examination of the left guttural pouch was performed 10 days...
Murakami K, Sentsui H, Shibahara T, Yokoyama T.Three horses were experimentally infected with equine infectious anemia virus (EIAV). All horses were febrile after inoculation with EIAV and then developed chronic symptoms with intermittent fever. The febrile period was characterized by a rise in body temperature with reduced PBL and erythrocyte counts. Flow cytometric analysis showed that the reduced number of lymphocytes was due to significant decreases in CD4+ and CD8+ T cells in the absence of any change in B cell number. At the end of the febrile period the body temperature began to recover and numbers of CD4+ and CD8+ T cells showed a ...
Shiels IA, Sanderson SD, Taylor SM.To develop an in vitro model of uveitis based on an ex situ perfused eye to evaluate the anti-inflammatory activity of new pharmacological products. Methods: Eyes were removed from more than 60 dogs and 9 horses immediately after euthanasia and perfused with nutrient medium through the lateral long ciliary artery. Perfused eyes produced aqueous humour, and perfusion pressure was adjusted to obtain an intraocular pressure in the physiological range. When the eyes were treated with histamine, a complement C5a analogue peptide and hydrogen peroxide, typical signs of uveitis were produced. These i...
Schneider DA, Parks AH, Eades SC, Tackett RL.To compare in vitro smooth muscle relaxation of palmar digital vessels from healthy horses with those from horses in the prodromal stage of experimentally (carbohydrate) induced laminitis. Methods: 16 adult horses. Methods: Segments of palmar digital vessels were obtained from 5 healthy horses and 6 horses given carbohydrate. Vascular rings from the palmar digital artery and vein were suspended in individual organ baths containing buffer solution and indomethacin; isometric tension was recorded, and contraction and relaxation were compared. Smooth muscle contraction in response to cumulative a...
Widmer WR, Buckwalter KA, Hill MA, Fessler JF, Ivancevich S.We tested an adaptation of a technique for performing magnetic resonance (MR) imaging of human cadaver limbs in the horse. The forelimbs from a normal horse were collected, frozen, and sealed with a paraffin-polymer combination prior to imaging with either a high- or midfield magnetic resonance scanner. Each forelimb was defrosted, scanned, and refrozen on two separate occasions. A five-point scale was used to evaluate the quality of each set of sagittal and transverse, T1-weighted images of each digit. There was no difference in image quality between first and second scans of either specimen ...
Jahrling PB, Geisbert TW, Geisbert JB, Swearengen JR, Bray M, Jaax NK, Huggins JW, LeDuc JW, Peters CJ.A passive immunization strategy for treating Ebola virus infections was evaluated using BALB/ c mice, strain 13 guinea pigs, and cynomolgus monkeys. Guinea pigs were completely protected by injection of hyperimmune equine IgG when treatment was initiated early but not after viremia had developed. In contrast, mice were incompletely protected even when treatment was initiated on day 0, the day of virus inoculation. In monkeys treated with one dose of IgG on day 0, onset of illness and viremia was delayed, but all treated animals died. A second dose of IgG on day 5 had no additional beneficial e...
Escala J, Gatherer ME, Voûte L, Love S.Altered intestinal permeability is implicated in the pathogenesis of diverse equine medical conditions including alimentary laminitis and protein-losing enteropathies associated with parasitic infection. The aims of this study were to assess the feasibility of applying the 51Cr-EDTA absorption test for the assessment of intestinal permeability in the horse, and to apply this test in horses with experimentally induced alterations in gastrointestinal function. Four healthy ponies were administered 36 MBq of 51Cr-EDTA via naso-gastric tube, and urine samples were collected into polythene bags str...
Zeng W, Alpaugh W, Stefanovski D, Schlingmann K, Dobrinski I, Turner RM.The study of spermatogenesis in the horse is challenging because of the absence of an in vitro system that is capable of reproducing efficient spermatogenesis and because of the difficulties and costs associated with performing well-controlled studies in vivo. In an attempt to develop novel methods for the study of equine spermatogenesis, we tested whether cells from enzymatically digested pre-pubertal equine testicular tissue were capable of de novo tissue formation and spermatogenesis following xenografting under the back skin of immunocompromised mice. Testes were obtained from normal pre...
Macêdo IN, Arruda LCP, de Santana BB, de Moura TCM, Guerra MMP, Bezerra DG, Carneiro GF, Silva SV.The objective of this study was to evaluate the effects of the addition of different concentrations of ozone to quarter horse semen submitted to cryopreservation. Six ejaculates from four stallions were collected and were divided in four experimental groups: a control group (BotuCRIO® extender) and three other groups with BotuCRIO® ozonized at concentrations of 6, 8 and 12 μg of O/mL. The semen samples were diluted (200 x 10 spermatozoa/mL), filled in straws and frozen. After thawing (37 ºC, 30s), the samples were evaluated at 0, 30 and 60 minutes of incubation regarding sperm kinetics by ...
Schamhardt HC, Hartman W, Lammertink JL.The present study was undertaken to determine the influence of the peroneus tertius muscle on the loading regime of the tibia in the horse. Strain gauge rosettes were bonded to the cranial and caudal cortices of the left and right tibiae in six Shetland ponies. In vivo bone strain recordings were made before and after unilateral transection of the peroneus tertius muscle. Relatively large individual variations in response to transection were observed in both the experimental and the contralateral control limbs. The principal strain values on the cranial and caudal cortices increased during the...
Snoeck PPDN, Pessoa THO, Pereira MGS, Bastos ICL, de Melo MIV.The objective of this study was to compare the BotuCrio extender with the Merk - egg yolk and the INRA 82 modified by the inclusion of acetamide, methyl cellulose and trehalose in substitution of glycerol for freezing equine semen. The semen was diluted after centrifugation to obtain 100 x 10 of sperm/ml in: BotuCrio (control); Merk - egg yolk or INRA 82 modified (Experiment 1). The extended semen was packaged in 0.5 ml straws, cooled and frozen in a freezing machine. The control extender was superior in preserving the motility, VCL, VSL, VAP, LIN, STR and the BCF when compared to the Merk - e...
Nagao JF, Neves Neto JR, Papa FO, Alvarenga MA, Freitas-Dell'Aqua CP, Dell'Aqua JA.This study aimed to determine whether deslorelin acetate could induce double ovulation in mares. In Experiment 1, eight mares were treated with prostaglandin on Day 8 (D8) after ovulation, then treated with saline or with 100 μg of a controlled-release formulation of deslorelin acetate vehicle intramuscularly (IM) every 12h from D8 after ovulation until at least two follicles reached 33 mm. At this time, ovulation was induced with 2500 IU of hCG. Artificial insemination was performed 24h after induction, and embryos were collected on the eighth day after ovulation was first detected. In Exper...
Brokken MT, Schneider RK, Roberts GD, Holmes SP, Gavin PR, Sampson SN, Farnsworth KD, Dahlgren LA.To evaluate the effects of a new microfracture and ligament splitting procedure on ligament healing and to examine the usefulness of magnetic resonance (MR) imaging for monitoring ligament healing over time using a collagenase model of hind limb proximal suspensory desmitis. Methods: Experimental in vivo study. Methods: Healthy adult horses (n=6). Methods: Horses were free of lameness with normal hind limb proximal suspensory ligaments (PSL). The origin of both hind limb PSL was injected with collagenase and underwent MR imaging 2 weeks later, followed by the microfracture and ligament splitti...
Kloppe LH, Varner DD, Elmore RG, Bretzlaff KN, Shull JW.A breeding trial was conducted to evaluate the effect of insemination timing on the fertility of mares bred with frozen/thawed equine semen. One stallion and 60 reproductively sound, estrous-synchronized mares were included in the study. Mares were assigned to one of three groups (n = 20): 1) insemination with fresh semen every other day during estrus from detection of a 35-mm follicle until ovulation, 2) insemination with frozen/thawed semen every day during estrus from detection of a 35-mm follicle until ovulation or 3) insemination with frozen/thawed semen once, within 6 h after ovulation. ...
Kovács G, van Dijke A, Leontjevas R, Enders-Slegers MJ.Attachment characteristics play a key role in mental health and in understanding mental disorders. The aim of this study was to gain insight into the role the attachment characteristics can play in treatment effects in adult patients with intrapsychic and interpersonal problems who underwent Equine-assisted Short-term Psychodynamic Psychotherapy (ESTPP). In the first part of the study, we compared the effects of ESTPP to treatment-as-usual from a previous dataset regarding psychological dysfunction. For this, an explorative experimental non-randomized pre-treatment and 1-year post-treatment de...
Salama SA, Dardiri AH, Awad FI, Soliman AM, Amin MM.African horsesickness virus was isolated from blood samples of street dogs in Aswan Province in Arab Republic of Egypt. Of six isolated "dog strain" African horsesickness viruses, three viruses designated D2, D6 and D10 have been identified as type 9 African horsesickness virus. Methods of isolation, tissue culture adaptation, serological indentification and typing are described. Horses experimentally infected with dog viruses showed febrile reaction and characteristic clinical and pathological signs of African horsesickness. Reisolation of African horsesickness virus type 9 was achieved from ...
Tetens J, Moore RM, Hosgood GL, Eades SC, Keowen ML, Horohov DW.To evaluate systemic effects of i.v. infusion of ATP-MgCl2 subsequent to infusion of a low dose of endotoxin in horses. Methods: 12 adult horses. Methods: Horses were administered endotoxin (lipopolysaccharide [LPS]) or saline (0.9% NaCl) solution i.v., during a 30-minute period. Immediately thereafter, horses in each group were infused i.v. with ATP-MgCl2 or saline solution. Two weeks later, horses were administered the opposite solution (LPS or saline solution), but it was followed by the same infusion as 2 weeks previously (ie, ATP-MgCl2 or saline solution). Cardiopulmonary and clinicopatho...
Sojka JE, Johnson MA, Bottoms GD.This study was conducted to investigate the effect of starting time on dexamethasone suppression test results in horses. Eight adult horses were used throughout the trial. Baseline cortisol levels were established by collecting cortisol levels twice daily, at 8:00 A.M. and 8:00 P.M. for 4 consecutive days. Morning baseline cortisol levels were 46.3 +/- 5.94 ng/ml, and evening baseline cortisol levels were 32.8 +/- 5.59 ng/ml. Although lower, the evening cortisol levels were not statistically different (P = 0.154) from the morning levels. Dexamethasone suppression tests initiated at either 9:00...
Donabedian M, Delguste C, Perona G, Lebecque P, Duboeuf F, Lepaga O, Martin-Rosset W.Bone mineral density (BMD) is correlated to mechanical properties of bone. In the horse, dual energy X-ray absorptiometry (DXA) has yet only been performed ex-vivo, but a new portable DXA device would be ideal for in-vivo BMD measurement. We explored field suitability, precision and accuracy of this device for in-vivo third metacarpal density assessment. Precision was analysed by calculating measurement variation under repeated measurement tests with (reproducibility) and without (repeatability) limb repositioning. Repeatability and reproducibility were tested ex-vivo, at the same time that in...
Catunda APN, Alves GES, Paes Leme FO, Carvalho AM, Leise BS, Johnson PJ, Faleiros RR.Inflammation and apoptosis in the hoof lamellar interface both contribute to the early stages of sepsis-associated laminitis, but it is not clear whether apoptosis is occurring before the onset of inflammation or is being provoked by inflammation. Apoptosis and inflammation were therefore measured in lamellar tissues obtained at different time points throughout the early stages of experimentally induced laminitis. Apoptotic cells and leukocyte were enumerated in archived paraffin embedded lamellar tissue samples from previous experiments in which acute laminitis was induced using Black Walnut ...
Gérard C, Valenchon M, Poulin N, Petit O.In collective movements, some individuals are more effective and attractive leaders than others. Parameters such as social network, personality, and physiologic needs failed to explain why group members follow one leader more than another. In this study in the domestic horse, we propose to focus on the leader's attitude and its impact to the followers' recruitment during two conditions: spontaneous group departures or experimentally induced departures. We postulate that the expressiveness of the leader could enhance its attractiveness and thus produce a successful followership. We found that a...
Boss MA, Chris Hammel P.The influence of proton diffusion on nuclear magnetic resonance (NMR) relaxation was investigated in the presence of horse spleen ferritin at 7 T. Binary mixtures of water and glycerol were used to control diffusion within the range of 0.6-2.0 × 10(-9)m(2)/s, which was confirmed by pulsed gradient techniques. The effect of chemical exchange by hydrolysis between water and glycerol on relaxation was characterized with Carr-Purcell-Meiboom-Gill (CPMG) dispersion experiments. The relaxation rate enhancement of the protons due to ferritin was found to be inversely proportional to the diffusion co...
Wells HC, Sizeland KH, Kirby N, Haverkamp RG.Thin, strong scaffold materials are needed for surgical applications. New materials are required, particularly those readily available, such as from non-human sources. Bovine amniotic membrane (antepartum) and equine amniotic membrane (postpartum) were characterized with tear and tensile tests. The structural arrangement of the collagen fibrils was determined by small-angle X-ray scattering, scanning electron microscopy, and ultrasonic imaging. Bovine amnion had a thickness-normalized tear strength of 12.6 (3.8) N/mm, while equine amnion was 14.8 (5.3) N/mm. SAXS analysis of the collagen fibri...
Schauvliege S, Van den Eede A, Duchateau L, Pille F, Vlaminck L, Gasthuys F.To compare cardiac output () measurements using lithium dilution (LiDCO) and pulse contour analysis (PulseCO) techniques in isoflurane-anaesthetized ponies before and during the administration of different inotropic/vasoactive drugs. Methods: Prospective randomized experimental cross-over trial. Methods: Six ponies aged 5.0 +/- 1.6 (4-6.5) years and weighing 286 +/- 53 (212-368) kg. Methods: After sedation (romifidine) and induction (midazolam + ketamine), anaesthesia was maintained with isoflurane in oxygen. After 90 minutes (= T0), one of four treatments was administered: saline 0.1 mL kg(-1...
Rossano MG, Schott HC, Kaneene JB, Murphy AJ, Kruttlin EA, Hines MT, Sellon DC, Patterson JS, Elsheikha HM, Dubey JP, Mansfield LS.To determine whether daily administration of pyrantel tartrate can prevent infection in horses experimentally challenged with Sarcocystis neurona. Methods: 24 mixed-breed specific-pathogen-free weanling horses, 10 adult horses, 1 opossum, and 6 mice. Methods: Sarcocystis neurona-naïve weanling horses were randomly allocated to 2 groups. Group A received pyrantel tartrate at the labeled dose, and group B received a nonmedicated pellet. Both groups were orally inoculated with 100 sporocysts/d for 28 days, 500 sporocysts/d for 28 days, and 1000 sporocysts/d for 56 days. Blood samples were collec...
Bidwell LA, Wilson DV, Caron JP.To measure concentrations of lidocaine serum after application of two 5% patches on horses. Methods: Prospective experimental trial Methods: Six client-owned, systemically healthy horses. Methods: The hair was clipped on the medial aspect above the carpus of both fore limbs and 2 patches of 5% lidocaine were applied within 30 minutes of jugular catheter placement and the area was then bandaged. Venous blood was drawn from a jugular vein catheter that was inserted using lidocaine as a local block. Samples were drawn immediately before and at 2, 4, 6, 8, and 12 hours after patch application. The...
Douglas HF, Southwood LL, Meyer-Ficca ML, Hart SK, Meyer RG.To evaluate the poly (ADP-ribose) polymerase-1 (PARP1) enzyme and its inhibition in horses and explore its potential as a novel therapeutic target for equine intestinal ischemia-reperfusion injury by (1) identifying poly (ADP-ribose) (PAR) as an indication of PARP1 activation in equine cells using available immunoblot analytical techniques, (2) inducing PARP1 activation in an in vitro oxidative DNA damage model, (3) and demonstrating the inhibition of PARP1 in equine cells using commercially available PARP1 inhibitors. Methods: Experimental study. Methods: Blood samples were collected from sys...
Babptiste KE, Holladay SD, Freeman LE.An improved technique for preparing casts of the equine guttural pouch is described. The new technique is simplified and inexpensive in comparison to previous techniques and produces highly accurate anatomic models which are both durable and flexible. Methods: Silicone rubber bathtub caulk was injected into the guttural pouches of horse cadavers. The silicone was allowed to cure overnight, and casts were removed by dissection. The new technique was then used to evaluate changes in the shape of the guttural pouch with changes in head position. Results: With flexion of the atlanto-occipital join...
Haffner JC, Neal DL, Hoffman RM, Grubbs ST.We investigated the stability of adrenocorticotropic hormone (ACTH) in plasma after freezing for different lengths of time. The plasma ACTH concentrations of 12 horses were measured on day 0 (baseline) and over time, after stimulation with thyrotropin-releasing hormone. Samples were stored at -80°C for 3, 7, 30, 60, and 90 d, or at -20°C for 3, 7, 30, and 60 d, or between ice packs at -20°C for 3 and 7 d prior to determination of ACTH concentration. ACTH concentrations were compared to baseline (non-frozen day 0 plasma) for each storage method using a mixed model with repeated measure...
Rossano MG, Schott HC, Murphy AJ, Kaneene JB, Sellon DC, Hines MT, Hochstatter T, Bell JA, Mansfield LS.Equine protozoal myeloencephalitis (EPM) is a serious neurological disease of horses in Americans. Most cases are attributed to infection of the central nervous system with Sarcocystis neurona. Parasitemia has not been demonstrated in immunocompetent horses, but has been documented in one immunocompromised foal. The objective of this study was to isolate viable S. neurona from the blood of immunocompetent horses. Horses used in this study received orally administered S. neurona sporocysts (strain SN 37-R) daily for 112 days at the following doses: 100/day for 28 days, followed by 500/day for 2...
van Dixhoorn ID, Meershoek LS, Huiskes R, Schamhardt HC.Motion of the navicular bone might play a role in the development of navicular disease in horses but is difficult to asses. In the present study, 3-dimensional motion of this bone was determined using roentgen stereophotogrammetric analysis. Tantalum pellets were inserted, in vitro, in the bones of 6 forelimbs of mature Shetland ponies and kinematics were measured during vertical loading up to 2 kN. The motions of the navicular bone and coffin joint were limited to flexion/extension, there were no substantial out-of-plane motions. There was only little flexion between the navicular bone and th...
Hjortkjaer RK.In the first series of experiments enema containing a water soluble marker was given to two groups of horses fasted for 1 and 18 hours, respectively. The marker was only in 1 out of 14 experiments found orally of the pelvic flexure (Table II). Fasting seemed to facilitate the flow in oral direction. The results were discussed with the possible significance in the treatment of large intestinal impactions. In the second series the effect of enemas on water, electrolyte and acid-base status in the acute furosemide-dehydrated horse was studied. Moderate acidifying and hypokalemic effect was encoun...
Enke N, Brinkmann L, Südekum KH, Tholen E, Gerken M.Horses lose high amounts of Na through excessive sweating. These fluid losses can often not be replaced completely by voluntary water intake, requiring saline solutions as rehydration therapy to regain electrolyte balance. The experiment aimed to evaluate the sensitivity and tolerance of Shetland ponies towards different Na concentrations in their drinking water and contained three phases: (1) control: only fresh water provided; (2) pairwise-preference test: choice between fresh water and saline solution with stepwise increasing sodium chloride (NaCl) concentration (0.25%, 0.5%, 0.75%, 1.0%, 1...
Sod GA, Riggs LM, Mitchell CF, Martin GS, Gill MS.To compare the monotonic biomechanical properties and fatigue life of a 5.5-mm-broad locking compression plate (5.5 LCP) fixation with a 4.5-mm-broad locking compression plate (4.5 LCP) fixation to repair osteotomized equine 3rd metacarpal (MC3) bones. Methods: In vitro biomechanical testing of paired cadaveric equine MC3 with a middiaphyseal osteotomy, stabilized by 1 of 2 methods for fracture fixation. 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 (1) 4-point bending single cycle to failure ...
Mouithys-Mickalad A, Storms N, Franck T, Ceusters J, de la Rebière de Pouyade G, Deby-Dupont G, Serteyn D.Experimental laminitis, characterized by a failure of the dermal-epidermal interface of the foot, can be induced in horses by the oral administration of a black walnut extract (BWE). In the early phase of this severe and painful disease, an activation of neutrophil occurs, with the release of myeloperoxidase (MPO), a pro-oxidant enzyme of neutrophils, in plasma, skin, and laminar tissue. Juglone, a naphthoquinone derivative endowed with redox properties, is found in walnuts and has been incriminated in this neutrophil activation. We report for the first time the inhibitory activity of juglone ...
