Intramuscular administration in horses involves the injection of medications directly into the muscle tissue. This method is commonly used for delivering vaccines, antibiotics, and other therapeutic agents. The technique requires knowledge of equine anatomy to ensure the injection is placed in the correct location, such as the neck or hindquarters, to minimize discomfort and avoid complications. Proper intramuscular administration can facilitate the absorption of medications into the bloodstream, allowing for effective therapeutic interventions. This page compiles peer-reviewed research studies and scholarly articles that explore the techniques, benefits, and potential complications associated with intramuscular administration in equine practice.
Fultz L, Giguère S, Berghaus LJ, Grover GS, Merritt DA.Administration of ceftiofur sodium via nebulisation has been recommended for the treatment of bronchopneumonia in horses, despite the lack of pharmacokinetic and safety data. Objective: To compare concentrations of desfuroylceftiofur acetamide (DCA) in plasma and pulmonary epithelial lining fluid (PELF) of foals after nebulisation or i.m. administration of ceftiofur sodium and to determine if nebulisation of ceftiofur sodium induces airway inflammation. Methods: Randomised experimental study. Methods: Six weanling foals received ceftiofur sodium (2.2 mg/kg bwt daily for 5 doses) by the i.m. ...
Risberg ÅI, Spadavecchia C, Ranheim B, Hendrickson EH, Lervik A, Haga HA.To elicit and evaluate the NWR (nociceptive withdrawal reflex) in 2 and 11 day old foals, to investigate if buprenorphine causes antinociception and determine if the NWR response changes with increasing age. The effect of buprenorphine on behaviour was also evaluated. Methods: Prospective, experimental cross-over trial. Methods: Nine Norwegian Fjord research foals. Methods: Buprenorphine, 10 μg kg(-1) was administered intramuscularly (IM) to the same foal at 2 days and at 11 days of age. The NWR and the effect of buprenorphine were evaluated by electromyograms recorded from the left deltoid m...
Perotta JH, Canola PA, Lopes MC, Evora PM, Martinez PE, Escobar A, Valadão CA.To evaluate the effects of intravenous (IV) or intramuscular (IM) hyoscine premedication on physiologic variables following IV administration of medetomidine in horses. Methods: Randomized, crossover experimental study. Methods: Eight healthy crossbred horses weighing 330 ± 39 kg and aged 7 ± 4 years. Methods: Baseline measurements of heart rate (HR), cardiac index (CI), respiratory rate, systemic vascular resistance (SVR), percentage of patients with second degree atrioventricular (2(o) AV) block, mean arterial pressure (MAP), pH, and arterial partial pressures of carbon dioxide (PaCO2 ) an...
Scofield D, Black J, Wittenburg L, Gustafson D, Ferris R, Hatzel J, Traub-Dargatz J, McCue P.Systemic administration of ceftiofur crystalline free acid (CCFA) may be a potential treatment for infectious endometritis caused by Streptococcus equi ssp. zooepidemicus (S.  zooepidemicus) and other susceptible bacterial organisms in the mare. Objective: To determine if i.m. administration of CCFA at the label dose will exceed the minimum inhibitory concentration (MIC) of S.  zooepidemicus in the endometrium following single administration and multiple administration protocols. Methods: Experimental pharmacokinetic study. Methods: Three mares (Group 1) were administered a single i.m. dos...
Foreman JH, Ruemmler R.There are no peer reviewed, blinded controlled studies regarding the skeletal analgesic efficacy of intramuscularly administered meperidine in horses. Objective: Using an adjustable heart bar shoe model of equine foot pain, the objective of this study was to test the hypothesis that meperidine (pethidine) administered intramuscularly would prove more efficacious in alleviating lameness than a saline placebo. Methods: Crossover pharmacodynamic experiment. Methods: Eight healthy adult Thoroughbred horses randomly underwent weekly i.m. treatments 1 h after lameness induction: saline placebo (1â...
Venner M, Credner N, Lämmer M, Giguère S.The objectives of the present study were to determine the relative efficacy of tulathromycin, azithromycin, or azithromycin with rifampin for the treatment of pulmonary abscesses on a farm with endemic infections caused by Rhodococcus equi. Foals with ultrasonographic evidence of pulmonary abscesses (abscess score 8.0-15 cm; n=120) were randomly allocated in four equal treatment groups: (1) tulathromycin intramuscularly; (2) azithromycin monotherapy, orally; (3) azithromycin with rifampin, orally; (4) saline intramuscularly as a placebo. Physical examination and thoracic ultrasonography were p...
Fultz L, Giguère S, Berghaus LJ, Davis JL.Current labelling for the use of ceftiofur crystalline free acid (CCFA) in horses states that 2 i.m. doses must be administered 4 days apart to provide 10 days of therapeutic coverage. A 10 day treatment regimen is not sufficient for the long-term treatment of horses with severe lung consolidation or pleuropneumonia. There are currently no data to guide an appropriate dosing interval when a longer treatment regimen is warranted. Objective: To determine steady-state plasma and pulmonary epithelial lining fluid (PELF) concentrations of desfuroylceftiofur acetamide (DCA) after weekly i.m. adminis...
Costello S, Heffron B, Taddei L, Benoit M, Hurt L, Simpson L, Bishop J, Folker-Calderon D, Negrusz A.Fluphenazine, a potent antipsychotic used to treat schizophrenia in humans, is used in racehorses as a performance-enhancing drug, and for that reason it has been banned by the Association of Racing Commissioners International. A liquid chromatography-tandem mass spectrometry method for detecting and quantitating fluphenazine in equine serum was developed and validated. The method was then employed to quantitate fluphenazine in serum samples collected from three study horses after intramuscular injection of fluphenazine decanoate. Stability testing showed that fluphenazine is stable in unextra...
Devine EP, KuKanich B, Beard WL.To determine the pharmacokinetics of morphine after IM administration in a clinical population of horses. Methods: Prospective clinical study. Methods: 77 horses. Methods: Morphine sulfate (0.1 mg/kg [0.045 mg/lb], IM) was administered to horses, and blood samples were obtained at predetermined time points. Plasma morphine concentrations were measured via liquid chromatography and mass spectrometry. In preliminary investigations, samples were obtained from 2 healthy horses at 12 time points (up to 12 hours after drug administration) and analyzed via 2-stage pharmacokinetic analysis. In the cli...
Gray BP, Viljanto M, Bright J, Pearce C, Maynard S.The detection of the abuse of anabolic steroids in equine sport is complicated by the endogenous nature of some of the abused steroids, such as testosterone and nandrolone. These steroids are commonly administered as intramuscular injections of esterified forms of the steroid, which prolongs their effects and improves bioavailability over oral dosing. The successful detection of an intact anabolic steroid ester therefore provides unequivocal proof of an illegal administration, as esterified forms are not found endogenously. Detection of intact anabolic steroid esters is possible in plasma samp...
Knych HK, Vidal MA, Casbeer HC, McKemie DS.The use of triamcinolone acetonide (TA) in performance horses necessitates establishing appropriate withdrawal times prior to performance. Objective: To describe the plasma pharmacokinetics of TA and time-related urine and synovial fluid concentrations following i.m. and intra-articular administration to exercised Thoroughbred horses. Methods: Block design. Methods: Twelve racing fit adult Thoroughbred horses received a single i.m. administration of TA (0.1 mg/kg bwt). After an appropriate washout period, the same horses then received a single intra-articular TA administration (9 mg) into the ...
Newman JC, Prange T, Jennings S, Barlow BM, Davis JL.The objectives of this study were to examine the pharmacokinetics of tobramycin in the horse following intravenous (IV), intramuscular (IM), and intra-articular (IA) administration. Six mares received 4 mg/kg tobramycin IV, IM, and IV with concurrent IA administration (IV+IA) in a randomized 3-way crossover design. A washout period of at least 7 days was allotted between experiments. After IV administration, the volume of distribution, clearance, and half-life were 0.18 ± 0.04 L/kg, 1.18 ± 0.32 mL·kg/min, and 4.61 ± 1.10 h, respectively. Concurrent IA administration could not be...
Anderson FL, Secombe CJ, Lester GD.A 9-year-old Thoroughbred gelding was presented for swelling over the left neck and inappetence. There was recent history of intramuscular administration of flunixin meglumine into the left neck. On examination, there was evidence of focal myositis, anaemia, haemolysis and pigmenturia. Culture of aspirated fluid from the left side of the neck produced a heavy growth of a Clostridium species. Complications of infection included haemolytic anaemia, hepatopathy, osteitis and transient hypertrophic cardiomyopathy. Treatment included intravenous fluid therapy, antibiotics, anti-inflammatory drugs, ...
Sekkin S, Gokbulut C, Kum C, Karademir U.This study was designed to investigate the plasma disposition and systemic availability of enrofloxacin (ENR) following intramuscular and intravenous administrations. Six donkeys (Equus asinus) were used in this study. The animals were allocated into two groups (intramuscular and intravenous groups). After a 2-week washout period, the experiment was repeated with the groups reversed according to a two-phase crossover design. In phase I, group I received intravenously the commercially available injectable solution of ENR at the dose of 5 mg/kg and group II received intramuscularly the same ENR ...
Soma LR, Uboh CE, Liu Y, Li X, Robinson MA, Boston RC, Colahan PT.This study investigated and compared the pharmacokinetics of intra-articular (IA) administration of dexamethasone sodium phosphate (DSP) into three equine joints, femoropatellar (IAS), radiocarpal (IAC), and metacarpophalangeal (IAF), and the intramuscular (IM), oral (PO) and intravenous (IV) administrations. No significant differences in the pharmacokinetic estimates between the three joints were observed with the exception of maximum concentration (Cmax ) and time to maximum concentration (Tmax ). Median (range) Cmax for the IAC, IAF, and IAS were 16.9 (14.6-35.4), 23.4 (13.5-73.0), and 46.9...
Figueiredo JP, Muir WW, Sams R.To compare the cardiorespiratory, gastrointestinal, analgesic, and behavioral effects between IV and IM administration of morphine in conscious horses with no signs of pain. Methods: 6 healthy adult horses. Methods: Horses received saline (0.9% NaCl) solution (IM or IV) or morphine sulfate (0.05 and 0.1 mg/kg, IM or IV) in a randomized, masked crossover study design. The following variables were measured before and for 360 minutes after drug administration: heart and respiratory rates; systolic, diastolic, and mean arterial blood pressures; rectal temperature; arterial pH and blood gas variabl...
McIlwraith CW, Frisbie DD, Kawcak CE.To assess clinical, radiographic, histologic, and biochemical effects of sodium pentosan polysulfate (NaPPS) administered IM for treatment of experimentally induced osteoarthritis in horses. Methods: 18 horses. Methods: Osteoarthritis was induced arthroscopically in 1 middle carpal joint of all horses. Nine horses received NaPPS (3 mg/kg, IM) on study days 15, 22, 29, and 36. Nine control horses received the same volume of saline (0.9% NaCl) solution IM on study days 15, 22, 29, and 36. Clinical, radiographic, gross, histologic, histochemical, and biochemical findings as well as findings of sy...
Soma LR, Uboh CE, You Y, Guan F, Boston RC.To compare pharmacokinetics of triamcinolone acetonide (TA) following i.v., intra-articular (i.a.), and i.m. administration and determine its effect on plasma concentrations of hydrocortisone and cortisone. Methods: 6 Thoroughbreds. Methods: TA (0.04 mg/kg) was administered i.v., i.m., or i.a., and plasma TA, hydrocortisone, and cortisone concentrations were determined. Results: I.v. administration of TA was fitted to a 2-compartment model. Median distribution half-life was 0.50 hours (range, 0.24 to 0.67 hours); elimination half-life was 6.1 hours (range, 5.0 to 6.4 hours). Transfer half-life...
Credille BC, Giguère S, Berghaus LJ, Burton AJ, Sturgill TL, Grover GS, Donecker JM, Brown SA.The objectives of this study were to determine the plasma and pulmonary disposition of ceftiofur crystalline free acid (CCFA) in weanling foals and to compare the plasma pharmacokinetic profile of weanling foals to that of adult horses. A single dose of CCFA was administered intramuscularly to six weanling foals and six adult horses at a dose of 6.6 mg/kg of body weight. Concentrations of desfuroylceftiofur acetamide (DCA) were determined in the plasma of all animals, and in pulmonary epithelial lining fluid (PELF) and bronchoalveolar lavage (BAL) cells of foals. After intramuscular (IM) admin...
Berghaus LJ, Giguère S, Sturgill TL, Bade D, Malinski TJ, Huang R.The objectives of this study were to determine the plasma and pulmonary disposition of gamithromycin in foals and to investigate the in vitro activity of the drug against Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) and Rhodococcus equi. A single dose of gamithromycin (6 mg/kg of body weight) was administered intramuscularly. Concentrations of gamithromycin in plasma, pulmonary epithelial lining fluid (PELF), bronchoalveolar lavage (BAL) cells, and blood neutrophils were determined using HPLC with tandem mass spectrometry detection. The minimum inhibitory concentration of gamithr...
Davis JL, Messenger KM, LaFevers DH, Barlow BM, Posner LP.The purpose of this study was to determine the pharmacokinetics of buprenorphine following intravenous (i.v.) and intramuscular (i.m.) administration in horses. Six horses received i.v. or i.m. buprenorphine (0.005 mg/kg) in a randomized, crossover design. Plasma samples were collected at predetermined times and horses were monitored for adverse reactions. Buprenorphine concentrations were measured using ultra-performance liquid chromatography with electrospray ionization mass spectrometry. Following i.v. administration, clearance was 7.97±5.16 mL/kg/min, and half-life (T(1/2)) was 3.58 h (ha...
Moeller BC, Sams RA, Guinjab-Cagmat J, Szabo NJ, Colahan P, Stanley SD.Testosterone is an anabolic androgenic steroid (AAS) that is endogenously produced by both male and female horses that also has the potential for abuse when administered exogenously to race horses. To recommend appropriate withdrawal guidelines so that veterinarians can discontinue therapeutic use prior to competition, the pharmacokinetics and elimination of testosterone were investigated. An aqueous testosterone suspension was administered intramuscularly in the neck of Thoroughbred horses (n = 20). The disposition of testosterone from this formulation was characterized by an initial, rapid a...
Collard WT, Cox SR, Lesman SP, Grover GS, Boucher JF, Hallberg JW, Robinson JA, Brown SA.Absolute bioavailability and dose proportionality studies were performed with ceftiofur in horses. In the absolute bioavailability study, thirty animals received either an intravenous dose of ceftiofur sodium at 1.0 mg/kg or an intramuscular (i.m.) dose of ceftiofur crystalline-free acid (CCFA) at 6.6 mg/kg. In the dose proportionality study, 48 animals received daily i.m. ceftiofur sodium injections at 1.0 mg/kg for ten doses or two doses of CCFA separated by 96 h, with CCFA doses of 3.3, 6.6, or 13.2 mg/kg. Noncompartmental and mixed-effect modeling procedures were used to assess pharmacokin...
Sturgill TL, Giguère S, Franklin RP, Cohen ND, Hagen J, Kalyuzhny AE.The objectives of the present study were to determine if administration of inactivated parapoxvirus ovis (IPPVO) can decrease the cumulative incidence of pneumonia and increase the number of IFN-γ- and IL-4-secreting cells among foals. Fifty-nine foals were randomly assigned to 2 treatment groups (IPPVO or placebo) prior to birth. At 24-48 h of age, foals received 2 ml of either IPPVO or a placebo by intramuscular injection. Injections were repeated 24h and 8 days later. The number of IFN-γ- and IL-4-secreting cells was measured using a validated ELISPOT assay on blood mononuclear cells coll...
van den Hoven R, Bauer A, Hackl S, Zickl M, Spona J, Zentek J.In this preliminary study, time-dependent changes in plasma CK and AST activity, tyrosine (Tyr), 3-methyl-histidine (3mHis), glucose and lactate concentrations were analysed in nine horses under two different conditions. Furthermore, intramuscular concentrations of Tyr, 3mHis and activities of cathepsin B, acid phosphatase (ACP), glucose-6-phosphate dehydrogenase (G6PDH) and mRNA expression of ubiquitin were determined at the same time. After studying the effects of exercise alone, the effects of exercise and feeding of an experimental protein/amino acid (AA) supplement were analysed. Horses w...
Riviere JE, Coppoc GL, Hinsman EJ, Carlton WW, Traver DS.Gentamicin pharmacokinetics and nephrotoxic potential were evaluated in twelve 2 to 3 month-old horses. Whereas recent evidence in our clinic indicated that young horses may be especially susceptible to gentamicin nephrotoxicity, young rabbits and rats are usually resistant. Gentamicin (4.5 mg/kg) was given by rapid intravenous injection. Serum gentamicin concentrations over a 13-hour period were fitted to an open, two-compartment, pharmacokinetic model. Subsequently, the same horses were divided into groups of 3 horses each. Each group received 0, 2.2, 4.4 or 8.8 mg gentamicin/kg, intramuscul...
Lees P, Serrano L.1 The butyrophenone tranquilizer, azaperone, was administered intramuscularly, at dose levels of 0.4 and 0.8 mg/kg, to ponies and its effects on cardiovascular and respiratory functions assessed. 2 Arterial blood pH, CO2 tension (PaCO2) and O2 tension (PaO2) remained relatively constant throughout the course of action of azaperone. 3 Azaperone did not modify plasma protein concentration but venous blood packed cell volume and haemoglobin concentration were reduced by 5 to 10% for at least 4 hours. These changes were probably caused by uptake of erythrocytes into the splenic reservoir. 4 Small ...
Parry BW, Anderson GA, Gay CC.The hypotensive effect of acepromazine maleate was related to both the dose and route of administration. The degree and duration of hypotension varied between individual horses. In general, intravenous administration produced a more rapid maximum effect than intramuscular injection and the larger the dose the longer blood pressure remained at low levels. Average systolic pressure (of 6 horses) remained significantly below control values for more than 6 h after an intramuscular injection of 0.05 mg acepromazine maleate/kg body weight. Respiratory rate was markedly decreased, with the duration, ...
Risberg ÅI, Ranheim B, Krontveit RI, Lervik A, Haga HA.To compare cardiac index and oxygen extraction at equivalent depths of anaesthesia between isoflurane-anaesthetized horses and horses anesthetized with isoflurane and dexmedetomidine CRI. Methods: Sequential, blinded, randomized, balanced, crossover study. Methods: Eight horses weighing a mean ± standard deviation of 478 ± 58 kg. Methods: Horses were premedicated with 0.03 mg kg(-1) acepromazine intramuscularly (IM) and 8 μg kg(-1) dexmedetomidine intravenously (IV). Anaesthesia was induced with 2.5 mg kg(-1) ketamine and 0.1 mg kg(-1) midazolam IV and maintained with isofluran...
Gray BP, Viljanto M, Bright J, Pearce C, Maynard S.The detection of the abuse of anabolic steroids in equine sport is complicated by the endogenous nature of some of the abused steroids, such as testosterone and nandrolone. These steroids are commonly administered as intramuscular injections of esterified forms of the steroid, which prolongs their effects and improves bioavailability over oral dosing. The successful detection of an intact anabolic steroid ester therefore provides unequivocal proof of an illegal administration, as esterified forms are not found endogenously. Detection of intact anabolic steroid esters is possible in plasma samp...
Belloli C, Crescenzo G, Lai O, Carofiglio V, Marang O, Ormas P.The objective of this study was to determine the pharmacokinetic behaviour of imidocarb in horses following a single i.m. injection at the dose commonly administered to treat Babesia caballi infections or to prevent babesiosis. Eight horses were injected i.m. with a single dose of 2.4 mg imidocarb dipropionate/kg bwt and blood, faecal, urine and milk samples were collected. For imidocarb determination, a high-performance liquid chromatographic method (HPLC) was used after weak cation-exchange solid phase, or liquid-liquid, extraction procedures. Twelve hours after treatment, no detectable plas...
Furr M.Eighteen normal horses were assigned to 1 of 3 treatment groups to investigate the effects of IM or intrathecal (IT) administration of ovalbumin on serum and cerebrospinal fluid (CSF) antibody production. Horses of group 1 were injected intramuscularly with ovalbumin and adjuvant, while horses in treatment groups 2 and 3 received ovalbumin intrathecally or intravenously, followed by IM injection as in group 1. Serum and CSF antibody titers were tested in group I every 30 days for 4 months, while serum and CSF were collected in group 2 and 3 horses at postvaccination day 60. Horses of group 1 (...
Slocombe JO, McCraw BM.Twelve pony foals were reared worm-free and inoculated with Strongylus vulgaris. On day 7 after inoculation, 6 ponies were given ivermectin IM at a dose of 200 micrograms/kg of body weight and on day 28 were necropsied. Ivermectin was effective in eliminating early 4th-stage S vulgaris larvae and reducing clinical signs associated with acute arteritis. After administrative ivermectin was effective against early 4th-stage Strongylus vulgaris larvae in ponies when administered at 100, 300, or 800 micrograms/kg of body weight. The purpose of the present study was to report on a more extensive tri...
Löscher W, Jaeschke G, Keller H.The pharmacokinetics of ascorbic acid were studied in 29 horses after intravenous (iv), subcutaneous, intramuscular (im) and oral administration. Following iv injection of 5 and 10 g ascorbic acid, respectively, a biphasic decline of ascorbic acid serum levels was found, indicating that the vitamin distributes in the body according to a two-compartment open model. The apparent volume of distribution (average value for Vd(ss) = 0.6 litre/kg) was approximately equivalent to the volume of total body water. The terminal half-life of the biexponential serum level-time curve (t1/2 beta) varied betwe...
Witte TS, Bergwerff AA, Scherpenisse P, Drillich M, Heuwieser W.Endometritis is one of the major problems in the horse breeding industry. The use of antibiotics for treatment of endometritis in the mare is recommended as best practice. The intrauterine application of antibiotics, however, has been under discussion over the last years because of concerns about its efficacy. The systemic use of antibiotics has been considered more effective because of its better distribution within the uterus. The objective of the present study was to determine the concentration of ceftiofur derivates in serum and endometrial tissue after intramuscular administration. Specif...
Anderson MG, Aitken MM.Adrenaline was given intramuscularly to resting horses. It increased heart rate, sweating, blood levels of lactic dehydrogenase, aldolase, creatine kinase, glucose, lactate, free fatty acids and glycerol. Responses to isoprenaline, to noradenaline and to adrenaline after pretreatment with propranolol indicated that beta receptors were involved in stimulation of tachycardia, sweating, lipolysis and muscle glycogenolysis, and alpha receptors in stimulation of liver glycogenolysis and leakage of intracellular enzymes. The time course and relative magnitude of the effects on different enzymes was ...
Scofield D, Black J, Wittenburg L, Gustafson D, Ferris R, Hatzel J, Traub-Dargatz J, McCue P.Systemic administration of ceftiofur crystalline free acid (CCFA) may be a potential treatment for infectious endometritis caused by Streptococcus equi ssp. zooepidemicus (S.  zooepidemicus) and other susceptible bacterial organisms in the mare. Objective: To determine if i.m. administration of CCFA at the label dose will exceed the minimum inhibitory concentration (MIC) of S.  zooepidemicus in the endometrium following single administration and multiple administration protocols. Methods: Experimental pharmacokinetic study. Methods: Three mares (Group 1) were administered a single i.m. dos...
French K, Pollitt CC, Pass MA.Experiments were performed to establish the pharmacokinetics of triamcinolone acetonide and the effects of the glucocorticoid on glucose metabolism in horses. The pharmacokinetics after intravenous (i.v.) dosing was best described by a three-compartment open model. There was rapid distribution from the central compartment followed by two phases of elimination. The half-life of the rapid elimination phase was 83.5 min and of the slower phase was 12 h. The term (Vss/Vc)-1was 12.3 indicating extensive distribution into the tissues. Triamcinolone acetonide given i.v. or intramuscularly (i.m. ) ind...
Sellon DC, Papich MG, Palmer L, Remund B.A two-way cross-over study of the pharmacokinetics of butorphanol after intravenous and intramuscular administration at 0.08 mg/kg in six adult horses was performed. Heparinized venous blood samples were obtained prior to drug administration and at 10, 20, 30, 45, 60, 120, 180, 240, and 360 min after IV injection. Samples were obtained at the same time points and at 6 h and 12 h after IM injection. Physical examination parameters were recorded at each time point. Plasma butorphanol concentrations were determined by high performance liquid chromatography. No significant differences in any physi...
Newman JC, Prange T, Jennings S, Barlow BM, Davis JL.The objectives of this study were to examine the pharmacokinetics of tobramycin in the horse following intravenous (IV), intramuscular (IM), and intra-articular (IA) administration. Six mares received 4 mg/kg tobramycin IV, IM, and IV with concurrent IA administration (IV+IA) in a randomized 3-way crossover design. A washout period of at least 7 days was allotted between experiments. After IV administration, the volume of distribution, clearance, and half-life were 0.18 ± 0.04 L/kg, 1.18 ± 0.32 mL·kg/min, and 4.61 ± 1.10 h, respectively. Concurrent IA administration could not be...
McCollum WH.Twenty horses that were seronegative for equine arteritis virus antibodies were inoculated IM with live equine arteritis virus vaccine. The inoculation did not cause clinical signs of disease. A mild, transient febrile reaction developed in 6 horses, 3 of which were in poor condition before inoculation. Six horses, 2 of which were in poor condition before inoculation, experienced mild lymphopenia. Necropsy revealed mild lesions in the lymph nodes of 6 horses (3 of which were in poor condition before inoculation). Maximum concentrations of virus were detected in the lymph nodes and were consist...
Glade MJ, Krook L, Schryver HF, Hintz HF.Epiphyseal and articular cartilages were examined in pony foals treated with intramuscular injections of either 0.5 mg dexamethasone per 100 kg bodyweight daily for 3, 8 or 11 months, or 5.0 mg per 100 kg for 11 months, and in horse foals treated with 5.0 mg per 100 kg for 20 weeks. The proximal femoral growth plates exhibited increased spatial separation between chondrocyte columns, narrowed zones of disorganized columnar and hypertrophic cartilage, abnormal penetration of hypertrophic cartilage by metaphyseal capillaries, retained cartilage in the spongiosa, distal terminal plate formation, ...
Jaglan PS, Roof RD, Yein FS, Arnold TS, Brown SA, Gilbertson TJ.Ceftiofur sodium, a broad spectrum cephalosporin antibiotic approved for veterinary use, is metabolized to desfuroylceftiofur which is conjugated to micro as well as macromolecules. Twelve horses, weighting 442-618 kg, were injected intramuscularly with a single dose of 2.2 mg ceftiofur/kg (1.0 mg/lb) body weight. Blood was collected at various intervals over 24 h after treatment. Three groups of four horses each were euthanized and lungs were collected at 1, 12, and 24 h after treatment. The concentration of desfuroylceftiofur and desfuroylceftiofur conjugates in the plasma and lungs was dete...
Sekkin S, Gokbulut C, Kum C, Karademir U.This study was designed to investigate the plasma disposition and systemic availability of enrofloxacin (ENR) following intramuscular and intravenous administrations. Six donkeys (Equus asinus) were used in this study. The animals were allocated into two groups (intramuscular and intravenous groups). After a 2-week washout period, the experiment was repeated with the groups reversed according to a two-phase crossover design. In phase I, group I received intravenously the commercially available injectable solution of ENR at the dose of 5 mg/kg and group II received intramuscularly the same ENR ...
Lee DH, Birhanu BT, Lee EB, Lee SJ, Boby N, Park YS, Park SC.Cefquinome is administered in horses for the treatment of respiratory infection caused by Streptococcus equi subsp. zooepidemicus, and septicemia caused by Escherichia coli. However, there have been no attempts to use cefquinome against Streptococcus equi subsp. equi (S. equi), the causative agent of strangles. Hence the objective of this study was to calculate an optimal dosage of cefquinome against S. equi based on pharmacokinetics and pharmacodynamics integration. Cefquinome (1.0Â mg/kg) was administered by intravenous and intramuscular routes to six healthy thoroughbred foals. Serum cefqui...
Sams RA, Ruoff WW.The pharmacokinetics and bioavailability of cefazolin given (IV, IM) to horses at the dosage of 11 mg/kg were investigated. The disposition of cefazolin given by IV route was characterized by a rapid disposition phase with a half-life of 5 to 10 minutes and a subsequent slower elimination phase with a half-life of 35 to 46 minutes. The total plasma clearance of cefazolin averaged 5.51 ml/min/kg and was due mainly to renal clearance (5.39 ml/min/kg) of unchanged drug. The volume of distribution at steady-state averaged 188 ml/kg. Plasma protein binding of cefazolin at a concentration of 10 micr...
Firth EC, Klein WR, Nouws JF, Wensing T.Single doses of sodium ampicillin (10 mg/kg) and kanamycin sulfate (5 mg/kg) were administered intramuscularly (i.m.) separately, and then together, to five pony mares. The plasma antibiotic concentration-time curves were constructed. The pharmacokinetic parameters of the antibiotics given separately were not altered by concurrent administration. Four of the five pony mares were then given the i.m. kanamycin/ampicillin combination 4 h after acute synovitis and fever had been induced by injection of lipopolysaccharide into the left intercarpal joint. The plasma concentration-time curves and the...
Torbert BJ, Kramer BS, Klei TR.A controlled test was used in ponies to compare the antiparasitic efficacy of ivermectin (22,23-dihydro-avermectin B1) in an injectable micelle solution administered IM with the efficacy of the same drug in an oral paste formulation. Parasite infections were naturally acquired in southern Louisiana. The drug was tested in both formulations at a dosage level of 0.2 mg/kg of body weight. Ivermectin in both formulations tested had an efficacy greater than 98% against Gasterophilus intestinalis and G nasalis larvae. Trichostrongylus axei, Habronema spp, Strongylus vulgaris, S. edentatus, and speci...
Arguedas MG, Hines MT, Papich MG, Farnsworth KD, Sellon DC.Despite frequent clinical use, information about the pharmacokinetics (PK), clinical effects, and safety of butorphanol in foals is not available. Objective: The purpose of this study was to determine the PK of butorphanol in neonatal foals after IV and IM administration; to determine whether administration of butorphanol results in physiologic or behavioral changes in neonatal foals; and to describe adverse effects associated with its use in neonatal foals. Methods: Six healthy mixed breed pony foals between 3 and 12 days of age were used. Methods: In a 3-way crossover design, foals received ...
Dart AJ, Little CB, Hughes CE, Chu O, Dowling BA, Hodgson DR, Rose RJ, Johnson KA.Recombinant equine growth hormone (reGH) has recently been evaluated for effects on body condition and wound healing. It has the potential to influence articular cartilage via stimulation of IGF-1. Objective: To investigate effects of administration on synovial joint metabolism. Methods: Six mature horses were given 20 microg/kg bwt reGH daily for 8 weeks by i.m. injection. Three control horses were injected with sterile water. Serum and synovial fluid samples were collected at 6, 8, 11 and 16 weeks for GH and IGF-1 assays. Articular cartilage harvested at week 16 was evaluated by Western anal...
Foreman JH, Ruemmler R.There are no peer reviewed, blinded controlled studies regarding the skeletal analgesic efficacy of intramuscularly administered meperidine in horses. Objective: Using an adjustable heart bar shoe model of equine foot pain, the objective of this study was to test the hypothesis that meperidine (pethidine) administered intramuscularly would prove more efficacious in alleviating lameness than a saline placebo. Methods: Crossover pharmacodynamic experiment. Methods: Eight healthy adult Thoroughbred horses randomly underwent weekly i.m. treatments 1 h after lameness induction: saline placebo (1â...
