The topic of drugs and horses encompasses the study of various pharmacological agents used in equine medicine for therapeutic purposes. This includes the administration of medications for pain management, disease treatment, and performance enhancement. The pharmacokinetics and pharmacodynamics of drugs in horses are key areas of research, as they determine the absorption, distribution, metabolism, and excretion of these substances. Additionally, the topic covers the detection and regulation of substances in competitive equestrian sports to ensure fair play and animal welfare. This page compiles peer-reviewed research studies and scholarly articles that explore the effects, safety, and regulatory aspects of drug use in equine health and performance.
RuÃz-López P, Morgaz J, Quirós-Carmona S, Navarrete-Calvo R, DomÃnguez JM, Gómez-Villamandos RJ, Granados MM.Autonomic nervous system (ANS) activity can modify cardiovascular parameters in response to nociceptive stimuli or drugs in anesthetized animals. The aim of this study was to determine if a surgical nociceptive stimulus and morphine, ketamine, and dobutamine administration would modify ANS activity observed as a change in the mean parasympathetic tone activity (PTAm) in anesthetized horses. In 20 anesthetized horses, heart rate (HR), mean arterial pressure (MAP), and PTAm were monitored before and 1, 3, and 5 min after surgical incision, and before and 10 min after the administration of morphi...
Liepman RS, Swink JM, Habing GG, Boyaka PN, Caddey B, Costa M, Gomez DE, Toribio RE.Alterations in the gastrointestinal microbiota after antimicrobial therapy in horses can result in loss of colonization resistance and changes in bacterial metabolic function. It is hypothesized that these changes facilitate gastrointestinal inflammation, pathogen expansion and the development of diarrhea. The objectives of this study were to determine the effect of intravenous administration of antimicrobial drugs (ceftiofur, enrofloxacin, oxytetracycline) on equine fecal bacterial communities over time, to investigate whether those changes are detectable after 5 days of treatment and whether...
Elbourne M, Cawley A, Stanley S, Bowen C, Fu S.Equine urine analysis has evolved over time to detect thousands of urinary compounds for doping control in the horse racing industry. The longitudinal assessment of 3-methoxytyramine to tyramine ratio (3-MT/T) values in equine urine by GC-MS profiling was investigated to support the Racing NSW Equine Biological Passport (EBP) for detection of dopaminergic manipulation in racehorses. This involved comparison of routine urine samples to administration studies of Sinemet, a common Parkinson's disease medication containing levodopa. Using an endogenous reference compound (ERC) in a urinary ratio e...
Fungwithaya P, Boonchuay K, Narinthorn R, Sontigun N, Sansamur C, Petcharat Y, Thomrongsuwannakij T, Wongtawan T.Staphylococci are commensal bacteria and opportunistic pathogens found on the skin and mucosa. Sports animals are more prone to injury and illness, and we believe that antimicrobial agents might be extensively used for the treatment and cause the existence of antimicrobial-resistant (AMR) bacteria. This study aimed to investigate the diversity and AMR profile of staphylococci in sports animals (riding horses, fighting bulls, and fighting cocks) in South Thailand. Unassigned: Nasal (57 fighting bulls and 33 riding horses) and skin swabs (32 fighting cocks) were taken from 122 animals. Staphyloc...
Khusro A, Sahibzada MUK, Khan SU, Rajagopal R, Elghandour MMMY, Salem AZM, Kuppusamy P, Alcala-Canto Y, Tirado-González DN.Greenhouse gases emission from livestock is the major concern for the ecosystem. Despite the lower contribution of non-ruminants towards greenhouse gas emission as compared to the ruminants, the emission of methane (CH) gas from equines is expected to be increased in future due to its increasing population. Thus, it is essential to find or screen potential anti-methanogenic agent in a cost-effective and quicker manner. Considering this, the present investigation was aimed to analyze anti-methanogenic characteristic of bioactive compounds of safflower oil by targeting methanogenesis catalyzing ...
Gustafsson K, Tatz AJ, Britzi M, Dahan R, Sutton GA, Kelmer G.Eight horses underwent IVRLP at two occasions through a 23-gauge 2Â cm long butterfly catheter. Regional anaesthesia of the ulnar, median and medial cutaneous antebrachial nerves was performed prior, and an 8Â cm rubber tourniquet was placed on the proximal radius for 30Â minutes following the infusion. The first infusion consisted of 2Â g of amikacin sulphate and 10Â mg of dexamethasone phosphate diluted with 0.9% NaCl to a total volume of 100Â ml. The second perfusion was performed after a 2-week washout period, the same protocol was used but without dexamethasone phosphate. Synovial fluid s...
Ishii H, Shibuya M, So YM, Wong JKY, Ho ENM, Kusano K, Sone Y, Kamiya T, Wakuno A, Ito H, Miyata K, Yamada M, Leung GN.IOX4, a hypoxia-inducible factor stabilizer, is classified as a banned substance for horses in both horse racing and equestrian sports. We recently reported the pharmacokinetic profiles of IOX4 in horse plasma and urine and also identified potential monitoring targets for the doping control purpose. In this study, a long-term longitudinal analysis of IOX4 in horse hair after a nasoesophageal administration of IOX4 (500 mg/day for 3 days) to three thoroughbred mares is presented for the first time for controlling the abuse/misuse of IOX4. Six bunches of mane hair were collected at 0 (pre), ...
Tou K, Cawley A, Bowen C, Sornalingam K, Fu S.The conventional detection of exogenous drugs in equine doping samples has been used for confirmation and subsequent prosecution of participants responsible. In recent years, alternative methods using indirect detection have been investigated due to the expanding number of pharmaceutical agents available with the potential of misuse. The monitoring of endogenous biomarkers such as hydrocortisone (HC) has been studied in equine urine with an international threshold of 1 μg/ml established; however, there is no current threshold for equine plasma. The aim of this research was to investigate pl...
Jurek KA, Schoonover MJ, Williams MR, Rudra P.To determine the influence of perfusate volume on synovial fluid amikacin concentrations in the joints of the hind limb after standing saphenous intravenous regional limb perfusion (IVRLP). Methods: Randomized crossover design. Methods: Six adult horses. Methods: Saphenous IVRLP was performed in 6 standing horses with 1 g of amikacin diluted with 0.9% NaCl to volumes of 10 ml, 60 ml, and 120 ml. Samples of synovial fluid from the tarsocrural, metatarsophalangeal, and hind limb distal interphalangeal joints were collected at 15 and 30 min after perfusate administration. Concentrations ...
Sellon DC, Sanz M, Kopper JJ.Little is known about the acquisition and use of equine analgesic drugs by horse owners in the United States (US). Objective: To determine factors associated with possession of analgesic drugs by horse owners in the US or with analgesic drug acquisition from sources noncompliant with a valid veterinarian-client-patient (VCPR) relationship. Methods: Cross-sectional survey. Methods: An internet-based questionnaire included items related to experiences with horses and equine analgesic drugs. Factors associated with possession of ≥5 types of analgesic drugs and with the acquisition of drugs from...
Samimi AS, Molaei MM, Azari O, Rezaei MA, Hashemian A.The present study aimed to compare the sedative and analgesic effects of caudal epidural administration of lidocaine alone or in combination with four different α-adrenergic agonists in Mediterranean miniature donkeys. A total of ten clinically healthy (five males and five females) Mediterranean miniature donkeys with an age of 5 ± 1 years, a weight of 100 ± 2 kg and a height at the withers of 0.8 ± 0.06 m (mean ± standard deviation) were used in experimental, crossover (Latin square), randomized, and blinded study. Animals were assigned to five treatment groups including lidocaine alone ...
Ferrari G, Pang LY, De Moliner F, Vendrell M, Reardon RJM, Higgins AJ, Chopra S, Argyle DJ.Bleomycin is a chemotherapy agent that, when administered systemically, can cause severe pulmonary toxicity. Bleosome is a novel formulation of bleomycin encapsulated in ultra-deformable (UD) liposomes that may be applicable as a topical chemotherapy for diseases such as non-melanoma skin cancer. To date, the ability of Bleosome to effectively penetrate through the skin has not been evaluated. In this study, we investigated the ability of Bleosome to penetrate through ex vivo skin explants from dogs and horses. We visualized the penetration of UD liposomes through the skin by transmission elec...
Ekstrand C, Nostell K, Gehring R, Bondesson U, Bröjer J.Septicaemia in the neonatal foal is caused by both Gram positive and Gram negative bacteria. The life-threatening nature of this condition requires treatment to be initiated with broad spectrum antimicrobial drugs pending antimicrobial susceptibility testing. Potentiated sulphonamides, for example, trimethoprim combined with sulfadiazine, could be clinically relevant options but their pharmacokinetics in the neonatal foal are unknown. To describe the plasma disposition of trimethoprim and sulfadiazine in neonatal foals and to relate the results to patterns in the minimum inhibitory concentrati...
Gold JR, Grubb TL, Cox S, Malavasi L, Villarino NL.The repeated administration of high doses of gabapentin may provide better analgesia in horses than current clinical protocols. Objective: Administration of gabapentin at 40 and 120 mg/kg PO q 12 h for 14 days will not alter serum biochemistry findings or cause adverse effects. Our objectives were to evaluate the effect of gabapentin on serum biochemistry, physical examination, and plasma pharmacokinetics of gabapentin. Methods: Six healthy adult mares. Methods: Horses received 40 and 120 mg/kg of gabapentin orally q 12 h for 14 days. Horses were examined and scored for ataxia and ...
Oberhaus EL, Wilson KM, Camp CM, Sones JL.Sulpiride in vegetable shortening (VS) stimulates prolactin in horses for up to 10 days. Although effective, a pharmaceutical grade vehicle is needed for clinical application of sulpiride in horses. Sucrose acetate isobutyrate (SAIB), a hydrophobic polymer, may be an alternative to VS. Four in vivo experiments assessed the efficacy of SAIB for delivery of sulpiride, estradiol cypionate (ECP), and estradiol benzoate (EB). The first three studies utilized geldings to compare prolactin and luteinizing hormone (LH) concentrations between sulpiride delivered in VS and SAIB, and ECP or EB delivered ...
Bergstrom TC, Kilcoyne I, Magdesian KG, Nieto JE.To determine whether IV regional limb perfusion (IVRLP) performed in the cephalic vein with a wide rubber tourniquet (WRT) applied proximal and distal to the carpus results in a higher peak concentration (Cmax) of amikacin in the radiocarpal joint (RCJ), compared with the Cmax for IVRLP using a single WRT proximal to the carpus. Methods: 7 healthy adult horses. Methods: Horses underwent IVRLP using standing sedation with 2 g of amikacin sulfate diluted to 60 mL by use of saline (0.9% NaCl) solution in the cephalic vein with 2 different tourniquet techniques; proximal WRT (P) and proximal and d...
Hunyadi L, Datta P, Rewers-Felkins K, Sundman E, Hale T, Fajt V, Wagner S.The objective of this study was to determine the pharmacokinetic parameters of oclacitinib maleate as a top dress given to adult horses. Six adult horses with a mean weight of 528Â kg were administered a single dose of 0.5Â mg/kg oclacitinib maleate. Blood was collected prior to drug administration and at 15Â min, 30Â min, 45Â min, 1, 2, 4, 6, 8, 12, 24, 48, and 72Â h after treatment. Oclacitinib maleate plasma concentrations were measured by liquid chromatography/mass spectrometry. Pharmacokinetic parameters were found best to fit a one-compartment model. Mean C was 486Â ng/ml (range 423-549Â...
Ziadi A, Ozmaie S, Asghari A, Rajaei SM.This study aims to assess the effect of topical 0.5% apraclonidine on Intraocular pressure (IOP) in horses and compare the effects of timolol maleate 0.5% with 0.5% apraclonidine in the equine eye. Twenty healthy female thoroughbred horses were used. Horses were divided into two groups. Ten horses received single dose of 0.2 mL of 0.5% apraclonidine in one randomly selected eye and the contralateral eye received single dose of 0.2 mL of artificial tears. In the second group, 10 horses received single dose of 0.2 mL of 0.5% timolol maleate in one eye and the opposite eye received single dose of...
Moorman VJ, Pezzanite LM, Griffenhagen GM.To compare the efficacy and duration of action for perineural analgesia with liposomal bupivacaine (LB) versus bupivacaine hydrochloride (BHCl) in a sole-pressure induced model of forelimb lameness in horses. Methods: 6 healthy adult research horses. Methods: In 1 randomly assigned forelimb, grade 3/5 lameness was induced by use of a sole-pressure lameness model. Objective lameness (vector sum [VS]) was determined with an inertial sensor system at 0, 1, 6, and 24 hours after lameness induction to evaluate the model. Mechanical nociceptive thresholds (MNTs) and objective lameness (VS and force ...
Rizk MA, El-Sayed SAE, Eltaysh R, Igarashi I.Equine piroplasmosis is a tick-transmitted disease that is considered one of the most serious infectious diseases affecting equines. Searching for novel antipiroplasm drugs remains indispensable due to the emergence and spreading of resistant piroplasm parasites against the limited currently used drugs, diminazene aceturate and imidocarb dipropionate. Therefore, novel drugs with specified targets need to be identified and exploited. The inhibitory effects of Medicines for Malaria Venture (MMV) Malaria Box compounds with potent in vitro anti-equine piroplasmosis activity were evaluated against ...
Piras C, Gugliandolo E, Castagna F, Palma E, Britti D.Ivermectin has a wide number of many diverse functions. Certainly, it is irreplaceable for the treatment of parasitic pathologies in both human and veterinary medicine, and the latter represents the major field of its application. It has been called the "drug for the world's poor" because of its role as a saviour for those living on the margins of society, in underdeveloped areas afflicted by devastating and debilitating diseases, such as Onchocerciasis and Lymphatic filariasis. It showed huge, unexpected potential as an antibacterial (Chlamydia trachomatis and mycobacteria), and it has antivi...
Waller P, Lomnicka I, Lucas C, Johnson S, Dirikolu L.The number of publications for most common drug violations in racehorses is limited. This study reports the most common medication violations in racehorses at four major racetracks in Louisiana between 2016 and 2020. During this 5-year period, 27,237 blood samples and 25,672 urine samples collected during the course of normal race meeting activities were analysed by initial screening procedure utilizing Liquid Chromatography Mass Spectrometry (LC-MS/MS). Following initial screening, suspect samples were subject to quantitative or semi- quantitative confirmation analysis by LC-MS/MS. The total ...
Hwang H, Dong HJ, Han J, Cho S, Kim Y, Lee I.Gastric ulcer is one of the prevalent diseases in racehorses. However, it has not been recognized as important in Korea, and drugs used to treat gastric ulcers are included in the doping test list, so they are not allowed to be administered to racehorses in training. Objective: This study was performed 1) to investigate the prevalence and the severity of gastric ulcers in Thoroughbred racehorses in Korea, 2) to confirm the therapeutic effect of ranitidine and omeprazole, and 3) to compare the efficacy between ranitidine and omeprazole. Methods: Forty-nine horses were randomly recruited, and ga...
Wise IK, Klöppel H, Leece EA.Ketamine-based total intravenous anaesthesia techniques are commonly used in equine practice for ponies requiring short procedures such as castration in field conditions. When a longer duration of recumbency than provided by the initial dose of anaesthetic agents is required, administration of supplementary 'top-up' doses of anaesthetic agents is required. Ideally, a single dose of anaesthetic agents would reliably achieve a longer duration of action whilst maintaining adequate anaesthetic, surgical and recovery qualities. Objective: This prospective, randomised and blinded study aimed to comp...
Knych HK, Janes J, Kennedy L, McKemie DS, Arthur RM, Samol MA, Uzal FA, Scollay M.Bisphosphonates are potent anti-resorptive agents that have the potential to adversely affect bone healing in equine athletes, and normal bone adaption in young racehorses. A concern exists that bisphosphonate inhibition of normal bone metabolism could lead to increased bone fractures during high-intensity exercise. We found only a single report describing concentrations of tiludronate in the bone of horses, and no studies describing clodronate. Knowledge of the residence time in bone could allow for a better understanding of the long-term effects of these compounds. Our objectives were to dev...
Redmond JS, Stang BV, Schlipf JW, Christensen JM.Diphenhydramine is an H1 receptor antagonist used to control urticaria and other allergic signs caused by type I hypersensitivity reactions in horses (Equus caballus). Limited studies have been conducted on pharmacokinetics of this drug in horses, with no studies involving oral formulations. Our study investigated pharmacokinetics of an oral diphenhydramine formulation compared to intravenous administration in non-fasted adult horses. Six healthy horses underwent a single administration of three different doses of diphenhydramine (1Â mg/kg intravenously, 1Â mg/kg intragastrically, and 5Â mg/kg...
Luethy D, Robinson MA, Stefanovski D, Haughan J, Torcivia C, Kowalski A, Ford M, You Y, Missanelli J, Slack J.Cardiac drugs with defined pharmacological parameters in horses are limited. The objective of this study was to characterize the pharmacokinetic properties and cardiovascular effects of intravenous and oral metoprolol tartrate (MET) in horses. In a 2-period randomized cross-over design, MET was administered IV (0.04Â mg/kg) and PO (6Â mg/kg) once to six healthy adult horses. Horses were monitored via continuous telemetry and non-invasive blood pressure (NIBP). Blood samples were serially collected for 72Â h post-administration, and concentrations were determined by LC-MS/MS. Pharmacokinetics w...
Sanchez LC, Elfenbein JR, Robertson SA.To evaluate effects of butorphanol, acepromazine, and N-butylscopolammonium bromide (NBB) on visceral and somatic nociception and duodenal motility in conscious, healthy horses. Methods: 6 adult horses. Methods: Visceral nociception was evaluated by use of colorectal distention (CRD) and duodenal distention (DD) threshold. Somatic nociception was evaluated via thermal threshold (TT). Nose-to-ground height, heart rate, and respiratory rate were also measured. Each horse received each treatment in randomized order; investigators were not aware of treatments. Butorphanol was administered IV as a ...
Queiroz-Neto A, Zamur G, Gonçalves SC, Carregaro AB, Mataqueiro MI, Harkins JD, Tobin T.Amitraz, an acaricide used to control ectoparasites in animals has a complex pharmacological activity, including alpha2-adrenergic agonist action. The purpose of this research was to investigate the possible antinociceptive and/or sedative effect of amitraz in horses. The sedative effect of the intravenous (i.v.) injection of dimethylformamide (DMF, 5 mL, control) or amitraz (0.05, 0.10, 0.15 mg/kg), was investigated on the head ptosis test. The participation of alpha2-adrenergic receptors in the sedative effect provoked by amitraz was studied by dosing yohimbine (0.12 mg/kg, i.v.). To measure...
Fuchs S, Klier J, May A, Winter G, Coester C, Gehlen H.Delivering active ingredients using biocompatible and biodegradable carriers such as gelatin nanoparticles (GNPs) to the lung constitutes a promising non-invasive route of administration. However, the pulmonary delivery of nanoparticle-based immunotherapy is still a field that requires more clarification. In this study, GNPs loaded with cytosine-phosphate-guanine oligodeoxynucleotides (CpG-ODN)-loaded and plain GNPs were aerosolised either by a conventional pressured metered dose inhaler (pMDI) or by active or passive vibrating-mesh (VM) nebulisers. GNP sizes after nebulisation by active and p...
Oswald S, Peters J, Venner M, Siegmund W.Clarithromycin (CLA) is a well established macrolide antibiotic which is frequently used in therapy of airway diseases in foals. It is extensively metabolized by CYP3A4 resulting in the antimicrobial active metabolite 14-hydroxyclarithromycin (OH-CLA). Rifampicin (RIF) is often comedicated to prevent resistance and augment therapy. RIF is a known inducer for metabolizing enzymes and transporter proteins. Therefore, comedication might bare the risks of pharmacokinetic drug interactions which were investigated in a clinical trial. As no adequate method to determine CLA, RIF and their main metabo...
Scarth JP, Teale P, Kuuranne T.A detailed understanding of equine drug metabolism is important for detection of drug abuse in horseracing and also in veterinary drug development and practice. To date, however, no comprehensive review of equine drug metabolism has been published. The majority of literature regarding equine drug metabolite profiles is derived from sports drug detection research and is generally targeted at detecting marker metabolites of drug abuse. However, the bulk of the literature on equine drug metabolism enzymology is derived from veterinary studies aimed at determining the molecular basis of metabolism...
Rashid HB, Chaudhry M, Rashid H, Pervez K, Khan MA, Mahmood AK.The present work was conducted to study the comparative efficacy of two anti-protozoan (babesicidal) drugs on the recovery and health of horses. A total of 80 horses, showing typical clinical symptoms of the disease, were selected for this study; the presence of babesiosis was confirmed through blood smear examination. These animals were divided into two groups i.e. A and B. Horses of Group A, were treated with diminazene diaceturate, while horses of Group B were treated with diminazene aceturate. Efficacy of the drugs was determined by the reversal of clinical signs and a negative blood smear...
Letendre LT, Tessman RK, McClure SR, Kvaternick VJ, Fischer JB, Hanson PD.To determine pharmacokinetic parameters and variables, firocoxib concentrations in urine and plasma, urine-to-plasma ratios, and the urine depletion profile of firocoxib and to evaluate whether the pharmacokinetic behavior of firocoxib was governed by linear processes after multiple doses of firocoxib were administered IV and orally. Methods: 6 healthy female horses (5 Paint horses and 1 Quarter Horse) in experiment 1 and 12 healthy male and female horses in experiment 2. Methods: In experiment 1, 6 horses were orally administered firocoxib paste once daily for 12 consecutive days, and plasma ...
Chapman MR, French DD, Monahan CM, Klei TR.Three fecal egg count reduction assays (FECR) and one critical trial were performed to determine the efficacy of pyrantel pamoate (PP) at 6.6 mg base kg-1 on a well managed stud farm in Louisiana where a loss of efficacy was suspected. Efficacy of PP based on FECR varied from 25% in mares to 83% in yearlings. Second treatments with PP 2 weeks following an initial treatment failed to reduce eggs per gram (EPG). A critical trial was performed to determine the cyathostome species resistant to PP. Three strongyle-naive ponies which acquired infections on the farm were used for this purpose. Follow...
Davis JL, Little D, Blikslager AT, Papich MG.Ussing chambers have been used to study the mucosal permeability of drugs in humans, rats and other species. This data can then be used to develop in vitro/in vivo correlations (IVIVC) for drugs based on the Biopharmaceutics Classification System (BCS). Due to the poor oral bioavailability of many drugs in the horse, this method may be useful for screening drugs before development to determine if they warrant further study. Cephalexin (CPX), marbofloxacin (MAR), metronidazole (MTZ) and fluconazole (FCZ) were chosen for this study based on the wide range of physicochemical properties and bioava...
Lyons ET, Drudge JH, Tolliver SC.Experimentally induced infections of Parascaris equorum in worm-free pony foals required 14 to 17 days for migration of the larvae through the liver and lungs, and 79 to 110 days to become gametogenically functional. Treatment of experimentally infected or naturally exposed foals during the parenteral phase of development, using levamisole at 8 mg/kg, a mixture of levamisole at 8 mg/kg plus piperazine at 88 mg base equivalent/kg, or dl-tetramisole at 10 mg/kg, was quite efficacious in (1) reducing the number of P. equorum larvae recovered from the small intestines of the foals at necropsy, or ...
Cohen ND, Slovis NM, Giguère S, Baker S, Chaffin MK, Bernstein LR.Macrolide-resistant isolates of Rhodococcus equi are emerging, prompting the search for clinically effective alternative antimicrobials. Objective: The proportion of foals with ultrasonographic evidence of pneumonia presumed to be caused by R. equi that had a successful outcome when administered gallium maltolate (GaM) PO would not be more than 10% inferior (ie, lower) than that of foals receiving standard treatment. Methods: Fifty-four foals with subclinical pulmonary abscesses among 509 foals at 6 breeding farms in Kentucky. Methods: Controlled, randomized, prospective noninferiority study. ...
Steffey EP, Pascoe PJ, Woliner MJ, Berryman ER.To quantitate dose- and time-related anesthetic-sparing effects of xylazine hydrochloride (XYL) during isoflurane-induced anesthesia in horses and to characterize selected physiologic responses of anesthetized horses to administration of XYL. Methods: 6 healthy adult horses. Methods: Horses were anesthetized 2 times to determine the minimum alveolar concentration (MAC) of isoflurane in O2 and to characterize the anesthetic-sparing effect (MAC reduction) after IV administration of XYL (0.5 and 1 mg/kg of body weight, random order). Selected measures of cardiopulmonary function, blood glucose co...
Zielinski K, Sekula B, Bujacz A, Szymczak I.Serum albumin, the most abundant transport protein of mammalian blood, interacts with various nonsteroidal anti-inflammatory drugs (NSAIDs) affecting their disposition, metabolism, and excretion. A big group of chiral NSAIDs transported by albumin, profens, is created by derivatives of 2-arylpropionic acid. The chiral center in the structures of profens is adjacent to the carboxylate moiety and often determines different pharmacological properties of profen enantiomers. This study describes crystal structures of two albumins, isolated from equine and leporine serum, in complexes with three pro...
Sweeney CR, Soma LR, Maxson AD, Thompson JE, Holcombe SJ, Spencer PA.The effects of furosemide on the racing times of 79 horses without exercise-induced pulmonary hemorrhage (EIPH) and 52 horses with EIPH were investigated. Racing times were adjusted to 1-mile equivalent racing times by 2 speed handicapping methods, and analysis of covariance was used to adjust actual racing times by winning time and distance for each race. All 3 methods of determining racing time indicated that geldings without EIPH had significantly faster racing times (P less than 0.05) when given furosemide before racing than when furosemide was not given before racing. Females and colts wi...
Ho EN, Leung DK, Wan TS, Yu NH.This paper reports two highly efficient liquid chromatography-mass spectrometry (LC-MS) methods for the screening of anabolic steroids, corticosteroids, and acidic drugs for the purpose of doping control in equine sports. Sample extraction was performed using a mixed-mode C8-SCX solid-phase extraction (SPE) cartridge. The first eluted fraction (acidic/neutral fraction) was base-washed and the resulting organic extract was used for the screening of anabolic steroids and corticosteroids by LC-MS using multiple reaction monitoring (MRM) in the positive electrospray ionisation (ESI) mode. The rema...
Williams DC, Aleman MR, Brosnan RJ, Fletcher DJ, Holliday TA, Tharp B, Kass PH, Steffey EP, LeCouteur RA.Previous study of the diagnostic validity of electroencephalography (EEG) to detect abnormalities in equine cerebral cortical function relied on the administration of various drugs for sedation, induction, and maintenance of general anesthesia but used identical criteria to interpret recordings. Objective: To determine the effects of 2 inhalation anesthetics on the EEG of healthy horses. Methods: Six healthy horses. Methods: Prospective study. After the sole administration of one of either isoflurane or halothane at 1.2, 1.4, and 1.6 times the minimum alveolar concentration, EEG was recorded d...
Gozalo-Marcilla M, Luna SP, Crosignani N, Filho JNP, Possebon FS, Pelligand L, Taylor PM.To evaluate intravenous (IV) detomidine with methadone in horses to identify a combination which provides sedation and antinociception without adverse effects. Methods: Randomized, placebo-controlled, blinded, crossover. Methods: A group of eight adult healthy horses aged (mean ± standard deviation) 7 ± 2 years and 372 ± 27 kg. Methods: A total of six treatments were administered IV: saline (SAL); detomidine (5 μg kg; DET); methadone (0.2 mg kg; MET) alone or combined with detomidine [2.5 (MLD), 5 (MMD) or 10 (MHD) μg kg]. Thermal, mechanical and electrical nociceptive thresholds were mea...
Shilo Y, Britzi M, Eytan B, Lifschitz T, Soback S, Steinman A.Tramadol is a centrally acting analgesic drug that has been used clinically for the last two decades to treat moderate to moderately severe pain in humans. The present study investigated tramadol administration in horses by intravenous, intramuscular, oral as immediate-release and oral as sustained-release dosage-form routes. Seven horses were used in a four-way crossover study design in which racemic tramadol was administered at 2 mg/kg by each route of administration. Altogether, 23 blood samples were collected between 0 and 2880 min. The concentration of tramadol and its M1 metabolite were ...
Ho EN, Leung DK, Leung GN, Wan TS, Wong AS, Wong CH, Soma LR, Rudy JA, Uboh C, Sams R.Administration studies of levamisole in horses were carried out using two different levamisole preparations, namely, levamisole hydrochloride oral bolus and levamisole phosphate injectable solution. These preparations were analysed in detail for the presence of aminorex-like impurities. Both levamisole preparations were found to contain 1-(2-mercaptoethyl)-4-phenyl-2-imidazolidinone (I) and 4-phenyl-2-imidazolidinone (II) as degradation impurities, but neither aminorex nor rexamino was detected in these preparations. After the administration of these preparations to horses, aminorex, rexamino,...
D'Arcy-Moskwa E, Noble GK, Weston LA, Boston R, Raidal SL.Newer NSAIDs that more selectively target the induced isoform of the cyclooxygenase enzyme (COX2) activity might reduce adverse effects while preserving therapeutic benefits of these drugs. Objective: To compare the effect of oral administration of multiple dose rates of meloxicam and phenylbutazone (PBZ) on gastric mucosal integrity in horses. Methods: Twenty-five light breed horses. Methods: In vivo toxicity study. Horses were randomly assigned to 5 treatment groups, receiving placebo, PBZ (4.4 mg/kg PO q12h day 1, 2.2 mg/kg PO q12h for 4 days, 2.2 mg/kg PO q24h for 9 days), or 3 dose rates ...
Chan GH, Ho EN, Leung DK, Wong KS, Wan TS.The use of anabolic androgenic steroids (AAS) is prohibited in both human and equine sports. The conventional approach in doping control testing for AAS (as well as other prohibited substances) is accomplished by the direct detection of target AAS or their characteristic metabolites in biological samples using hyphenated techniques such as gas chromatography or liquid chromatography coupled with mass spectrometry. Such an approach, however, falls short when dealing with unknown designer steroids where reference materials and their pharmacokinetics are not available. In addition, AASs with fast...
Lyons ET, Tolliver SC, Kuzmina TA, Collins SS.The activity of three anthelmintics (fenbendazole-FBZ; oxibendazole-OBZ; and pyrantel pamoate-PRT) was ascertained against the ascarid Parascaris equorum in horse foals on eight farms in Central Kentucky (2009-2010) in field tests. A total of 316 foals were treated, and 168 (53.2%) were passing ascarid eggs on the day of treatment. Evaluation of drug efficacy was determined qualitatively by comparing the number of foals passing ascarid eggs in their feces before and after treatment. The main purpose was to obtain data on current activity of these compounds against ascarids. Additionally, the o...
Cooper LG, Caffe G, Cerutti J, Nielsen MK, Anziani OS.Macrocyclic lactones are the most widely used drugs for the control of gastrointestinal nematodes of horses in Argentina. Ivermectin and moxidectin are used as broad spectrum anthelmintics and although there are several international reports on the resistance of Parascaris spp., the resistance status of the local nematode population is largely unknow. This report informs a case of suboptimal efficacy to both drugs to control Parascaris spp in foals in central Argentina. In February 2018, routine fecal parasite egg counts showed a moderate-high number of Parascaris spp eggs (mean = 680 eggs p...
Song Y, Day CM, Afinjuomo F, Tan JE, Page SW, Garg S.While the global market for veterinary products has been expanding rapidly, there is still a lack of specialist knowledge of equine pharmaceutics. In many cases, the basic structure of the gastrointestinal tract (GIT) and integumentary system of the horse shares similarities with those of humans. Generally, the dosage form developed for humans can be repurposed to deliver equine medications; however, due to physiological variation, the therapeutic outcomes can be unpredictable. This is an area that requires more research, as there is a clear deficiency in literature precedence on drug delivery...
Ringer SK, Portier K, Torgerson PR, Castagno R, Bettschart-Wolfensberger R.To compare xylazine and romifidine constant rate infusion (CRI) protocols regarding degree of sedation, and effects on postural instability (PI), ataxia during motion (A) and reaction to different stimuli. Methods: Blinded randomized experimental cross-over study. Methods: Ten adult horses. Methods: Degree of sedation was assessed by head height above ground (HHAG). Effects on PI, A and reaction to visual, tactile and acoustic stimulation were assessed by numerical rating scale (NRS) and by visual analogue scale (VAS). After baseline measurements, horses were sedated by intravenous loading dos...
Cordeiro Rde A, Bittencourt PV, Brilhante RS, Teixeira CE, Castelo-Branco Dde S, Silva ST, De Alencar LP, Souza ER, Bandeira Tde J, Monteiro AJ....Respiratory infections are a common problem among equines and occur with variable rates of morbidity and mortality. Although some fungal species are considered primary agents of respiratory tract infections in several mammals, their relevance in respiratory diseases of equines is frequently neglected. In the present study, we performed an active search for Candida spp. in the nasal cavity of horses. The presence of Candida spp. was investigated through the use of nasal swabs that were streaked on culture media. These yeasts were identified through physiological testing and their in vitro antif...
Sánchez-Aparicio P, Florán B, RodrÃguez Velázquez D, Ibancovichi JA, Varela Guerrero JA, Recillas S.Osteoarticular equine disease is a common cause of malady; in general, its therapy is supported on steroids and nonsteroidal anti-inflammatories. Nevertheless, many side effects may develop when these drugs are administered. Nowadays, the use of new alternatives for this pathology attention is demanded; in that sense, cannabinoid CB2 agonists may represent a novel alternative. Cannabinoid belongs to a group of molecules known by their psychoactive properties; they are synthetized by the Cannabis sativa plant, better known as marijuana. The aim of this study was to contribute to understand the ...
Roelvink ME, Goossens L, Kalsbeek HC, Wensing T.The analgesic and spasmolytic effects of dipyrone (Novalgin) (2500 mg/100 kg bodyweight) hyoscine-N-butylbromide (Buscopan) (20 mg/100 kg bodyweight) and a combination of both drugs were evaluated in a balloon-induced model of colic, using five ponies with caecal fistulae. The drugs were given intravenously and 0.9 per cent sodium chloride solution (5 ml/100 kg bodyweight) was used as a control. The physiological saline solution and dipyrone had no effect on caecal contractions. After the injection of hyoscine-N-butylbromide and the drug combination caecal contractions ceased within 30 seconds...
Peters J, Block W, Oswald S, Freyer J, Grube M, Kroemer HK, Lämmer M, Lütjohann D, Venner M, Siegmund W.The delivery of clarithromycin (CRL) to its site of action in bronchial/alveolar epithelial cells (EC), bronchial epithelial lining fluid (ELF), and bronchoalveolar lavage cells (BALC) may be influenced by CYP3A4 and the drug transporters, ATP-binding cassette (ABC) B1 and ABCC2 and organic anion-transporting polypeptides (OATPs), which can be modulated and/or up-regulated via the nuclear pregnane X receptor (PXR) by rifampicin (RIF). Therefore, we evaluated the disposition and pulmonary distribution of CLR (7.5 mg/kg b.i.d., 21 days) and expression of ABCB1, ABCC2, OATP1A2, and OATP2B1 in EC ...
