Topic:Pain Management
Pain management in horses involves various strategies and interventions designed to alleviate discomfort and improve the well-being of equine patients. It encompasses pharmacological approaches, such as the use of non-steroidal anti-inflammatory drugs (NSAIDs), opioids, and other analgesics, as well as non-pharmacological methods like physical therapy, acupuncture, and environmental modifications. Effective pain management aims to address both acute and chronic pain conditions, which can result from injuries, surgeries, or diseases such as laminitis and arthritis. This page aggregates peer-reviewed research studies and scholarly articles that explore the mechanisms, efficacy, and safety of different pain management techniques in horses, contributing to the understanding and advancement of equine veterinary care.
Efficacy of tiludronate in the treatment of horses with signs of pain associated with osteoarthritic lesions of the thoracolumbar vertebral column. To evaluate the efficacy of tiludronate for the treatment of horses with signs of pain associated with lesions of the thoracolumbar vertebral column. Methods: 29 horses with clinical manifestations of pain associated with lesions of the thoracolumbar vertebral column and abnormal radiographic findings indicative of osteoarthritis of the articular processes-synovial intervertebral joints. Methods: Horses were initially examined in accordance with a standardized protocol, which included radiographic, ultrasonographic, and scintigraphic examinations. Fifteen horses were randomly assigned to recei...
Effects of butorphanol on the withdrawal reflex using threshold, suprathreshold and repeated subthreshold electrical stimuli in conscious horses. To assess the effects of a single intravenous dose of butorphanol (0.1 mg kg(-1)) on the nociceptive withdrawal reflex (NWR) using threshold, suprathreshold and repeated subthreshold electrical stimuli in conscious horses. Methods: 'Unblinded', prospective experimental study. Methods: Ten adult horses, five geldings and five mares, mean body mass 517 kg (range 487-569 kg). Methods: The NWR was elicited using single transcutaneous electrical stimulation of the palmar digital nerve. Repeated stimulations were applied to evoke temporal summation. Surface electromyography was performed to record a...
Ultrasound-guided coxofemoral arthrocentesis in horses. Coxofemoral joint pain is probably underestimated due to difficulties in identifying hip pain. The deep location of the joint and proximity of the sciatic nerve make arthrocentesis based on external landmarks a difficult and potentially risky procedure in mature horses. Objective: To describe an ultrasound-guided injection technique of the coxofemoral joint in standing horses and to evaluate its accuracy and potential difficulties/complications. Methods: Nine mature horses had both pelvic areas prepared for sterile ultrasound examination (3.5 MHz curvilinear probe). Coxofemoral joints were loc...
Innervation and nerve injections of the lumbar spine of the horse: a cadaveric study. The distal limb innervation of the horse has been studied extensively to allow use of local anaesthetic techniques to detect the origin of pain in lameness. However, the innervation of the lumbar spine has so far been poorly described and a more precise description may assist clinicians to localise back pain in the horse. Objective: To gain better knowledge of the innervation of the lumbar spine and identify salient anatomical features that might be used for diagnostic and therapeutic ultrasound guided injections. Methods: The spines of 8 mature horses were dissected. Branches of the dorsal ra...
Comparison of intraoperative pain responses following intratesticular or mesorchial injection of lidocaine in standing horses undergoing laparoscopic cryptorchidectomy. To compare pain responses in stallions undergoing standing laparoscopic cryptorchidectomy following intratesticular or mesorchial infiltration of lidocaine. Methods: Clinical trial. Methods: 20 stallions with 1 or 2 undescended testes. Methods: Standing horses were administered a nonsteroidal anti-inflammatory drug and a caudal epidural injection of detomidine hydrochloride and underwent laparoscopic cryptorchidectomy. The undescended testis (1/horse) was grasped to determine the preoperative pain response (present vs absent) and assess severity of pain (by use of a visual analog scale [VAS])....
Laparoscopic cryptorchidectomy and ovariectomy in horses. Laparoscopic surgery has become commonplace in the field of equine urogenital surgery. As with most surgical procedures, the limiting factors in developing new surgical techniques are limited to the patient size and demeanor, the skills of the surgeon, and the available equipment. Some of the greatest benefits of laparoscopic surgery in the horse include better visualization of the important structures; tension-free amputation of the testes or ovaries,which generally leads to less postoperative pain; and the ability to evaluate the transected stump carefully to make sure there is no hemorrhage...
Pressure algometry to quantify muscle pain in racehorses with suspected sacroiliac dysfunction. Despite the prevalence of orthopaedic injuries to horses, there is no objective means of quantifying the intensity of musculoskeletal pain. Objective: Mechanical nociceptive thresholds (MNT) can be measured repeatably by pressure algometry in horses and MNTs are correlated with both severity of clinical signs and subjective scores of muscle pain on palpation in horses with suspected sacroiliac dysfunction (SID). Methods: The technique of pressure algometry and its repeatability was tested at 4 anatomical sites on either side of the thoracolumbar and pelvic region in 12 Thoroughbreds in trainin...
Magnetic resonance imaging, ultrasonography and histology of the suspensory ligament origin: a comparative study of normal anatomy of warmblood horses. The diagnosis of lameness caused by proximal metacarpal and metatarsal pain can be challenging. Magnetic resonance imaging (MRI) offers the possibility for further diagnosis but there have been no studies on the normal MRI appearance of the origin of the suspensory ligament (OSL) in conjunction with ultrasonography and histology. Objective: To describe the MRI appearance of the OSL in fore- and hindlimbs of sound horses and compare it to the ultrasonographic and histological appearance. The findings can be used as reference values to recognise pathology in the OSL. Methods: The OSL in the fore...
MRI and CT diagnosis of acute desmopathy of the lateral collateral sesmoidean (navicular) ligament and long-term outcome in a horse. Clinical, magnetic resonance imaging (MRI) and computed tomography (CT) findings of acute desmopathy of the lateral collateral sesmoidean (navicular) ligament (CSL) in a 13-year-old Hanoverian mare are presented. On admission to the clinic the horse showed a grade 5/6 left front-limb lameness at the walk, pain on coffin joint manipulation, and coffin joint effusion. Despite a positive palmar digital nerve block, radiographs and ultrasonography did not indicate reasons for the severe clinical signs. However, MRI revealed damage to the CSL and bone marrow oedema of the navicular bone (NB), where...
Mandibular condylectomy and meniscectomy for the treatment of septic temporomandibular joint arthritis in a horse. To report use of mandibular condylectomy for treatment of advanced degenerative joint disease of the temporomandibular joint (TMJ) caused by sepsis. Methods: Clinical case report. Methods: Two-year-old Noriker filly. Methods: Computed tomography (CT) was used to confirm advanced degenerative joint disease of the left TMJ and for follow-up after mandibular condylectomy and removal of necrotic meniscus. Results: Painful swelling (3 weeks duration) with drainage located just caudal to the left lateral canthus of the eye was associated with atrophy of the left masseter muscle, masticatory problems...
Regional differences in transdermal penetration of fentanyl through equine skin. The rate and regional differences for the penetration of fentanyl through equine skin was investigated in vitro using a commercial transdermal therapeutic system (TTS) or 'patch'. Skin collected from the thorax, groin and leg (dorsal metacarpal) regions of five horses was placed in diffusion cells and a fentanyl TTS applied to each skin sample. Drug penetration through each skin sample over 48 h measured using high performance liquid chromatography (HPLC). Cumulative penetration (microg/cm2) was plotted against time (h) and used to regress the steady state flux (microg/cm2/h) of fentanyl throu...
Evidence of bias affecting the interpretation of the results of local anaesthetic nerve blocks when assessing lameness in horses. 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...
Use of magnetic resonance imaging to diagnose distal sesamoid bone injury in a horse. A 5-year-old Appaloosa mare was examined for severe left forelimb lameness of 4 months' duration. Results: Lameness was evident at the walk and trot and was exacerbated when the horse circled to the left. Signs of pain were elicited in response to hoof testers placed over the frog of the left front hoof, and a palmar digital nerve block eliminated the lameness. Radiographs revealed no abnormalities, but magnetic resonance imaging (MRI) revealed increased bone density in the medullary cavity of the distal sesamoid (navicular) bone in the proton density and T2-weighted images and a defect in the...
Prevalence of gastric squamous ulceration in horses with abdominal pain. Prevalence of gastric ulcerations differs widely according to breed and circumstances of management. Further study of the biological variables involved is required in order to identify more exactly the reasons for the reported range. Objective: The objectives of this present study, which do not appear to have been addressed previously in the literature, were 1) the prevalence of gastric ulceration in horses with abdominal pain. 2) difference in prevalence in horses responding to medical therapy and those requiring surgical intervention. 3) whether gastric ulceration is associated with any part...
Arthrogenic lameness of the fetlock: synovial fluid markers of inflammation and cartilage turnover in relation to clinical joint pain. Joint pain is one of the most common causes of lameness in the horse but its pathogenesis is poorly understood. Objective: To investigate which synovial fluid markers may be related to the presence of clinically detectable joint pain in the horse. Methods: Concentrations of structural (CPII, C2C, GAG) and inflammatory markers (PGE2, LTB4, CysLTs, bradykinin and substance P) were measured in fetlock joint fluid from 22 horses in which lameness was localised to the fetlock region by perineural anaesthesia. Levels of these markers were then compared in horses that responded (n = 15) to those that...
Risk factors for colic in horses after general anaesthesia for MRI or nonabdominal surgery: absence of evidence of effect from perianaesthetic morphine. Post anaesthetic colic is a recognised risk of general anaesthesia (GA), but causes are poorly understood. Objective: To identify risk factors for development of colic following GA for magnetic resonance imaging (MRI) or nonabdominal surgery and to test whether the use of perianaesthetic morphine was associated with an increased risk of post anaesthetic colic. Methods: A total of 553 anaesthetic and clinical records of 500 horses anaesthetised at the Animal Health Trust were analysed, 342 (62%) involved MRI and 211 (38%) nonabdominal, predominantly orthopaedic surgery. Multivariable logistic r...
Maggot debridement therapy for serious horse wounds – a survey of practitioners. Hoof disease and injuries are common and serious problems for equines. Maggot debridement therapy (MDT) has been used to treat problematic wounds in humans, but has been used only rarely in other animals. US veterinarians who had employed MDT were surveyed to investigate their reasons for the choice of this treatment and their clinical experiences with it. Between 1997 and 2003, 13 horses were treated by eight veterinarians who used MDT to control infection or debride wounds, which could not easily be reached surgically or were not responding to conventional therapy. Seven animals were lame, a...
Force platform evaluation of lameness severity following extracorporeal shock wave therapy in horses with unilateral forelimb lameness. To measure alterations in lameness severity that occur following use of extracorporeal shock wave therapy (ESWT) in horses with naturally occurring unilateral forelimb lameness. Methods: Nonrandomized clinical trial. Methods: 9 horses with unilateral forelimb lameness. Methods: Force platform gait analysis was performed prior to administration of any treatments (baseline) and after use of local anesthesia to eliminate the lameness. Extracorporeal shock wave therapy was then administered, and gait analysis was repeated 8 hours later and then daily for 7 days. Results: Compared with the baseline...
Antinociceptive effects, metabolism and disposition of ketamine in ponies under target-controlled drug infusion. Ketamine is widely used as an anesthetic in a variety of drug combinations in human and veterinary medicine. Recently, it gained new interest for use in long-term pain therapy administered in sub-anesthetic doses in humans and animals. The purpose of this study was to develop a physiologically based pharmacokinetic (PBPk) model for ketamine in ponies and to investigate the effect of low-dose ketamine infusion on the amplitude and the duration of the nociceptive withdrawal reflex (NWR). A target-controlled infusion (TCI) of ketamine with a target plasma level of 1 microg/ml S-ketamine over 120 ...
Equine laminitis: bites by Bothrops spp cause hoof lamellar pathology in the contralateral as well as in the bitten limb. The envenoming caused by Bothrops snakebite includes local symptoms, such as pronounced edema, hemorrhage, intense pain, vesicles, blisters and myonecrosis. The principal systemic symptom consists in the alteration of blood clotting, due to fibrinogen consumption and platelet abnormalities. The horses involved in this study had this symptomatology and one of them exhibited symptoms consistent with laminitis in the bitten and in the contralateral limbs. Laminitis lesions were characterized by separation of the hoof lamellar basement membrane (BM) from basal cells of the epidermis. These results...
Needle electromyographic activity of myofascial trigger points and control sites in equine cleidobrachialis muscle–an observational study. Myofascial trigger points are commonly described in humans, and many studies have shown abnormal spontaneous electrical activity, spike activity and local twitch responses at these sites. Myofascial trigger points have only rarely been described in horses, and studies of their electrophysiological characteristics have not previously been published. The objective of this study was to explore the electromyographic (EMG) and other characteristics of myofascial trigger points in equine muscle, and to compare them with normal muscle tissue. Methods: Four horses with chronic pain signs and impaired ...
Analgesic effects of subarachnoidally administered hyperbaric opioids in horses. To evaluate the effects of subarachnoidally administered hyperbaric morphine, buprenorphine, and methadone on avoidance threshold to noxious electrical stimulation of the perineal, sacral, lumbar, and thoracic regions in horses. Methods: 6 healthy adult horses. Methods: Horses were assigned to receive subarachnoid administration of hyperbaric morphine (0.01 mg/kg), buprenorphine (0.001 mg/kg), methadone (0.01 mg/kg), or 10% dextrose solution in equal volumes (5 mL). Electrical stimulation was applied every 10 minutes for 60 minutes and every 30 minutes for 120 minutes after subarachnoid inject...
Pharmacokinetics of the opioid antagonist N-methylnaltrexone and evaluation of its effects on gastrointestinal tract function in horses treated or not treated with morphine. To determine the pharmacokinetics and effects of the morphine antagonist N-methylnaltrexone (MNTX) on gastrointestinal tract function in horses when administered alone and in combination with morphine. Methods: 5 healthy adult horses. Methods: Horses were treated with MNTX (1 mg/kg, IV), and serial blood samples were collected for determination of drug pharmacokinetics. For evaluation of effects on the gastrointestinal tract when administered alone, MNTX was administered at a dosage of 0.75 mg/kg, IV, twice daily for 4 days. For evaluation of effects when administered concurrently with morphin...
Effectiveness of acupuncture in veterinary medicine: systematic review. Acupuncture is a popular complementary treatment option in human medicine. Increasingly, owners also seek acupuncture for their animals. The aim of the systematic review reported here was to summarize and assess the clinical evidence for or against the effectiveness of acupuncture in veterinary medicine. Systematic searches were conducted on Medline, Embase, Amed, Cinahl, Japana Centra Revuo Medicina and Chikusan Bunken Kensaku. Hand-searches included conference proceedings, bibliographies, and contact with experts and veterinary acupuncture associations. There were no restrictions regarding t...
The effects of i.v. fentanyl administration on the minimum alveolar concentration of isoflurane in horses. Fentanyl decreases the minimum alveolar concentration (MAC) of inhaled anaesthetics and has been used clinically to reduce the requirements of other anaesthetic drugs in humans and small animals. We hypothesized that i.v. fentanyl would decrease the MAC of isoflurane in horses in a dose-dependent manner. Methods: Following determination of baseline MAC of isoflurane, fentanyl was administered i.v. to target plasma concentrations of 1, 8 and 16 ng ml(-1). Each horse was randomly assigned two of three target concentrations administered in ascending order. Loading and infusion doses for each hors...
Evaluation of administration of isoflurane at approximately the minimum alveolar concentration on depression of a nociceptive withdrawal reflex evoked by transcutaneous electrical stimulation in ponies. To investigate effects of isoflurane at approximately the minimum alveolar concentration (MAC) on the nociceptive withdrawal reflex (NWR) of the forelimb of ponies as a method for quantifying anesthetic potency. Methods: 7 healthy adult Shetland ponies. Methods: Individual MAC (iMAC) for isoflurane was determined for each pony. Then, effects of isoflurane administered at 0.85, 0.95, and 1.05 iMAC on the NWR were assessed. At each concentration, the NWR threshold was defined electromyographically for the common digital extensor and deltoid muscles by stimulating the digital nerve; additional el...
Use of intra-articular administration of ethyl alcohol for arthrodesis of the tarsometatarsal joint in healthy horses. To evaluate the efficacy and safety of intra-articular administration of ethyl alcohol for arthrodesis of tarsometatarsal joints in horses. Methods: 8 healthy female horses without lameness or radiographic evidence of tarsal joint osteoarthritis. Methods: In each horse, 1 tarsometatarsal joint was treated with 4 mL of 70% ethyl alcohol and the opposite joint was treated with 4 mL of 95% ethyl alcohol. Lameness examinations were performed daily for 2 weeks, followed by monthly evaluations for the duration of the 12-month study. Radiographic evaluations of both tarsi were performed 1 month after...
Morphine-associated pruritus after single extradural administration in a horse. Pruritus following a single administration of 100 microg kg(-1) of preservative-free morphine sulphate given via an extradural catheter was seen in a 580 kg horse. The catheter was placed in the first intercoccygeal space. Focal irritation, represented by both local alopecia over the left gluteal muscles and serum exudation, occurred 4-8 hours after injection. This was attributed to the extradural morphine administration.
Morphine administration in horses anaesthetized for upper respiratory tract surgery. To determine the effect of morphine administration on commonly monitored cardio-respiratory variables and recovery quality in horses undergoing anaesthesia and surgery. Methods: Prospective, randomized clinical study. Methods: Thirty-eight thoroughbred horses, 32 geldings and six mares, 3-13 years old, weighing 411-600 kg. Methods: A standard anaesthetic technique was used. Twenty minutes after induction of anaesthesia horses received 0.1 mg kg(-1) (0.1 m) or 0.2 mg kg(-1) (0.2 m) morphine by intravenous injection. A control group did not receive morphine. Heart rate, respiratory rate (fr), me...