Topic:Analgesia
Analgesia in horses involves the use of medications and techniques to alleviate pain caused by injury, surgery, or chronic conditions. Effective pain management is important for the welfare and recovery of equine patients, as unmanaged pain can lead to complications and prolonged healing. Common analgesic agents used in horses include non-steroidal anti-inflammatory drugs (NSAIDs), opioids, and local anesthetics. These agents work through various mechanisms to reduce pain perception and improve comfort. This page compiles peer-reviewed research studies and scholarly articles that explore the pharmacology, application, and clinical outcomes of analgesic strategies in equine medicine.
Standing Sedation and Iocoregional Analgesia in Equine Dental Surgery. Procedural sedation has become popular for describing a semiconscious state that allows patients to be comfortable during certain surgical or diagnostic procedures. Sedation may be enhanced by locoregional anesthetic techniques to produce sufficient analgesia and muscle relaxation for surgery to occur. Sedation and local anesthesia for standing diagnostic and surgical procedures on the horse's head circumvents the potential complications of general anesthesia (particularly, complications related to recovery). However, the implementation of a locoregional anesthetic technique requires a thoroug...
Upper body movement analysis of multiple limb asymmetry in 367 clinically lame horses. Compensatory lameness is common in horses and evaluation can be challenging. Objective: To investigate patterns of compensatory movements in clinical cases with fore- or hindlimb lameness before and after diagnostic analgesia. Methods: Retrospective clinical study. Methods: Multiple limb lameness of 367 horses was characterised by type (push-off, impact or mixed), limb (fore- or hindlimb in predominant lameness) and side (ipsi- or contralateral in concurrent lameness) using a body-mounted inertial sensor (BMIS). Diagnostic analgesia was performed until the percentage improvement of the vector ...
Meperidine pharmacokinetics and effects on physiologic parameters and thermal threshold following intravenous administration of three doses to horses. Meperidine is a synthetic opioid that belongs to the phenylpiperidine class and is a weak mu receptor agonist. In horses there are a limited number of published studies describing the analgesic effects of systemically administered meperidine in horses. The objective of this study was to describe the pharmacokinetics, behavioral and physiologic effects and effect on thermal threshold of three doses of intravenously administered meperidine to horses. Eight University owned horses (four mares and four geldings, aged 3-8 years were studied using a randomized balanced 4-way cross-over design. Hors...
Epidural administration of opioid analgesics improves quality of recovery in horses anaesthetised for treatment of hindlimb synovial sepsis. Opioid epidural analgesia has been shown to provide effective analgesia in horses. There is a lack of evidence regarding the effect of opioid epidural analgesia on quality of recovery in horses. Objective: Identify whether opioid epidural analgesia influences quality of recovery in horses undergoing general anaesthesia required for management of hindlimb synovial sepsis. Methods: Single-centre retrospective cross-sectional study. Methods: Data were obtained from the clinical records of horses which had undergone arthroscopic or tenoscopic surgery for management of hindlimb synovial sepsis over...
Objective Assessment of Acute Pain in Foals Using a Facial Expression-Based Pain Scale. Pain assessment is very important for monitoring welfare and quality of life in horses. To date, no studies have described pain scales for objective assessment of pain in foals. Studies in other species have shown that facial expression can be used in neonatal animals for objective assessment of acute pain. The aim of the current study was to adapt a facial expression-based pain scale for assessment of acute pain in mature horses for valid pain assessment in foals. The scale was applied to fifty-nine foals (20 patients and 39 healthy controls); animals were assessed from video recordings (30-6...
Selection of Potent Inhibitors of Soluble Epoxide Hydrolase for Usage in Veterinary Medicine. The veterinary pharmacopeia available to treat pain and inflammation is limited in number, target of action and efficacy. Inhibitors of soluble epoxide hydrolase (sEH) are a new class of anti-inflammatory, pro-resolving and analgesic drugs being tested in humans that have demonstrated efficacy in laboratory animals. They block the hydrolysis, and thus, increase endogenous concentrations of analgesic and anti-inflammatory signaling molecules called epoxy-fatty acids. Here, we screened a library of 2,300 inhibitors of the sEH human against partially purified feline, canine and equine hepatic sEH...
Mechanical nociceptive assessment of the equine hoof following distal interphalangeal joint intra-articular anesthesia. With the hypothesis that equine dorsal lamellar tissue can be desensitized by anesthesia injection into distal interphalangeal joint (DIPJ), the objective was to assess the mechanical nociceptive threshold of hoof dorsal lamellae following intra-articular (IA) administration of lidocaine into this joint. Methods: The DIPJ of the forelimbs of six adult healthy horses were injected with either 5 mL of lidocaine, or 5 mL of lactated Ringer's solution. Treatments were randomly distributed, with each forelimb undergoing a single treatment. The hooves were evaluated pre- and post-injection at pre-se...
Post-operative pain behaviour associated with surgical castration in donkeys (Equus asinus). Recognising pain in donkeys is challenging because they are stoic. Objective: To identify the responses of donkeys before and after surgical pain. Methods: Prospective, short-term longitudinal pre- and post-intervention observations. Methods: Forty adult donkeys underwent surgical castration after sedation with intravenous (IV) xylazine, induction with guaiphenesin/thiopental IV and maintenance of anaesthesia with isoflurane and local anaesthetic blockade. Four hours after recovery from anaesthesia, flunixin meglumine 1.1 mg/kg, dipyrone 10 mg/kg and morphine 0.2 mg/kg IV were administered....
Comparison of analgesic and tissue effects of subcutaneous perineural injection of liposomal bupivacaine and bupivacaine hydrochloride in horses with forelimb lameness induced via circumferential clamp. To evaluate the analgesic and tissue effects of liposomal bupivacaine administered SC as an abaxial sesamoid nerve block in horses with experimentally induced lameness. Methods: 6 healthy mature light-breed horses. Methods: In a randomized crossover study, a circumferential hoof clamp was applied to a forelimb to induce reversible lameness. An abaxial sesamoid nerve block of the lame forelimb was performed by SC perineural injection of 10 mg of liposomal bupivacaine or bupivacaine HCl/site. Quantitative gait data were objectively obtained with a body-mounted inertial sensor system before (base...
Effectiveness of a paraverterbral nerve block versus local portal blocks for laparoscopic closure of the nephrosplenic space: A pilot study. To compare the effectiveness of a paravertebral nerve block vs local portal blocks for laparoscopic closure of the nephrosplenic space in standing sedated research horses. Methods: Randomized clinical trial. Methods: Twelve horses were randomly allocated to two groups (n = 6 per group), paravertebral block of nerves T , L , and L or local blocks of the three laparoscopic portals. Methods: Horses were sedated with dexmedetomidine (4 μg/kg IV and constant rate infusion [CRI] of 2.5 μg/kg/h) and morphine (50 μg/kg IV and CRI of 30 μg/kg/h). According to group allocation, 20 mL of either lid...
Comparison of lameness outcomes in horses with acute or chronic digital lameness that underwent magnetic resonance imaging. Aims: To compare the outcome, in terms of lameness score or return to athletic function, of horses with acute vs. chronic digital lameness that underwent magnetic resonance imaging (MRI) of the distal limb and to compare the proportion of horses that received intra-articular therapy of the distal interphalangeal (DIP) joint and pattern of diagnostic analgesia in these groups. Methods: This is a retrospective study of horses (n = 95) with acute (≤12 weeks; n = 46) or chronic (>12 weeks; n = 49) digital lameness that underwent MRI of the distal limb from 2009-2016, at two equine re...
Antinociceptive Effect of Intravenous Regional Analgesia in Horses Underwent Selected Short-Time Distal Limb Surgeries. The aim of the present study was to establish appropriate doses for both lidocaine hydrochloride (Hcl) and mepivacaine in intravenous regional analgesia (IVRA) and to assess their intraoperative and postoperative analgesic effects in horses with distal limb surgeries. A total of 55 draft horses were included in the present study. Six clinically healthy horses were selected randomly for establishing the doses of lidocaine Hcl and mepivacaine in IVRA in horse limbs. After selection, 32 horses suffered from various distal limb surgical affections were randomly allocated into three groups: thiopen...
Comparison of speed of onset and analgesic effect of 2% mepivacaine hydrochloride deposited within or outside the neurovascular bundle at the level of the proximal sesamoid bones in horses with naturally occurring forefoot-related lameness. To compare the speed of onset and analgesic effect of mepivacaine deposited within or immediately outside the neurovascular bundle at the base of the proximal sesamoid bones in horses. Methods: 6 horses with naturally occurring forefoot-related lameness. Methods: In a crossover study design, horses were randomly assigned to receive 1 of 2 treatments first, with the second treatment administered 3 to 7 days later. Trotting gait was analyzed with an inertial sensor-based motion analysis system immediately before treatment to determine degree of lameness. Afterward, ultrasound guidance was used t...
Dexmedetomidine and Bupivacaine Association in Caudal Epidural Injection in Mares. The objective of the study was to compare the effects of caudal epidural bupivacaine and dexmedetomidine (DEX) combination, with bupivacaine or DEX plain for perineal analgesia in mares. Six healthy saddle mares weighing 330-370 kg and aged 10-15 years were used in this study. Each mare was assigned to receive three treatments: 0.04 mg/kg 0.25% bupivacaine (BP), 2 μg/kg DEX (DX), or 0.02 mg/kg bupivacaine and 1 μg/kg DEX (BPDX). The order of treatments was randomized. All drugs were injected into the caudal epidural space (Co1-Co2) through a 16-G Tuohy epidural needle. After the epidur...
Diffusion of Radiodense Contrast Medium Following Perineural Injection of the Deep Branch of the Lateral Plantar Nerve Using Two Different Techniques in Horses: an In Vivo Study. This article evaluates and compares the diffusion pattern of radiopaque contrast medium following perineural analgesia of the deep branch of the lateral plantar nerve performed using two different techniques: weight-bearing or flexed. Methods: This was an experimental study. Methods: Eight horses were enrolled. Perineural injection of the right and left deep branch lateral plantar nerves was performed with a weight-bearing or flexed technique, using radiopaque contrast medium (iohexol). Radiographic evaluation was performed after 5 (T5), 15 (T15) and 30 (T30) minutes. The diffusion o...
Ultrasound-Guided Transversus Abdominis Plane Block in Shetland Ponies: A Description of a Three-Point Injection Technique and Evaluation of Potential Analgesic Effects. Colic surgery is one of the most painful procedures carried out in horses. Common strategies to alleviate immediate postsurgical abdominal pain include the administration of potent systemic analgesics; however, these may cause unwanted adverse effects such as cardiovascular depression, ileus, and ataxia. The administration of local anesthetics at the incision site in form of an ultrasound-guided subcostal transversus abdominis plane (TAP) block may therefore be preferred to provide adequate analgesia without significant side effects. To date, no technique for a TAP block in horses undergoing m...
Ultrasonography-Guided Perineural Injection of the Ramus ventralis of the 7 and 8th Cervical Nerves in Horses: A Cadaveric Descriptive Pilot Study. To describe the feasibility and dye diffusion of selective perineural injection of the 7 and 8th cervical nerve (C7 and C8) under ultrasonographic guidance in horses. Prospective experimental pilot cadaver study. Four equine cadavers of similar body weight (420-480 kg) and neck conformation. Five C7 and five C8 were perineurally injected with a dye solution. Anatomic dissections including vertebral canal opening were conducted to confirm nerve dye staining and describe the extent of color diffusion. The of the spinal cervical nerves was visualized in all cadavers. All the injections we...
Systemic and local effects of lidocaine or mepivacaine when used for intravenous regional anaesthesia of the distal limb in standing sedated horses. 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...
Effects of acepromazine and xylazine on subjective and objective assessments of forelimb lameness. To facilitate lameness evaluation, sedatives such as xylazine and acepromazine are regularly used in the clinical setting, despite concerns that they may confound lameness assessment. Objective: The objective of this study was to determine the effect of low doses of acepromazine and xylazine on subjective and objective lameness assessment. Methods: Randomised, blinded, crossover study. Methods: Six horses with experimentally induced solar pain were evaluated over a 1-hour period after treatment with intravenous xylazine (0.1 or 0.2 mg/kg), intravenous acepromazine (0.02 or 0.04 mg/kg), intra...
Plasma disposition of gabapentin after the intragastric administration of escalating doses to adult horses. In humans, gabapentin an analgesic, undergoes non-proportional pharmacokinetics which can alter efficacy. No information exists on the pharmacokinetics of dosages >20 mg/kg, escalating dosages or dose proportionality of gabapentin in horses. Objective: Gabapentin exposure in plasma would not increase proportionally relative to the dose in horses receiving dosages ≥20 mg/kg. To assess the plasma pharmacokinetics of gabapentin after nasogastric administration of gabapentin at dosages of 10 to 160 mg/kg in adult horses. Methods: Nine clinically healthy adult Arabian and Quarter Horses....
Long-term outcome and effect of diagnostic analgesia in horses undergoing interspinous ligament desmotomy for overriding dorsal spinous processes. To report the long-term outcome of horses treated with interspinous ligament desmotomy (ISLD) for pain associated with overriding dorsal spinous processes (ORDSP) and determine the influence of preoperative diagnostic analgesia on long-term outcome. Methods: Retrospective study. Methods: Eighteen horses. Methods: Data were collected from horses presenting for ISLD to the University of Pennsylvania New Bolton Center between January 2013 and May 2018. Follow-up of ≥3 months postsurgically was obtained from the owner, trainer, or referring veterinarian. Long-term improvement was compared betw...
Pharmacopuncture Analgesia Using Flunixin Meglumine Injection into the Acupoint GV1 (Ho Hai) After Elective Castration in Horses. The study evaluated the effect of a 1/10 dose of flunixin meglumine administered into the governing vessel 1 (GV1) acupoint in horses that underwent castration. Twenty animals received 0.02 mg/kg detomidine intravenously, followed by 2.2 mg/kg ketamine and 0.1 mg/kg diazepam by the same route, and also a local anesthesia with 30 mL lidocaine. As postoperative analgesia, the animals received 1.1 mg/kg flunixin meglumine IV (FIV) or 0.11 mg/kg flunixin meglumine into the GV1 acupoint (FGV). Behavioral parameters were assessed 12 hours before the procedure (baseline) and at 4, 6, 12, and 2...
Effect of 3% chloroprocaine hydrochloride when used for median and ulnar regional nerve blocks in lame horses. To assess onset of analgesia for 3% chloroprocaine hydrochloride and 2% mepivacaine hydrochloride when used for median and ulnar nerve blocks in lame horses. Methods: 6 naturally lame horses. Methods: A crossover experiment was conducted. Horses were assigned to 1 of 2 treatment groups (3% chloroprocaine or 2% mepivacaine first). Median and ulnar nerve blocks were performed in the lame limb with the assigned treatment. Lameness was objectively evaluated before treatment administration and at various points for 120 minutes after treatment with a wireless inertial sensor-based motion analysis sy...
Comparative Effect of Epidural Administration of Xylazine or Dexmedetomidine on Echocardiographic Dimensions and Cardiac Indices in Clinically Healthy Donkeys (Equus asinus). The aim of the present study was to assess and compare the changes of the echocardiographic dimensions and cardiac function indices after epidural injection of xylazine or dexmedetomidine in clinically healthy donkeys. In an experimental prospective randomized cross-over study, 10 healthy adult donkeys were injected with saline solution, xylazine (0.20 mg kg), and dexmedetomidine (0.005 mg kg) into the epidural space between the second and third coccygeal vertebrae. Echocardiographic dimensions as well as cardiac function indices were assessed using a 2-3.9 MHz sector transducer, at the l...
Efficacy of orally administered gabapentin in horses with chronic thoracic limb lameness. To evaluate the analgesic effects of orally administered gabapentin on horses with chronic thoracic limb lameness. Methods: Randomized, crossover design. Methods: A total of 14 adult horses with chronic thoracic limb lameness. Methods: Following baseline measurement of lameness, horses were administered each of four treatments orally in grain: treatment G, gabapentin (20 mg kg) twice daily for 13 doses; treatment F, firocoxib (171 mg once, then 57 mg once daily for six doses); treatment GF, gabapentin and firocoxib at previously stated doses and frequencies; or treatment C, grain only as a con...
BEVA primary care clinical guidelines: Analgesia. Primary care guidelines provide a reference point to guide clinicians based on a systematic review of the literature, contextualised by expert clinical opinion. These guidelines develop a modification of the GRADE framework for assessment of research evidence (vetGRADE) and applied this to a range of clinical scenarios regarding use of analgesic agents. Key guidelines produced by the panel included recommendations that horses undergoing routine castration should receive intratesticular local anaesthesia irrespective of methods adopted and that horses should receive NSAIDs prior to surgery (ove...
Thermal, mechanical and electrical stimuli in antinociceptive studies in standing horses: an update. To perform a literature review of the thermal and mechanical antinociceptive devices used in pharmacological studies in standing horses published after 2011 (2012-2019). To complete a full literature review about electrical stimulation used for evaluation in similar studies. Methods: PubMed, Google Scholar and Web of Science. Conclusions: A high level of standardization has been reached in antinociceptive studies in standing horses using thermal and mechanical stimuli in most recent years. Commercially available testing devices to deliver thermal, mechanical and electrical stimuli, with observ...
Pharmacokinetic-pharmacodynamic modelling of the antinociceptive effect of a romifidine infusion in standing horses. 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...
Synovial butorphanol concentrations and mechanical nociceptive thresholds after intravenous regional limb perfusion in standing sedated horses. 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...
Extracorporeal shockwave therapy raises mechanical nociceptive threshold in horses with thoracolumbar pain. Although extracorporeal shockwave therapy (ESWT) is a common treatment for horses with back pain, effects on mechanical nociceptive threshold (MNT) and multifidus muscle cross sectional area (CSA) in the spine are unknown. Objective: To evaluate effects of ESWT on spinal MNT and multifidus muscle CSA in horses with thoracolumbar pain. Methods: Non-randomised trial. Methods: Thoracolumbar spines of 12 horses with thoracolumbar pain were radiographed to document existing pathology. Each horse received three ESWT treatments, 2 weeks apart (days 0, 14, 28). Palpation scores were documented (days ...