Intravenous administration in horses involves the delivery of substances directly into the bloodstream through a vein. This method is used to administer fluids, medications, and nutrients efficiently, ensuring rapid distribution throughout the body. It is commonly employed in veterinary practice for rehydration, anesthesia, and treatment of various medical conditions. The technique requires skill and knowledge to ensure proper vein selection and catheter placement, minimizing the risk of complications such as infection or thrombosis. This page compiles peer-reviewed research studies and scholarly articles that explore the methodologies, applications, and potential complications associated with intravenous administration in equine medicine.
Yamashita K, Satoh M, Umikawa A, Tsuda A, Yajima Y, Tsubakishita S, Seno T, Katoh S, Izumisawa Y, Kotani T.The anesthetic and cardiovascular effects of a combination of continuous intravenous infusion using a mixture of 100 g/L guaifenesin-4 g/L ketamine-5 mg/L medetomidine (0.25 ml/kg/hr) and oxygen-sevoflurane (OS) anesthesia (GKM-OS anesthesia) in horses were evaluated. The right carotid artery of each of 12 horses was raised surgically into a subcutaneous position under GKM-OS anesthesia (n=6) or OS anesthesia (n=6). The end-tidal concentration of sevoflurane (EtSEV) required to maintain surgical anesthesia was around 1.5% in GKM-OS and 3.0% in OS anesthesia. Mean arterial blood pressure (MABP)...
Haven ML, Dave K, Burrow JA, Merritt AM, Harris D, Zhang D, Hickey GJ.The antisecretory activity of omeprazole on gastric acid when administered i.v., intragastrically or per os, was evaluated in 2 female and 3 castrated male horses. Each horse had been prepared with a chronic indwelling gastric cannula. A single i.v. administration of omeprazole (1.5 mg/kg bwt) was effective in abolishing basal and pentagastrin (PG)-stimulated acid secretion. Once daily, nasogastric administration of omeprazole in acid-stable granules for 5 days inhibited acid secretion in a dose-dependent manner: 57% (1.5 mg/kg bwt) and 98% (5.0 mg/kg bwt) reduction of PG-stimulated acid secre...
Woods PR, Drost WT, Clarke CR, Rodebush CJ.Ten healthy horses were injected intravenously with 99mTc-MAG3 and the disappearance of radioactivity from the blood was measured. The total body clearance (Cl(B)) and elimination half-life (t1/2(beta)) were 7.9 +/- 1.5 ml/kg/minute and 32.8 +/- 4.1 minutes, respectively. The disappearance of 99mTc-MAG3 from the blood of 2 horses with compromised renal function was also measured. The data suggest that 99mTc-MAG3 is a useful and clinically applicable radiopharmaceutical for measurement of effective renal blood flow in the horse.
Bertone AL, Tremaine WH, Macoris DG, Simmons EJ, Ewert KM, Herr LG, Weisbrode SE.To evaluate clinical safety of administration of injectable enrofloxacin. Methods: Randomized controlled clinical trial. Methods: 24 adult horses. Methods: Healthy horses were randomly allocated into 4 equal groups that received placebo injections (control) or IV administration of enrofloxacin (5 mg/kg [2.3 mg/lb], 15 mg/kg [6.8 mg/lb], or 25 mg/kg [11.4 mg/lb] of body weight, q 24 h) for 21 days. Joint angles, cross-sectional area of superficial and deep digital flexor and calcaneal tendons, carpal or tarsal osteophytes or lucency, and midcarpal and tarsocrural articular cartilage lesions wer...
Higuchi T, Arakawa T, Hashikura S, Inui T, Senba H, Takai S.The effect on foals of prophylactic administration of hyperimmune plasma to prevent R. equi infection was investigated on three farms at which R. equi infection was endemic. Sixteen foals between 10 and 39 days of age were intravenously given 1-21 of hyperimmune plasma. ELISA antibody titres against R. equi were significantly increased and maintained at high levels for over 30 days in most of the recipient foals. The prevalence of R. equi infection was 6.3% (1/16) in the foals that received the immune plasma, and 26.3% (5/19) in the control foals not given the immune plasma on the three farms....
Hagedorn HW, Meiser H, Zankl H, Schulz R.The misuse of opiates in racehorses relates to their effect of increasing locomotor activity. Because methadone, a narcotic analgesic, has been suspected of use as a doping compound in the past, it was added to the list of banned drugs and should be considered in doping control. Because the literature fails to provide information on detection of methadone in blood or urine of horses, an enzyme-linked immunosorbent assay was developed to monitor this narcotic in equine body fluids. Combined with high-performance liquid chromatography, the immunoassay also served to confirm positives indicated b...
Manohar M, Goetz TE.To determine whether intravenous infusion of nitroglycerin would modify pulmonary arterial, capillary, or venous hypertension in strenuously exercising Thoroughbreds. Methods: 5 healthy Thoroughbred horses. Methods: Right atrial, right ventricular, and pulmonary vascular pressures were measured. Each horse was used in a control treatment (not medicated) and a nitroglycerin infusion (20 microg/kg of body weight/min) at rest and during exercise on a treadmill. Sequence of treatments was randomized for each horse, and treatments were separated by a 7-day interval. Galloping at 14.2 m/s on a 5% up...
Bayly WM, Slocombe RF, Schott HC, Hodgson DR.To determine whether i.v. administration of furosemide (250 mg) to horses before maximal exercise affected maximal oxygen consumption (VO2max), breathing mechanics, or gas exchange during exercise. Methods: 7 healthy, well-conditioned Thoroughbred horses. Methods: 5 horses initially performed an incremental treadmill exercise test to determine VO2max 4 hours after i.v. administration of furosemide (250 mg i.v.) or placebo (saline [0.9% NaCl] solution). Time to fatigue and distance run were recorded. All 7 horses were then used to determine the effects of furosemide on gas exchange and breathin...
Bueno AC, Cornick-Seahorn J, Seahorn TL, Hosgood G, Moore RM.To determine the cardiopulmonary and sedative effects of medetomidine hydrochloride in adult horses and to compare those effects with effects of an equipotent dose of xylazine hydrochloride. Methods: 10 healthy adult female horses. Methods: 5 horses were given medetomidine (4 microg/kg of body weight, i.v.), and the other 5 were given xylazine (0.4 mg/kg, i.v.). Heart rate, respiratory rate, arterial blood pressures, pulmonary arterial blood pressures, and cardiac output were recorded, and sedation and ataxia scores were assigned before and every 5 minutes after drug administration for 60 minu...
Coakley M, Peck KE, Taylor TS, Matthews NS, Mealey KL.To compare serum disposition of flunixin meglumine after i.v. administration of a bolus to horses, donkeys, and mules. Methods: 3 clinically normal horses, 5 clinically normal donkeys, and 5 clinically normal mules. Methods: Blood samples were collected at time zero (before) and 5, 10, 15, 30, and 45 minutes, and at 1, 1.25, 1.5, 1.75, 2, 2.5, 2.75, 3, 3.5, 4, 4.5, 5, 5.5, 6, and 8 hours after i.v. administration of a bolus of flunixin meglumine (1.1 mg/kg of body weight). Serum was analyzed in duplicate by the use of high-performance liquid chromatography for determination of flunixin meglumi...
el-Banna HA.The pharmacokinetic aspects of sulphadimidine were studied in clinically healthy (control) and Flunixin-medicated horses after a single intravenous and oral administration of 100 mg/kg body weight. Plasma sulphadimidine concentration were determined by high-performance liquid chromatography (HPLC). Following the intravenous injection, all plasma sulphadimidine data were best approximated by a two-compartment open model using sequential, weight non-linear regression. Flunixin induced a 67% increase in the rate of sulphadimidine return to the central compartment from peripheral tissues (K21) and...
Jaraiz MV, Rodriguez C, San Andres MD, Gonzalez F, San Andres MI.Suxibuzone (SBZ), a nonsteroidal anti-inflammatory drug, was administered to 6 horses at a dose rate of 7.5 mg/kg bwt by intravenous (i.v.) route. Plasma and synovial fluid concentrations of suxibuzone and its main active metabolites, phenylbutazone (PBZ) and oxyphenbutazone (OPBZ), were measured simultaneously by a sensitive and specific high-performance liquid chromatographic method. The pharmacokinetic parameters were determined by noncompartmental analysis. Plasma SBZ concentrations rapidly decreased and were not detectable beyond 20 min after treatment. The parent drug was not detected in...
Corveleyn S, Henrist D, Remon JP, Van Der Weken G, Baeyens W, Haustraete J, Aboul-Enein HY, Sustronck B, Deprez P.Ketoprofen (KTP) is a chiral non-steroidal anti-inflammatory drug (NSAID) of the propionic acid class, approved by the FDA for the allevation of pain associated with musculoskeletal disorders in horses. The present study was designed to examine the bioavailability of ketoprofen enantiomers after rectal administration of the racemate to healthy horses. One gram of racemic ketoprofen was injected intravenously and administered rectally as a fat based suppository in a cross-over design study (n = 4). Blood samples were analysed for KTP enantiomers using HPLC. After IV administration, the S(+) ena...
Doherty TJ, Andrews FM, Provenza MK, Frazier DL.The effect of sedation on gastric emptying was evaluated in six ponies by monitoring serum concentrations of acetaminophen (AP) after intragastric administration. Methods: Prospective randomized experimental study. Methods: Six adult ponies, 135 to 275 kg. Methods: Fifteen minutes after the intravenous administration of xylazine (1 mg/kg), butorphanol (0.05 mg/kg), acepromazine (0.05 mg/kg) or saline, ponies were given AP (20 mg/kg in 350 mL water) by stomach tube. Blood for AP analysis was collected at baseline and 15, 30, 45, 75, 90, 105, and 120 minutes after AP administration. The time (Tm...
Hudson NP, Church DB, Trevena J, Nielsen IL, Major D, Hodgson DR.Two Thoroughbred horses were presented with various clinical signs which included sweating, agitation, muscle twitching and synchronous diaphragmatic flutter. These signs were associated with profound hypocalcaemia. A diagnosis of primary hypoparathyroidism was made on the basis of low serum ionised calcium concentration, hyperphosphataemia and markedly reduced serum immunoreactive parathyroid hormone concentrations in the presence of normal renal function. Treatment with a combination of intravenous calcium and subsequently oral calcium, magnesium and a vitamin D analogue (dihydrotachysterol)...
Breuhaus BA, DeGraves FJ, Honore EK, Papich MG.To determine pharmacokinetics of ibuprofen in healthy foals and to determine clinical effects after oral administration for 6 days. Methods: 7 healthy 5- to 10-week-old foals. Methods: Serum concentrations of ibuprofen were measured after IV and oral (nasogastric tube) administration at dosages of 10 and 25 mg/kg of body weight. Foals were given ibuprofen (25 mg/kg, PO, q 8 h) as a paste for 6 days. Serum and urine were obtained before and after the 6-day period. Results: Half-life of elimination (Kel t1/2) of IV-administered ibuprofen (ie, 10 and 25 mg/kg), was 79 and 108 minutes, maximal ser...
Tetens J, Bueno AC, Cornick-Seahorn JL, Hosgood G, Eades SC, Moore RM.To determine hemodynamic and metabolic effects of IV infusion of ATP-MgCl2 combination and maximal safe IV infusion rate in conscious horses. Methods: 6 adult female horses. Methods: All horses received an IV infusion of ATP-MgCl2 combination, beginning at a rate of 0.05 mg of ATP/kg of body weight/min, which was increased by 0.05 mg/kg/min increments at 10-minute intervals until a rate of 1.0 mg/kg/min was achieved. Data were collected prior to the start of the infusion, at the end of each infusion rate, and at 15-minute intervals for the next hour after discontinuation of the infusion. Measu...
Sams RA, Gerken DF, Ashcraft SM.The objectives of the study were to compare various methods to determine flunixin in test samples collected periodically from horses after intramuscular (IM) and intravenous (IV) dosing at the maximum recommended dosage and to document detection times for this drug in test samples. Flunixin, a nonsteroidal anti-inflammatory drug approved for use in horses, was administered to eight mares in five consecutive daily doses of 1.1 mg per kilogram of body weight by the IM or IV route. Flunixin was detected in urine samples collected at various times after drug administration by flunixin enzyme-linke...
Luna SP, Taylor PM, Brearley JC.Glucose was infused intravenously into six ponies during halothane anaesthesia, to evaluate its effect on their endocrine response to anaesthesia. The ponies were premedicated with acepromazine, and anaesthesia was induced with thiopentone and maintained with halothane in oxygen for two hours. Glucose was infused to maintain the plasma glucose concentration above 20 mmol/litre. Anaesthesia was associated with hypothermia, a decrease in haematocrit, hypotension, hyperoxaemia, respiratory acidosis and an increase in the plasma concentrations of lactate and arginine vasopressin. The concentration...
Freeman SL, England GC.To compare sedative effects of romifidine following IV, IM, or sublingual (SL) administration in horses. Methods: 30 horses that required sedation for routine tooth rasping. Methods: Horses (n = 10/group) were given romifidine (120 microg/kg) IV, IM, or SL. Heart rate, respiratory rate, head height, distance between the ear tips, thickness of the upper lip, response to auditory stimulation, response to tactile stimulation, and degree of ataxia were recorded every 15 minutes for 180 minutes. Tooth rasping was performed 60 minutes after administration of romifidine, and overall adequacy of sedat...
Perkins G, Ainsworth DM, Yeager A.This report documents the successful conservative medical management of hemothorax in 2 horses. Hemothorax occurred after a lung biopsy procedure (horse 1) and strenuous exercise on a treadmill (horse 2). The horses had tachypnea, tachycardia, nostril flaring, hemoptysis, and pawing. Hemothorax was suspected based upon absence of auscultable ventral lung sounds; development of cool extremities and pale, tacky mucous membranes; the ultrasonographic appearance of moderate to severe amounts of pleural fluid; and a concurrent decrease in hematocrit and total plasma protein. Both horses were treate...
Bettschart-Wolfensberger R, Clarke KW, Vainio O, Aliabadi F, Demuth D.The pharmacokinetics of intravenous (i.v.) medetomidine (7 mcg kg(-1)) were best described by a two-compartment model in five ponies. Total body clearance was 4 (SD 0.60) 1 kg h,(-1)t(1/2alpha)7. 6 (0.91) minutes and t(1/2beta)51.3 (13.09) minutes. In one pony the one-compartmental model was best fit, and total body clearance was 4. 2 l kg h(-1)and t(1/2)was 11 minutes. Medetomidine plasma levels had fallen below the limits of quantification (0.05 ng ml(-1)) within 4 hours. Medetomidine 5 mcg kg(-1)i.v. followed by an infusion of 3.5 mcg kg h(-1)for two hours provided a constant level of sedat...
Grubb TL, Constable PD, Benson GJ, Foreman JH, Olson WO, Thurmon JC, Tranquilli WJ, Davis LE.To determine the most repeatable method for evaluating right ventricular relaxation rate in horses and to determine and compare effects of isoflurane or halothane with and without the added influence of intravenously administered calcium gluconate on right ventricular relaxation rates in horses. Methods: 6 Thoroughbred horses from 2 to 4 years old. Methods: 6 models (2 for monoexponential decay with zero asymptote, 3 for monoexponential decay with variable asymptote, and 1 for biexponential decay) for determining right ventricular relaxation rate were assessed in conscious and anesthetized hor...
Lees P, May SA, Hoeijmakers M, Coert A, Rens PV.The pharmacodynamics and enantioselective pharmacokinetics of vedaprofen were studied in six ponies in a two period cross-over study, in which a mild acute inflammatory reaction was induced by carrageenan soaked sponges implanted subcutaneously in the neck. Vedaprofen, administered intravenously at a dosage of 1 mg/kg, produced significant and prolonged inhibition of ex vivo serum thromboxane B2 (TXB2) synthesis and short-lived inhibition of exudate prostaglandin E2 (PGE2) and TXB2 synthesis. Vedaprofen also partially inhibited oedematous swelling and leucocyte infiltration into exudate. Vedap...
Matsuda Y, Hobo S, Naito H.Five Thoroughbreds were classified into 4 groups according to the administration method used for saline solution (saline), ambroxol, and cephalothin sodium (cephalothin). In group A, cephalothin was injected intravenously after oral administration of ambroxol. In group B, cephalothin was injected intravenously after oral administration of saline. Groups C and D were used as control groups. The dose of cephalothin or ambroxol was clinically administrated. Venous blood and bronchoalveolar lavage fluid (BALF) were sampled from each group. In groups A and B, cephalothin concentrations in plasma re...
Gustafsson A, Båverud V, Franklin A, Gunnarsson A, Ogren G, Ingvast-Larsson C.Six healthy adult horses were given repeated administrations of trimethoprim/ sulfadiazine (TMP/SDZ) intravenously (i.v.) (2.5 mg/kg TMP and 12.5 mg/kg SDZ) and orally (p.o.) as a paste (5 mg/kg TMP and 25 mg/kg SDZ). Both formulations were given twice daily for 5 days, with a 3-week interval between i.v. and oral administration. The influence of the drug combination on the intestinal microflora was examined and the plasma concentrations, pharmacokinetic parameters and plasma protein binding were determined. There were no major changes in the bacterial intestinal flora and no clinical evidence...
Lakritz J, Wilson WD, Mihalyi JE.To determine pharmacokinetics and bioavailability of erythromycin base after intragastric administration and erythromycin lactobionate after IV administration to healthy foals and to compare a microbiologic assay with a high-performance liquid chromatography (HPLC) method to determine plasma concentrations of erythromycin A. Methods: 6 healthy foals that were 2 to 4 months old. Methods: Foals were given single doses of erythromycin (10 mg/kg of body weight, IV, and 25 mg/kg, intragastrically) in a crossover study. Venous blood samples were obtained at specific times after drug administration, ...
Dyson DH, Pascoe PJ, McDonell WN.The purpose of this study was to determine the heart rate (HR) and blood pressure (BP) effect of glycopyrrolate in anesthetized horses with low HR ( 5 beats/min within 10 min), glycopyrrolate (same dose) was administered. Heart rate increased by > 5 beats/min in 3 out of 9 horses following the initial glycopyrrolate treatment. Overall changes in HR and mean BP were not significantly different, while systolic and diastolic BP increased significantly (P 5 beats/min, which was significant. A significant increase in BP was produced following treatment with 2.5 micrograms/kg BW, but not followi...
Lester G, Clark C, Rice B, Steible-Hartless C, Vetro-Widenhouse T.To examine effect of pre-exercise administration of furosemide (FUR) on mean pulmonary arterial pressure (PAP) during work and RBC concentration in bronchoalveolar lavage fluid (BALF) collected 40 minutes after exercise. Methods: 10 adult Thoroughbreds. Methods: A modified 10 X 10 crossover design comprising 10 horses during 10 weeks was used. Each horse received each of 5 treatments twice. Treatment structure included a control plus a 2 X 2 factorial and consisted of the following: A, control; B, FUR, 250 mg, IV, 30 minutes before exercise; C, FUR, 250 mg, IV, 240 minutes before exercise; D, ...
Dirikolu L, McFadden ET, Ely KJ, ElkHoly H, Lehner AF, Thompson K.Clonidine is classified as a class 3 performance-enhancing agent by the Association of Racing Commissioners International and thus has the potential to influence the outcome of a race. In this study, the authors developed and validated a sensitive gas chromatograph and mass spectrometer method to determine the pharmacokinetic parameters of clonidine in equine plasma samples after IV administration of a single dose (0.025 mg/kg) of clonidine in horses. At this dose, clonidine produced rapid and profound sedation, which cold be quickly reversed with yohimbine. Clonidine was able to produce an an...
Firth EC, Nouws JF, Klein WR, Driessens F.A pilot study in two ponies showed that the plasma concentrations of intramuscularly administered procaine penicillin were higher if phenylbutazone was administered concurrently. In two other trials, each involving five horses, intravenous sodium penicillin was administered with and without concurrent intravenously injected phenylbutazone, and procaine penicillin was injected intramuscularly with and without oral phenylbutazone. In both cases the plasma concentrations of penicillin were higher when phenylbutazone was given. The pharmacokinetic parameters indicated that the effect was probably ...
Brown MP, Gronwall RR, Houston AE.Six healthy adult horse mares were each given a single injection of sodium cephapirin (20 mg/kg of body weight, IV), and serum cephapirin concentrations were measured serially over a 6-hour period. The mean elimination rate constant was 0.78 hour-1 and the elimination half-life was 0.92 hours. The apparent volume of distribution (at steady state) and the clearance of the drug were estimated at 0.17 L/kg and 598 ml/hour/kg, respectively. Each mare was then given 4 consecutive IM injections of sodium cephapirin (400 mg/ml) at a dosage level of 20 mg/kg. Cephapirin concentrations in serum, synovi...
Rivas LJ, Hinchcliff KW.To investigate the effect of i.v. administration of fluids on the furosemide-induced reduction in right atrial pressure (RAP) and relative change in blood volume (BV) of splenectomized mares. Methods: 5 splenectomized mares. Methods: RAP was measured by use of a micromanometer placed in the right atrium. Jugular venous blood was collected for measurement of hematocrit, plasma total protein concentration, and hemoglobin concentration. Right atrial pressure was recorded and blood samples were collected immediately before furosemide (1 mg/kg of body weight, i.v.) administration, then every 15 min...
Young DR, Divers TJ, Benson CE.Clinical septicemia developed in 2 clinically normal horses after both were administered a portion of an amino acid solution IV. Serratia marcescens was subsequently isolated from blood of both horses. The isolates were shown to be identical on the basis of antibiograms and plasmid biochemistry, incriminating the infusate as the source of bacterial infection. The horses recovered after supportive and antimicrobial treatment.
Perkins G, Ainsworth DM, Yeager A.This report documents the successful conservative medical management of hemothorax in 2 horses. Hemothorax occurred after a lung biopsy procedure (horse 1) and strenuous exercise on a treadmill (horse 2). The horses had tachypnea, tachycardia, nostril flaring, hemoptysis, and pawing. Hemothorax was suspected based upon absence of auscultable ventral lung sounds; development of cool extremities and pale, tacky mucous membranes; the ultrasonographic appearance of moderate to severe amounts of pleural fluid; and a concurrent decrease in hematocrit and total plasma protein. Both horses were treate...
Davidson GS.Anesthetization of large animals, such as the horse, is a challenge for veterinarians and compounding pharmacists. This article discusses the technique of intravenous anesthesia by using a combination of xylazine and ketamine in the horse for short-term unconsciousness; a combination of xylazine, diazepam, and ketamine, for improved sedation and muscle relaxation; and a combination of xylazine, ketamine, and guaifenesin, referred to as Triple Drip, for the maximum 1-hour duration of unconsciousness. Compounding pharmacists that have the facilities and training required to prepare sterile compo...
Perez-Ecija A, Buzon-Cuevas A, Aguilera-Aguilera R, Gonzalez-De Cara CA, Mendoza FJ.Preanalytical factors such as storage time and temperature are proved to induce marked artifactual changes in hematological parameters in horses, small animals and humans. These errors can mirror findings typical of endotoxemia, leading to dangerous misdiagnosis. Since donkeys are common in warm climates and remote regions, blood samples from this species can be subjected to long lasting travels from the farm to the nearest laboratory, frequently under suboptimal conditions. Moreover, as other equids, donkeys are prone to suffer endotoxemia. Nonetheless, stability has not been evaluated in sam...
Cornick JL.A 2-year-old Trakehner filly with pulmonary histoplasmosis is presented. Clinical signs included weight loss, intermittent fever, dyspnea and depression. Diagnosis was based on thoracic radiography, transtracheal wash cytology and lung aspirate cytology. A 5-week regimen of Amphotercin-B administered intravenously resulted in clinical recovery and return of the animal to normal activity. A brief review of histoplasmosis in man and animal is included.
Roussel AJ, Hooper RN, Cohen ND, Bye AD, Hicks RJ, Schulze JL.To evaluate effects of IV administration of penicillin G potassium (KPEN) or potassium chloride (KCl) on defecation and myoelectric activity of the cecum and pelvic flexure of horses. Methods: 5 healthy horses. Methods: Horses with 12 bipolar electrodes on the cecum and pelvic flexure received KPEN or KCl solution by IV bolus 4 hours apart. Each horse received the following: 2 X 10(7) U of KPEN (high-dose KPEN) followed by 34 mEq of KCl (high-dose KCl), 1 X 10(7) U of KPEN (low-dose KPEN) followed by 17 mEq of KCl (low-dose KCl), high-dose KCl followed by high-dose KPEN, and low-dose KCl follo...
Pashen RL.Levels of the major circulating metabolite of prostaglandin F-2 alpha, 13, 14 dihydro-15-oxo-prostaglandin F-2 alpha (PGFM) were measured during the induction of foaling using small (2.5-10 iu) intravenous doses of oxytocin. PGFM levels rose rapidly in all animals within 15 min of injection and were associated with typical signs of second stage labour. Because these small doses of oxytocin are effective in successfully triggering parturition it is suggested that higher doses (40-120 iu) used to induce birth in other studies are unnecessary and could be potentially dangerous to the foetal foal....
Hubbell JA, Hinchcliff KW, Schmall LM, Muir WW, Robertson JT, Sams RA.To determine sedative, cardiorespiratory and metabolic effects of xylazine hydrochloride, detomidine hydrochloride, and a combination of xylazine and acepromazine administered i.v. at twice the standard doses in Thoroughbred horses recuperating from a brief period of maximal exercise. Methods: 6 adult Thoroughbreds. Methods: Horses were preconditioned by exercising them on a treadmill to establish a uniform level of fitness. Each horse ran 4 simulated races, with a minimum of 14 days between races. Simulated races were run at a treadmill speed that caused horses to exercise at 120% of their ma...
Lees P, Tavernor WD.1. In horses anaesthetized with halothane the intravenous administration of suxamethonium chloride, at a dose level of 0.2 mg/kg, produced a short-lived period of hypoventilation, which was associated with increases in arterial blood PCO(2) levels and in plasma concentrations of bicarbonate, sodium and potassium ions, and reductions in arterial blood pH and PO(2) values.2. The respiratory depressant action of suxamethonium chloride 0.2 mg/kg was accompanied by increases in blood pressure and heart rate. Doses of suxamethonium chloride 0.4 mg/kg produced similar but quantitatively greater chang...
Hopster K, Watkins AR, Hurcombe SD.To compare the antinociceptive effects of morphine administered via cervical epidural catheter to intravenously administered morphine using a thermal threshold (TT) testing model in healthy adult horses. Methods: Prospective, randomized, blinded experimental study. Methods: A total of six university-owned adult horses. Methods: Horses were instrumented with a cervical (C1-C2) epidural catheter and TT testing device with probes at withers and thoracic limb coronary bands. All horses underwent three TT testing cycles including cervical epidural morphine administration (treatment EpiM; 0.1 mg kg-...
Puigdemont A, Riu JL, Guitart R, Arboix M.The propafenone kinetics after intravenous (i.v.) administration have been studied in the horse by a comparative analysis of compartmental and noncompartmental models. The pharmacokinetic parameters showed a large distribution (Vdss = 1021 +/- 211 L) and a high clearance (CI = 7019 +/- 1746 mL/min) of the drug. The plasma concentrations were very low, under 1 microgram/mL, in most cases; after 30 min these concentrations can be considered as nonefficient for the treatment of arrhythmia. There were no significant differences between pharmacokinetic parameters found with the use of compartmental...
Mendez-Angulo JL, Granados MM, Modesto R, Serrano-Rodriguez JM, Funes FJ, Quiros S, Gomez-Villamandos RJ, Zaldívar S, Trumble TN.Local anaesthetics are being combined clinically with amikacin in intravenous regional limb perfusion (IVRLP), with limited knowledge on the analgesia provided and its onset and duration of action after tourniquet application and release. Objective: To evaluate the systemic clinical effect, limb withdrawal to nociceptive stimulation, and plasma and synovial fluid concentrations after IVRLP with lidocaine or mepivacaine in standing sedated horses. Methods: Prospective, controlled, randomised, cross-over study. Methods: Six healthy adult horses were sedated and received IVRLP with lidocaine, mep...
Henninger RW, Horst J.Magnesium sulfate, a saline laxative, is often used for treatment of intestinal impactions in horses. Clinical signs of hypermagnesemia are an uncommon complication following oral administration of magnesium sulfate. Overdose of magnesium sulfate in combination with renal insufficiency, hypocalcemia, or compromise of intestinal integrity may predispose horses to magnesium toxicosis. Establishment of diuresis with fluids and IV administration of calcium may provide successful treatment of magnesium toxicosis in horses.
Kelmer G, Catasus CT, Saxton AM, Elliot SB.The feasibility of maintaining indwelling intravenous catheters in the saphenous, cephalic or palmar digital vein of horses for seven days to infuse antimicrobial drugs was investigated in 18 horses. The horses were randomly assigned to six groups according to the vein catheterised and whether they received amikacin or erythromycin. None of the catheters was replaced more than once, and 11 of the 18 catheters remained patent for all seven days. Neither the drug administered nor the vein catheterised significantly affected the survival of the catheter. In all but three cases, complications, inc...
Serteyn D, Blais D, Abou Madi NA, Coppens P, Mottart E, Philippart C.Ketamine (0.3 mg/kg) administered intravenously to 12 halothane anesthetized horses caused a significant respiratory depression during ten minutes when respiration was spontaneous. Significant hemodynamic effects were not observed except for cardiac index. Clinical application was also discussed. Ketamine (0.3 mg/kg) administered intravenously to 12 halothane anesthetized horses caused a significant respiratory depression during ten minutes when respiration was spontaneous. Significant hemodynamic effects were not observed except for cardiac index. Clinical application was also discussed.
Gordon ME, McKeever KH.This study tested the hypothesis that grain and intravenous dextrose challenges would alter plasma concentrations of active ghrelin, adiponectin, leptin, glucose, insulin, and cortisol in Standardbred mares. To deliver 0.5 g of glucose (dextrose solution for the intravenous test)/kg of BW, mares received intravenous dextrose (50% solution) or oral grain administration in 2 trials. In response to the oral grain challenge, plasma glucose and insulin concentrations increased (P < 0.001) by 56 and 802%, respectively. Plasma ghrelin concentration initially decreased (P < 0.001) by 40%, then s...
Woods PR, Drost WT, Clarke CR, Rodebush CJ.Ten healthy horses were injected intravenously with 99mTc-MAG3 and the disappearance of radioactivity from the blood was measured. The total body clearance (Cl(B)) and elimination half-life (t1/2(beta)) were 7.9 +/- 1.5 ml/kg/minute and 32.8 +/- 4.1 minutes, respectively. The disappearance of 99mTc-MAG3 from the blood of 2 horses with compromised renal function was also measured. The data suggest that 99mTc-MAG3 is a useful and clinically applicable radiopharmaceutical for measurement of effective renal blood flow in the horse.
Rose RJ, Kohnke JR, Baggot JD.Plasma phenylbutazone concentrations were determined for up to 12 h in 6 horses following intravenous and oral phenylbutazone administration. To evaluate the bioavailability of different oral preparations, phenylbutazone was administered in a paste as well as the traditional powder form. The effect of the state of stomach contents on the absorption of phenylbutazone was investigated by administering the paste before and after feeding; the powder was given in a small bran mash and a full feed of lucerne chaff, wheaten chaff and bran. Despite great variability among individual horses both the pa...
Muir WW, Kohn CW, Sams R.The effects of IV administered furosemide upon plasma volume (PV) and extracellular fluid volume were determined in horses at rest and after exercise. Serum sodium, potassium, chloride, and osmolality determinations were made. Furosemide caused a significant (P less than 0.05) decrease in PV and serum potassium concentrations in resting horses only. Furosemide's effects upon PV and electrolytes were evident longer than its hemodynamic effects.
Lee YL, Clarke KW, Alibhai HI, Song DY.To evaluate the effect of ephedrine on intramuscular blood flow and hemodynamic parameters during equine anesthesia. Methods: Prospective experimental study. Methods: Six healthy adult Welsh Mountain ponies (five males, one female, mean weight: 267 kg, range: 213-347 kg). Methods: Halothane-anesthetized ponies received an IV bolus of ephedrine (0.1 mg kg), followed 30 minutes later by a second IV ephedrine injection (0.2 mg kg). Changes in intramuscular blood flows (IMBF) in upper and lower triceps brachii were measured by laser Doppler flowmetry. Cardiopulmonary measurements were made at inte...
Court MH, Engelking LR, Dodman NH, Anwer MS, Seeler DC, Clark M.The pharmacokinetics of dantrolene sodium were investigated in horses following both intravenous (2 mg/kg) and intragastric (4 mg/kg) administration. Two ponies also received dantrolene sodium intravenously (2 mg/kg) in a pilot study to obtain preliminary kinetic data and to determine urinary and biliary excretion of the intact drug. Distribution and elimination of dantrolene was rapid, resulting in an elimination half-life of 129 +/- 8 (SEM) min and a whole body clearance of 4.16 +/- 0.52 ml/min/kg. Following intragastric administration, dantrolene rapidly acheived peak concentrations within ...
Rumbaugh GE, Carlson GP, Harrold D.Clinicopathologic effects of rapid intravenous infusion of 3 L of 5% dextrose in water containing 150 g of sodium bicarbonate were evaluated in 8 clinically normal horses. A highly significant metabolic alkalosis was produced in all the horses. This response was maximal at the end of the 20-minute infusion but persisted for as long as 8 hours. Packed cell volume, total plasma proteins, plasma potassium, and plasma chloride concentration decreased significantly after infusion, while plasma sodium concentration increased significantly. The clinical and clinicopathological responses of the horses...
Short CR, Beadle RE, Aranas T, Pawlusiow J, Clarke CR.The pharmacokinetics of cephapirin sodium and its distribution into a tissue chamber implanted subcutaneously in the neck of mature horses are described. Cephapirin was administered as an intravenous bolus dose of 20 mg/kg. The serum concentration vs time curve was best described by a two-compartment open model. Cephapirin disappeared from serum rapidly (t1/2 beta = 18.8 min), and had only a modest volume of distribution (Vd(area) approximately equal to 346 mg/kg, Vd(ss) approximately equal to 204 ml/kg). Total clearance was also rapid (approximately equal to 13 ml/min.kg). Concentrations of t...
Fielding CL, Magdesian KG, Elliott DA, Craigmill AL, Wilson WD, Carlson GP.The purpose of this study was to describe the pharmacokinetics of bromide in horses and to evaluate the corrected bromide space as an indicator of extracellular fluid volume (ECFV) in horses after the administration of a single dose of bromide by intravenous infusion. Sodium bromide (30 mg/kg of body weight, IV) was administered to 6 clinically healthy mares over a period of 3 minutes. Blood samples were collected before infusion and at intervals between 0.5 hours and 53 days after infusion. Mean elimination half-life (harmonic mean) was 126 hours (5.2 days), clearance was 1.4 +/- 0.09 mL/(kg ...
Clarke CR, Burrows GE, MacAllister CG, Spillers DK, Ewing P, Lauer AK.Single-dose pharmacokinetic variables of pyrimethamine were studied in horses. Pyrimethamine (1 mg/kg of body weight) was administered IV and orally to 6 adult horses, and plasma samples were obtained at frequent intervals thereafter. Plasma pyrimethamine concentration was assayed by gas chromatography, and concentration-time data were analyzed, using a pharmacokinetic computer program. The IV and oral administration data were best described by 3-compartment and 1-compartment models, respectively. The median volume of distribution at steady state after IV administration was 1,521 ml/kg and the...
Rutkowski JA, Eades SC, Moore JN.A chronic model with an ultrasonic transit time blood flow probe and strain gauge force transducers implanted on the cecum was used to evaluate cecal mechanical activity and cecal arterial blood flow in 4 conscious adult horses. Intravenous administration of xylazine (1.1 mg/kg of body weight) significantly decreased heart rate and cardiac output, but significantly increased diastolic pulmonary arterial pressure, mean pulmonary arterial pressure, carotid arterial pressure, and central venous pressure. Lateral cecal arterial blood flow after xylazine administration was decreased substantially m...
