Local anaesthesia in horses involves the administration of agents that temporarily block nerve conduction, resulting in a loss of sensation in a specific area of the body. This technique is employed in various veterinary procedures to facilitate pain management and allow for the performance of minor surgical interventions without the need for general anaesthesia. Common local anaesthetic agents used in equine medicine include lidocaine, mepivacaine, and bupivacaine. These agents are selected based on their duration of action and specific application requirements. The use of local anaesthesia can help minimize stress and recovery time for horses undergoing treatment. This page compiles peer-reviewed research studies and scholarly articles that explore the pharmacology, application methods, and clinical outcomes associated with local anaesthesia in equine practice.
Bolt DM, Ishihara A, Weisbrode SE, Bertone AL.To evaluate the effects of triamcinolone acetonide (TA), sodium hyaluronate (HA), amikacin sulfate (AS), and mepivacaine hydrochloride (MC) on articular cartilage morphology and matrix composition in lipopolysaccharide (LPS)-challenged and unchallenged equine articular cartilage explants. Methods: 96 articular cartilage explants from 4 femoropatellar joints of 2 adult horses. Methods: Articular cartilage explants were challenged with LPS (100 ng/mL) or unchallenged for 48 hours, then treated with TA, HA, AS, and MC alone or in combination for 96 hours or left untreated. Cartilage extracts were...
Driessen B, Scandella M, Zarucco L.To develop a technique for placing continuous peripheral nerve block (CPNB) catheters adjacent to palmar nerves in horses and to evaluate the effect of low-volume local anesthetic (LA) infusion on nociception in the distal equine thoracic limb. Methods: In vitro and in vivo laboratory investigation. STUDY MATERIAL AND ANIMALS: Forty-two thoracic limbs from 22 equine cadavers and five horses. Methods: Thoracic limb specimens were dissected to find landmarks for catheter insertion adjacent to medial and lateral palmar nerves. Based on the anatomy of the proximal metacarpus, a technique for placi...
Pollock PJ, Russell T, Hughes TK, Archer MR, Perkins JD.To report a technique for eye enucleation in standing sedated horses and to report outcome in 40 horses. Methods: Retrospective study. Methods: Horses (n=40) requiring eye enucleation. Methods: The eye was enucleated using a transpalpebral technique in 40 horses restrained in stocks and sedated. Anesthesia of orbital structures was provided by local nerve blocks and infiltration of the surgical site with local anesthetic solution. Results: Affected eyes were successfully enucleated with the horse standing. Short-term complications included moderate swelling (5 horses) and wound discharge (1). ...
Staszyk C, Bienert A, Bäumer W, Feige K, Gasse H.To provide anaesthesia of the maxillary cheek teeth, a local block of the infraorbital nerve in the pterygopalatine fossa has been suggested. The aim of this study was to re-examine the anatomy of the pterygopalatine fossa, giving special attention to relevant arteries, veins and nerves; simulate the infiltration of an anaesthetic by injecting a contrast medium; improve the injection technique to avoid puncturing of relevant anatomical structures. Five heads and two living horses were investigated using contrast medium injections and computed tomography (CT). Needles were inserted using two in...
Imboden I, Waldern NM, Wiestner T, Lischer CJ, Ueltschi G, Weishaupt MA.Extracorporeal shock wave therapy (ESWT) is an accepted form of treatment for chronic cases of proximal suspensory desmitis (PSD). Subjective evaluation of horses shortly after being treated with ESWT has led clinicians to comment on an immediate reduction in lameness. This study aimed to evaluate the analgesic effect of ESWT on 16 horses with PSD or PSD-like pain in a fore- or hindlimb. To objectively assess lameness, gait analysis was performed on an instrumented treadmill before and 6, 24, 48 and 72h after ESWT of the origin of the suspensory ligament and the results compared to the effects...
Harper J, Schumacher J, Degraves F, Schramme M, Schumacher J.Specific analgesic techniques are required in diagnosis of lameness to isolate the exact origin of pain to the many structures of the foot that may be involved. Objective: To determine if analgesia of the digital flexor tendon sheath (DFTS) results in anaesthesia of other portions of the foot, such as the sole, distal interphalangeal joint (DIPJ), or navicular bursa (NB). Methods: Lameness caused by pain in the dorsal margin or heel region of the sole of the foot was induced in 18 horses by: using set-screws to create solar pressure (Trial 1: n = 5); or administering endotoxin intrasynovially ...
Bidwell LA, Wilson DV, Caron JP.To measure concentrations of lidocaine serum after application of two 5% patches on horses. Methods: Prospective experimental trial Methods: Six client-owned, systemically healthy horses. Methods: The hair was clipped on the medial aspect above the carpus of both fore limbs and 2 patches of 5% lidocaine were applied within 30 minutes of jugular catheter placement and the area was then bandaged. Venous blood was drawn from a jugular vein catheter that was inserted using lidocaine as a local block. Samples were drawn immediately before and at 2, 4, 6, 8, and 12 hours after patch application. The...
Hewes CA, Keoughan GC, Gutierrez-Nibeyro S.Enucleation was performed in 5 horses under local anesthesia and sedation with the horse standing. Minimal hemorrhage occurred during the surgical procedure, and there were no other reported complications. Standing enucleation is a surgery that is safe to perform in horses. L’énucléation a été réalisée chez 5 chevaux en position debout sous anesthésie locale et sédation. Une hémorragie minime est survenue pendant la procédure chirurgicale et il n’y a pas eu de complications rapportées. L’énucléation debout est une chirurgie sécuritaire chez le cheval. (Traduit par Docteur ...
Russell TM, Maclean AA.Repair of spiral and long diaphyseal metacarpal and metatarsal fractures under anaesthesia can be problematic and associated with a high incidence of complications, including fracture propagation necessitating euthanasia. Objective: To report on a practical repair technique for which general anaesthesia is not required. Methods: Thirteen racehorses with a spiral/propagating condylar fracture had the fracture repaired using local anaesthesia and sedation, without the need for general anaesthetic. Results: Ten of the horses returned to training and 8 raced again. Two horses were retired directly...
Arkell M, Archer RM, Guitian FJ, May SA.Eighteen observers were influenced to different extents in the grades of lameness they allocated to eight horses by whether they knew that a nerve block had been administered; on a scale from 0 to 10 the mean difference in grade allocated once the observer knew a horse had been nerve-blocked was increased by 0.4. The consistency of the assessments made by the individual observers was good, with a an average of 0.6 of a grade difference when grading the same horse on two occasions. The agreement between the assessments of four orthopaedic experts was reasonable (+/-1 grade), but significantly p...
Hubert JD, Burba DJ, Moore RM.To describe a laparoscopic technique for granulosa cell tumor removal using a vessel sealing device (LigaSuretrade mark) in standing mares. Methods: Retrospective study. Methods: Eight mares (8-24 years old; weighing, 406-525 kg). Methods: Before surgery, ovarian size and adjacent body wall thickness was determined by ultrasonography. Mares were sedated and after local anesthesia (inverted L and local infiltration), laparoscopic cannulation was performed without insufflation. The mesovarium was anesthetized and the LigaSure instrument applied to the mesovarium for hemostasis and resection to r...
Holm KR, Wennerstrand J, Lagerquist U, Eksell R, Johnston C.Diagnostic infiltration of local anaesthetic solution is commonly used in cases of equine back pain. Evaluation is subjective and it is not known how local analgesia of the back affects horses without clinical signs of back pain. Objective: To evaluate the effect of infiltration of local anaesthetics on the movement of the back in horses without clinical signs of back pain, and to evaluate the usefulness of kinematic studies as an objective and quantitative tool in evaluating local analgesia in clinical practice. Methods: The kinematics of the back in 10 clinically sound horses were measured o...
Saulez MN, Slovis NM, Louden AT.Tracheal trauma with resultant rupture is uncommonly reported in veterinary literature. We report the case of a 16-year-old Thoroughbred gelding that sustained a 1 cm longitudinal perforation of the dorsal tracheal membrane in the proximal cervical region. The horse subsequently developed dyspnoea due to acute upper respiratory obstruction secondary to severe emphysema of the guttural pouches. A temporary tracheostomy caudal to the site of tracheal perforation was performed under local anaesthesia. This procedure helped relieve the upper airway obstruction and aided resolution of the injury by...
Smith CL, Dowling BA, Dart AJ.Laparoscopy is a minimally invasive procedure that has applications as a diagnostic, therapeutic and prognostic technique. Specialized equipment is necessary to perform equine laparoscopy, and there is a large range of instruments, both disposable and non-disposable available. Laparoscopic procedures described include ovariectomy, cryptorchidectomy, adhesiolysis and herniorrhaphy. Laparoscopy can be performed in a standing or dorsally recumbent position, depending on surgeon preference, patient status and the procedure to be performed. Stapling equipment is frequently used in gastrointestinal ...
Erkert RS, Macallister CG, Campbell G, Payton ME, Shawley R, Clarke CR.Local anesthesia and tissue inflammation associated with lidocaine infiltration and lidocaine/prilocaine topical anesthetic cream for episioplasty in mares were compared. Twenty-two mares were randomly assigned to lidocaine or lidocaine/prilocaine topical anesthetic cream treatment groups. Perineum and vulva were cleaned, 8-12 g (approximately 1 g/cm per side of vulva) of topical anesthetic cream was applied, and the area was covered by plastic wrap 30 min prior to beginning procedure. Alternately, lidocaine was injected (1 mL) every centimeter just prior to the procedure. Episioplasty was con...
Bidwell LA, Brown KE, Cordier A, Mullineaux DR, Clayton HM.Perineural analgesics are used for lameness diagnosis but the duration of effect, knowledge of which would provide valuable information when performing subsequent blocks, is unknown. Objective: To evaluate the duration of a palmar digital nerve block using force plate measurements. Methods: Ten horses diagnosed with unilateral navicular syndrome were trotted at range of 3 +/- 0.15 m/sec over a force plate to record ground reaction forces for 5 trials of each forelimb. Data were recorded before nerve block, and then at 15 mins, 1, 2 and 24 h post nerve block. Results: Before nerve block, peak v...
Robertson SA.Several ocular procedures, including examination, removal of corneal foreign bodies, nictitans surgery, eyelid repair, and tumor excision,can be successfully performed in the appropriately restrained and sedated standing horse. Sedation is best achieved with xylazine,with or without the addition of acepromazine. Additional analgesia can be provided with appropriate local anesthetic blocks. Surgical conditions are greatly improved by using an auriculopalpebral and supraorbital block and topical anesthetics. More elaborate standing sedation involving continuous rate infusions of lidocaine or det...
Desmaizières LM, Martinot S, Lepage OM, Bareiss E, Cadoré JL.To report our experience and complications associated with different cannula insertion techniques for laparoscopy in standing horses. Methods: Retrospective study. Methods: Forty horses that had laparoscopy for diagnostic or surgical purposes. Methods: After a physical examination, including rectal palpation, standing laparoscopy was performed in 40 sedated horses. Local anesthetic was injected at each site of cannula insertion in the left flank. Horses were divided into 5 groups: Pneumoperitoneum was induced before cannula insertion using a Verres needle (group 1, n = 3) or a 12-g catheter (g...
López-Sanromán J, Cruz J, Santos M, Mazzini R, Tabanera A, Tendillo FJ.The objective of this study was to determine the effects of the alkalinization on the local analgesic efficacy of 1% ketamine in the abaxial sesamoid nerve block in horses. Thirty-six mature healthy horses were randomly assigned to four groups for the following treatments; an abaxial sesamoid block with 5 mL of saline solution (control saline); an abaxial sesamoid block with 5 mL of a solution containing 1% ketamine (KETs 1%); an abaxial sesamoid block with 5 mL of a solution containing saline solution and 0.5 mEq of sodium bicarbonate (control bicarbonate); and an abaxial sesamoid block with ...
Schumacher J, Schumacher J, Gillette R, DeGraves F, Schramme M, Smith R, Perkins J, Coker M.Analgesia of the palmar digital (PD) nerves has been demonstrated to cause analgesia of the distal interphalangeal (DIP) joint as well as the sole. Because the PD nerves lie in close proximity to the navicular bursa, we suspected that that analgesia of the navicular bursa would anaesthetise the PD nerves, which would result in analgesia of the DIP joint. Objective: To determine the response of horses with pain in the DIP joint to instillation of local anaesthetic solution into the navicular bursa. Methods: Lameness was induced in 6 horses by creating painful synovitis in the DIP joint of one f...
Keoughan CG, Rodgerson DH, Brown MP.To describe a hand-assisted, laparoscopic technique to remove the left kidney in standing horses. Methods: Prospective evaluation. Methods: Eight horses. Methods: Food was withheld for a minimum of 12 hours. Horses were sedated with detomidine hydrochloride (0.01-0.02 mg/kg, intravenously) and restrained in standing stocks. The left paralumbar fossa was prepared for surgery, and the surgical site was infiltrated with 2% mepivacaine. Hand-assisted, laparoscopic removal of the left kidney was performed through an incision in the center of the paralumbar fossa; the surgeon's hand was used to isol...
Holmes LC, Gaughan EM, Gorondy DA, Hogge S, Spire MF.Infrared thermography is an imaging modality gaining popularity as a diagnostic aid in the evaluation of equine lameness. Anecdotal reports of skin hyperthermia induced by local anesthesia, detected by thermography, have been made; however, no controlled studies have been reported. The purpose of this study was to examine the effects of perineural anesthesia on infrared thermographic images of the forelimb digits in normal horses. After environmental acclimation, infrared thermographs were made at intervals of 0, 5, 10, 15, 30, and 45 min from administration of mepivacaine hydrochloride or pho...
Dyson S, Murray R.There has been no large study of horses with suspected sacroiliac (SI) joint region pain in which the clinical diagnosis has been supported by either abnormal radiopharmaceutical activity in the SI joint region or by periarticular infiltration of local anaesthetic solution. Objective: To describe the clinical features of horses with SI joint region pain, to document the age, breed, sex, discipline, size and conformation of affected horses and to compare these with the author's (SD) normal case population and to document the results of infiltration of local anaesthetic solution around the SI jo...
López-Sanromán FJ, Cruz JM, Santos M, Mazzini RA, Tabanera A, Tendillo FJ.To evaluate the local analgesic effect of ketamine in a palmar digital nerve block at the base of the proximal sesamoid (abaxial sesamoid block) in horses. Methods: 36 mature healthy Andalusian horses. Methods: Horses were randomly assigned to 4 groups of 9 horses each and received an abaxial sesamoid block in a randomly chosen forelimb with 1 of the following: saline (0.9% NaCl) solution, 1% ketamine solution, 2% ketamine solution, or 3% ketamine solution. To determine analgesia, the radiant heat lamp-hoof withdrawal model was used as a noxious thermal stimulus. Before each nerve block, basel...
Zekas LJ, Forrest LJ.The purpose of this study was to describe ultrasonographic changes of the equine palmar metacarpal area attributed to the infiltration of local anesthetic solution and to determine whether these changes were noted immediately or at 24 h. The palmar metacarpal region of one forelimb in each of six horses was examined ultrasonographically with a 10-MHz linear array transducer and a 7.5-MHz curvilinear transducer. Transverse and longitudinal images were recorded at 5-cm intervals distal to the accessory carpal bone. High and low palmar and palmar metacarpal nerve blocks were performed with a 2% m...
Robinson EP, Natalini CC.Intercoccygeal, or caudal, epidural injection of local anesthetics is a convenient method of producing analgesia and local anesthesia of the tail and perineal structures in conscious standing horses. This technique has been further developed to provide long duration analgesia and anesthesia by placement of catheters into the epidural space of horses. More recently, opioid, alpha-2 adrenergic agonists, ketamine and other analgesic agents have been administered by caudal epidural injection, providing pain relief in both conscious, standing and anesthetized, recumbent horses. This chapter describ...
Gough MR, Mayhew G, Munroe GA.This paper tests the hypothesis that the local analgesic agent mepivacaine diffuses between adjacent equine synovial structures in the forelimb and with greater frequency than latex, gelatine dye or contrast media. We report the incidence of diffusion of mepivacaine between the distal interphalangeal joint (DIPJ) and navicular bursa (NB) of the forelimbs and between the intercarpal (IC) and radiocarpal (RC) joints of 31 fresh equine cadavers. The DIPJ of one forelimb and the NB of the contra lateral forelimb and the RC joint of one forelimb and the IC joint of the contra lateral forelimb were ...
Gough MR, Munroe GA, Mayhew G.This paper tests the hypothesis that the local analgesic agent mepivacaine diffuses between adjacent equine synovial structures in the hindlimb and with greater frequency than latex, gelatine dye or contrast media. We report the incidence of diffusion of mepivacaine between the tarsometatarsal, centrodistal and tarsocrural joints, and the 3 synovial compartments of the stifle in 33 fresh equine cadavers. The tarsometatarsal joint and one synovial compartment of the stifle in the left limb and the centrodistal joint and a different synovial compartment of the stifle in the right limbs were inje...
Schumacher J, Schumacher J, de Graves F, Schramme M, Smith R, Coker M, Steiger R.We hypothesised that analgesia of the navicular bursa is not selective for the navicular apparatus; and that solar pain in some horses can be temporarily abolished or attenuated by analgesia of the navicular bursa. To test this hypothesis, we caused lameness in horses by inducing pain in the dorsal margin or the angles of the sole and then evaluated the ability of a local analgesic solution administered into the navicular bursa to attenuate lameness. The response of horses with solar pain in the dorsal or palmar aspect of the foot to 3.5 ml local analgesic solution administered into the navicu...
Harkins JD, Karpiesiuk W, Lehner A, Woods WE, Dirikolu L, Carter WG, Boyles J, Tobin T.This report evaluates the pharmacological responses, urinary detection and mass spectral confirmation of ropivacaine in horses. Ropivacaine, a potent local anesthetic (LA) recently introduced in human medicine, has an estimated highest no-effect dose (HNED) of about 0.4 mg/site as determined in our abaxial sesamoid block model. Apparent ropivacaine equivalents were detectable by ELISA screening using a mepivacaine ELISA test after administration of clinically effective doses. Mass spectral examination of postadministration urine samples showed no detectable parent ropivacaine, but a compound i...
Regnier A, Berton I, Concordet D, Douet JY.To assess the degree and duration of corneal anaesthesia provided by topical application of a non-ophthalmic 2% lidocaine gel in horses. Methods: Experimental, 'blinded', randomized prospective study. Methods: Twelve adult horses without relevant ocular abnormalities. Methods: Baseline corneal touch threshold (CTT) measurements were obtained bilaterally by use of a Cochet-Bonnet aesthesiometer just prior to topical treatment. A volume of 0.2mL of 2% lidocaine gel was administered in one randomly selected eye and the same volume of a viscous lubricant in the other eye to serve as control. The C...
López-Sanromán FJ, Cruz JM, Santos M, Mazzini RA, Tabanera A, Tendillo FJ.To evaluate the local analgesic effect of ketamine in a palmar digital nerve block at the base of the proximal sesamoid (abaxial sesamoid block) in horses. Methods: 36 mature healthy Andalusian horses. Methods: Horses were randomly assigned to 4 groups of 9 horses each and received an abaxial sesamoid block in a randomly chosen forelimb with 1 of the following: saline (0.9% NaCl) solution, 1% ketamine solution, 2% ketamine solution, or 3% ketamine solution. To determine analgesia, the radiant heat lamp-hoof withdrawal model was used as a noxious thermal stimulus. Before each nerve block, basel...
Gaynor JS, Hubbell JA.Local and regional anesthetic techniques are useful tools for the equine practitioner. These techniques allow surgery to be performed without the risk and cost of general anesthesia. There are, however, risks associated with the local and regional techniques. Neurotoxicity, although rare, may occur when 200 mL or more of a local anesthetic are infiltrated in a short period of time to a 450-kg horse. More likely, horses may become ataxic after nerve blockade in the limbs. This ataxia may lead to self trauma because the horse may not know where the limbs are actually being placed. Although local...
Lund CM, Ragle CA, Lutter JD.An 11-year-old Arabian gelding was evaluated for hematuria, stranguria, and pollakiuria that had been observed for 1 week. Results: Transrectal palpation revealed a 5-cm firm round mass in the urinary bladder. Cystoscopy and transrectal ultrasonography confirmed the diagnosis of urinary bladder urolithiasis. Results: A multiportal transparalumbar fossa laparoscopic approach was selected for cystotomy and urolith removal. Cystotomy and urolith removal was performed with sedation and local anesthesia with the horse standing. No perioperative complications were observed. Urination returned to nor...
Harding PG, Smith RL, Barakzai SZ.To compare two approaches to performing the inferior alveolar nerve block in the horse and to evaluate the consistency of described topographical landmarks. Methods: Experimental cadaver model. Methods: Eleven cadaver heads were positioned to mimic a standing sedated horse and the position of the mandibular foramen approximated. The vertical approach to the approximate location of the mandibular foramen was undertaken and red dye was deposited. The angled approach was then undertaken and blue ink was used to identify it. The heads were then dissected to determine the location of the dye. Place...
Bramlage LR, Gabel AA, Hackett RP.Five horses with avulsion fractures of the proximal origin of the suspensory ligament were examined for lameness. The horses in the series each had lameness of acute onset; four were severely lame, and one was moderately lame. The condition was difficult to diagnose because commonly used local anesthetic blocks did not result in improvement during the routine examination. Local infiltration of the area with local anesthetic returned the horses to soundness. After a period of rest, varying from a few weeks in the acute injury to 6 months in the chronic injuries, the horses were returned to raci...
Morris TB, Lumsden JM, Dunlop CI, Locke V, Sommerauer S, Hurcombe SDA.The nociceptive blockade of locoregional anesthesia prior to surgical stimulation can decrease anesthetic agent requirement and thereby potential dose-dependent side effects. The use of an ipsilateral second and third cervical spinal nerve locoregional anesthetic block for prosthetic laryngoplasty in the anesthetized horses has yet to be described. Anesthetic records of 20 horses receiving locoregional anesthesia prior to laryngoplasty were reviewed and compared to 20 horses of a similar patient cohort not receiving locoregional anesthesia. Non-blocked horses were 11 times more likely to requi...
Nagy A, Bodò G, Dyson SJ, Compostella F, Barr AR.Evidence-based information is limited on distribution of local anaesthetic solution following perineural analgesia of the palmar (Pa) and palmar metacarpal (PaM) nerves in the distal aspect of the metacarpal (Mc) region ('low 4-point nerve block'). Objective: To demonstrate the potential distribution of local anaesthetic solution after a low 4-point nerve block using a radiographic contrast model. Methods: A radiodense contrast medium was injected subcutaneously over the medial or the lateral Pa nerve at the junction of the proximal three-quarters and distal quarter of the Mc region (Pa inject...
Ruggles AJ, Ross MW, Freeman DE.The frontal, caudal maxillary, and rostral maxillary sinuses of 10 equine cadavers were examined endoscopically, and the findings were confirmed by sinusotomy. Similar endoscopic examinations were performed in five conscious, adult horses by using sedation and local anesthesia. Useful portals of entry for the arthroscope in adult horses were: for the frontal sinus, 60% of the distance in a lateral direction from midline to the medial canthus and 0.5 cm caudal to the medial canthus; for the caudal maxillary sinus, 2 cm rostral and 2 cm ventral to the medial canthus; and for the rostral maxillar...
Harkins JD, Mundy GD, Woods WE, Lehner A, Karpiesiuk W, Rees WA, Dirikolu L, Bass S, Carter WG, Boyles J, Tobin T.Lidocaine is a local anaesthetic agent that is widely used in equine medicine. It is also an Association of Racing Commissioners International (ARCI) Class 2 foreign substance that may cause regulators to impose substantial penalties if residues are identified in post race urine samples. Therefore, an analytical/pharmacological database was developed for this drug. Using our abaxial sesamoid local anaesthetic model, the highest no-effect dose (HNED) for the local anaesthetic effect of lidocaine was determined to be 4 mg. Using enzyme-linked immunosorbent assay (ELISA) screening, administration...
Bowker RM, Linder K, Sonea IM, Holland RE.The sensory innervation of the navicular bone (os sesamoideum distale) and its suspensory ligaments [ligamenta sesamoidea collateralia (CSL) and ligamentum sesamoideum distale impar or distal sesamoidean impar (DS-impar) ligament] and the navicular bursa (podotrochlearis) was examined in the neonatal foal using immunocytochemistry. With antisera raised to substance P (SP) and human calcitonin gene-related peptide (CGRP), immunoreactive nerves were demonstrated to innervate the CSL and navicular bursa. Within CSL, and SP- and CGRP-like nerves were present in the synovial lining of the navicular...
Gaesser AM, Varner KM, Douglas HF, Barr CA, Hopster K, Levine DG.To evaluate the effects of intra-articular (IA) mepivacaine administration prior to carpal arthroscopy on anesthetic drug requirements, blood pressure support, hemodynamic variables, and quality of recovery in horses. Methods: Experimental, analytical, cohort study. Methods: Twenty-two horses (n = 11 horses/group). Methods: Horses were anesthetized by using the same protocol, but an IA injection of mepivacaine or saline was performed before carpal arthroscopy. End-tidal isoflurane concentration, heart rate, and mean arterial pressure were recorded at specific time points. Quality of recovery w...
Harkins JD, Mundy GD, Stanley S, Woods WE, Rees WA, Thompson KN, Tobin T.The highest no effect doses (HNEDs) for the local anaesthetic (LA) effects of procaine, cocaine, bupivacaine and benzocaine were determined using the heat lamp/hoof withdrawal model of Kamerling et al. (1985b) and the abaxial sesamoid block model of local anaesthesia. The heat lamp rapidly (4 or 5 s) increased the temperature of the superficial skin layers of the pastern to about 90 degrees C, at which point the animal sharply withdrew its hoof. Effective LA blockade precluded this response and superficial skin temperatures exceeded 120 degrees C. Thermal stimulus experiments were routinely te...
Watts AE, Nixon AJ, Reesink HL, Cheetham J, Fubini SL, Looney AL.To investigate the efficacy and safety of a low-volume, single-catheter, continuous peripheral neural blockade (CPNB) technique to locally deliver bupivacaine to alleviate signs of severe forelimb pain resulting from experimentally induced tendonitis in horses. Methods: Randomized controlled experimental trial. Methods: 14 horses and 5 forelimbs from equine cadavers. Methods: Horses underwent collagenase-induced superficial digital flexor tendonitis in the midmetacarpal region of 1 forelimb. To deliver analgesia, a closed-tip catheter was placed from lateral to medial, approximately 12 cm dist...
LeBlanc PH.Organ toxicity from local anesthetic agents is rare. This makes these agents an attractive option in the high-risk patient. Complications associated with local anesthetics are related to overdosage. Overdosage with local anesthetic agents administered epidurally may cause motor paralysis and hind-limb weakness. Systemic signs of local anesthetic overdosage include changes in central nervous system activity (excitement or depression), muscle tremors, and hypotension. Because the dose required to produce these effects in the horse is high (12 mg/kg), this complication is uncommon. Few side effec...
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...
Gottschalk RD, van den Berg SS.Bilateral ovariectomy was performed in 11 mares and unilateral ovariectomy in 2 mares. The horses were standing and sedated for surgery. After appropriate preparation a laparoscope was inserted into the abdomen through the paralumbar fossa and the ovary was identified and anaesthetised with local anaesthetic via a custom-built needle. The ovary was then withdrawn from the abdomen through a separate flank incision and removed. The abdomen was not distended with gas before surgery. This method proved to be minimally invasive, rapid and effective.
Bell BT, Bridge IS, Sullivan ST.Seventeen horses diagnosed as having navicular syndrome on the basis of history, clinical findings, regional local anaesthesia and radiography were subjected to bilateral navicular suspensory desmotomy. Before surgery, the duration of navicular lameness ranged from 6 weeks to 4 years. Previous unsuccessful treatments prior to surgery included nonsteroidal anti-inflammatories, corrective shoeing, rest and isoxsuprine. For the seventeen horses subject to surgery, twelve horses were sound, one horse was improved and four horses were lame at a minimum of 6 months after surgery.
Tulamo RM, Bramlage LR, Gabel AA.The case histories and follow-up data for 11 horses with slab fractures of the central or 3rd tarsal bones were examined for information pertaining to the diagnosis, which was difficult to identify, treatment, which was proven ineffective, and the prognosis, which was shown to be poor for return to racing. The purpose of the study was to define the results that could be obtained by nonoperative methods, in an attempt to determine whether surgical treatment was advisable. Nine of the horses were Standardbreds and 2 were Thoroughbreds; all horses were 2 to 4 years old and were being exercised at...
Reeves MJ, Trotter GW, Kainer RA.The anatomical and functional communications of the synovial sacs of the equine stifle joint were evaluated in 50 stifle joints of 25 horses. Femoropatellar joint (FPJ) sacs were injected with 50 ml of gelatin-based dye and horses were then walked for 50 m. Horses were subsequently killed, the stifle joints dissected and the location of the dye recorded. Twenty-three horses (46 joints) had clinically normal stifle joints and in this group, anatomical communications of the stifle joints were bilaterally symmetrical in each horse. In 15 of these 23 horses (65 per cent), direct anatomical communi...
Hontoir F, Rejas E, Falticeanu A, Nisolle JF, Simon V, Nicaise C, Clegg PD, Vandeweerd JE.Diffusion of drugs injected into the distal interphalangeal joint or the navicular (podotrochlear) bursa can influence diagnosis and treatment of foot pain. Previous anatomical and radiographic studies of the communication between these synovial structures have produced conflicting results and did not identify the location of any communication if present. This anatomic study aimed to assess the presence and site of communication between the distal interphalangeal joint and the navicular bursa in the horse by computed tomography arthrography. Sixty-six pairs of cadaver forelimbs were injected w...
Marcatili M, Voss SJ, Pollock PJ.To describe a surgical technique for thyroidectomy in horses with thyroid neoplasia under standing sedation and local anesthesia. Methods: Retrospective study. Methods: Client-owned horses (n = 10). Methods: Medical records of horses with a history of thyroid enlargement were included in the study if thyroid gland enlargement was treated surgically via hemi- or bilateral thyroidectomy, with the horse standing and sedated. Data derived from follow-up clinical examination, performance level, recurrence, and cosmetic outcome were evaluated. Results: Thyroid enlargement was unilateral in 8 and...
Russell TM, Maclean AA.Repair of spiral and long diaphyseal metacarpal and metatarsal fractures under anaesthesia can be problematic and associated with a high incidence of complications, including fracture propagation necessitating euthanasia. Objective: To report on a practical repair technique for which general anaesthesia is not required. Methods: Thirteen racehorses with a spiral/propagating condylar fracture had the fracture repaired using local anaesthesia and sedation, without the need for general anaesthetic. Results: Ten of the horses returned to training and 8 raced again. Two horses were retired directly...
Harkins JD, Lehner A, Karpiesiuk W, Woods WE, Dirikolu L, Boyles J, Carter WG, Tobin T.Bupivacaine is a potent local anaesthetic used in equine medicine. It is also classified as a Class 2 foreign substance by the Association of Racing Commissioners International (ARCI). The identification of residues in postrace urine samples may cause regulators to impose significant penalties. Therefore, an analytical/pharmacological database was developed for this medication. The highest no-effect dose (HNED) for the local anaesthetic effect of bupivacaine was determined to be 0.25 mg by using an abaxial sesamoid local anaesthetic model. Administration of the HNED of bupivacaine to eight hor...
Yang VY, Eaton JS, Harmelink K, Hetzel SJ, Sanchez A, Lund JR, Smith LJ.Injection techniques for retrobulbar anaesthesia are published in horses, but neither safety nor anaesthetic efficacy and duration have been evaluated objectively in vivo. Objective: To characterise the safety and efficacy of one published technique for retrobulbar anaesthesia. Methods: Randomised, controlled descriptive experiment. Methods: Unilateral retrobulbar injection with 10 mL lidocaine (2%) was performed in eight sedated adult mares. Contralateral eyes served as untreated controls. Neurophthalmic parameters, intraocular pressure (IOP), and corneal and periocular sensation were measur...
Hahn CN, Mayhew IG.The precise appearance of ptosis due to lesions at different sites was investigated in experimental ponies. The angles of the eyelashes to the head was used as an objective measurement of ptosis after local anaesthesia of the sympathetic trunk or the palpebral nerve and the administration of an ocular alpha agonist or antagonist. It was shown that ptosis is not an inevitable consequence of palpebral nerve pathology, that ocular alpha antagonists can induce ptosis, and that alpha agonist eyedrops have an inconsistent effect on the equine pupil, but are consistent at reversing ptosis induced by ...
Harkins JD, Karpiesiuk W, Woods WE, Lehner A, Mundy GD, Rees WA, Dirikolu L, Bass S, Carter WG, Boyles J, Tobin T.Mepivacaine is a local anaesthetic drug that is widely used in equine medicine and is classified by the Association of Racing Commissioners International (ARCI) as a Class 2 foreign substance that may cause regulators to impose significant penalties if residues are identified in post-race urine samples. Therefore, an analytical/pharmacological database was developed for this agent and its metabolites. Using an abaxial sesamoid local anaesthetic model, it was determined that the highest no-effect dose (HNED) for its local anaesthetic effect was 2 mg. Using enzyme-linked immunosorbent assay (ELI...
Higgins AJ, Lees P, Sedgwick AD.An equine model of acute non-immune inflammation has been developed to facilitate studies of the inflammatory process and the actions of novel anti-inflammatory drugs. Five polyester sponge strips soaked in sterile 2% carrageenin solution were placed in subcutaneous pouches prepared under local anaesthesia in the necks of conscious ponies. Serial removal of the strips and harvesting of the exudate enabled studies to be made of the cellular, biochemical and mediator aspects of the localised, acute inflammation, and the heat generated by the lesion was monitored by infra-red thermometry. Maximal...
