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.
Effect of palmar digital perineural analgesia (as a model for “nerving”) on forelimb loading over varied surfaces at the walk and trot – a pilot study. Navicular syndrome is characterized by palmar foot pain and is a common cause of lameness in horses. Palmar digital neurectomy (nerving) removes sensation to the heel region of the hoof and may serve as a treatment for navicular-afflicted horses, while analgesia (blocking) results in temporary loss of sensation. Objective: The purpose of this pilot study was to examine the effect of loss of sensation in the heel on the forelimb area and force while tracking on soft and hard ground at the walk and trot. Methods: Three horses that scored a 0 or 1 on the AAEP lameness scale were fitted to Tekscan...
Pharmacopuncture with low-dose dexmedetomidine and saline aquapuncture at acupoint Governing Vessel 24 provides sedation in healthy adult horses. To evaluate sedation in horses following pharmacopuncture with dexmedetomidine at acupoint Governing Vessel 24 (GV-24) compared to aquapuncture at GV-24 or an equivalent dose of dexmedetomidine administered via IV or SC routes. Unassigned: 10 adult mares received 4 treatments in a blinded, randomized, crossover design: (1) dexmedetomidine administered at GV-24 (DexmedGV24; 1 μg/kg); (2) saline administered at GV-24 (SalineGV24; 1.5 mL); (3) dexmedetomidine administered SC on the lateral neck (DexmedSC; 1 μg/kg); or (4) dexmedetomidine administered IV (DexmedIV; 1 μg/kg). Sedation scores (fa...
Survey describing the perspectives and practices of Australian veterinarians to pain management in horses. To describe Australian practices and attitudes regarding equine analgesia. Methods: Cross-sectional anonymous, voluntary survey of Australian veterinarians treating equine patients. Methods: Australian veterinarians in equine or mixed practices completed a six-section, 60-question survey between November 2019 to August 2020. Information was gathered on demographics, analgesia prescription, pain assessment and attitudes surrounding specific analgesics. Respondents assigned a pain score ranging from 0 to 10 for various conditions; these were averaged to give each respondent an "average pain scor...
Effect of a Constant Rate Infusion of Ketamine on a Variable Rate Infusion of Xylazine in Standing Horses Undergoing Ventriculocordectomy and Laryngoplasty. Standing sedation in horses provides immobilization and analgesia for surgery while avoiding the high risks of general anesthesia. Ketamine at subanesthetic doses may enhance sedation and reduce xylazine requirements, but evidence in clinical settings is limited. In a randomized blinded trial, we evaluated whether adding a low-dose ketamine infusion could reduce the xylazine dose required for effective sedation during standing ventriculocordectomy and laryngoplasty. Fifty-one horses were randomly assigned to sedation with xylazine alone (SX group) or xylazine plus ketamine (KX group) in a cont...
Extracorporeal shock wave therapy for equine musculoskeletal disorders: from biological mechanisms to clinical applications. Musculoskeletal injuries represent a primary cause of suboptimal performance and early retirement in equine athletes. To address this challenge, the veterinary community has long endeavored to develop safer and more effective therapeutic strategies. Extracorporeal shock wave therapy (ESWT), as a treatment for equine musculoskeletal injuries, has garnered substantial attention among equine veterinarians. Focused on the theme ESWT Therapy for Equine Musculoskeletal Disorders: From biological mechanisms to clinical applications, this article systematically reviews existing literature on the biolo...
Correction: An anatomical study of the subarachnoid space surrounding the trigeminal ganglion in horses-in preparation for a controlled glycerol rhizotomy in equids. [This corrects the article DOI: 10.3389/fvets.2024.1424890.].
Dexmedetomidine Prolongs the Duration of Ropivacaine Corneal Anesthesia After Subconjunctival Injection in Healthy Horses. To determine whether dexmedetomidine prolongs corneal anesthesia following subconjunctival ropivacaine injection in healthy equine eyes. Methods: Ten horses with normal ophthalmic exams were enrolled in a randomized, blinded, crossover experiment with a minimum 4-week washout between treatments. Baseline corneal touch thresholds (CTT, cm) were measured via esthesiometry and a subconjunctival injection was performed in the treatment eye with ropivacaine (R, 0.3 mL 0.5%) or dexmedetomidine-ropivacaine (DR, 0.1 mL 0.5 mg/mL + 0.2 mL 0.5%) and saline (control, 0.3 mL) in the contrala...
Introducing an Innovative Pain Scale for Assessing Postpartum Pain in Mares: Preliminary Clinical Evaluation. Pain after giving birth is commonly observed in horses, yet there has not been a specific tool developed for assessing this pain in postpartum mares. The goal was to adapt existing equine pain scales and to preliminarily validate a practical pain scale for use by veterinarians and caregivers after foaling. Methods: The pain scale was developed by adapting items from other pain scales, including established orthopedic and colic equine pain scales, and incorporating caregiver feedback. The final scale includes eight areas for assessing pain: behavior, facial expressions, vital signs, udder exami...
Physiological and behavioural effects of continuous remifentanil-xylazine administration in donkeys. Remifentanil and xylazine are used as continuous infusions to facilitate standing surgery in horses. Their use for this purpose has not been reported in donkeys. Objective: To evaluate the behavioural, sedative, and cardiorespiratory effects of continuous intravenous infusion of remifentanil and xylazine in donkeys. Methods: Non-blinded in vivo experiments. Methods: Ten donkeys were sedated with an intravenous bolus of xylazine (0.8 mg/kg). After 3 min, continuous infusions of xylazine (0.65 mg/kg/h) and remifentanil (6 μg/kg/h) were administered for 60 min. Cardiorespiratory physio...
Tachycardia and muscle tremors following intravenous administration of detomidine to a horse undergoing standing surgery. Detomidine hydrochloride is an alpha adrenoceptor agonist that is commonly used in equine practice to provide sedation and analgesia for horses undergoing standing procedures. Reported effects following intravenous administration of detomidine in horses include bradycardia, bradyarrhythmias, transient hypertension, sweating, piloerection and dose-dependent sedation, ataxia and analgesia. This case report describes a novel response characterised by tachycardia and profound muscle tremors following the administration of intravenous detomidine to a horse undergoing a standing procedure.
Liposomal bupivacaine caudal epidural in horses results in adverse effects without analgesia. To evaluate the analgesic properties and adverse effects of liposomal bupivacaine administered via caudal epidural in horses. Methods: Pharmacodynamic study. Methods: A total of 10 healthy adult horses. Methods: Liposomal bupivacaine (10 mL; 1.3%) was administered into the caudal epidural space via an indwelling epidural catheter inserted to a length of 15 cm. Mechanical nociceptive threshold (MNT) testing with pressure algometry was used to measure analgesia at four anatomic locations for 72 h following injection. Physical examinations (including rectal temperature, heart rate, respirat...
Efficacy of acupuncture in racehorses: A review. Racehorses endure high physical demands, which often result in musculoskeletal pain, fatigue, and reduced performance. Although conventional therapies are effective, competition-related drug regulations restrict their use. Acupuncture, rooted in Traditional Chinese Veterinary Medicine, has gained interest as a non-pharmacological alternative for managing pain, enhancing recovery, and promoting overall welfare in equine athletes. This review aims to critically evaluate the current evidence on the efficacy of acupuncture in racehorses, focusing on musculoskeletal pain management, post-exercise r...
Standing excision of the nasal septum of 12 horses. To describe the technique of and complications associated with excising the nasal septum of horses with the horse standing and to report the outcome of horses undergoing this procedure. Methods: Retrospective study. Methods: A total of Twelve horses affected with disease of the nasal septum. Methods: The septum of each horse was excised with the horse sedated. All horses underwent rhinotomy, and six also underwent laryngotomy, to position three loops of obstetrical wire used to make three of four septal incisions. The sites of laryngotomy and rhinotomy were desensitized by infiltrating local a...
Impact of sequential administration of detomidine, butorphanol, and midazolam on sedation, ataxia, stimulus response, and bispectral index in horses. Standing sedation is a safe and cost-effective alternative to general anesthesia in horses, but challenges include achieving adequate drug effect to block the stimulus response without inducing ataxia or recumbency. A benefit of midazolam has been reported in equine dental procedures. Seeking synergy, a combination of lower doses of several pharmacologic agents, including midazolam, may improve the quality of sedation while minimizing adverse effects. Bispectral index (BIS) correlates with sedation scores in human ICU patients, but the correlation between sedation scores and BIS has not been e...
Mapping the Metabolic Fate of Suzetrigine in Equine and Camel Models: A Step Toward Reliable Antidoping Detection. Effective pain management remains a persistent challenge, with opioids limited by tolerance, dependence, respiratory depression, and misuse. This has created demand for safer, nonaddictive alternatives. Suzetrigine (VX-548, Journavx) is a novel analgesic with promising efficacy, but its potential misuse in competitive racing requires investigation. Limited information is available on its metabolism and detection, emphasizing the need for metabolic characterization to aid antidoping strategies. Methods: In vitro metabolism of suzetrigine was evaluated using equine liver microsomes and homogeniz...
Cervical epidural catheter for administration of detomidine and morphine in a model of carpal synovitis in the horse. To determine the analgesic effects of detomidine and morphine administered by cervical epidural catheter (CEC) on a model of thoracic limb pain. Methods: Prospective, randomized, blinded crossover study. Methods: Five adult horses. Methods: Cervical epidural catheters were placed under ultrasound guidance, followed by induction of lipopolysaccharide (LPS)-mediated carpal synovitis. Horses received either saline or detomidine/morphine (DM; 10 μg/kg, 0.1 mg/kg, respectively) via CEC 4 h after synovitis. After a 7 day washout, synovitis was induced in the contralateral carpus, and the alternate ...
Equine Abdominal Surgery: Predicting and Preventing Postoperative Complications. Morbidity after equine abdominal surgery is common and post-operative complications can be costly to owners. The focus of this article is on intraoperative decision-making and current evidence, including surgical techniques and prognostic information that can prevent and predict complications. Emerging techniques for intra-operative monitoring and intestinal viability assessment, anastomotic techniques, body wall suturing, peritonitis treatment, and pain management are discussed.
Clinical and ultrasonographic findings in horses with desmopathy of the palmar/plantar abaxial ligaments of the proximal interphalangeal joint: 20 cases. To describe the clinical and ultrasonographic findings in horses with desmopathy of the abaxial palmar/plantar ligament (APL) of the proximal interphalangeal joint and the prevalence of concurrent musculoskeletal injuries in the pastern and foot. Unassigned: Horses presenting to New Bolton Center between March 2017 and November 2022 with an age ranging from 5 to 20 years that underwent lameness evaluation in which lameness was localized to the distal limb and had an ultrasonographic diagnosis of APL desmopathy. Unassigned: Horses included were those that (1) presented for a lameness examinatio...
Oral cannabidiol increases thermal threshold in horses without physiologic adverse effects. To investigate the effect of cannabidiol (CBD) on thermal and mechanical thresholds and physiologic variables in horses. Unassigned: 6 horses (3 geldings and 3 mares) were enrolled in a prospective, randomized, masked crossover design from March 18 through May 3, 2025. Horses received 3.48 mg/kg CBD oil or placebo (sesame oil) orally every 24 hours for 3 days. Thermal and mechanical thresholds were determined at baseline and 4 and 12 hours after treatment administration on each day. Physiologic variables, including heart rate, respiratory rate, and rectal temperature, were recorded at the same...
Optimizing equine standing sedation: continuous infusion of detomidine and butorphanol enhances stability but prolongs ataxia. This study aimed to compare the sedation quality and cardiorespiratory and behavioral effects of detomidine administered intravenously, either in intermittent boluses or as a continuous rate infusion, with butorphanol in horses pre-medicated with acepromazine for odontoplasty procedures. Unassigned: A prospective clinical study was conducted with fifteen adult horses randomly assigned to two groups: Bolus group (BG, = 7) and Infusion group (IG, = 8). Both groups received acepromazine premedication, followed by detomidine administration (bolus or infusion). Butorphanol was administered either...
The impact of transdermal application site on pharmacokinetics and selected pharmacodynamics of buprenorphine in horses. To assess absorption after transdermal application of buprenorphine to different sites and assess behavioral, antinociceptive and adverse effects. It was hypothesized that the dose and site of transdermal buprenorphine administration would influence absorption, plasma drug concentrations, physiological, antinociceptive and behavioral effects in horses. Methods: Two-part study; prospective randomized balanced three-way crossover (study 1) and single-dose (study 2) experimental study. Methods: Six (study 1) and eight (study 2) horses, aged 3-14 years. Methods: In study 1, horses were administere...
Analgesic and Gastrointestinal Effects of Methadone in Horses Undergoing Orchiectomy. A multimodal approach is recommended to optimize perioperative pain control in animals, although opioid use in horses remains limited due to the risks of central nervous system (CNS) stimulation and reduced intestinal motility. A group of 19 healthy, male, mixed-breed horses were divided into two groups and medicated with acepromazine (0.05 mg kg) and detomidine (10 µg kg), with methadone (0.05 mg kg) (ADM) or saline (ADS) administered intravenously (IV). Physiological variables, intestinal motility, gastric distention, and facial pain (EQUUS-FAP) were evaluated one day before (DB), before th...
Ultrasound-Guided Radiofrequency Ablation and Pulsed Radiofrequency Treatment for Chronic Lameness Due to Distal Forelimb Disease in Horses: A Pilot Study. Radiofrequency ablation (RFA) and pulsed radiofrequency (PRF) are non-pharmacological techniques employed in humans for chronic pain, but their veterinary application is unexplored. This pilot study evaluated clinical effects of RFA and PRF in twenty-four horses with chronic distal forelimb lameness. Ultrasound-guided RFA (N = 8; 60-90 °C, 2-8 min) or PRF (N = 16; 42 °C; 12 min) was applied to palmar digital nerves. Lameness was scored (American Association of Equine Practitioners scale) at baseline and monthly for six months (T1-T6). At T2, partial- and non-responders in both groups receive...
The effect of cervical epidural injection of morphine and the combination of morphine and detomidine on recovery from anesthesia in adult horses. To evaluate the effect of cervical epidural injection of morphine alone and morphine in combination with detomidine on recovery from anesthesia in horses. Methods: Blinded, randomized, crossover, Latin square design. Methods: A group of six healthy adult horses aged 9 ± 3 years and weighing 471 ± 76 kg (mean ± standard deviation). Methods: Horses were administered each of three treatments during a 1 hour general anesthetic with a 4 day washout period. Treatments were: 1) cervical epidural injection of saline 0.011 mL kg (S); 2) morphine 0.1 mg kg (M); and 3) morphine 0.1 mg kg with detomidi...
An Ultrasound-Guided Thoracolumbar Erector Spinae Plane Block: An Experimental Preliminary Study in Horses. The objective of this study was to evaluate the feasibility and efficacy of the ultrasound-guided thoracolumbar erector spinae plane (TL-ESP) block in standing horses. A total of 24 injections ( = 12) were performed at the L1 level using either 0.1 mL/kg of saline solution (SS group) or 2% lidocaine (LID group). The block feasibility was assessed based on needle visualization and injection time, while efficacy was evaluated through craniocaudal and dorsoventral (DV) spread using the pinprick technique over 270 min. Desensitization was observed at least once in 100% of horses in the LID group a...
Pregabalin contributes to increased recovery time from isoflurane anaesthesia for magnetic resonance imaging in horses. Pregabalin reduces excitatory neurotransmitter release and is used for anxiolysis in humans, cats, and horses. The effects of pregabalin on equine recovery following isoflurane anaesthesia are unknown. Objective: To determine if pre-anaesthetic oral pregabalin influences recovery time and/or quality from isoflurane anaesthesia in horses undergoing elective magnetic resonance imaging (MRI) of the appendicular skeleton. Methods: Retrospective cohort study. Methods: Anaesthetic and recovery data from 52 healthy horses in which pregabalin (PG) was administered and 76 control horses (CG) undergoing...
A comparison of a transdermal eutectic lidocaine/prilocaine cream and subcutaneous lidocaine injection prior to jugular vein catheterization in horses: a randomized crossover study. To compare horses' aversive behavioural responses to the application of 5% prilocaine/lidocaine eutectic mixture of local anaesthetics (EMLA) cream versus subcutaneous infiltration of 2% lidocaine, followed by jugular vein catheterization. Methods: Blinded, randomized study. Methods: A group of 26 university-owned research horses. Methods: Each horse received both treatments at opposite jugular sites with ≥ 12 hours between procedures. One randomly assigned jugular site received 1 g cm of 5% EMLA cream 60 minutes before catheterization, while the contralateral site received 1.5 mL of 2% lido...
Efficacy of caudal epidural injection of Xylazine-Lidocaine HCl and detomidine-lidocaine HCl in domestic horses (Equus ferus caballus). The current study was prepared to compare the efficacy of xylazine-lidocaine HCl and detomidine-lidocaine HCl following caudal epidural injection in horses, evaluating sedation, analgesia, physiological parameters, and hemato-biochemical values. This study was applied to six healthy adult horses (300-350 kg, > 4 years of age). The horses were randomly divided into two equal groups. Group 1 (seven horses) received xylazine (0.17 mg/kg bwt) + lidocaine HCl (0.06 mg/kg bwt), while Group 2 received detomidine (0.03 mg/kg bwt) + lidocaine HCl (0.06 mg/kg bwt) via caudal epidural inje...
Lameness improvement in horses with distal tarsal pain after intra-articular injection of botulinum neurotoxin type A. To evaluate the effect of IA injections of botulinum toxin type A (BoNT-A) in horses with chronic, naturally occurring distal tarsal osteoarthritis. Unassigned: 9 horses were selected after physical and radiographic assessments. Horses also underwent an objective lameness examination and were included if they had a hindlimb impact lameness (Pmin ≥ 3 mm), which positively responded (≥ 50%) to the tarsometatarsal and centrodistal joints' anesthetic block. Horses randomly received an intra-articular injection of BoNT-A or an equivalent volume of saline solution. Horses were reevaluated at pos...