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.
Kamerling SG.The recognition and alleviation of animal pain is a growing veterinary and public concern. Pain can be of an acute or chronic nature with different behavioral manifestations. Physiologically, pain is a dynamic and complex phenomenon that produces changes in the central and autonomic nervous systems as well as in the endocrine system. Horses and other animals appear to possess an endogenous pain-suppressing system involving the brainstem and spinal cord. This system can modulate pain perception and the responses to it. The recently discovered endogenous opioid peptides (endorphins and enkephali...
Wright IM.The clinical features are reported from 118 horses (mean age 9.2 years) which were diagnosed as suffering from navicular disease using predetermined criteria. The animals were used for a variety of purposes and had been lame for periods between 1 and 72 months. The majority of cases (84.7%) had been treated using various techniques before evaluation. The severity of lameness was related to the duration of clinical signs: 78% of horses were bilaterally affected but there was no left:right limb predominance. Broken foot/pastern axes were recorded in 75% of horses while 45% also exhibited mediola...
Dyson SJ, Romero JM.A positive radiographic contrast agent was injected into the tarsometatarsal (TMT) joints of both hindlimbs of 10 horses. Lateromedial radiographic views were obtained at 5, 15 and 30 mins after injection. Injection was successful in 19 of 20 limbs. Communication between the centrodistal (CD) and TMT joints was identified in 7 limbs (35%). Contrast agent extended around the tendons of tibialis cranialis (TC) and fibularis tertius (FT) in 18 limbs, and in 7 limbs some contrast entered the tarsal sheath. Slight to moderate plantar and/or distal extension of contrast agent was identified in 13 li...
Lapointe JM, Laverty S, Lavoie JP.Case histories, results of synovial fluid analyses, treatment regimens and outcome are described for 15 adult Standardbred horses with confirmed post-injection septic arthritis. Joint sepsis followed injection of corticosteroids, hyaluronic acid, polysulphated glycosaminoglycan, or local anaesthetic. The median interval from injection to appearance of clinical signs was 2.5 days, and median interval from injection to referral was 9 days. The median initial synovial leucocyte count on admission was 57 x 10(9)/litre, but there was a wide range of values (18-258 x 10(9)/litre). The median synovia...
Day TK, Skarda RT.Understanding of the pharmacology of local anesthesia is important for selection of a local anesthetic for use in equine standing surgery. In general, the action potential is inhibited by local anesthetics by preventing the influx of sodium ions across the axonal membrane. The physicochemical properties of each local anesthetic determine the onset of action, potency, and duration of action. Procaine, chlorprocaine, lidocaine, and mepivacaine are the local anesthetics still used clinically in horses; lidocaine is the most widely used. The future of equine local anesthesia may see the introducti...
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...
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...
Baxter GM, Moore JN, Budsberg SC.An open radial fracture in an adult horse (450 kg) was repaired by internal fixation, using two 18-hole 4.5-mm broad dynamic compression plates and 5.5- and 4.5-mm bone screws. The fracture healed completely, but when evaluated 9 months after surgery, the horse was lame on the fractured limb at a trot. Local infiltration of anesthesia along the distal half of the bone plates greatly ameliorated the lameness, suggesting that the plates were irritating the soft tissues and extensor tendons along the cranial and lateral aspects of the antebrachium. Both bone plates were removed simultaneously wit...
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...
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...
Schmotzer WB, Timm KI.Successful diagnostic local anesthesia is dependent upon a thorough knowledge of appendicular anatomy, application of correct technique, and accurate interpretation. Use of cadaver specimens to review anatomy and practice needle placement is strongly recommended. A marker solution, such as new methylene blue, can be injected into cadaver limbs, which can be subsequently dissected to verify accuracy. Detailed interpretation of local anesthetic blocks in the lame horse reaches beyond the scope of this article. Interpretive difficulties, however, can be responsible for the failure of a block to p...
Gaughan EM, Wallace RJ, Kallfelz FA.The effects of two local anesthetic agents on the diagnostic quality of nuclear medical bone images (NMBIs) of distal parts of the equine fore limb were investigated. Local effects on bone uptake of technetium 99m methylene diphosphonate (99mTc-MDP) 4 and 24 hours after perineural and intraarticular injection of mepivacaine hydrochloride and bupivacaine hydrochloride were evaluated in the carpal and metacarpophalangeal regions of 12 horses and ponies. Neither mepivacaine hydrochloride nor bupivacaine hydrochloride significantly altered the diagnostic quality of the NMBIs. The injection and sub...
White KK, Hodgson DR, Hancock D, Parry BW, Cordell C.The effects of repeated arthrocentesis and injection of local anesthetic agents, lidocaine HCl or mepivacaine HCl on the equine middle carpal joint were investigated. Synovial fluid samples were evaluated before, and 12, 24 and 48 hours following, treatment. The greatest changes from pretreatment values occurred in synovial fluid cellularity. Repeated arthrocentesis caused a moderate increase in cell counts, while injection of local anesthetics caused a greater increase. Alterations in mucin clot quality, hyaluronic acid content, fluid viscosity, total protein and immunoglobulin G were general...
LeBlanc PH, Caron JP, Patterson JS, Brown M, Matta MA.Local anesthetics given in the epidural space of a horse may cause hind limb weakness in addition to analgesia. Because alpha 2 agonists given by epidural injection cause sensory blockade without motor effects in human beings and other species, their use in veterinary anesthesia is appealing. This study was designed to examine the effectiveness of xylazine HCl, an alpha 2 agonist commonly used in horses. Xylazine, 0.9% NaCl, and lidocaine were given by epidural injection to horses subjected to perineal electrical stimulation. Administration of xylazine (0.17 mg/kg of body weight, diluted to a ...
Dyson S.The carpus and metacarpus of 40 horses which were free from lameness and 40 horses with lameness associated with the metacarpophalangeal joint or more distal limb were examined radiographically (Group A). The opacity of the proximal third of the third metacarpal bone was regular, with a uniform trabecular pattern. Osseous cyst-like lesions (OCLLs) were identified in the radial carpal bone (1), the ulnar carpal bone (2), the second carpal bone (15) and the fourth carpal bone (1). Thirty-one of 638 horses (4.8 percent) with forelimb lameness had pain localised to the proximal metacarpal region u...
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...
Dyson S.Methods of investigating horses with suspected shoulder lameness are described and discussed. The gait of shoulder lameness is characterised and compared with that of lower forelimb lameness. If lameness is slight, differentiation may be difficult, but if moderate, upper forelimb lameness usually results in shortening of the cranial phase of the stride and a low limb flight. Clinically, it may not be possible to differentiate between shoulder and elbow lameness without intra-articular anaesthesia. Practical aspects of intra-articular anaesthesia of the shoulder joint are reviewed. Synovial flu...
Tate LP, Newman HC, Cullen JM, Sweeney C.Laryngeal surgery in the equine is customarily and routinely performed by means of a ventral laryngotomy incision. Such procedures are usually performed under deep general anesthesia with the horse in dorsal recumbency. The objective of this work was to determine the efficacy of an endoscopic approach coupled to a Nd:YAG laser fiber in performing arytenoidectomy. Arytenoidectomy is commonly indicated in the treatment of arytenoid chondritis and in the failure of prosthetic implantation for left laryngeal hemiplegia. This preliminary study was undertaken to determine the feasibility of the endo...
Schumacher J, Bratton GR, Williams JW.The pudendal and caudal rectal nerves in four male and five female adult crossbred horses were anesthetized with a local solution. The injection site was located at the foramen for the caudal gluteal artery and vein in the sacrosciatic ligament. Twenty milliliters of local anesthetic solution were injected via a 15-cm, 18-gauge needle. Quantitative data on anesthesia were determined from these injections. Dye was injected with the anesthetic in four additional horses so that accurate placement of the solution could be determined at postmortem examination. Satisfactory anesthesia of the anus, p...
Skarda RT, Muir WW, Ibrahim AI.The CSF concentrations of mepivacaine in 10 Standardbred horses and of procaine in 10 Holstein cows given the drugs by thoracolumbar subarachnoid injection were determined. Mepivacaine hydrochloride was injected into the horses (502 +/- 60.5 kg) at an average dosage of 30 mg (1.5 ml of 20 mg/ml solution). Analgesia was produced 7.5 +/- 4.3 minutes after injection, extended between spinal cord segments T13 and L3 on both sides of the spinal column, and lasted 47 +/- 18.7 minutes at the T18 dermatome. Procaine hydrochloride was injected into cows (614 +/- 51.5 kg) at a dosage ranging between 75 ...
Kamerling SG, Dequick DJ, Weckman TJ, Sprinkle FP, Tobin T.The effects of procaine, mepivacaine and phenylbutazone on pain perception in the equine were studied using two behavioral assays of nociception; the thermal evoked hoof withdrawal reflex and skin twitch reflex. Pain perception threshold was measured as the latency from onset of thermal stimuli to reflex withdrawal of the forelimb or contraction of the cutaneous musculature. Procaine 2% and mepivacaine 2% prolonged the hoof withdrawal reflex latency when administered locally by producing a block of the palmar and metacarpal nerves. Significant analgesia lasted 90 min and 210 min for procaine a...
Moss M S..A review of positive Jockey Club "dope tests" during the 12 years from 1970 to 1981 inclusive is presented and a comparison made with certain overseas racing authorities for varying periods between 1975 and 1981. Urinary pH of post race urine samples is predominantly acidic (although varying in a significant manner throughout the year) and thus favours excretion of the generally more potent basic drugs. The proportion of positive results was about the same in winners and non-winners, ie, one in 400 horses sampled. Drugs found fell mainly into four categories: methylxanthines; non-steroidal ant...
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...
Raphel CF, Gunson DE.Percutaneous lung biopsies with a cutting needle (Vim Tru Cut) were obtained from 20 horses. The procedure was performed in standing horses under a local anesthesia without sedation. All lung tissue specimens were suitable for histologic examinations and contained both pulmonary parenchyma and large airways. The only complication was hemoptysis in 2 (10%) horses which required no therapy. All horses were subsequently killed, and no gross abnormalities were present at the biopsy site.
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...
Gabel AA.A prospective study of the diagnostic results on 25 previously untreated, slightly lame Standardbred horses showed that manipulative tests are of some help in diagnosis. The lameness of each horse was diminished or the horse went lame on the opposite limb after being given an injection of anesthetic in the cunean bursa, and lameness improved more when local anesthetic was injected in the distal intertarsal and tarsometatarsal articulations. In four horses, lesions of the distal articulation of the hock were evident on radiography.
Harkins JD, Karpiesiuk W, Tobin T, Dirikolu L, Lehner AF.Ropivacaine is a local anesthetic that has a high potential for abuse in racing horses. It can be recovered from urine collected after administration as a hydroxylated metabolite following beta-glucuronidase treatment of the urine. Based on these findings, it has been inferred that ropivacaine is present in equine urine as a glucuronide metabolite; however, these metabolites have never been directly identified. Using ESI+/MS/MS, the presence of a [M+H]+ molecular ion of m/z 467 was demonstrated in urine corresponding to the calculated mass of a hydroxyropivacaine glucuronide +1. The abundance ...
Knych HK, Mama KR, Moore CE, Hill AE, McKEMIE DS.The use of intra-articular (IA) local anaesthetics has proven to be an effective means to treat post-operative pain. The effects of local anaesthetics on equine chondrocytes are mixed with some studies reporting chondrodestruction and others no adverse effects. A liposomal formulation of bupivacaine is used in people and dogs by intra- and peri-articular administration to provide up to 72 h of analgesia. The potential uses, side effects including chondrotoxicity, and likelihood of abuse (long-term analgesic effects) has not been evaluated in horses. Objective: Describe bupivacaine concentrati...
Cota LO, Malacarne BD, Dias LA, Neto ACP, Kneipp MLA, Cavalcante MA, Cunha MSLD, Paz CFR, Carvalho AM, Faleiros RR, Xavier ABDS.The analgesic specificity of navicular bursa (NB) anesthetic infiltration is still questionable. The study aimed to determine the mechanical nociceptive threshold of non-specific analgesia in the dorsal lamellar stratum, as well as in the sole, coronary band, and heel bulbs of the hoof, after navicular bursa anesthetic infiltration. Six healthy horses with no clinical or radiographic changes of the digits and no communication between the NB and the distal interphalangeal joint, were used. After random selection, the NB of one of the forelimbs was infiltrated with 2% lidocaine and the contralat...
Schumacher J, Taintor J, Schumacher J, Degraves F, Schramme M, Wilhite R.The role of the communicating branch between the medial and lateral palmar nerves of horses (i.e. the ramus communicans) in conveying sensory impulses proximally should be determined to avoid errors in interpreting diagnostic anaesthesia of the palmar nerves. Objective: Sensory nerve fibres in the ramus communicans of horses pass proximally from the lateral palmar nerve to merge with the medial palmar nerve, but not vice versa. Objective: To determine the direction of sensory impulses through the ramus communicans between lateral and medial palmar nerves. Methods: Pain in a thoracic foot was c...
Anderson BH, Ethell MT.A number of methods for the local delivery of drugs to musculoskeletal tissues in the horse are now available. Further research is required to document the disposition of drugs delivered by such methods and to correlate this information with efficacy. Perhaps the greatest potential area for the methods discussed is the treatment of synovial and bone infections. To be able to provide high and sustained therapeutic concentrations of antimicrobials to the site of infection should increase the chances of success in such cases. These methods of drug delivery need to be used in conjunction with othe...
Baxter GM, Moore JN, Budsberg SC.An open radial fracture in an adult horse (450 kg) was repaired by internal fixation, using two 18-hole 4.5-mm broad dynamic compression plates and 5.5- and 4.5-mm bone screws. The fracture healed completely, but when evaluated 9 months after surgery, the horse was lame on the fractured limb at a trot. Local infiltration of anesthesia along the distal half of the bone plates greatly ameliorated the lameness, suggesting that the plates were irritating the soft tissues and extensor tendons along the cranial and lateral aspects of the antebrachium. Both bone plates were removed simultaneously wit...
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...
McGlinchey L, Agne G, Passler T, Cole R, Schumacher J.The median nerve, along with the ulnar nerve, is often anesthetized when performing a lameness examination in horses. Because of the close proximity of the median nerve to the cubital joint, proximal migration of local anesthetic might ameliorate pain originating from the cubital joint. The objective of this study was to determine if a median nerve block will ameliorate lameness caused by pain in the cubital joint. A forelimb lameness was induced in six healthy horses by injecting 100 ng of recombinant equine interleukin 1 beta (IL-1β) into the cubital joint. The median nerve of the lame leg...
Adler DMT, Jørgensen E, Cornett C.To determine the synovial fluid (SF) concentrations of lidocaine and mepivacaine after intra-articular injection with clinically relevant doses to the distal interphalangeal (DIP), metacarpophalangeal (MCP), middle carpal (MC), and tarsocrural (TC) joint at two different time points after injection in order to be able to compare concentrations with previously established concentrations associated with cytotoxicity and antimicrobial activity. Unassigned: In the first of two experiments, 20 joints (5 MC, 5 MCP, 10 DIP joints) of five horses under general anesthesia were injected with clinically ...
Keegan KG, Wilson DJ, Wilson DA, Frankeny RL, Loch WE, Smith B.To determine the effect of local anesthesia of the palmar digital nerves on forelimb kinematics in Quarter Horses with and without navicular disease. Methods: 12 adult Quarter Horses; 5 clinically normal (sound) and 7 with navicular disease. Methods: Kinematic measurements were made on adult horses trotting on a treadmill, before and after palmar digital nerve block (PDNB). Twenty-three displacement, joint angle, and temporal gait measurements of the right forelimb and head were made for 5 strides in each horse. Initial (before local anesthesia) right forelimb measurements were obtained after ...
Dyson S.The carpus and metacarpus of 40 horses which were free from lameness and 40 horses with lameness associated with the metacarpophalangeal joint or more distal limb were examined radiographically (Group A). The opacity of the proximal third of the third metacarpal bone was regular, with a uniform trabecular pattern. Osseous cyst-like lesions (OCLLs) were identified in the radial carpal bone (1), the ulnar carpal bone (2), the second carpal bone (15) and the fourth carpal bone (1). Thirty-one of 638 horses (4.8 percent) with forelimb lameness had pain localised to the proximal metacarpal region u...
Schumacher J, Bratton GR, Williams JW.The pudendal and caudal rectal nerves in four male and five female adult crossbred horses were anesthetized with a local solution. The injection site was located at the foramen for the caudal gluteal artery and vein in the sacrosciatic ligament. Twenty milliliters of local anesthetic solution were injected via a 15-cm, 18-gauge needle. Quantitative data on anesthesia were determined from these injections. Dye was injected with the anesthetic in four additional horses so that accurate placement of the solution could be determined at postmortem examination. Satisfactory anesthesia of the anus, p...
Modesto RB, Rodgerson DH, Masciarelli AE, Spirito M.This retrospective study describes placement of distal radial transphyseal screws in Thoroughbred yearlings with carpal varus deformities while standing, and identifes short- and long-term complications following the procedure. Data gathered from 2009 to 2013 identified 8 yearlings that met the inclusion criteria. Horses were sedated intravenously and a single 4.5-mm cortical screw was placed in the distal lateral radial physis following application of local anesthetic and surgical preparation of a pre-placed hole. All horses were evaluated weekly after surgery and screw removal was performed ...
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...
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...
Gonzalez GA, Betbeze C, Wills R, Eddy A, Mochal-King C, Fontenot RL.To evaluate corneal sensitivity and adverse events following subconjunctival administration of three local anesthetics in horses. Methods: Randomized, masked, crossover study. Methods: Twelve healthy adult mares. Methods: The subconjunctival space of the treated eye was injected with 0.2 mL of liposomal bupivacaine (1.3%), ropivacaine (0.5%), or mepivacaine (2%). All horses received each medication once and the contralateral eye received saline (control). Corneal touch threshold (CTT) was measured using a Cochet-Bonnet esthesiometer before sedation, after sedation, and at specified intervals...
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...
McClure SR, Taylor TS, Honnas CM, Schumacher J, Chaffin MK, Hoffman AG.Permanent tracheal stomas were created in seven sedated, standing horses with severe upper airway obstruction. After local anesthesia, a 3-cm by 6-cm rectangle of skin was removed from the ventral surface of the neck, 3 cm distal to the cricoid cartilage. The sternothyrohyoideus muscles were clamped proximally and distally, then transected to expose the tracheal rings. The ventral third of four tracheal rings was dissected from the tracheal mucosa that was then incised in a double "Y." Two layers of suture were used to achieve mucocutaneous closure. Stomas healed without serious complications;...
Tate LP, Newman HC, Cullen JM, Sweeney C.Laryngeal surgery in the equine is customarily and routinely performed by means of a ventral laryngotomy incision. Such procedures are usually performed under deep general anesthesia with the horse in dorsal recumbency. The objective of this work was to determine the efficacy of an endoscopic approach coupled to a Nd:YAG laser fiber in performing arytenoidectomy. Arytenoidectomy is commonly indicated in the treatment of arytenoid chondritis and in the failure of prosthetic implantation for left laryngeal hemiplegia. This preliminary study was undertaken to determine the feasibility of the endo...
Malton R, Nagy A.Diffusion of local anaesthetic solution after a mid-pastern ring block has not been investigated. Objective: To demonstrate potential distribution of local anaesthetic solution following injection of radiodense contrast medium as performed for a mid-pastern ring block. Methods: Experimental. Methods: Twelve mature horses were used. One and a half ml radiodense contrast medium was injected over the medial or lateral palmar digital nerve at the level of the proximal aspect of the ungular cartilages. A dorsal ring block was performed on the ipsilateral side, 1.5 cm proximal to the palpable palm...
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...
Désévaux C, Laverty S, Doizé B.To develop a technique for sternal bone biopsy in standing horses. Methods: Experimental study. Methods: Five adult horses. Methods: Horses were restrained in a standing stocks and sedated. The sternal biopsy site, identified by ultrasonographic examination, was clipped and prepared for aseptic surgery and infiltrated with local anesthetic. An electric bone biopsy drill (Osteocore; Institut Straumann AG, CH-4437, Waldenburg, Switzerland)), which yielded 4-mm-diameter bone specimens, was used to obtain sternal biopsies through a small skin incision. Sections (7 microm) of the bone specimens wer...
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...
Dyson S.Proximal suspensory desmitis of the hindlimb was diagnosed using local analgesic techniques and ultrasonography in 42 horses. Subtarsal analgesia resulted in substantial improvement in lameness in 36 of 41 horses in which local analgesic techniques were used. In the remaining five horses lameness was improved by perineural analgesia of the tibial nerve (three) or the tibial and fibular nerves. Intra-articular analgesia of the tarso-metatarsal joint produced a similar degree of improvement in two of 24 horses in which lameness had been improved by subtarsal analgesia. Ultrasonographic abnormali...
Nagy A, Bodo G, Dyson SJ, Szabo F, Barr AR.Proximal diffusion of local anaesthetic solution after perineural anaesthesia may lead to the desensitisation of structures other than those intended. However, there is no evidence-based study demonstrating the potential distribution and diffusion of local anaesthetic solution after perineural analgesia in the distal limb. Objective: To document the potential diffusion of local anaesthetic solution using a radiopaque contrast model and to evaluate the influence of walking compared with confinement in a stable after injection. Methods: Radiopaque contrast medium was injected subcutaneously over...
de Linde Henriksen M, Brooks DE.Standing ophthalmic surgery without general anesthesia allows for several routine ophthalmic procedures including eyelid lacerations and enucleations to be performed in the horse, but does contain increased risk of causing tissue damage arising from the inability to eliminate eye and head movements. Heavy sedation and local nerve blocks of the involved motor and sensory nerves are essential in achieving a good outcome from ophthalmic surgery in the nonanesthetized horse. The inability to use an operating microscope in standing surgery in horses prevents performing precise corneal and intraocul...
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...
Harkins JD, Tobin T.Fentanyl and other opioid drugs have their effect in the central nervous system; however, activity at peripheral sites has also been demonstrated. Pain-suppression activity at peripheral sites raises the possibility of skilled individuals producing local anaesthetic effects with small doses of opioid drugs that would be difficult to detect forensically and could be used to affect the outcome of a race. Therefore, the local pain-suppression effect (peripheral nerve inhibition) of fentanyl was tested using an abaxial sesamoid block/hoof withdrawal model. With this model, fentanyl did not produce...
Davis EW.The purpose of this study was to determine the feasibility of using laparoscopy to remove cryptorchid testes from standing horses. Methods: Prospective clinical study. Methods: Eleven client-owned horses ranging in age from 4 months to 2 years. Methods: Abdominal insufflation was initiated and maintained using a 20 F insufflation tube, attached via a stopcock, to the low pressure regulator on a standard carbon dioxide pressure tank. After trocar and laparoscope placement in the ipsilateral flank the testes were identified. Local anesthesia of the structures to be manipulated was administered t...
Lean NE, Sole-Guitart A, Ahern BJ.To investigate the feasibility and describe the clinical experience of performing laryngeal tie-forward (LTF) in standing horses unaffected (experimental) and affected (clinical) by intermittent dorsal displacement of the soft palate (iDDSP). Methods: Experimental study and case series. Methods: Five normal experimental controls and five client owned horses affected by iDDSP. Methods: Standing LTF was performed and evaluated in five experimental horses and five clinical cases diagnosed with iDDSP. Standing LTF was performed under endoscopic guidance with horses sedated and the surgical site de...
