Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Drug
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.
Randomized, controlled clinical trial of safety and plasma concentrations of diclofenac in healthy neonatal foals after repeated topical application of 1% diclofenac sodium cream. OBJECTIVE To determine the plasma pharmacokinetics and safety of 1% diclofenac sodium cream applied topically to neonatal foals every 12 hours for 7 days. ANIMALS Twelve 2- to 14-day old healthy Arabian and Arabian-pony cross neonatal foals. PROCEDURES A 1.27-cm strip of cream containing 7.3 mg of diclofenac sodium (n = 6 foals) or an equivalent amount of placebo cream (6 foals) was applied topically to a 5-cm square of shaved skin over the anterolateral aspect of the left tarsometatarsal region every 12 hours for 7 days. Physical examination, CBC, serum biochemistry, urinalysis, gastric endos...
Carbapenemase-Producing Aeromonas veronii Disseminated in the Environment of an Equine Specialty Hospital. The emergence of bacterial resistance to carbapenem antibiotics is an urgent public health threat. Carbapenem drugs are a last resort treatment option for life-threatening infections. The frequent use of broad-spectrum antibiotics to treat hospitalized patients provides significant selection pressure favoring the emergence and dissemination of resistant organisms, including carbapenem-resistant Enterobacteriaceae (CRE). CREs have been reported in animal populations, but only rarely in horses. Our objective was to determine the prevalence of CRE in the environment of a referral equine specialty...
A survey of macrocyclic lactone efficacy in Australian cyathostomin populations. The macrocyclic lactone (ML) drugs are central to the control of equine strongyles but recent international reports raise concerns about reduced efficacy of these drugs against cyathostomins. The objectives of the present study were firstly, to evaluate the efficacy of ML drugs against cyathostomins on a cross-section of Australian horse farms, and secondly, to determine the egg reappearance period (ERP) following treatment of horses with MLs. A total of 419 horses on 43 properties were treated orally with ivermectin, abamectin or moxidectin, at recommended dose rates and drug efficacy was det...
Pharmacokinetics of ceftiofur sodium in equine pregnancy. Eleven pregnant pony mares (D270-326) were administered ceftiofur sodium intramuscularly at 2.2 mg/kg (n = 6) or 4.4 mg/kg (n = 5), once daily. Plasma was obtained prior to ceftiofur administration and at 0.5, 1, 2, 4, 8, 12, and 24 hr after administration. Eight pony mares were re-enrolled in the study at least 3 days from expected foaling to ensure steady-state concentrations of drug at the time of foaling. Mares were administered ceftiofur sodium (4.4 mg/kg, IM) daily until foaling. Parturition was induced using oxytocin 1 hr after ceftiofur sodium administration. Allantoic and am...
Pharmacokinetics and pulmonary distribution of gamithromycin after intravenous administration in foals. The long-acting azalide antibiotic gamithromycin is marketed for intramuscular treatment of bovine and swine infections. Off-label use in foals leads to severe local lesions likely caused by hyperosmolality of the injected solution. We provide evidence from a pharmacokinetic study in 10 warm-blooded healthy foals for intravenous bolus injection of gamithromycin diluted in distilled water to be a safe and well tolerated alternative. By intravenous dosing, markedly higher plasma exposure and better penetration into bronchoalveolar lavage cells but lower distribution into epithelial lining fluid ...
Pharmacokinetics of betamethasone in plasma, urine, and synovial fluid following intra-articular administration to exercised thoroughbred horses. The use of corticosteroids, such as betamethasone, in performance horses is tightly regulated. The objective of the current study was to describe the plasma pharmacokinetics of betamethasone as well as time-related urine and synovial fluid concentrations following intra-articular administration to horses. Twelve racing-fit adult Thoroughbred horses received a single intra-articular administration (9 mg) of a betamethasone sodium phosphate and betamethasone acetate injectable suspension into the right antebrachiocarpal joint. Blood, urine, and synovial fluid samples were collected prior to and...
Effects of sedation and salbutamol administration on hyperpnoea and tidal breathing spirometry in healthy horses. Sedation is often required to perform pulmonary function testing (PFT) in horses, but drug effects may influence respiratory function. The current study was designed to characterise the effects of sedation and bronchodilator administration on absolute and relative indices of pulmonary function during eupnoeic respiration and carbon dioxide-induced hyperpnoea (rebreathing) in healthy horses using a pneumotachographic spirometry system. Sedation with acetylpromazine (ACP), xylazine, or both drugs in combination was associated with significant reductions in respiratory frequency, minute ventilati...
Efficacy of a morantel-abamectin combination for the treatment of resistant ascarids in foals. This study was performed to investigate the efficacy of a morantel-abamectin combination for the treatment of macrocyclic lactone (ML)-resistant Parascaris spp. infections in foals. Methods: Foals on five properties with a Parascaris faecal egg count (FEC) > 50 eggs per gram were used to estimate the FEC reduction (FECR) and efficacy of the anthelmintic combination. Conclusions: On all properties, resistance to ivermectin and abamectin was present and the Parascaris FECR in foals administered the morantel-abamectin combination was > 99%, indicating that this combination effective...
Pharmacological indices and pulmonary distribution of rifampicin after repeated oral administration in healthy foals. The treatment of equine lung infections by Rhodococcus equi with rifampicin is empirically based because pharmacokinetic/pharmacodynamic (PK/PD) indices and pivotal clinical outcome data are not available. Objective: To evaluate the pharmacokinetics and pulmonary distribution of rifampicin into epithelial lining fluid (ELF) and bronchoalveolar lavage cells (BALC) to predict antimicrobial activity in the lung using PK/PD indices. Methods: Controlled, randomised, two-period, crossover, repeated-dose study with an initial arm to measure disposition after i.v. administration of rifampicin. Methods...
Testosterone metabolism of equine single CYPs of the 3A subfamily compared to the human CYP3A4. Cytochrome P450 enzymes (CYPs) are responsible for the phase I metabolism of drugs, xenobiotics and endogenous substances. Knowledge of single CYPs and their substrates is important for drug metabolism, helps to predict adverse effects and may prevent reduced drug efficacy in polypharmacy. In this study, three equine isoenzymes of the 3A subfamily, the equine flavoprotein NADPH-P450 oxidoreductase (POR), and the cytochrome b5 (CYB5) were cloned, sequenced and heterologously expressed in a baculovirus expression system. Testosterone, the standard compound for characterization of the human CYP3A...
Pharmacokinetics and pharmacodynamics of intravenous romifidine and propranolol administered alone or in combination for equine sedation. Propranolol has been suggested for anxiolysis in horses, but its sedation efficacy and side effects, both when administered alone and in combination with α-adrenoceptor agonists, remain undetermined. This study aimed to document the pharmacokinetics and pharmacodynamics of propranolol, romifidine and their combination. Methods: Randomized, crossover study. Methods: Six adult horses weighing 561 ± 48 kg. Methods: Propranolol (1 mg kg; treatment P), romifidine (0.1 mg kg; treatment R) or their combination (treatment PR) were administered intravenously with a minimum of 1 week between treatment...
The effects of dose and diet on the pharmacodynamics of esomeprazole in the horse. Esomeprazole warrants further investigation as a treatment for equine gastric ulcer syndrome. Objective: To investigate the duration of intraday acid suppression achieved with two doses of esomeprazole under two dietary conditions. Methods: A four way crossover design. Methods: Six adult Thoroughbreds instrumented with percutaneous gastrotomy tubes were used. Intragastric pH was measured for continuous 23 h periods (08.00-07.00 h) for 6 consecutive days (Days 0-5). Baseline data was recorded on Day 0 and esomeprazole was administered on Days 1-5. Two doses (0.5 and 2.0 mg/kg bwt/day per os onc...
Comparative efficacy of oral meloxicam and phenylbutazone in 2 experimental pain models in the horse. The efficacy of oral phenylbutazone [PBZ; 4.4 mg/kg body weight (BW), q12h], a non-selective non-steroidal anti-inflammatory drug (NSAID), and oral meloxicam (MXM; 0.6 mg/kg BW, q24h), a COX-2 selective NSAID, were evaluated in 2 experimental pain models in horses: the adjustable heart bar shoe (HBS) model, primarily representative of mechanical pain, and the lipopolysaccharide-induced synovitis (SYN) model, primarily representative of inflammatory pain. In the HBS model, PBZ reduced multiple indicators of pain compared with the placebo and MXM. Meloxicam did not reduce indicators of pain rela...
In vitro phase I metabolism of selective estrogen receptor modulators in horse using ultra-high performance liquid chromatography-high resolution mass spectrometry. Selective estrogen receptor modulators (SERMs) are chemicals that possess the anti-oestrogenic activities that are banned 'in' and 'out' of competition by the World Anti-Doping Agency (WADA) in human sports, and by the International Federation of Horseracing Authorities (IFHA) in horseracing. SERMs can be used as performance-enhancing drugs to boost the level of androgens or to compensate for the adverse effects as a result of extensive use of androgenic anabolic steroids (AASs). SERMs have indeed been abused in human sports; hence, a similar threat can be envisaged in horseracing. Numerous an...
Screening of over 100 drugs in horse urine using automated on-line solid-phase extraction coupled to liquid chromatography-high resolution mass spectrometry for doping control. A fast method for the direct analysis of enzyme-hydrolysed horse urine using an automated on-line solid-phase extraction (SPE) coupled to a liquid-chromatography/high resolution mass spectrometer was developed. Over 100 drugs of diverse drug classes could be simultaneously detected in horse urine at sub to low parts per billion levels. Urine sample was first hydrolysed by β-glucuronidase to release conjugated drugs, followed by centrifugal filtration. The filtrate (1mL) was directly injected into an on-line SPE system consisting of a pre-column filter and a SPE cartridge column for the separa...
Nonsteroidal Anti-inflammatory Drug Use in Horses. Nonsteroidal anti-inflammatory drugs (NSAIDs) are effective anti-inflammatory and analgesic agents and are arguably the most commonly used class of drugs in equine medicine. This article provides a brief review of the mechanism of action, therapeutic uses, pharmacokinetics, and adverse effects associated with their use in horses. The use of COX-2 selective NSAIDs in veterinary medicine has increased over the past several years and special emphasis is given to the use of these drugs in horses. A brief discussion of the use of NSAIDs in performance horses is also included.
The Analysis of Phenylbutazone and Its Active Metabolite, Oxyphenbutazone, in Equine Tissues (Muscle, Kidney, and Liver), Urine, and Serum by LC-MS/MS. This study reports the use of two validated LC with tandem MS (MS/MS) methods to study the residue depletion profile of phenylbutazone (PBZ) and its metabolite oxyphenbutazone (OXPBZ) from equine serum, urine, and muscle, kidney, and liver tissues. One LC-MS/MS method, with an LOQ of 1.0 ng/mL for PBZ and 2.0 ng/mL for OXPBZ, was used for the analysis of the two drugs in the biological fluids (equine urine and serum); the other LC-MS/MS method, with an LOQ of 0.5 ng/g for PBZ and OXPBZ, was used for the analysis of the drugs in the equine tissue samples. PBZ was administered intravenously to t...
Effects of Single-Dose Prucalopride on Intestinal Hypomotility in Horses: Preliminary Observations. Abnormalities of gastrointestinal motility are often a challenge in horses; however, the use of prokinetic drugs in such conditions must be firmly established yet. For this reason we carried out a preliminary study on the effects of prucalopride on intestinal motor activity of horses with gut hypomotility. The effect of prucalopride per os by oral dose syringe (2 mg/100 kg body weight) was assessed by abdominal ultrasound (evaluating duodenal, cecal, and colonic motor activity) in six horses with gut hypomotility. After administration of prucalopride, a significant increase of contractile ...
Pharmacokinetics and in vitro efficacy of salicylic acid after oral administration of acetylsalicylic acid in horses. Although acetylsalicylic acid (ASA) is not frequently used as a therapeutic agent in horses, its metabolite SA is of special interest in equestrianism since it is a natural component of many plants used as horse feed. This led to the establishment of thresholds by horse sport organizations for SA in urine and plasma. The aim of this study was to investigate plasma and urine concentrations of salicylic acid (SA) after oral administration of three different single dosages (12.5 mg/kg, 25 mg/kg and 50 mg/kg) of acetylsalicylic acid (ASA) to eight horses in a cross-over designed study. Results:...
Effects of xylazine and dexmedetomidine on equine articular chondrocytes in vitro. To assess the effects of xylazine and dexmedetomidine on equine chondrocytes, in vitro. Methods: Prospective, experimental study. Methods: Equine articular chondrocytes from five male horses. Methods: Chondrocytes were isolated from healthy equine articular cartilage of the metacarpo/metatarsophalangeal joints. Cell viability was assessed using the WST-8 assay by exposing chondrocytes to xylazine (0.5, 1, 2, 4, 8, 16.6, 25, 50 mg mL) or dexmedetomidine (0.001, 0.005, 0.01, 0.05, 0.175, 0.25 mg mL) for 15, 30 and 60 minutes. Based on the results of these tests, cells were treated with xyla...
Detection and pharmacokinetics of salmeterol in thoroughbred horses following inhaled administration. Salmeterol is a man-made beta-2-adrenergic receptor agonist used to relieve bronchospasm associated with inflammatory airway disease in horses. Whilst judicious use is appropriate in horses in training, they cannot race with clinically effective concentrations of medications under the British Horseracing Authority's Rules of Racing. Salmeterol must therefore be withdrawn prior to race day and pharmacokinetic (PK) studies used to establish formal detection time advice. Salmeterol xinafoate (Serevent Evohaler ) was administered (0.1 mg twice daily for 4.5 days) via inhalation to six horses. Ur...
Pharmacokinetics and selected pharmacodynamics of romifidine following low-dose intravenous administration in combination with exercise to quarter horses. Romifidine is an alpha-2 adrenergic agonist used for sedation and analgesia in horses. As it is a prohibited substance, its purported use at low doses in performance horses necessitates further study. The primary goal of the study reported here was to describe the serum concentrations and pharmacokinetics of romifidine following low-dose administration immediately prior to exercise, utilizing a highly sensitive liquid chromatography-tandem mass spectrometry assay that is currently employed in many drug testing laboratories. An additional objective was to describe changes in heart rate and rhyt...
Anti-inflammatory drugs decrease infection of brain endothelial cells with EHV-1 in vitro. Equine herpesvirus-associated myeloencephalopathy is the result of endothelial cell infection of the spinal cord vasculature with equine herpesvirus-1 (EHV-1) during cell-associated viraemia. Endothelial cell infection requires contact between infected peripheral blood mononuclear and endothelial cells. Inflammation generated during viraemia likely upregulates adhesion molecule expression on both cell types increasing contact and facilitating endothelial cell infection. Objective: Evaluating the role of anti-inflammatory drugs in decreasing endothelial cell infection with EHV-1. Methods: In vi...
Pharmacokinetics and pharmacodynamics of the injectable formulation of methadone hydrochloride and methadone in lipid nanocarriers administered orally to horses. We investigated the thermal, electrical and mechanical antinociceptive and physiological effects (heart rate, respiratory rate, arterial blood pressure, head height and abdominal auscultation score), and pharmacokinetics, of 0.5 mg/kg of the injectable formulation (ORAL) or nanoparticulated methadone (NANO) given orally, in six adult mares, using a crossover, blind and prospective design. Repeated-measure models were used to compare parametric data between and within treatments, followed by Tukey's test. Nonparametric data were analysed with Wilcoxon signed-rank, adjusted by Bonferroni tests....
The effect of anesthetic drug choice on accuracy of high-definition oscillometry in laterally recumbent horses. To determine the accuracy of high-definition oscillometry (HDO) for arterial pressure measurement during injectable or inhalation anesthesia in horses. Methods: Prospective, clinical study. Methods: Twenty-four horses anesthetized for procedures requiring lateral recumbency. Methods: Horses were premedicated with xylazine, and anesthesia induced with diazepam-ketamine. Anesthesia was maintained with xylazine-ketamine-guaifenesin combination [TripleDrip (TD; n = 12) or isoflurane (ISO; n = 12)]. HDO was used to obtain systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures, and he...
Comparison between the effects of postanesthetic xylazine and dexmedetomidine on characteristics of recovery from sevoflurane anesthesia in horses. To compare postanesthetic xylazine and dexmedetomidine on recovery characteristics from sevoflurane anesthesia in horses. Methods: Randomized, crossover study. Methods: Six geldings, mean±standard deviation (SD) (range), 17±4 (11-24) years and 527±80 (420-660) kg. Methods: Horses were anesthetized with sevoflurane for 60 minutes under standardized conditions for a regional limb perfusion study. In recovery, horses were administered either xylazine (200 μg kg) or dexmedetomidine (0.875 μg kg) intravenously. Recoveries were unassisted and were video-recorded for later evaluation of rec...
Evaluation of direct Etest for antimicrobial susceptibility testing of bacteria isolated from synovial fluid of horses using enrichment bottles. This study evaluated the Etest for direct antimicrobial susceptibility testing (AST) of bacteria from equine synovial specimens, incubated in BACTEC enrichment bottles. Ninety-four culture-positive broths were inoculated onto agar to directly determine the minimum inhibitory concentrations (MICs) of 13 antimicrobials, using the Etest (direct Etest). Results were compared with those obtained with the agar dilution reference method, the standard Etest, and the disc diffusion method, after subculture and standardisation of the inoculum. For categorical comparison of AST results, MICs were transla...
Pharmacokinetics of intravenous continuous rate infusions of sodium benzylpenicillin and ceftiofur sodium in adult horses. OBJECTIVE To determine plasma drug concentrations after IV administration of a bolus followed by continuous rate infusion (CRI) of sodium benzylpenicillin and ceftiofur sodium to healthy adult horses. ANIMALS 6 Thoroughbred mares (3 to 9 years old; mean ± SD body weight, 544 ± 55 kg) with no history of recent antimicrobial treatment. PROCEDURES Horses were used in 2 experiments conducted 14 days apart. For each experiment, horses were housed individually in stables, and catheters were placed bilaterally in both jugular veins for drug administration by CRI (left catheter) and for intermittent...
Effects of various antiplatelet drugs on ex vivo platelet activation induced by equine herpesvirus type 1. OBJECTIVE To evaluate the effects of treatment of horses with standard platelet inhibitors on ex vivo inhibition of platelet activation by equine herpesvirus type I (EHV-I). ANIMALS II healthy adult horses. PROCEDURES In a double-blinded, placebo-controlled crossover study, horses were treated orally for 5 days with theophylline (5 mg/kg, q 12 h), pentoxifylline (10 mg/kg, q 12 h), clopidogrel bisulfate (4 mg/kg, q 24 h), acetylsalicylic acid (20 mg/kg, q 24 h), or placebo. Horses received all treatments, each separated by a 3-week washout period. Platelet-rich plasma was prepared from citrate...
Effect of neostigmine on contractility of equine pre-ovulatory follicles: An in vitro study. In this study, the Authors investigated the modulatory effect of three single doses (10, 10, and 10 M) of neostigmine on the spontaneous contractility of equine pre-ovulatory follicles in an isolated organ bath, to establish the relationship between this acetylcholinesterase inhibitor and ovulation, in the mare. The results indicate that neostigmine increases pre-ovulatory contractility in equine follicles at each dose, but in a different manner. Indeed, the rise in contractility induced by neostigmine at 10 M and 10 M was phasic, while at 10 M it was tonic. The data obtained indicate poss...
