Pharmacology in horses involves the study and application of drugs and medications to diagnose, treat, and prevent diseases and conditions in equine species. This field encompasses the understanding of pharmacokinetics and pharmacodynamics specific to horses, including how drugs are absorbed, distributed, metabolized, and excreted by the equine body. Commonly studied pharmacological agents in horses include non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics, sedatives, and anthelmintics. Research in equine pharmacology focuses on determining appropriate dosages, understanding drug interactions, and minimizing adverse effects. This page compiles peer-reviewed research studies and scholarly articles that investigate the efficacy, safety, and regulatory aspects of pharmacological interventions in equine veterinary practice.
Farag AMM, Ibrahim HMM.The current study was undertaken to investigate the effect of intravenous administration of ondansetron on the small and large intestinal motility in donkeys (Equus asinus) using non-invasive transabdominal ultrasonography. The current prospective, randomized, placebo-controlled, crossover study was conducted on thirty healthy donkeys (15 males and 15 females). The selected donkeys underwent two trials; the first was performed by intravenous administration of saline solution as a placebo, while the second was carried out by intravenous administration of ondansetron hydrochloride. The contracti...
Abu-Basha EA, Bani Ismail Z, Ababneh MM, Hamzeh E, Gehring R.This study was designed to investigate the safety and pharmacokinetic (PK) profile of tildipirosin in horses after intravenous (i.v.) and subcutaneous (s.c.) injection of a single dose at 4 mg/kg of body weight (b.w.). A total of 12 healthy mixed breed horses were used in the study. Horses were monitored for systemic and local adverse effects, and whole blood samples were collected for hematology and plasma biochemistry analysis at time (0) and at 6, 24, and 72 h after drug administration. For PK analysis, blood samples were collected at pre-determined times before and after tildipirosin adm...
Fujiyama M, Jones T, Duke-Novakovski T.To evaluate perioperative stress-related hormones in isoflurane-anesthetized horses administered infusions of dexmedetomidine alone or with butorphanol or remifentanil, compared with ketamine-morphine. Methods: Randomized, prospective, nonblinded clinical study. Methods: A total of 51 horses undergoing elective surgical procedures. Methods: Horses were premedicated with xylazine, anesthesia induced with ketamine-diazepam and maintained with isoflurane and one of four intravenous infusions. Partial intravenous anesthesia (PIVA) was achieved with dexmedetomidine (1.0 μg kg hour; group D; 12 hor...
Gretler SR, Finno CJ, Kass PH, Knych HK.In humans, the drug metabolizing enzyme CYP2D6 is highly polymorphic resulting in substantial differences in the metabolism of drugs including anti-arrhythmics, neuroleptics, and opioids. The objective of this study was to phenotype a population of 100 horses from five different breeds and assess differences in the metabolic activity of the equine CYP2D6 homolog using codeine as a probe drug. Administration of a probe drug is a common method used for patient phenotyping in human medicine, whereby the ratio of parent drug to metabolite (metabolic ratio, MR) can be used to compare relative enzym...
Kim A, Sasaki N, Lee I, Seo JP.The purpose of this study was to assess the cardiorespiratory and behavioral responses to the combination of medetomidine and tramadol (M-T) or butorphanol (M-B) in standing laparoscopic ovariectomy in horses. One ovary was removed under M-T and the contralateral ovary was removed under M-B with at least 4 weeks between operations at random. Horses were sedated using intravenous medetomidine (5 µg/kg) followed by tramadol (1 mg/kg) or butorphanol (10 µg/kg) after 5 min. Sedation was maintained through the repeated injection of medetomidine (1 µg/kg) and tramadol (0.4 mg/kg) or medetomidine ...
Macpherson ML, Giguère S, Pozor MA, Burden CA, Berghaus LJ, Berghaus RD, Varner JC, Hayna JT, Benson SM, Randell SA, Lyle SK, Kelleman AA, Hart KA....Minimal evidence exists supporting therapeutic selections for equine placentitis. The goal of this study was to characterize the anti-inflammatory effects of firocoxib when administered to mares with placentitis. Mares (gestation D270-300) were assigned to: INFECT (n = 6; placentitis, no treatment), FIRO (n = 6; placentitis, firocoxib, 0.1 mg/kg, PO, daily), and NORM (n = 6; no infection/treatment). Allantoic fluid (8 hours, 24 hours, birth) and amniotic fluid (birth) were collected from mares after infection. Concentrations of IL-1β, IL-6, TNF-α, IL-10, PGF , and PGE in fluids were...
Aldrich K, Velez-Irizarry D, Fenger C, Schott M, Valberg SJ.Recurrent exertional rhabdomyolysis (RER) is a chronic muscle disorder of unknown etiology in racehorses. A potential role of intramuscular calcium (Ca2+) dysregulation in RER has led to the use of dantrolene to prevent episodes of rhabdomyolysis. We examined differentially expressed proteins (DEP) and gene transcripts (DEG) in gluteal muscle of Thoroughbred race-trained mares after exercise among three groups of 5 horses each; 1) horses susceptible to, but not currently experiencing rhabdomyolysis, 2) healthy horses with no history of RER (control), 3) RER-susceptible horses treated with dant...
Fenner MF, Gatta G, Sattler S, Kuiper M, Hesselkilde EM, Adler DMT, Smerup M, Schotten U, Sørensen U, Diness JG, Jespersen T, Verheule S....Small-conductance Ca2+-activated K+ (KCa2) channels have been proposed as a possible atrial-selective target to pharmacologically terminate atrial fibrillation (AF) and to maintain sinus rhythm. However, it has been hypothesized that the importance of the KCa2 current-and thereby the efficacy of small-conductance Ca2+-activated K+ current (I K,Ca) inhibition-might be negatively related to AF duration and the extent of AF-induced remodeling. Unassigned: To address the hypothesis of the efficacy of I K,Ca inhibition being dependent on AF duration, the anti-arrhythmic properties of the I K,Ca inh...
Mikhail E, Siccardi E, Bawazir A, Rajesh A, Prathyush S, Al Wazani DMK, Sabeek M, John T.IOX-2 is a potent inhibitor of enzyme prolyl hydroxylases-2 (PHD) that plays a critical role in regulating hypoxia inducible factor (HIF) abundance and oxygen homeostasis. Federation for Equestrian Sports has listed HIF activators as prohibited substances to prevent their usage in doping. Consequently, it became essential to develop adequate knowledge and testing methods to detect it in equine sports drug testing samples. The validated method utilizes ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry in order to detect extremely low concentration of the ...
Bourebaba L, Kornicka-Garbowska K, Al Naem M, Röcken M, Łyczko J, Marycz K.Protein tyrosine phosphatase 1B (PTP1B) is one of the major negative regulators of leptin and insulin signaling, and has been strongly implicated in insulin resistance development in the course of obesity and metabolic syndrome conditions; however, its exact role in controlling adipose tissue biogenesis is still poorly understood. This investigation aimed to elucidate whether selective inhibition of PTP1B using MSI-1436 compound may improve and restore the defective adipogenicity of ASCs isolated from EMS-affected horses. Equine ASC EMS cells were cultured under adipogenic conditions in the pr...
Studer N, Bernal SD, Thormann W, Levionnois O, Spadavecchia C.To evaluate the antinociceptive effect of a bolus of intravenous levomethadone administered to horses during romifidine constant rate infusion (CRI). Methods: Prospective, randomized, masked, crossover experimental study. Methods: A group of eight adult Warmblood horses (seven geldings, one mare) aged 6.6 ± 4.4 years, weighing 548 ± 52 kg [mean ± standard deviation (SD)]. Methods: Levomethadone 0.1 mg kg or an equivalent volume of saline (control) was administered intravenously to standing horses 60 minutes after starting a romifidine CRI. Blood samples to quantify romifidine and levomethad...
Loganathan D, Yi R, Patel B, Zhang J, Kong N.Resolution of cathinone enantiomers in equine anti-doping analysis is becoming more important to distinguish the inadvertent ingestion of plant-based products from those of deliberate administration of designer synthetic analogs. With this in mind, a rapid and sensitive method was developed and validated for the detection, resolution and quantitative determination of cathinone enantiomers in horse blood plasma and urine. The analytes were recovered from the blood plasma and urine matrices by using a liquid-liquid extraction after adjusting the pH to 9. The recovered analytes were derivatized w...
Sullivan SN, Cole SL, Stewart MC, Brokken MT, Durgam S.To investigate the effects of triamcinolone acetonide (TA) and methylprednisolone acetate (MPA) on the viability of resident cells within the fibrocartilage on the dorsal surface of the deep digital flexor tendon (FC-DDFT) and fibrocartilage on the flexor surface of the navicular bone (FC-NB) of horses. Methods: 12 to 14 explants of FC-DDFT and of FC-NB from grossly normal forelimbs of 5 cadavers of horses aged 9 to 15 years without evidence of musculoskeletal disease. Methods: Explants were incubated with culture medium (control) or TA-supplemented (0.6 or 6 mg/mL) or MPA-supplemented (0.5 or...
Moss AL, Hritz RL, Hector RC, Wotman KL.To investigate the effects of orally administered trazodone on intraocular pressure (IOP), pupil diameter measured in the vertical plane (ie, vertical pupil diameter [VPD]), selected physical examination variables, and sedation level in healthy equids. Methods: 7 horses and 1 pony. Methods: Food was withheld for 12 hours prior to drug administration. After baseline (time 0) sedation scoring, physical examination, and measurement of IOP and VPD, equids received 1 dose (approx 6 mg/kg) of trazodone orally. Examination and measurement procedures were repeated 0.5, 1, 2, 4, 8, 12, and 24 hours aft...
Box JR, Karikoski NP, Tanskanen HE, Raekallio MR.Alpha-2-adrenoceptor agonists are sedatives that can cause fluctuations in serum insulin and blood glucose (BG) concentrations in horses. The objectives of this study were to investigate the effects of detomidine and vatinoxan on BG, insulin, and glucagon concentrations in horses with and without insulin dysregulation (ID). In a blinded cross-over design, eight horses with ID and eight horses without ID were assigned to each of four treatments: detomidine (0.02 mg/kg; DET), vatinoxan (0.2 mg/kg; VAT), detomidine + vatinoxan (DET + VAT), and saline control (SAL). Blood samples were taken at 0, ...
Siwinska N, Zak A, Paslawska U.Acute kidney injury (AKI) in horses may develop as a complication of a primary disease or following the administration of nephrotoxic drugs, and may pose a diagnostic challenge. Hence, the main objective of this study was to evaluate the concentrations and diagnostic significance of serum symmetric dimethylarginine (SDMA) and conventional renal dysfunction biomarkers in healthy horses, horses at risk of developing AKI, and horses with clinically evident AKI. A second aim was to assess how gastrointestinal disease and exposure to potentially nephrotoxic drugs affected SDMA levels. Thirty health...
Meier A, McGree J, Klee R, Preuß J, Reiche D, de Laat M, Sillence M.Endocrinopathic, or hyperinsulinaemia-associated laminitis (HAL) is a common and debilitating equine foot disease, and although no pharmacological treatments are registered, several are under development. To evaluate the effect of such treatments, an accurate and consistent method is needed to track the clinical signs of laminitis over time, and the natural history of the disease, in terms of a 'normal' pattern of improvement, needs to be understood. This study examined the improvement pattern in clinical cases of naturally-occurring HAL subjected to a range of best-practice interventions, usi...
Ferreira JC, Pires RH, Costa GBD, Carrijo BN, Guiotto FG, Rodrigues VS.The goal of the present study was to characterize the antimicrobial action of different ozone (O) presentations against Pythium insidiosum isolated from horses. In experiment 1, P. insidiosum was treated with ozonated distilled water, ozonated sunflower oils with distinct peroxide indexes or O gas (72 μg O mL). In experiment 2, samples were exposed one or three times to oxygen (O) or O gas (72 μg O mL; 30 min/day). In experiment 3, P. insidiosum was treated with different concentrations of O gas (Ø, 32, 52, or 72 μg O mL) for three days (30 min/day). In experiment 4, samples were ex...
Silva EC, Oliveira TJ, Moreli FC, Harada LK, Vila MMDC, Balcão VM.In the present research work, we propose a new antimicrobial treatment for pyoderma via cutaneous permeation of bacteriophage particles conveyed in a hydroxyethylcellulose (HEC) gel integrating ionic liquid as a permeation enhancer. Ionic liquids are highly viscous fluids constituted exclusively by ions, that are usually hydrolytically stable and promote solubilization of amphipathic molecules such as proteins, hence serving as green solvents and promoting the transdermal permeation of biomolecules. In the research effort entertained herein, the synthesis and use of choline geranate for integr...
Trenholme HN, Sakai DM, Berghaus LJ, Hanafi AL, Knych HK, Ryan CA, McHale B, Banovic F, Quandt JE, Barletta M, Reed RA. To evaluate changes in immunological parameters following subcutaneous (SC) and intramuscular (IM) administration of meperidine in horses through quantitative analysis of plasma tryptase, histamine, and IgE levels. Six adult horses were enrolled in a prospective randomized crossover design. Horses were administered one treatment per day, with a seven day washout period: (a) meperidine 1 mg/kg IM, saline 6 mL SC; (b) saline 6 mL IM, meperidine 1 mg/kg SC; (c) saline 6 mL SC, saline 6 mL IM. Blood samples were obtained for plasmatic histamine (baseline, 5, 10, 15, 30, and 60 min) via LC-MS/MS ...
Decloedt A, Van Steenkiste G, Vera L, Buhl R, van Loon G.Atrial fibrillation (AF) is suspected by an irregularly irregular rhythm during auscultation at rest and should be confirmed by electrocardiography. Heart rate monitoring is potentially interesting for AF detection by horse owners, based on the disproportionally high heart rate during exercise or increased heart rate variability. Echocardiography and laboratory analysis are useful to identify underlying cardiac disease. Horses with severe cardiac disease should not undergo cardioversion due to the risk of recurrence. Cardioversion is recommended especially in horses performing high intensity e...
Douglas H, Hopster K, Cerullo M, Hopster-Iversen C, Stefanovski D, Driessen B.Flumazenil antagonises the actions of benzodiazepines. There has been no prior research specifically investigating this anaesthetic reversal agent for horses. Objective: To determine the effects of flumazenil administration in horses on (a) ventilatory parameters after midazolam-ketamine induction and maintenance with isoflurane in oxygen and on (b) the characteristics of recovery from general anaesthesia. Methods: Blinded, randomised, crossover experiment. Methods: Six horses were randomly assigned to receive high-dose flumazenil (F , 20 µg/kg), low-dose flumazenil (F , 10 µg/kg) and sali...
Ishii H, Shibuya M, Leung GN, Yamashita S, Yamada M, Kushiro A, Kasashima Y, Okada J, Kawasaki K, Kijima-Suda I.The use of GW1516, a peroxisome proliferator-activated receptor δ (PPAR δ) agonist, is strictly prohibited in both horseracing and equestrian competitions. However, little is known about its metabolic fate in horses. To the best of our knowledge, this is the first reported metabolic study of GW1516 in equine urine. Methods: Urine samples obtained from a thoroughbred after nasoesophageal administration with GW1516 were protein-precipitated and the supernatants were subsequently analyzed by liquid chromatography/electrospray ionization high-resolution mass spectrometry (LC/ESI-HRMS) with a Q-E...
Sears K, Knowles D, Dinkel K, Mshelia PW, Onzere C, Silva M, Fry L.Control of , the primary cause of equine theileriosis, is largely reliant on acaracide use and chemosterilization with imidocarb dipropionate (ID). However, it is currently unknown if ID is effective against , the recently identified second causative agent of equine theileriosis, or if the drug maintains effectiveness against in the presence of co-infection. The purpose of this study was to address these questions using ID treatment of the following three groups of horses: (1) five infected horses; (2) three - infected horses; and (3) three - infected horses. Clearance was first evaluated u...
Klingberg J, Cawley A, Shimmon R, Fu S.The constant evolution of the illicit drug market makes the identification of unknown compounds problematic. Obtaining certified reference materials for a broad array of new analogues can be difficult and cost prohibitive. Machine learning provides a promising avenue to putatively identify a compound before confirmation against a standard. In this study, machine learning approaches were used to develop class prediction and retention time prediction models. The developed class prediction model used a naïve Bayes architecture to classify opioids as belonging to either the fentanyl analogues, AH...
Silva MG, Bastos RG, Stone Doggett J, Riscoe MK, Pou S, Winter R, Dodean RA, Nilsen A, Suarez CE.The most common apicomplexan parasites causing bovine babesiosis are Babesia bovis and B. bigemina, while B. caballi and Theileria equi are responsible for equine piroplasmosis. Treatment and control of these diseases are usually achieved using potentially toxic chemotherapeutics, such as imidocarb diproprionate, but drug-resistant parasites are emerging, and alternative effective and safer drugs are needed. The endochin-like quinolones (ELQ)-300 and ELQ-316 have been proven to be safe and efficacious against related apicomplexans, such as Plasmodium spp., with ELQ-316 also being effective aga...
Cavalero TMS, Segabinazzi LGTM, Scheeren VFDC, Freitas-Dell'Aqua CP, Papa FO.The present study compared the quality of sperm collected by artificial vagina or pharmacologically induced ejaculation from a 10-year-old thoroughbred stallion with seminal vesiculitis. The pharmacological protocol involved intravenous administration of detomidine (0.01 mg/kg) and oxytocin (20 IU) and successfully induced ejaculation in all attempts of semen collection. Sperm motility, plasma membrane and acrosome integrity (PMAI), reactive oxygen species (ROS) levels, polymorphonuclear neutrophil (PMN) percentage, and bacterial profiles of fresh and cooled semen (5°C for 24 hr) were eval...
Panzani D, Quaresma M, Fanelli D, Camillo F, Moroni R, Rota A, Martins-Bessa A, Nóvoa M, Catalán J, Canisso IF, Conte G, Mirò J.Due to the long courtship needed to attain excitation and erection, donkey semen collection can take up to 90 min. ProstaglandinF2α (PGF2α) has been reported to hasten the onset of erection and ejaculation in domesticated mammals, presumably by inducing smooth muscle contractions in the internal genitalia. However, while it has been anecdotally used in donkeys, it has yet to be critically evaluated. This study aimed to compare behavioral and semen parameters in Catalan, Balearic, Amiata, and Miranda jacks treated with the PGF2α analogue cloprostenol sodium immediately prior to exposure to a...
Tomlinson JE, Blikslager AT.Recent studies have shown that flunixin prevented recovery of equine jejunum post ischaemia. However, the use of a purported cyclooxygenase (COX)-2 preferential inhibitor, etodolac, also prevented recovery. These findings may have implications for the use of nonsteroidal anti-inflammatory drugs in colic patients. Objective: To compare the effects of deracoxib, a highly selective canine COX-2 inhibitor, with flunixin on in vitro recovery of ischaemic-injured equine jejunum. Methods: Six horses underwent 2 h jejunal ischaemia, after which mucosa was mounted in Ussing chambers and recovered for 2...
de Lagarde M, Rodrigues N, Chevigny M, Beauchamp G, Albrecht B, Lavoie JP.Bronchospasm results in airway obstruction in horses with heaves. Atropine is the most potent bronchodilator drug currently available for horses, but is associated with side effects that limit its use. Like atropine, N-butylscopolammonium bromide (NBB) is an anticholinergic agent with bronchodilatory properties. Objective: To compare the bronchodilating effects and side effects of atropine and NBB in horses with heaves. Methods: Cross-over experiment using horses with heaves. Methods: Eight horses with heaves were administered atropine and NBB, using a cross-over design. Heart rate, pupillary ...
Robertson SA, Bailey JE.To compare the arterial pH and blood gas values, heart rate and mean arterial blood pressure, in hypoxaemic anaesthetized horses, before and after treatment, with a salbutamol (albuterol) aerosol. Methods: Eighty-one client-owned horses weighing between 114 and 925 kg. Fifty-seven underwent emergency abdominal surgery and 24 were anaesthetized for elective procedures. Methods: Pre-anaesthetic medication included xylazine, detomidine, butorphanol and morphine, alone or in various combinations. Induction of anaesthesia was achieved with guaifenesin and ketamine, diazepam and ketamine, or guaifen...
Boivin R, Vargas A, Lefebvre-Lavoie J, Lauzon AM, Lavoie JP.Overexpression of the (+)insert smooth muscle myosin heavy chain (SMMHC) isoform could contribute to airway bronchospasm by increasing the velocity of contraction. Whether the (+)insert isoform is present in the small airways and its expression is reversible in asthma are unknown. Objective: To determine the anatomical location and the expression kinetics of the (+)insert SMMHC isoform in airways of horses with heaves and to evaluate its modulation in response to disease status. Methods: We evaluated the (+)insert SMMHC isoform in the airways of horses with heaves during disease exacerbation a...
Giguère S, Knowles HA, Valverde A, Bucki E, Young L.The objectives of this study were to assess, in anesthetized neonatal foals, the accuracy of 2 automated indirect oscillometric monitors for measurement of mean arterial pressure (MAP), to determine the optimal site of cuff placement for MAP monitoring, and to determine the relationship between arterial blood pressure and cardiac output. Ten neonatal foals were anesthetized and instrumented with a catheter in the metatarsal artery for direct MAP monitoring and measurement of cardiac output by lithium dilution. Concurrent MAP measurements were obtained with Cardell and Dinamap oscillometric mon...
Saps M, Miranda A.There is little evidence for most of the medications currently used to treat functional abdominal pain disorders (FAPDs) in children. Not only are there very few clinical trials, but also most have significant variability in the methods used and outcomes measured. Thus, the decision on the most appropriate pharmacological treatment is frequently based on adult studies or empirical data. In children, peppermint oil, trimebutine, and drotaverine have shown significant benefit compared with placebo, each of them in a single randomized clinical trial. A small study found that cyproheptadine was be...
Berry DB, Sullins KE.To determine whether povidone iodine ointment or 2 forms of silver sulfadiazine applied topically to wounds of the distal aspect of the limbs in horses affect the rate of second intention healing and to evaluate the additional influence of bandaging with these antimicrobials on granulation tissue formation. Methods: 6 healthy adult horses. Methods: Six standardized 2.5-cm2 skin wounds/horse were distributed between the dorsomedial surfaces of the metacarpi and metatarsi. One of the following 6 treatments was applied to each wound: 1% silver sulfadiazine cream with bandage, 1% silver sulfadiazi...
Borlone C, Morales N, Henriquez C, Folch H, Olave C, Sarmiento J, Uberti B, Moran G.Neutrophils participate in innate immunity as the first line of host defense against microorganisms. However, exacerbated neutrophil activity can be harmful to surrounding tissues; this is important in a range of diseases, including allergic asthma and chronic obstructive pulmonary disease in humans, and equine asthma (also known as recurrent airway obstruction (RAO). Tamoxifen (TX) is a non-steroidal estrogen receptor modulator with effects on cell growth and survival. Previous preliminary studies showed that TX treatment in horses with induced acute pulmonary inflammation promoted early apop...
Azab W, Tsujimura K, Kato K, Arii J, Morimoto T, Kawaguchi Y, Tohya Y, Matsumura T, Akashi H.Equine herpesvirus 4 (EHV-4) is an important equine pathogen that causes respiratory tract disease among horses worldwide. A thymidine kinase (TK)-deletion mutant has been generated by using bacterial artificial chromosome (BAC) technology to investigate the role of TK in pathogenesis. Deletion of TK had virtually no effect on the growth characteristics of WA79DeltaTK in cell culture when compared to the parent virus. Also, virus titers and plaque formation were unaffected in the absence of the TK gene. The sensitivity of EHV-4 to inhibition by acyclovir (ACV) and ganciclovir (GCV) was studied...
Haga HA, Dolvik NI.To determine whether the bispectral index (BIS) can be used as an indicator of degree of CNS depression in isoflurane-anesthetized horses. Methods: 10 Standardbred and 6 Norwegian cold-blooded trotter stallions admitted for routine castration. Methods: A 2-channel referential electrode configuration was used to record EEG for calculation of BIS by the EEG monitor. The BIS was calculated before (awake) and after (sedated) administration of detomidine (0.01 mg/kg of body weight, IV) and butorphanol (0.01 mg/kg, IV). Anesthesia was induced with ketamine hydrochloride (2.5 mg/kg, IV) and diazepam ...
Allen WR, Wilsher S.Over the past 50 years, per season pregnancy rate in Thoroughbred mares have risen from 70 to >90% and foaling rates from 55 to >80%. Some of the significant pharmacological treatments and diagnostic methods which have driven this marked improvement in breeding efficiency are reviewed. They include the application of artificial lighting to hasten the onset of ovulatory oestrous cyclicity in early Spring, rapid steroid hormone assays to aid in determining the stage and normality of the mare's cycle, prostaglandin analogues, synthetic progestagens and Gonadotrophin-releasing Hormone (GnRH) anal...
Kelmer G, Bell GC, Martin-Jimenez T, Saxton AM, Catasus C, Elliot SB, Meibohm B.Previous studies have shown that regional limb perfusion (RLP) using the palmar digital (PD) vein delivers therapeutic concentration of amikacin to the distal limb. Our hypothesis was that using the cephalic and saphenous veins for RLP will enable delivery of therapeutic concentrations of amikacin to the distal limb. Nineteen healthy horses participated in the study. The cephalic, saphenous, or PD vein was used to perfuse the limb with amikacin. Two grams of amikacin was used for RLP using the saphenous and the cephalic veins, and one gram was used in the PD vein. Synovial samples were collect...
Kupczyk P, Rykala M, Serek P, Pawlak A, Slowikowski B, Holysz M, Chodaczek G, Madej JP, Ziolkowski P, Niedzwiedz A.The endocannabinoid system (ECS) is composed of cannabinoid receptors type 1 (CBR1) and type 2 (CBR2), cannabinoid-based ligands (endogenous chemically synthesized phytocannabinoids), and endogenous enzymes controlling their concentrations. Cannabinoid receptors (CBRs) have been identified in invertebrates and in almost all vertebrate species in the central and peripheral nervous system as well as in immune cells, where they control neuroimmune homeostasis. In humans, rodents, dogs, and cats, CBRs expression has been confirmed in the skin, and their expression and tissue distribution become di...
Sladek S, Kearney C, Crean D, Brama PAJ, Tajber L, Fawcett K, Labberte MC, Leggett B, Brayden DJ.Polyelectrolyte nanoparticle constructs (NPs) comprising salmon calcitonin (sCT), chitosan (CS), and hyaluronic acid (HA) were previously established as having anti-inflammatory potential when injected via the intra-articular (i.a.) route to a mouse model. We attempted to translate the formulation to a large animal model, the lipopolysaccharide (LPS)-stimulated equine model of joint inflammation. The aim was to manufacture under aseptic conditions to produce sterile pyrogen-free NPs, to confirm physicochemical characteristics, and to test toxicity and efficacy in a pilot study. NP dispersions ...
López-Sanromán FJ, Holmbak-Petersen R, Santiago I, Gómez de Segura IA, Barrey E.The aim of the present study was to verify the efficacy and sensitivity of an accelerometric device in detecting and quantifying the degree of movement alteration produced in horses sedated with xylazine. Horses (n=6) were randomly administered either xylazine or a control by intravenous injection, with at least 1 week between each treatment. A triaxial accelerometric device was used for the accelerometric gait assessment 15 min before (baseline) and 5, 15, 30, 45, 60, 75, 90, 105 and 120 min after each treatment. Eight different accelerometric parameters were calculated, including speed, stri...
Pedersen SK, Cribb AE, Read EK, French D, Banse HE.In equids, phenylbutazone at high doses induces gastric disease, primarily in the glandular portion of the stomach. However, the mechanism of nonsteroidal anti-inflammatory drug (NSAID)-induced gastric disease in horses has yet to be determined. While phenylbutazone-associated ulceration is often attributed to a decrease in basal gastric prostaglandins, this has not been demonstrated in the horse. Twelve horses were randomly assigned to treatment (n = 6; 4.4 mg/kg phenylbutazone PO in 20 ml molasses q 12 hr for 7 days) or placebo (n = 6; 20 ml molasses PO q 12 hr for 7 days) groups....
Yasui M, Suzuki N, Liu X, Okamoto Y, Kim SY, Laxmi YR, Shibutani S.4-Hydroxyequilenin (4-OHEN)-dC is a major, potentially mutagenic DNA adduct induced by equine estrogens used for hormone replacement therapy. To study the miscoding property of 4-OHEN-dC and the involvement of Y-family human DNA polymerases (pols) eta, kappa and iota in that process, we incorporated 4-OHEN-dC into oligodeoxynucleotides and used them as templates in primer extension reactions catalyzed by pol eta, kappa and iota. Pol eta inserted dAMP opposite 4-OHEN-dC, accompanied by lesser amounts of dCMP and dTMP incorporation and base deletion. Pol kappa promoted base deletions as well as ...
Seo JP, Son WG, Gang S, Lee I.This study was performed to evaluate the sedative and analgesic effects of xylazine (X) and tramadol (T) intravenously (IV) administered to horses. Six thoroughbred saddle horses each received X (1.0 mg/kg), T (2.0 mg/kg), and a combination of XT (1.0 and 2.0 mg/kg, respectively) IV. Heart rate (HR), respiratory rate (RR), rectal temperature (RT), indirect arterial pressure (IAP), capillary refill time (CRT), sedation, and analgesia (using electrical stimulation and pinprick) were measured before and after drug administration. HR and RR significantly decreased from basal values with X and XT t...
Furr M, Cohen ND, Axon JE, Sanchez LC, Pantaleon L, Haggett E, Campbell R, Tennent-Brown B.The use of anti-ulcer medication in the neonatal intensive care unit (ICU) is common due to the concern for development of catastrophic gastric ulcerdisease. In man, however, the use of acid-suppressive medication has been shown in some studies to be a substantial riskfactorfor the development of Clostridium difficile-associated diarrhoea (CDAD), bacteraemia and neonatal sepsis. Objective: The purpose of the study reported herein is to evaluate the influence of anti-ulcer medications on the development of diarrhoea in the neonatalfoal. Objective: The use of anti-ulcer medication does not alter...
Robion FC, Doizé B, Bouré L, Marcoux M, Ionescu M, Reiner A, Poole AR, Laverty S.In vivo the effects of intra-articular (IA) corticosteroids on articular cartilage remain controversial. This study was designed to examine this issue using synovial fluid (SF) markers of cartilage metabolism. Paired radiocarpal joints, without clinical or radiographic signs of joint disease, were studied in 10 adult horses. Aseptic arthrocentesis was performed weekly for 13 weeks. IA injections of methylprednisolone acetate (MPA) into the treatment joint and the vehicle into the control joint were performed at weeks 3, 5 and 7. We used radioimmunoassays on SF samples which measure a keratan s...
Hesselkilde EZ, Carstensen H, Haugaard MM, Carlson J, Pehrson S, Jespersen T, Buhl R, Platonov PG.Atrial fibrillatory cycle length has been considered one of the indices of atrial electrical remodelling during atrial fibrillation (AF), which can be assessed from surface ECG by computer-assisted calculation of atrial fibrillatory rate (AFR). Horses have been suggested as a bona fide model for AF studies since horses too, develop lone AF, however data on AF characteristics in horses are extremely sparse and non-invasive characterization of AF complexity using surface ECG processing has not been reported. Objective: The aim was to study characteristics of induced AF and its modification by fl...
Songsermsakul P, Böhm J, Aurich C, Zentek J, Razzazi-Fazeli E.Concentration profile of zearalenone (ZON) and its metabolites in plasma, urine and faeces samples of horses fed with Fusarium toxin-contaminated oats is described. In plasma, β-zearalenol (β-ZOL) was detected at high levels on day 10 of the study (3.21-6.24 μg/l). β-Zearalenol and α-zearalenol were the major metabolites in urine. Zearalenone, α-ZOL and β-ZOL were predominantly found in faeces. Zearalanone could also be detected in urine (1.34-5.79 μg/l) and faeces (1 μg/kg). The degree of glucuronidation was established in all sample types, approximately 100% in urine and plasm...
Thurmon JC, Steffey EP, Zinkl JG, Woliner M, Howland D.Xylazine given IV at doses of 0.5, 1.0, and 1.5 mg/kg to mares caused a significant (P less than 0.05) dose-related increase in serum glucose concentration and urine volume. Serum glucose concentrations as much as 150 mg/dl were recorded in mares after they were given the largest xylazine dose. The greatest urine volume, similar to changes in peak glucose concentration, always occurred during the first hour after dosing with xylazine and averaged 1.82, 3.93, and 5.68 ml/kg/hour after the 0.5-, 1.0-, and 1.5-mg/kg doses, respectively, were given. Urine osmolality and specific gravity were signi...
Lefebvre D, Pirie RS, Handel IG, Tremaine WH, Hudson NP.There is a need for an improved understanding of equine post operative ileus (POI), in terms of both clinical definition and optimal management. Although the pharmacological strategies that are used to treat POI continue to evolve, little is known about the supplementary strategies used to prevent and manage this condition. Objective: To report the current strategies used to diagnose, prevent and manage POI following emergency abdominal surgeries. Methods: Cross-sectional survey. Methods: An electronic survey invitation was sent by email to 306 European college diplomates (European Colleges of...
Gozalo-Marcilla M, de Oliveira AR, Fonseca MW, Possebon FS, Pelligand L, Taylor PM, Luna SPL.Standing surgery avoids the risks of general anaesthesia in horses. Objective: To assess sedation, antinociception and gastrointestinal motility in standing horses after a detomidine loading dose and 2-h constant rate intravenous (i.v.) infusion, with or without methadone. Methods: Blinded, randomised, crossover with seven healthy adult cross-bred horses, three geldings and four females (404 ± 22 kg). Methods: Five i.v. treatments were administered to all horses with 1-week washout period: saline (SAL), detomidine low (2.5 μg/kg bwt + 6.25 μg/kg bwt/h) (DL) and high doses (5 μg/kg ...
Busschers E, Holt JP, Richardson DW.To determine effects of interleukin (IL)-1 beta and glucocorticoids on total glycosaminoglycan (GAG) loss and aggrecanase-mediated matrix degradation in equine cartilage. Methods: Cartilage from 24 equine cadavers free of sepsis and musculoskeletal disease. Methods: Effects of IL-1 beta, IL-1 beta with glucocorticoids (dexamethasone and triamcinolone, 10(-6) and 10(-7)M), and glucocorticoids alone on degradation of equine articular and nasal cartilage explants were assessed by measuring GAG release in media and GAG content in cartilage. Aggrecanase-mediated cleavage within the interglobular do...
Kingston JK, Bayly WM, Sellon DC, Meyers KM, Wardrop KJ.To investigate the effects of sodium citrate, low molecular weight heparin (LMWH), and prostaglandin E1 (PGE1) on aggregation, fibrinogen binding, and enumeration of equine platelets. Methods: Blood samples obtained from 4 Thoroughbreds. Methods: Blood was collected into syringes in the ratio of 9 parts blood:1 part anticoagulant. Anticoagulants used were sodium citrate, LMWH, sodium citrate and LMWH, or 300 nM PGE1/ml of anticoagulant. Platelet aggregation in response to ADP, collagen, and PGE1 was assessed, using optical aggregometry. Platelet activation was evaluated, using flow cytometry, ...
Fugler LA, Eades SC, Moore RM, Koch CE, Keowen ML.To establish an in vivo method for matrix metalloproteinase (MMP)-2 and MMP-9 induction in horses via IV administration of lipopolysaccharide (LPS) and to evaluate the ability of doxycycline, oxytetracycline, flunixin meglumine, and pentoxifylline to inhibit equine MMP-2 and MMP-9 production. Methods: 29 adult horses of various ages and breeds and either sex. Methods: In part 1, horses received an IV administration of LPS (n = 5) or saline (0.9% NaCl) solution (5). Venous blood samples were collected before and at specified times for 24 hours after infusion. Plasma was harvested and analyzed f...
Regan FH, Hockenhull J, Pritchard JC, Waterman-Pearson AE, Whay HR.To identify pain-related behaviour in working donkeys in order to assist their owners and veterinarians to recognise and manage pain. Objective: To identify general and specific behaviours associated with pain or its relief using a trial with the nonsteroidal anti-inflammatory drug meloxicam (Metacam). Methods: Observer-blinded, placebo-controlled trial. Methods: Forty adult male working donkeys with common clinical abnormalities were randomly assigned to receive either a single loading dose of meloxicam (1.2 mg/kg bwt per os; n = 20) or a placebo (30 mg honey/250 ml water per os; n = 20...
Stepnik CT, Outerbridge CA, White SD, Kass PH.This retrospective study reports on the clinical presentation of equine atopic skin disease and evaluates response to treatment with allergen-specific immunotherapy (ASIT) based on intradermal testing and/or serum testing. Computerized medical records from January 1991 to December 2008 yielded 54 horses included in the study. Presenting clinical signs (CS) included urticaria (n=28), pruritus (n=8) or both (n=18). Forty-one of 54 horses received ASIT, and response to ASIT (n=32) was evaluated via telephone survey. Eighty-four per cent (n=27) of owners reported that ASIT reduced their horse's CS...
