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 alkalinization on the local analgesic efficacy of ketamine in the abaxial sesamoid nerve block in horses. The objective of this study was to determine the effects of the alkalinization on the local analgesic efficacy of 1% ketamine in the abaxial sesamoid nerve block in horses. Thirty-six mature healthy horses were randomly assigned to four groups for the following treatments; an abaxial sesamoid block with 5 mL of saline solution (control saline); an abaxial sesamoid block with 5 mL of a solution containing 1% ketamine (KETs 1%); an abaxial sesamoid block with 5 mL of a solution containing saline solution and 0.5 mEq of sodium bicarbonate (control bicarbonate); and an abaxial sesamoid block with ...
Pharmacokinetics of fentanyl following intravenous and transdermal administration in horses. Although fentanyl has been reported to cause CNS excitation in horses, a transdermal therapeutic system (TTS) containing this mu agonist has recently been used empirically in equine medicine to treat moderate to severe pain. A better understanding of the disposition of fentanyl following transdermal administration would facilitate the clinical use of TTS fentanyl to obtain analgesia in horses. Objective: To determine the pharmacokinetics of fentanyl following i.v. and TTS patch administration in healthy, mature horses and to evaluate the tolerance of horses to TTS fentanyl administration. Meth...
The effects of local anaesthetic solution in the navicular bursa of horses with lameness caused by distal interphalangeal joint pain. Analgesia of the palmar digital (PD) nerves has been demonstrated to cause analgesia of the distal interphalangeal (DIP) joint as well as the sole. Because the PD nerves lie in close proximity to the navicular bursa, we suspected that that analgesia of the navicular bursa would anaesthetise the PD nerves, which would result in analgesia of the DIP joint. Objective: To determine the response of horses with pain in the DIP joint to instillation of local anaesthetic solution into the navicular bursa. Methods: Lameness was induced in 6 horses by creating painful synovitis in the DIP joint of one f...
Outcome of epidural catheterization for delivery of analgesics in horses: 43 cases (1998-2001). To determine reasons for epidural catheter placement among horses examined at a veterinary teaching hospital, efficacy of epidural administration of analgesics, duration of catheter placement, reasons for catheter removal, and complications encountered. Methods: Retrospective study. Methods: 43 horses. Methods: Medical records were reviewed. Results: A total of 50 epidural catheters were placed in the 43 horses. Underlying conditions included fractures, lacerations, septic arthritis, myositis, perineal injuries, and cellulitis. Horses ranged from 2 to 21 years old and weighed between 365 and 7...
Evaluation of the local analgesic effect of ketamine in the palmar digital nerve block at the base of the proximal sesamoid (abaxial sesamoid block) in horses. To evaluate the local analgesic effect of ketamine in a palmar digital nerve block at the base of the proximal sesamoid (abaxial sesamoid block) in horses. Methods: 36 mature healthy Andalusian horses. Methods: Horses were randomly assigned to 4 groups of 9 horses each and received an abaxial sesamoid block in a randomly chosen forelimb with 1 of the following: saline (0.9% NaCl) solution, 1% ketamine solution, 2% ketamine solution, or 3% ketamine solution. To determine analgesia, the radiant heat lamp-hoof withdrawal model was used as a noxious thermal stimulus. Before each nerve block, basel...
Effects of alpha-2 adrenoceptor agonists during recovery from isoflurane anaesthesia in horses. Recovery from inhalant anaesthesia in the horse is a critical and difficult period to manage; however, several factors could help to obtain a calm recovery period including choice of anaesthetic and analgesic procedure used and the conditions under which anaesthetic maintenance and recovery occur. Objective: The objective of this study was to evaluate and compare the quality of recovery in horses administered saline, xylazine, detomidine or romifidine during recovery from isoflurane anaesthesia. Methods: Six mature and healthy horses were premedicated with i.v. xylazine and butorphanol, and an...
Comparison of electroacupuncture and butorphanol on respiratory and cardiovascular effects and rectal pain threshold after controlled rectal distention in mares. To compare effects of electroacupuncture and butorphanol on hemodynamic and respiratory variables and rectal analgesia in mares after controlled rectal distention. Methods: 8 healthy mares. Methods: Each horse received saline (0.9% NaCl) solution (0.01 mL/kg, IV; control treatment), butorphanol tartrate (0.1 mg/kg, IV), or 2 hours of electroacupuncture (EA) at acupoints Bladder 21, 25, and 27 on both sides of the vertebral column, Bai hui, and Stomach 36 (right side only). Order of treatments in each mare was randomized. At least 7 days elapsed between treatments. A balloon was inserted in the...
Managing chronic arthritis. Many compounds are being investigated for the control of symptoms of osteoarthritis in people and animals. Ideally, treatment should include analgesia, inflammation control, and chondroprotection. With further progress in this area, combination therapies tailored to the needs of the individual animal should enable us to maximize efficacy and minimize side effects. Only a few of the newer therapies and pharmaceutic agents have been investigated in the horse, however. With more rigorous investigation, they may be determined to be ineffective or unsafe. Meanwhile, as much information should be ga...
Effects of analgesia of the distal interphalangeal joint and navicular bursa on experimental lameness caused by solar pain in horses. It has been hypothesized that pain originating from the dorsal margin of the sole of the hoof in horses can be attenuated by analgesia of either the distal interphalangeal (DIP) joint, or of the navicular bursa (NB). To test this hypothesis, an experimental lameness was induced in the toe region of the left forelimb in six adult horses. After this, both synovial structures were blocked and the effects on the lameness were semi-quantitatively scored. Lameness was induced by creating pressure on the dorsal margin of the sole with the help of set-screws that were screwed into a nut, welded to the...
Pilot epidemiological study of attitudes towards pain in horses. This preliminary study investigated the attitudes, and evaluated the current practice of a sample of the veterinary profession in the UK in relation to the management of pain in horses. In June 2001, a questionnaire was posted to 260 veterinarians in specialised equine practice, and 140 veterinarians in general practice with a significant equine caseload. There was a 25 per cent response rate to the questionnaire, which recorded information about the availability and prescription of analgesic drugs, the factors influencing the selection of analgesics and their administration, and estimates of ...
Clinical comparison of xylazine and medetomidine for premedication of horses. To compare the analgesic and cardiopulmonary effects of medetomidine and xylazine when used for premedication of horses undergoing general anesthesia. Methods: Randomized clinical trial. Methods: 40 horses. Methods: Twenty horses were premedicated with medetomidine (10 microg/kg [4.5 microg/lb], i.m.) and the other 20 were premedicated with xylazine (2 mg/kg [0.9 mg/kg], i.m.). Horses were then anesthetized with a combination of guaifenesin and ketamine; anesthesia was maintained with halothane. Additional doses of medetomidine or xylazine were given if horses were not sufficiently sedated at ...
Cutaneous analgesia, hemodynamic and respiratory effects, and beta-endorphin concentration in spinal fluid and plasma of horses after acupuncture and electroacupuncture. To determine cutaneous analgesia, hemodynamic and respiratory effects, and beta-endorphin concentration in spinal fluid and plasma of horses after acupuncture and electroacupuncture (EA). Methods: 8 healthy 10- to 20-year-old mares that weighed between 470 and 600 kg. Methods: Each horse received 2 hours of acupuncture and 2 hours of PAES at acupoints Bladder 18, 23, 25, and 28 on both sides of the vertebral column as well as sham needle placement (control treatment). Each treatment was administered in a random order. At least 7 days elapsed between treatments. Nociceptive cutaneous pain thres...
The effects of xylazine, detomidine, acepromazine and butorphanol on equine solid phase gastric emptying rate. The aim of this study was to measure the effects of specific commonly used sedative protocols on equine solid phase gastric emptying rate, using the 13C-octanoic acid breath test (13C-OABT). The gastric emptying of a standard 13C-labelled test meal was measured once weekly in 8 mature horses over two 4 week treatment periods. Each horse acted as its own control. In treatment Period 1, saline (2 ml i.v.), xylazine (0.5 mg/kg i.v.), detomidine (0.01 mg/kg i.v.) or detomidine/butorphanol combination (0.01/0.02 mg/kg i.v.) was administered in randomised order after ingestion of the test meal. Duri...
Use of infrared thermography to detect injections and palmar digital neurectomy in horses. Thermography is a non-contact, non-invasive technique that detects surface heat emitted as infrared radiation. Because skin temperature reflects the status of underlying tissue metabolism and blood circulation, abnormal thermal patterns can signify areas of superficial inflammation. The objective of this study was to determine if thermography could detect the injection of analgesic and neurolytic agents and surgical palmar digital neurectomy. Procedures evaluated include injection of the lumbar region, suspensory ligaments, tibial nerve, palmar digital nerves, and palmar digital neurectomy. Th...
Evaluation of a method to experimentally induce colic in horses and the effects of acupuncture applied at the Guan-yuan-shu (similar to BL-21) acupoint. To evaluate the reliability of a method for inducing colic via small intestinal distention in horses and to examine the analgesic potential of bilateral electroacupuncture (EAP) at the Guan-yuan-shu (similar to BL21) acupoint. Methods: 5 healthy adult horses, each with a gastric cannula. Methods: A polyester balloon connected to an electronic barostat was introduced into the duodenum via the gastric cannula. At 2 specified intervals (before and after commencement of EAP), the balloon was inflated to a barostat-controlled pressure that induced signs of moderate colic. Each inflation was maintai...
Epidural anesthesia and analgesia in horses. Intercoccygeal, or caudal, epidural injection of local anesthetics is a convenient method of producing analgesia and local anesthesia of the tail and perineal structures in conscious standing horses. This technique has been further developed to provide long duration analgesia and anesthesia by placement of catheters into the epidural space of horses. More recently, opioid, alpha-2 adrenergic agonists, ketamine and other analgesic agents have been administered by caudal epidural injection, providing pain relief in both conscious, standing and anesthetized, recumbent horses. This chapter describ...
Management of gastrointestinal pain. Choice of an analgesic for gastrointestinal pain requires consideration of the cause of the pain, desired duration of pain relief, need for sedation, and potential side effects and toxicity, particularly in light of other drugs being used and effects on the gastrointestinal tract. It is imperative that close monitoring be continued to ensure that surgical lesions or worsening conditions are detected. Recent research in the field may lead to new drugs, drug combinations, and avenues of treatment that minimize the side effects of these drugs while maximizing their efficacy.
Alpha-2 adrenergic agonists as analgesics in horses. Administration of alpha-2 agonists to horses produces a variety of behavioral effects (sedation, somnolence, analgesia), and physiological effects. One of the most significant beneficial effects of administering alpha-2 agonists is the degree of analgesia they provide. Alpha-2 agonists have been the mainstay of analgesia for colic pain in horses since their introduction to clinical veterinary medicine. The increased potency of the more recently introduced alpha-2 agonists allows the provision of analgesia for conditions not previously relieved by other drugs. Unfortunately, there are significa...
Management of equine orthopedic pain. Pain management is an extremely vital part of equine orthopedic surgery. Providing optimum analgesia for the patient will decrease recovery time, decrease physiologic stress on the animal, and provide maximum comfort during the post-operative period. The major analgesic drug categories and routes covered are nonsteroidal anti-inflammatory drugs, local anesthetics, intra-articular drugs, and epidurals.
Use of opioids for pain and anesthetic management in horses. REGIONAL ADMINISTRATION: There is limited, but convincing, evidence that epidural administration of morphine and some other mu-agonist opioids consistently relieves regional pain in horses. In addition, this effect is not accompanied by notable undesirable effects. On the other hand, a clinically important analgesic action has not been demonstrated for similarly administered kappa-agonist opioids. There has been little objective data presented to support the analgesic effectiveness of intra-articularly administered opioids in horses. However, the evidence of local opioid receptors legitimately...
Subjective and quantitative scintigraphic assessment of the equine foot and its relationship with foot pain. It was hypothesised that in solar bone images of the front feet of clinically normal horses, or horses with lameness unrelated to the front feet, there would be less than a 10% difference in the ratio of uptake of radiopharmaceutical in either the region of the navicular bone, or the region of insertion of the deep digital flexor tendon (DDFT), compared to the peripheral regions of the distal phalanx. Nuclear scintigraphic examination of the front feet of 15 Grand Prix show jumping horses, all of which were free from detectable lameness, was performed using dorsal, lateral and solar images. Th...
Analgesic effect of butorphanol and levomethadone in detomidine sedated horses. The analgesic potency of butorphanol 25 microg/kg bodyweight (BW) and levomethadone 100 microg/kg BW, administered together with detomidine 10 microg/kg BW, was measured in twelve Warmblood horses in a randomized, blinded cross-over study. Detomidine with saline 10 ml 0.9% was used as placebo. The nociceptive threshold was determined using a constant current and a pneumatic pressure model for somatic pair Detomidine alone and in combination with butorphanol or levomethadone caused a significant temporary increase (P < 0.05) of the nociceptive threshold with a maximum effect within 15 min and a...
A comparison of the effects of local analgesic solution in the navicular bursa of horses with lameness caused by solar toe or solar heel pain. We hypothesised that analgesia of the navicular bursa is not selective for the navicular apparatus; and that solar pain in some horses can be temporarily abolished or attenuated by analgesia of the navicular bursa. To test this hypothesis, we caused lameness in horses by inducing pain in the dorsal margin or the angles of the sole and then evaluated the ability of a local analgesic solution administered into the navicular bursa to attenuate lameness. The response of horses with solar pain in the dorsal or palmar aspect of the foot to 3.5 ml local analgesic solution administered into the navicu...
Analgesic, hemodynamic, and respiratory effects induced by caudal epidural administration of meperidine hydrochloride in mares. To determine the analgesic, hemodynamic, and respiratory effects induced by caudal epidural administration of meperidine hydrochloride in mares. Methods: 7 healthy mares. Methods: Each mare received meperidine (5%; 0.8 mg/kg of body weight) or saline (0.9% NaCl) solution via caudal epidural injection on 2 occasions. At least 2 weeks elapsed between treatments. Degree of analgesia in response to noxious electrical, thermal, and skin and muscle prick stimuli was determined before and for 5 hours after treatment. In addition, cardiovascular and respiratory variables were measured and degree of se...