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.
Knych HK, Weiner D, Arthur RM, Baden R, McKemie DS, Kass PH.Corticosteroids are potent anti-inflammatory drugs and as such are commonly administered to performance and racehorses. The objectives of the current study were to describe blood and urine concentrations and the pharmacokinetics and effects on cortisol and inflammatory mediator concentrations, following intravenous and oral administration to 12 exercised horses. Horses received an intravenous administration of 40 mg of dexamethasone sodium phosphate and 20 mg of dexamethasone tablets with a 4 week washout in between administrations. Blood and urine samples were collected prior to and for up to...
Schumacher SA, Toribio RE, Scansen B, Lakritz J, Bertone AL.The objectives of this study were to describe pharmacokinetic and pharmacodynamic changes as a result of a single intravenous administration of magnesium sulfate (MgSO ) to healthy horses. MgSO is a magnesium salt that has been used to calm horses in equestrian competition and is difficult to regulate because magnesium is an essential constituent of all mammals. Six healthy adult female horses were administered a single intravenous dose of MgSO at 60 mg/kg of body weight over 5 min. Blood, urine, and cerebrospinal fluid (CSF) samples were collected, and cardiovascular parameters were monitor...
de Grauw J, van Loon T.To compare the effects of two different doses of butorphanol combined with detomidine administered intravenously (IV) on quality of sedation, degree of ataxia and anaesthetic induction in horses. Methods: Randomized, blinded, clinical study. Methods: A total of 40 client-owned healthy warmblood horses scheduled for elective surgery under general anaesthesia. Methods: Horses were randomly allocated to be administered 8 μg kg-1 detomidine IV plus either 20 or 50 μg kg-1 butorphanol IV, with the principal investigator blinded to group allocation. Head height was measured before drug injection a...
Hopster K, Soma LR, Li X, Hopster-Iversen C, Boston RC, Driessen B.Intravenous (i.v.) bolus administration of xylazine (XYL) (0.5 mg/kg) immediately followed by a continuous rate infusion (CRI) of 1 mg kg hr for 2, 4, and 6 hr produced immediate sedation, which lasted throughout the duration of the CRI. Heart rate decreased and blood pressure increased significantly (p > .05) in all horses during the first 15 min of infusion, both returned to and then remained at baseline during the duration of the infusion. Compartmental models were used to investigate the pharmacokinetics of XYL administration. Plasma concentration-time curves following bolus an...
Mund SJK, Kawamura E, Awang-Junaidi AH, Campbell J, Wobeser B, MacPhee DJ, Honaramooz A, Barber S.Limb wounds on horses are often slow to heal and are prone to developing exuberant granulation tissue (EGT) and close primarily through epithelialization, which results in a cosmetically inferior and non-durable repair. In contrast, wounds on the body heal rapidly and primarily through contraction and rarely develop EGT. Intravenous (IV) multipotent mesenchymal stromal cells (MSCs) are promising. They home and engraft to cutaneous wounds and promote healing in laboratory animals, but this has not been demonstrated in horses. Furthermore, the clinical safety of administering >1.00 × 108 alloge...
Pallarols NB, Lamuraglia R, Guglielminetti A, Ortiz de Elguea MF, Carossino M, Funcia JP.Xylazine and remifentanil in constant rate infusion (CRI) could be used for sedation in horses without adverse effects. The objective was to evaluate behavioral and cardiopulmonary effects of an intravenous (IV) infusion of xylazine and remifentanil for sedation in horses. Xylazine (0.8 mg/kg IV) followed after 3 minutes by a CRI of xylazine and remifentanil (0.65 mg/kg/h and 6 μg/kg/h, respectively) was administered in 10 healthy horses for 60 minutes. Sedation, ataxia, and cardiopulmonary, hematological, and blood gases variables were evaluated. Heart rate decreased significantly durin...
Martins FC, Keating SC, Clark-Price SC, Schaeffer DJ, Lascola KM, DiMaio Knych H.To determine the physiologic and behavioral effects and pharmacokinetic profile of hydromorphone administered intravenously (IV) to horses. Methods: Prospective, randomized, crossover study. Methods: A group of six adult healthy horses weighing 585.2 ± 58.7 kg. Methods: Each horse was administered IV hydromorphone (0.025 mg kg; treatment H0.025), hydromorphone (0.05 mg kg; treatment H0.05) or 0.9% saline in random order with a 7 day washout period. For each treatment, physiologic, hematologic, abdominal borborygmi scores and behavioral data were recorded over 5 hours and fecal output was tota...
Rostang A, Desjardins I, Espana B, Panzuti P, Berny P, Prouillac C, Pin D.This study aimed to investigate both the pharmacokinetic behavior and tolerance of methotrexate (MTX) in horses to design a specific dosing regimen as a new immunomodulatory drug for long-term treatment. To determine the primary plasma pharmacokinetic variables after single intravenous, subcutaneous or oral administration, six horses were administered 0.3 mg/kg MTX in a crossover design study. After a 10-week washout, MTX was administered subcutaneously to three of the six previously treated horses at a dose of 0.3 mg/kg once per week for 3 months. In both studies, MTX and metabolite concen...
Guedes A, Knych H, Tucker L, Almeida DC, Baldo CF, Wendt-Hornickle E, Allweiler S.This study determined the pharmacokinetics and compared the clinical effects of xylazine and dexmedetomidine in horses recovering from isoflurane anesthesia. Six healthy horses aged 8.5 ± 3 years and weighing 462 ± 50 kg were anesthetized with isoflurane for 2 hr under standard conditions on two occasions one-week apart. In recovery, horses received 200 μg/kg xylazine or 0.875 μg/kg dexmedetomidine intravenously and were allowed to recover without assistance. These doses were selected because they have been used for postanesthetic sedation in clinical and research studies. Serial ...
Wang J, Qiu J, Xiao H, Gong X, Sun P, Li J, Zhang S, Cao X.The pharmacokinetic properties of three formulations of vitacoxib were investigated in horses. To describe plasma concentrations and characterize the pharmacokinetics, 6 healthy adult Chinese Mongolian horses were administered a single dose of 0.1 mg/kg bodyweight intravenous (i.v.), oral paste, or oral tablet vitacoxib in a 3-way, randomized, parallel design. Blood samples were collected prior to and at various times up to 72 hr postadministration. Plasma vitacoxib concentrations were quantified using UPLC-MS/MS, and pharmacokinetic parameters were calculated using noncompartmental analysis...
Kritchevsky JE, Muir GS, Leschke DHZ, Hodgson JK, Hess EK, Bertin FR.In metabolically stable horses, alpha-2-agonists suppress insulin secretion with transient hyperglycemia and rebound hyperinsulinemia. In horses with insulin dysregulation (ID), the effect of alpha-2-agonists has not been investigated; however, both the alpha-2-agonist-induced suppression of insulin secretion and rebound hyperinsulinemia could have clinical relevance. Objective: In horses with ID, alpha-2-agonists will alter insulin and glucose dynamics. Methods: Seven horses with ID and 7 control horses. Methods: In this randomized crossover study, xylazine hydrochloride (1.1 mg/kg) or detomi...
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...
Paine SW, Bright J, Scarth JP, Hincks PR, Pearce CM, Hannan C, Machnik M, Hillyer L.In equine and racing practice, detomidine and butorphanol are commonly used in combination for their sedative properties. The aim of the study was to produce detection times to better inform European veterinary surgeons, so that both drugs can be used appropriately under regulatory rules. Three independent groups of 7, 8 and 6 horses, respectively, were given either a single intravenous administration of butorphanol (100 µg/kg), a single intravenous administration of detomidine (10 µg/kg) or a combination of both at 25 (butorphanol) and 10 (detomidine) µg/kg. Plasma and urine concentratio...
Fouché N, Graubner C, Lanz S, Schweighauser A, Francey T, Gerber V.Four 2-month-old foals were presented to an equine hospital with acute kidney injury caused by Leptospira interrogans infection. Clinical signs were nonspecific and included lethargy, fever, and unwillingness to nurse. The most important hematologic and clinicopathologic findings were azotemia, anemia, thrombocytopenia, hyponatremia, and hypochloremia. The diagnosis was based on urinary real-time PCR, serology using a microscopic agglutination test, or both. The most important serovars involved were L. interrogans serogroup australis serovar Bratislava and Australis. Treatment consisted of IV ...
Carregaro AB, Ueda GI, Censoni JB, Bisetto SP, Alonso BB, Reginato GM.The aim of this study was to compare the effects of methadone combined with detomidine or acepromazine on the quality of sedation and its influence over dissociative anesthesia in healthy horses. In a crossover design, seven horses were administered with 0.1 mg/kg methadone and 0.02 mg/kg detomidine intravenously (group MD) or 0.1 mg/kg methadone and 0.05 mg/kg acepromazine intravenously (group MA). Subsequently, anesthesia was induced with a combination of 2.2 mg/kg ketamine and 0.1 mg/kg midazolam intravenously. Descriptive scales and footages were used to evaluate the quality of sedat...
Snowden RT, Schumacher J, Blackford JT, Cypher EE, Cox SK, Sun X, Whitlock BK.To determine whether therapeutic concentrations (> 0.5 to 1.0 μg/mL) of polymyxin B (PB) were achieved in the tarsocrural joint of horses when the drug was administered by IV regional limb perfusion (IV-RLP) via a saphenous vein at doses of 25, 50, and 300 mg and to describe any adverse systemic or local effects associated with such administration. Methods: 9 healthy adult horses. Methods: In the first of 2 experiments, 6 horses each received 25 and 50 mg of PB by IV-RLP via a saphenous vein with at least 2 weeks between treatments. For each treatment, a tourniquet was placed at the midmetata...
Schumacher SA, Toribio RE, Lakritz J, Bertone AL.The objective of this study was to characterize the pharmacokinetics and pharmacodynamics of intravenous administration of magnesium sulfate to horses using a novel radio-telemetry system for physiologic signal capture. Five Horses were surgically implanted with a radio-telemetric carotid catheter. Implants were paired with a non-invasive telemetric unit which acquired a six lead ECG and 3-axis acceleration to assess activity acquired wirelessly in real-time for future analysis. Horses were exposed to a new stall environment before (baseline) and after 60 mg/kg (30 mL) of magnesium sulfate (Mg...
Reed RA, Knych HK, Barletta M, Sakai DM, Ruch MM, Smyth CA, Ryan CA.To compare the pharmacokinetics and pharmacodynamics of hydromorphone in horses after intravenous (IV) and intramuscular (IM) administration. Methods: Randomized, masked, crossover design. Methods: A total of six adult horses weighing [mean ± standard deviation (SD))] 447 ± 61 kg. Methods: Horses were administered three treatments with a 7 day washout. Treatments were hydromorphone 0.04 mg kg IV with saline administered IM (H-IV), hydromorphone 0.04 mg kg IM with saline IV (H-IM), or saline IV and IM (P). Blood was collected for hydromorphone plasma concentration at multiple time points for ...
Habershon-Butcher J, Cutler C, Viljanto M, Hincks PR, Biddle S, Paine SW.Xylazine is widely used worldwide as a short-acting sedative in general equine and racing practice. In the UK, although it has a legitimate use during training, equine anti-doping rules state it is a prohibited substance on race day. The aim of the study was to produce a detection time (DT) to better inform European veterinary surgeons so that xylazine can be used appropriately under regulatory rules. Previous publications have various limitations pertaining to analysis method, particularly for plasma and limited length of time of sample collection. In this study, pharmacokinetic data were pro...
Kopper JJ, Bolger ME, Kogan CJ, Schott HC.Obtaining commercial fluids for intravenous administration (IVF) was challenging during a recent shortage. This necessitated use of custom-made non-sterile fluids for intravenous administration (JUGs) in some hospitals. There are no studies comparing outcome of horses treated with JUG versus IVF and limited information is available about adverse effects of JUGs. Objective: To evaluate death, complications, blood pH, and plasma electrolyte concentrations of horses that received JUG versus IVFs. Methods: One hundred eighty-six horses that received IVFs and 37 that received JUGs. Methods: A retro...
Gozalo-Marcilla M, Moreira da Silva R, Pacca Loureiro Luna S, Rodrigues de Oliveira A, Werneck Fonseca M, Peporine Lopes N, Taylor PM, Pelligand L.The alpha(α) -agonist detomidine is used for equine sedation with opioids such as methadone. We retrieved the data from two randomized, crossover studies where detomidine and methadone were given intravenously alone or combined as boli (STUDY 1) (Gozalo-Marcilla et al., 2017, Veterinary Anaesthesia and Analgesia, 2017, 44, 1116) or as 2-hr constant rate infusions (STUDY 2) (Gozalo-Marcilla et al., 2019, Equine Veterinary Journal, 51, 530). Plasma drug concentrations were measured with a validated tandem Mass Spectrometry assay. We used nonlinear mixed effect modelling and took pharmacokinetic...
Ellerbrock RE, Curcio BR, Zhong L, Honoroto J, Wilkins P, Lima FS, Giguere S, Canisso IF.Enrofloxacin may be an alternative antimicrobial for unresponsive cases of severe bacterial infections in pregnant mares. As pregnancy may affect drug bioavailability, distribution, metabolism and excretion, dose adjustment might be necessary. Objective: To determine the disposition of orally and intravenously administered enrofloxacin in pregnant and non-pregnant mares. Methods: Randomised cross-over experiment. Methods: Six light-breed, healthy pregnant mares (260 days gestation) were given a single dose of either intravenous (5 mg/kg bwt) or oral compounded (7.5 mg/kg bwt) enrofloxacin, ...
Diez Bernal S, Studer N, Thormann W, Spadavecchia C, Levionnois O.To evaluate the effect of a romifidine infusion on antinociception and sedation, and to investigate its relationship with plasma concentration. Methods: Prospective, experimental, nonrandomized trial. Methods: A total of 10 healthy adult warmblood horses. Methods: Romifidine (loading dose: 0.08 mg kg, infusion: 0.03 mg kg hour) was administered intravenously over 120 minutes. Romifidine plasma concentrations were determined by capillary electrophoresis. Sedation quality and nociceptive thresholds were evaluated at regular time points before, during and after romifidine administration. The noci...
Crabtree NE, Mochal-King CA, Sloan PB, Eddy AL, Wills RW, Meredith AN, Fontenot RL.To determine synovial butorphanol concentrations and mechanical nociceptive threshold (MNT) changes after butorphanol intravenous regional limb perfusion (IVRLP). Methods: Experimental ANIMALS: Six adult horses. Methods: Cephalic IVRLP was performed with 10 mg butorphanol in sedated horses with a wide rubber tourniquet and a total volume of 30 mL. Radiocarpal synovial fluid and serum concentrations along with MNT were evaluated prior to and 0.5, 1, 2, 4, and 6 hours after IVRLP. Butorphanol concentrations were determined with liquid chromatography coupled to tandem mass spectrometry posi...
Wenzel RG, Major D, Hesp KF, Hall E, Doble P.To monitor cobalt concentrations in urine, red blood cells and plasma after chronic parenteral administration of cobalt chloride evaluate these results against the current International Federation of Horseracing Authorities thresholds for detecting cobalt misuse. Methods: Eight mares were randomly assigned to four treatment groups, with two mares in each group: Group 1 - control group, Group 2 - 25 milligrams cobalt intravenously as CoCl weekly, Group 3 - 50 milligrams cobalt intravenously as CoCl weekly, and Group 4 - 25 milligrams cobalt intravenously mid-week and at the end of the week. Uri...
Villarino NF, Lopez CM, Sams RA, Bayly WM.The primary objective of this study was to assess the disposition of furosemide in Thoroughbred horses treated intravenously with 1 mg/kg of furosemide 4 and 24 h before supramaximal treadmill exercise without and with controlled access to water, respectively. Another objective was to determine whether furosemide was detectable in the plasma of horses after exposure to supramaximal treadmill exercise. Thoroughbred horses (n = 4-6) were administered single intravenous doses of 1 mg/kg of furosemide at 4 and 24 h before supramaximal exercise on a high-speed treadmill, with controlled ...
Knych HK, Arthur RM, Kanarr KL, McKemie DS, Kass PH.Methamphetamine is a central and peripheral nervous system stimulant. There is only a single study that describes exposure to and disposition of this compound in horses. The potential for abuse and inadvertent exposure in equine athletes along with the limited data available necessitates further study. The objectives of the current study were to describe drug and metabolite concentrations, develop an analytical method that could be used to regulate its use, and describe selected pharmacodynamic effects. In phase 1, six horses were randomized into three transmucosal dose groups (n = 2/group; ...
Samimi AS, Samimi K, Karimiafshar M, Tajik J.The objective of this study was to comparatively evaluate the anti-inflammatory effects of intravenous administration of insulin (in different doses) and flunixin on physiological variables, acute-phase responses, and cardiovascular biomarkers during inflammatory phase which was induced by Escherichia coli lipopolysaccharide (LPS) serotype O55:B5 in miniature donkeys. A total of twenty-four clinically healthy male adult miniature donkeys aged 5 ± 1 year and weighing 120 ± 10 kg were studied. The animals were assigned randomly to four experimental groups (three treatment and one positive co...
Luethy D, Johnson AL, Stefanovski D, Boston RC, Orsini JA.Equine metabolic syndrome (EMS) is prevalent in the equine population, and somatostatin analogs might be useful for diagnosis and/or treatment of EMS in horses. The purpose of this study was to evaluate the glucose and insulin responses to subcutaneous and intravenous administration of somatostatin. Six healthy research horses were included in this prospective study. An initial pilot study was performed to assess several different doses (10-22 µg/kg [4.5-10 µg/lb]) in two horses, then a final dosage of 22 µg/kg (10 µg/lb) was administered to six horses IV and SQ in a two-period random...
Latimer FG, Colitz CM, Campbell NB, Papich MG.To determine the pharmacokinetics of fluconazole in horses. Methods: 6 clinically normal adult horses. Methods: Fluconazole (10 mg/kg of body weight) was administered intravenously or orally with 2 weeks between treatments. Plasma fluconazole concentrations were determined prior to and 10, 20, 30, 40, and 60 minutes and 2, 4, 6, 8, 10, 12, 24, 36, 48, 60, and 72 hours after administration. A long-term oral dosing regimen was designed in which all horses received a loading dose of fluconazole (14 mg/kg) followed by 5 mg/kg every 24 hours for 10 days. Fluconazole concentrations were determined i...
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...
McKellar QA, Bogan JA, von Fellenberg RL, Ludwig B, Cawley GD.Carprofen, a non-steroidal anti-inflammatory drug (NSAID) was administered to three Thoroughbred geldings and three Shetland ponies to determine its plasma disposition and tolerance. The main pharmacokinetic characteristics of carprofen in horses and ponies were a volume of distribution of 0.08 to 0.32 litres/kg (mean +/- se = 0.23 +/- 0.04) a systemic clearance of 26.4 to 78.5 ml/min (mean +/- se = 44.9 +/- 8.0) and a plasma elimination half-life of 14.5 to 31.4 h (mean +/- se = 21.9 +/- 2.3). There was no evidence of any accumulation of carprofen in plasma when the drug was given orally at a...
Lees P, McKellar Q, May SA, Ludwig B.The pharmacokinetics and pharmacodynamics of the nonsteroidal anti-inflammatory drug (NSAID) carprofen have been evaluated in 6 horses using a model of acute non-immune inflammation. Following intravenous administration of 0.7 mg racemic carprofen/kg bwt, mean values for pharmacokinetic parameters were 18.1 h (elimination half-life); 0.25 l/kg (volume of distribution, Vd[area]); 58.9 ml/min (clearance); and 57.9 micrograms/ml.h (area under plasma concentration time curve). Mean exudate:plasma concentration ratios exceeded 1.0 at all sampling times between 2 and 48 h. Swelling at the site of ac...
Morresey PR, Mackay RJ.To measure serum polymyxin B concentration after single and repeated IV infusions in horses. Methods: 5 healthy horses. Methods: In study 1, 1 mg (6,000 U) of polymyxin B/kg was given IV and blood samples were collected for 24 hours. In study 2, 1 mg of polymyxin B/kg was given IV every 8 hours for 5 treatments and blood samples were collected until 24 hours after the last dose. Polymyxin B concentration was measured as the ability to suppress nitrite production by murine macrophages stimulated with lipopolysaccharide and interferon-alpha. Urine was collected prior to the first drug infusion a...
Burrows GE.The response of the pony to increasing doses of Escherichia coli endotoxin was evaluated using intravenous and intraperitoneal administration models. Marked changes were seen in all parameters measured following endotoxin administration. Leukopenia (neutropenia, lymphopenia) and thrombocytopenia were not dose-dependent. Similarly, elevated plasma fibrinogen and altered glucose concentrations (hyperglycemia and hypoglycemia), pyrexia and increased lactate/pyruvate ratios were apparent at all endotoxin doses but were not dose related. The widely used packed cell volume and capillary refill time,...
Guglick MA, MacAllister CG, Clarke CR, Pollet R, Hague C, Clarke JM.To determine pharmacokinetics of i.v., i.m., and oral administration of cefepime in horses and to compare pharmacokinetics of i.m. administration of cefepime with those of ceftiofur sodium. Methods: 6 clinically normal adult horses. Methods: Horses received 3 doses of cefepime (11 mg/kg of body weight, PO; 2.2 mg/kg, i.v.; and 2.2 mg/kg, i.m.) and 1 dose of ceftiofur (2.2 mg/kg, i.m.). Two horses also received L-arginine, p.o. and i.v., at doses identical to those contained in the cefepime dihydrochloride-L-arginine preparations previously administered. Blood samples were collected for 24 hour...
Foreman JH, Barange A, Lawrence LM, Hungerford LL.The objective was to test the hypothesis that phenylbutazone (PBZ) alleviates lameness in an adjustable heart bar shoe model of equine foot pain. Eight Quarter Horse mares underwent 4-weekly treatments randomly: 0.9% saline placebo (SAL: 1 mL/45 kg body weight i.v.) with no lameness; SAL with lameness; PBZ (4.4 mg/kg body weight i.v.) with no lameness; and PBZ with lameness. Blinded heart rate (HR) and lameness score (LS) were assessed every 20 min for 2 h and then hourly through 9 h. At 1 h SAL or PBZ was administered. Jugular venous samples were obtained at hours 0, 1, 2, 4, 6, and 8 and wer...
Zaugg JL, Lane VM.We evaluated the efficacy of buparvaquone in eliminating Babesia equi of European origin in carrier horses and in experimentally infected splenectomized ponies. When administered at the rate of 2.5 mg/kg of body weight, IM, 4 times at 96-hour intervals, buparvaquone was effective in eliminating B equi carrier infection in 1 horse. Such results could not be repeated at the same dosage or at 3.5 or 5 mg/kg, IM. Buparvaquone given at the rate of 4 to 6 mg/kg IV and/or IM was therapeutically effective in 4 of 5 acute B equi infections in splenectomized ponies. The treated ponies became carriers.
Briganti A, Portela DA, Grasso S, Sgorbini M, Tayari H, Bassini JR, Vitale V, Romano MS, Crovace A, Breghi G, Staffieri F.The aim of this study was to evaluate the correlation of commonly used oxygenation indices with venous admixture (Qs/Qt) in anaesthetised horses under different infusion rates of dobutamine. Six female horses were anaesthetised with acepromazine, xylazine, diazepam, ketamine, and isoflurane, and then intubated and mechanically ventilated with 100% O2. A Swan-Ganz catheter was introduced into the left jugular vein and its tip advanced into the pulmonary artery. Horses received different standardised rates of dobutamine. For each horse, eight samples of arterial and mixed venous blood were simul...
Holland B, Fogle C, Blikslager AT, Curling A, Barlow BM, Schirmer J, Davis JL.The objectives of this study were to compare the pharmacokinetics and COX selectivity of three commercially available formulations of firocoxib in the horse. Six healthy adult horses were administered a single dose of 57 mg intravenous, oral paste or oral tablet firocoxib in a three-way, randomized, crossover design. Blood was collected at predetermined times for PGE2 and TXB2 concentrations, as well as plasma drug concentrations. Similar to other reports, firocoxib exhibited a long elimination half-life (31.07 ± 10.64 h), a large volume of distribution (1.81 ± 0.59L/kg), and a slow clearanc...
Frisbie DD, McIlwraith CW, Kawcak CE, Werpy NM.OBJECTIVE To evaluate the efficacy of IV administration of a product containing hyaluronan, sodium chondroitin sulfate, and N-acetyl-d-glucosamine for prevention or treatment of osteoarthritis in horses. ANIMALS 32 healthy 2- to 5-year-old horses. PROCEDURES The study involved 2 portions. To evaluate prophylactic efficacy of the test product, horses received 5 mL of the product (n = 8) or saline (0.9% NaCl) solution (8; placebo) IV every fifth day, starting on day 0 (when osteoarthritis was induced in the middle carpal joint of 1 forelimb) and ending on day 70. To evaluate treatment efficacy, ...
Erkert RS, MacAllister CG, Payton ME, Clarke CR.To use force plate analysis to evaluate the analgesic efficacies of flunixin meglumine and phenylbutazone administered i.v. at typical clinical doses in horses with navicular syndrome. Methods: 12 horses with navicular syndrome that were otherwise clinically normal. Methods: Horses received flunixin (1.1 mg/kg), phenylbutazone (4.4 mg/kg), or physiologic saline (0.9% NaCI; 1 mL/45 kg) solution administered IV once daily for 4 days with a 14-day washout period between treatments (3 treatments/horse). Before beginning treatment (baseline) and 6, 12, 24, and 30 hours after the fourth dose of each...
Clarke KW, Taylor PM.Detomidine, given intravenously at doses of 5 to 30 (mean 13) micrograms/kg bodyweight (bwt), provided adequate sedation for a variety of clinical procedures in 93 per cent of administrations, and improved the ease of handling in the remaining animals. Side effects of ataxia and bradycardia were minimal at the lower dose rates. Higher doses were required for intramuscular use. In experimental trials 10 and 20 micrograms/kg bwt resulted in deep sedation and also significant hypertension and bradycardia of over 15 mins duration. Current literature on the use of detomidine in horses is reviewed.
McGowan KT, Elfenbein JR, Robertson SA, Sanchez LC.Pain management is an important component of foal nursing care, and no objective data currently exist regarding the analgesic efficacy of opioids in foals. Objective: To evaluate the somatic antinociceptive effects of 2 commonly used doses of intravenous (i.v.) butorphanol in healthy foals. Our hypothesis was that thermal nociceptive threshold would increase following i.v. butorphanol in a dose-dependent manner in both neonatal and older pony foals. Methods: Seven healthy neonatal pony foals (age 1-2 weeks), and 11 healthy older pony foals (age 4-8 weeks). Five foals were used during both age ...
Mama KR, Steffey EP, Pascoe PJ.This study provides baseline information on the potential use of propofol as a general anesthetic for horses. Using a Latin square design, propofol (2, 4, and 8 mg/kg) was administered intravenously on three separate occasions to six mature horses. Information about anesthetic induction, duration, and recovery was recorded along with results of rectal temperature, heart rate, respiratory rate, pHa, PaCO2 and PaO2. Statistical analysis included a mixed model analysis of variance, a general linear model analysis and least square means test for post hoc comparisons. A P < .05 was considered si...
Mealey KL, Matthews NS, Peck KE, Burchfield ML, Bennett BS, Taylor TS.To compare plasma disposition of the R(-) and S(+) enantiomers of carprofen after IV administration of a bolus dose to donkeys and horses. Methods: 5 clinically normal donkeys and 3 clinically normal horses. Methods: Blood samples were collected from all animals at time 0 (before) and at 10, 15, 20, 30, and 45 minutes and 1, 1.5, 2, 2.5, 3, 4, 5, 6, 8, 10, 24, 28, 32, and 48 hours after IV administration of a bolus of carprofen (0.7 mg/kg). Plasma was analyzed in triplicate via high-performance liquid chromatography to determine the concentrations of the carprofen enantiomers. A plasma concent...
Messenger KM, Davis JL, LaFevers DH, Barlow BM, Posner LP.To describe the pharmacokinetics and adverse effects of intravenous (IV) and sublingual (SL) buprenorphine in horses, and to determine the effect of sampling site on plasma concentrations after SL administration. Methods: Randomized crossover experiment; prospective study. Methods: Eleven healthy adult horses between 6 and 20 years of age and weighing 487-592 kg. Methods: In the first phase; buprenorphine was administered as a single IV or SL dose (0.006 mg kg(-1)) and pharmacokinetic parameters were determined for each route of administration using a noncompartmental model. In the second phas...
Wojtasiak-Wypart M, Soma LR, Rudy JA, Uboh CE, Boston RC, Driessen B.Romifidine HCl (romifidine) is an α(2)-agonist commonly used in horses. This study was undertaken to investigate the pharmacokinetics (PK) of romifidine following intravenous (i.v.) administration and describe the relationship between PK parameters and simultaneously recorded pharmacodynamic (PD) parameters. Romifidine (80 μg/kg) was administered by i.v. infusion over 2 min to six adult Thoroughbred horses, and plasma samples were collected and analyzed using liquid chromatography-mass spectrometry. Limit of quantification was <0.1 ng/mL. PD parameters and arterial blood gases were measur...
Desta B, Maldonado G, Reid H, Puschner B, Maxwell J, Agasan A, Humphreys L, Holt T.Just prior to an international polo event, 21 horses from one team exhibited clinical signs of central nervous system disturbance, hyperexcitability, sweating, ataxia, tachycardia, dyspnea, pyrexia, and rapid death. The suspected cause of this peracute onset of illness and death included intentional contamination of feed or iatrogenic administration of performance-enhancing drugs resulting in a severe adverse reaction. Six horses were submitted to the Bronson Animal Disease Diagnostic Laboratory for necropsy and toxicological examination. The clinical signs and sudden death, the similarity to ...
Ryan CA, Sanchez LC, Giguère S, Vickroy T.Proton pump inhibitors (PPIs) are a mainstay of treatment for acid-related ulceration in man and horses. Currently, only an oral preparation of omeprazole is approved for use in horses in the USA. Intravenous administration of a PPI would provide a useful therapeutic alternative for those foals in which oral medication is not feasible. Objective: To investigate the pharmacokinetics and pharmacodynamics of pantoprazole following i.v. or intragastric administration in healthy neonatal foals. Methods: Seven healthy foals age 6-12 days at the start of the study were evaluated. Treatments included ...
de Vries A, Pakkanen SA, Raekallio MR, Ekiri A, Scheinin M, Taylor PM, Vainio OM.To investigate the effects of MK-467 on sedation quality, and cardiopulmonary and pharmacokinetic variables in horses sedated intravenously (IV) with romifidine. Methods: Experimental, randomized, crossover design. Methods: Seven healthy mares. Methods: Romifidine (80 μg kg-1 ; R) and MK-467 (200 μg kg-1 ; MK) were administered IV alone and in combination (R + MK). Levels of sedation and borborygmi were scored. Heart rate (HR), direct arterial blood pressure (ABP) and respiratory rate (fR ) were recorded. Arterial and venous blood gas analyses were performed and venous plasma drug conc...
Larenza MP, Knobloch M, Landoni MF, Levionnois OL, Kronen PW, Theurillat R, Schatzmann U, Thormann W.The pharmacokinetics of ketamine and norketamine enantiomers after administration of intravenous (IV) racemic ketamine (R-/S-ketamine; 2.2 mg/kg) or S-ketamine (1.1 mg/kg) to five ponies sedated with IV xylazine (1.1mg/kg) were compared. The time intervals to assume sternal and standing positions were recorded. Arterial blood samples were collected before and 1, 2, 4, 6, 8 and 13 min after ketamine administration. Arterial blood gases were evaluated 5 min after ketamine injection. Plasma concentrations of ketamine and norketamine enantiomers were determined by capillary electrophoresis and wer...
Hyde RM, Lynch TM, Clark CK, Slone DE, Hughes FE.This study investigated the influence of perfusate volume on antimicrobial concentration in synovial fluid following intravenous regional limb perfusion (IVRLP) and assessed the efficacy of low volume IVRLP. The front limbs of 9 horses were randomly assigned to 1 of 3 volume groups: 10 mL (Group 1), 30 mL (Group 2), or 60 mL (Group 3). A tourniquet was applied distal to the carpus and the limbs were perfused with 500 mg genta-micin diluted to the assigned volume via a catheter placed in the lateral palmar digital vein at the level of the proximal sesamoid bones. Synovial fluid samples were col...
Casoni D, Spadavecchia C, Wampfler B, Thormann W, Levionnois OL.Intravenous anaesthetic drugs are the primary means for producing general anaesthesia in equine practice. The ideal drug for intravenous anaesthesia has high reliability and pharmacokinetic properties indicating short elimination and lack of accumulation when administered for prolonged periods. Induction of general anaesthesia with racemic ketamine preceded by profound sedation has already an established place in the equine field anaesthesia. Due to potential advantages over racemic ketamine, S-ketamine has been employed in horses to induce general anaesthesia, but its optimal dose remains und...
Brightman AH, Manning JP, Benson GJ, Musselman EE.Schirmer I tear tests were conducted on 14 horses. The test was performed before and after IV administration of xylazine hydrochloride, during maintenance anesthesia with halothane in oxygen, and 3 hours after discontinuation of anesthesia. Xylazine hydrochloride did not decrease tear production from the mean base-line value of 23.94 +/- 5.23 mm/min after its IV administration. Tear production was decreased to mean values of 15.57 +/- 4.29 mm/min at 30 minutes and 13.84 +/- 4.25 mm/min at 60 minutes during the maintenance of halothane anesthesia. Three hours after anesthesia was discontinued, ...
Oreff GL, Dahan R, Tatz AJ, Raz T, Britzi M, Kelmer G.To determine the influence of 3 perfusate volumes on amikacin concentration in the metacarpophalangeal joint following cephalic regional limb perfusion (RLP) in standing horses. Methods: Seven healthy horses. Methods: Three perfusate volumes (100, 60, and 30 mL), containing 2 grams of amikacin, were tested during intravenous RLP at the cephalic vein, placing the tourniquet at mid antebrachium, in standing sedated horses. Synovial fluid was collected from the metacarpophalangeal joint before perfusion and at 30 and 120 minutes after perfusion. Serum samples were taken from the jugular vein at t...
Davis JL, Salmon JH, Papich MG.To determine the pharmacokinetics of itraconazole after IV or oral administration of a solution or capsules to horses and to examine disposition of itraconazole in the interstitial fluid (ISF), aqueous humor, and polymorphonuclear leukocytes after oral administration of the solution. Methods: 6 healthy horses. Methods: Horses were administered itraconazole solution (5 mg/kg) by nasogastric tube, and samples of plasma, ISF, aqueous humor, and leukocytes were obtained. Horses were then administered itraconazole capsules (5 mg/kg), and plasma was obtained. Three horses were administered itraconaz...
