Comparison of flunixin meglumine and meloxicam for post operative management of horses with strangulating small intestinal lesions

Pharmacologic Interventions to Immunologic and Immune-Mediated Conditions in Horses

Immunomodulators can stimulate, suppress, or regulate one or many aspects of the immune response. Use of a variety of immunostimulants, immunosuppressors, and anti-inflammatory drugs are described in horses, but the evidence supporting their efficacy is variable. Corticosteroids and nonsteroidal anti-inflammatory drugs are the best characterized immunomodulators in horses, but further study is needed to fully define their ideal dosing protocols and indications and to characterize the efficacy of other immunomodulators in equine medicine.

Retrospective evaluation of the effects of a single intraoperative dose of dexamethasone in horses undergoing exploratory laparotomy for small intestinal lesions (2008-2019): 240 cases

OBJECTIVE

To determine the effect of a single intraoperative dose of dexamethasone on the risk of postoperative reflux (POR) in horses undergoing small intestinal surgery and to investigate its association with incisional complications and short-term survival.

DESIGN

Retrospective cohort study over an 11-year period (2008-2019).

SETTING

UK-based private referral center.

ANIMALS

Two hundred and forty client-owned horses >6 months of age undergoing exploratory laparotomy for treatment of a small intestinal lesion.

INTERVENTIONS

Ninety-seven horses received a single intraoperative dose of dexamethasone (0.1 mg/kg, IV).

MEASUREMENTS AND MAIN RESULTS

Of 97 horses that received dexamethasone, 52 (53.6%) required small intestinal resection. Of 143 horses that did not receive dexamethasone, small intestinal resection was performed in 78 (54.5%). A total of 70 horses (29%) developed POR. There was no difference in the risk of POR between horses that received dexamethasone (25/97; 26%) and those that did not (45/143; 31%, P = 0.34). Risk factors associated with the development of POR included small intestinal resection (odds ratio [OR]: 4.55, 95% confidence interval [CI]: 2.27-9.11, P < 0.001), a PCV >40% 24 hours postoperatively (OR: 4.11, 95% CI: 2-8.45, P < 0.001), and a WBC count >10 × 109/L on admission (OR: 3.29, 95% CI: 1.47-7.41, P = 0.004). Dexamethasone was not associated with the odds of POR. Horses undergoing repeat laparotomy had a higher risk of incisional infection (OR: 8.07, 95% CI: 1.98-32.81, P = 0.004). Dexamethasone administration was not associated with incisional infection. The development of POR was negatively associated with short-term survival (OR: 0.07, 95% CI: 0.03-0.17, P ≤ 0.001). Dexamethasone administration was not retained in the final multivariable model for survival.

CONCLUSIONS

Intraoperative dexamethasone was not associated with the development of POR in this study population, nor did it have an effect on postoperative survival or incisional infection in horses undergoing surgical management of small intestinal disease.

Analgesic Efficacy of Non-Steroidal Anti-Inflammatory Drug Therapy in Horses with Abdominal Pain: A Systematic Review

This systematic review aimed to identify the evidence concerning the analgesic efficacy of non-steroidal anti-inflammatory drugs to treat abdominal pain in horses, and to establish whether one non-steroidal anti-inflammatory drug could provide better analgesia compared to others. This systematic review was conducted following the "Systematic Review Protocol for Animal Intervention Studies". Research published between 1985 and the end of May 2023 was searched, using three databases, namely, PubMed, Embase, and Scopus, using the words equine OR horse AND colic OR abdominal pain AND non-steroidal anti-inflammatory drug AND meloxicam OR flunixin meglumine OR phenylbutazone OR firocoxib OR ketoprofen. Risk of bias was assessed with the SYRCLE risk of bias tool, and level of evidence scored according to the Oxford Centre for Evidence-based Medicine. A total of 10 studies met the inclusion criteria. From those only one study judged pain with a validated pain score, and a high risk of bias was identified due to the presence of selection, performance, and "other" types of bias. Therefore, caution is required in the interpretation of results from individual studies. To date, the evidence on analgesic efficacy to determine whether one drug is more potent than another regarding the treatment of abdominal pain in horses is sparse.

Pharmacokinetics and effect on renal function and average daily gain in lambs after castration and tail docking, of firocoxib and meloxicam

AIMS

To evaluate and compare the pharmacokinetics of IM and oral firocoxib, and IM meloxicam, and detect their effect on renal function and average daily gain (ADG) in lambs undergoing tail docking and castration.

METHODS

Seventy-five male Romney lambs, aged 3-6 weeks, were randomised into five treatment groups (n = 15 per group): IM firocoxib (1 mg/kg); oral firocoxib (1 mg/kg); IM meloxicam (1 mg/kg); normal saline (approximately 2 mL, oral); or sham. Following the treatment administration, hot-iron tail docking and rubber ring castration were performed in all groups except the sham group, which did not undergo the procedures, but the animals were handled in the same manner as castrated and tail docked lambs. Blood samples were collected before and 1, 2, 4, 6, 8, 24, 48, 72, 96 and 120 hours after treatment administration, and drug concentrations in plasma were quantified by liquid chromatography and mass spectrometry. Plasma urea and creatinine concentrations were determined at a commercial laboratory. Lamb body weights were recorded before and 2, 4 and 8 weeks after tail docking and castration. The pharmacokinetic analysis was carried out using a non-compartmental approach. Between-group and between-time-point differences were compared using mixed model analyses.

RESULTS

There was no evidence for a difference in plasma elimination half-life between firocoxib given IM (LSM 18.6 (SE 1.4) hours), firocoxib given orally (LSM 18.2 (SE 1.4) hours), and meloxicam given IM (LSM 17. 0 (SE 1.4) hours). Firocoxib (IM) had a significantly greater volume of distribution (LSM 3.7 (SE 0.2) L/kg) than IM meloxicam (LSM 0.2 (SE 0.2) L/kg). Lambs in the meloxicam group had higher (p < 0.05) plasma urea and creatinine concentrations than those in the firocoxib, saline and sham groups. Lambs' ADG was decreased (p < 0.01) compared to the other treatment groups in the 0-2 week period following meloxicam administration.

CONCLUSIONS AND CLINICAL RELEVANCE

Both formulations of firocoxib had a long plasma elimination half-life and large volume of distribution. There was a transient reduction in ADG in the meloxicam group, possibly due to mild renal toxicity. Comparative studies on dose-response effects of firocoxib and meloxicam in lambs following the procedures are required.Abbreviations: ADG: Average daily gain; Cmax: Maximum concentration; COX: Cyclooxygenase; LOD: Limit of detection; NSAID: Non-steroidal anti-inflammatory drugs; CL: Plasma clearance; T1/2el: Plasma elimination half-life; Tmax: Time to achieve Cmax; Vd: Volume of distribution.

Effect of Firocoxib and Flunixin Meglumine on Large Colon Mural Thickness of Healthy Horses

Nonsteroidal anti-inflammatory drug (NSAID) administration carries risks of gastrointestinal toxicity. Selective COX-2 inhibitors ("coxibs") were designed to reduce risks of adverse effects but are still associated with gastrointestinal complications in humans. The effect of coxibs on colonic inflammation and integrity in horses is unknown. The study objective was to compare the effects of the coxib firocoxib and the nonselective NSAID flunixin meglumine on ultrasonographic indicators of colonic inflammation in healthy horses. Twelve healthy adult horses were administered flunixin meglumine (1.1 mg/kg IV q12h) and omeprazole (1 mg/kg PO q24h) for 5 days, allowed a 6-month washout period, then administered firocoxib (0.3 mg/kg PO once, then 0.1 mg/kg PO q24h for 4 days) and omeprazole. Transabdominal ultrasonographic examination and serum chemistry profiles were performed at the beginning and end of each treatment week. Colon wall thickness increased over time when horses received firocoxib (median post treatment 5.8 mm, interquartile range 2.8 mm; P < .001), but not flunixin (median 3 mm, interquartile range 1.2 mm; P = .7) and was significantly greater following firocoxib compared to flunixin (P = .003). Subjectively, colonic edema was noted more frequently following treatment with firocoxib (11/12 horses), compared to flunixin (1/12 horses). There were no clinically significant alterations in hematologic parameters after administration of either drug. The increase in colon wall thickness following treatment with the COX-2 selective NSAID firocoxib may suggest a risk of subclinical colitis in healthy horses. Monitoring colonic health when NSAIDs are used in a clinical setting is warranted.

The Clinical Pharmacology and Therapeutic Evaluation of Non-Steroidal Anti-Inflammatory Drugs in Adult Horses

This review firstly examines the underlying pathophysiology of pain and inflammation associated with orthopedic disease and endotoxemia. Then, it reviews the clinical pharmacology (pharmacokinetics and pharmacodynamics) of both conventional and non-conventional NSAIDs in the adult horse, and finally provides an overview of different modalities to evaluate the therapeutic efficacy of NSAIDs in research.

Updates on Diagnosis and Management of Colic in the Field and Criteria for Referral

Gastrointestinal colic is the most common primary care equine emergency and affects nearly one of four horses per year. Colic is a significant welfare concern for equine patients and a financial and emotional burden for owners. The primary care practitioner is instrumental in identifying critical cases quickly and making appropriate management recommendations to improve patient outcomes.

Basic Postoperative Care of the Equine Colic Patient

The 3 time periods around colic surgery (preoperative, operative, and postoperative) are all critical to successful outcomes. Although much focus is often paid to the first 2 time periods, the importance of sound clinical judgment and rational decision-making in the postoperative period cannot be overstated. This article will outline the basic principles of monitoring, fluid therapy, antimicrobial therapy, analgesia, nutrition, and other therapeutics routinely used in patients following colic surgery. Discussions of the economics of colic surgery and expectations for normal return to function will also be included.

Changes in Perioperative Antimicrobial and Anti-Inflammatory Drugs Regimens for Colic Surgery in Horses: A Single Center Report

Simple Summary

The administration of postoperative anti-inflammatory and antimicrobial drugs after colic surgery is based on an empirical approach, and for this reason, in recent years, it has been questioned. Recent guidelines recommend that antimicrobials should be administered for the shortest effective period possible. The use of non-steroidal anti-inflammatory drugs is also discussed given the side effects especially on the gastrointestinal tract. Consequently, the antimicrobial and anti-inflammatory drugs administration in horses has changed in our practice over the years to modulate therapies according to the postoperative complications that eventually arise. The description of these changes and the reasons behind them can help define an appropriate stewardship. Over the years, the administration of postoperative antibiotics has been limited, and treatments have been started only in case of complications that justified their use. As for anti-inflammatories, there was a variation of dosages of flunixin meglumine and the addition of new types of anti-inflammatories, both non-steroidal anti-inflammatory drugs and corticosteroids. These changes in prophylaxis protocols were not associated with an increase in postoperative complications.

Abstract

Reducing postoperative incisional infection is the main reason to administer postoperative antimicrobials (AMD) after emergency laparotomy in horses, while reducing inflammation and providing analgesia are the reasons to administer anti-inflammatory drugs (AID). The basis for postoperative AMD and AID administration is empirical and only recently has been questioned. Empirical approaches can be changed, and these changes, along with the description of their outcomes, can help produce appropriate stewardship. The aim of this study is to report the changes in AMD and AID regimens in horses undergoing emergency laparotomy at a referral teaching hospital between 2017 and 2021. Signalment, pathology, surgery, prophylactic AMD and AID administration were obtained from the medical records. Difference in AMD and AID regimens throughout the study period were also reported. In 234 postoperative records considered, ninety-two horses received prophylactic AMD, while 142 received pre-operative antimicrobials only. There was a progressive change in regimens throughout the years, increasing the number of AID molecules used. AMD and AID administration in horses has changed in our practice over the years to modulate therapies according to the postoperative complications that eventually arise. In this study, horses not receiving postoperative routine AMD treatment did not show an increased incidence of complications.

Short-term administration of flunixin meglumine or firocoxib does not alter viscoelastic coagulation profiles in healthy horses

OBJECTIVE

To evaluate the effect of the cyclooxygenase-2-selective NSAID firocoxib, compared to the nonselective NSAID flunixin meglumine on viscoelastic coagulation parameters in healthy horses.

ANIMALS

12 healthy adult mixed-breed horses.

PROCEDURES

Following a crossover protocol, horses were administered flunixin meglumine (1.1 mg/kg, IV, q 12 h for 5 days), allowed a 6-month washout period, and then administered firocoxib (0.3 mg/kg, PO, once, then 0.1 mg/kg, PO, q 24 h for 4 days). Omeprazole (1 mg/kg, PO, q 24 h) was administered concurrently with each NSAID. Viscoelastic coagulation profiles and traditional coagulation parameters (prothrombin time, partial thromboplastin time, and fibrinogen) were measured before and after each treatment.

RESULTS

Viscoelastic coagulation parameters were within reference intervals before and after both treatments. There was a statistically significant difference between treatments for amplitude at 10 minutes after clot time (P = .02) and maximum clot formation (P = .02); however, the magnitude of change was not clinically significant.

CLINICAL RELEVANCE

Short-term administration of flunixin meglumine and firocoxib did not result in significant alteration of viscoelastic coagulation profiles in healthy horses. However, clinicians should be aware of possible coagulopathy secondary to NSAID administration with long-term use or critical illness, and further study is indicated.

Comparison of Flunixin Meglumine, Meloxicam and Ketoprofen on Mild Visceral Post-Operative Pain in Horses

Simple Summary

Pain management following surgical intervention is key. In horses, several anti-inflammatories (flunixin meglumine, meloxicam and ketoprofen) are available for the management of pain following castration. However, their analgesic efficacy remains unclear for mild visceral pain. The aim of this study was to compare the analgesic efficacy of the above-mentioned anti-inflammatory drugs, following a simple surgery (inguinal castration). Horses were administered a randomly assigned anti-inflammatory drug before and after surgery. A pain score was recorded using a previously described pain assessment scale (PASPAS) before administration, and after the first and second administrations by a senior clinician and a veterinary student. Thirty horses were evaluated, and there was no significant effect of the drug administered on the pain score. Horse welfare was not compromised regardless of drug assigned. Horses showed mild pain post-operatively, which decreased significantly within 24 h. Pain scores were significantly different when assessed by a veterinary student and a senior clinician. The authors found that the anti-inflammatory drug studied provided a similar level of analgesia for the management of mild visceral pain in horses, but that the pain scale used is not suitable for junior evaluators or, by extension, owners.

Abstract

The analgesic efficacy of meloxicam and ketoprofen against equine visceral pain is unclear. The aim of this study was to compare the analgesic efficacy of meloxicam (M) and ketoprofen (K) to flunixin meglumine (F) following inguinal castration. Horses undergoing inguinal castration under general anesthesia were randomly assigned F (1.1 mg/kg), M (0.6 mg/kg) or K (2.2 mg/kg) intravenously two hours pre-operatively and 24 h later. A pain score (out of 31) was recorded blindly by a senior clinician and veterinary student before NSAIDs administration (T₀), and after the first (T₁) and second (T₂) administrations, using a modified post-abdominal surgery pain assessment scale (PASPAS). Pain was classified as mild (score ≤ 7), moderate (score = 8–14) or severe (score > 14). Thirty horses (12 F, 10 M, 8 K) aged 6.2 ± 4.9 years, mostly warmbloods, were included. Horse welfare was not compromised regardless of the drug assigned. There was no statistically significant effect of NSAIDs on pain score. Mean pain scores were significantly higher at T₁ than T₀ for each NSAID (F: 5.08 ± 2.50 vs. 1.58 ± 1.38 (p < 0.001); M: 4.60 ± 2.32 vs. 1.10 ± 1.20 (p < 0.001); K: 5.25 ± 1.39 vs. 1.50 ± 1.51 (p < 0.0001)) and lower at T₂ than T₁ for F (2.92 ± 2.423 vs. 5.08 ± 2.50 (p < 0.001)) and M (2.90 ± 1.37 vs. 4.60 ± 2.32 (p < 0.0325)). At T₁, senior pain scores were significantly different than for junior (5.56 ± 0.54 vs. 3.22 ± 0.62, p = 0.005). This study indicates that meloxicam and ketoprofen provide a similar level of analgesia to flunixin meglumine for the management of mild visceral pain in horses. PASPAS is not reliable for junior evaluators.

Preparation, evaluation, and pharmacokinetics in beagle dogs of a taste-masked flunixin meglumine orally disintegrating tablet prepared using hot-melt extrusion technology and D-optimal mixture design

Flunixin meglumine (FM) is a nonsteroidal anti-inflammatory drug limited by irritation of the respiratory tract and mucosa in veterinary tissue. This study aimed to develop a taste-masked FM solid dispersion (SD) by hot-melt extrusion (HME) and formulate an orally disintegrating tablet (ODT) with selected excipients by direct compression. Eudragit® E PO was chosen as the matrix, and HME parameters were optimized: extrusion temperature, 135℃; screw speed, 100 rpm; and drug loading, 20%. Characterization techniques proved that FM was rendered amorphous in the HME extrudate. In vitro dissolution studies showed that FM SD released significantly slower than the corresponding physical mixture in artificial saliva. Excipients were selected based on compression formability, disintegration, and solubility. A D-optimal mixture design was used to optimize the composition: 25% FM SD, 18.75% microcrystalline cellulose, 52.5% mannitol, 3.75% low-substituted hydroxypropyl cellulose, and 1% magnesium stearate. Taste-masked FM ODT had a tensile strength of 0.7 ± 0.01 MPa and a disintegration time of 17.6 ± 0.1 s. E-tongue and E-nose analysis showed that FM ODT had a better taste-masked effect than commercial granules. Finally, a pharmacokinetic study proved that the main pharmacokinetic parameters of FM ODT were not significantly different from those of commercial granules, which indicated that these formulations had similar pharmacokinetic behaviours in beagles.

Postoperative Ileus: Comparative Pathophysiology and Future Therapies

Postoperative ileus (POI), a decrease in gastrointestinal motility after surgery, is an important problem facing human and veterinary patients. 37.5% of horses that develop POI following small intestinal (SI) resection will not survive to discharge. The two major components of POI pathophysiology are a neurogenic phase which is then propagated by an inflammatory phase. Perioperative care has been implicated, namely the use of opioid therapy, inappropriate fluid therapy and electrolyte imbalances. Current therapy for POI variably includes an early return to feeding to induce physiological motility, reducing the inflammatory response with agents such as non-steroidal anti-inflammatory drugs (NSAIDs), and use of prokinetic therapy such as lidocaine. However, optimal management of POI remains controversial. Further understanding of the roles of the gastrointestinal microbiota, intestinal barrier function, the post-surgical inflammatory response, as well as enteric glial cells, a component of the enteric nervous system, in modulating postoperative gastrointestinal motility and the pathogenesis of POI may provide future targets for prevention and/or therapy of POI.

Meloxicam ameliorates the systemic inflammatory response syndrome associated with experimentally induced endotoxemia in adult donkeys

Background

Little information is available about endotoxemia in donkeys. Characterizing the systemic inflammatory response (SIRS) to lipopolysaccharide (LPS) in donkeys would provide valuable clinical and therapeutic information. The effects of meloxicam on endotoxemia have not been studied in this species.

Objectives

To study the pathophysiology and gene expression associated with experimentally induced endotoxemia, and evaluate the effects of meloxicam on experimentally induced endotoxemia in donkeys and in equine monocyte cultures.

Animals

Six healthy adult female donkeys.

Methods

Endotoxemia was induced by an IV infusion of LPS for 30 minutes. Animals either received 20 mL of saline or 0.6 mg/kg of meloxicam IV after LPS infusion. The experiments lasted 6 hours. Blood samples were collected serially for hematology, serum biochemistry, interleukin measurement, and leukocyte gene expression analysis. Vital signs were recorded throughout the study. Monocyte cultures were used to test the effects of meloxicam on LPS‐activated monocytes.

Results

Lipopolysaccharide induced fever, leukopenia, and neutropenia of similar magnitude in both groups, but meloxicam attenuated increases in plasma lactate, tumor necrosis factor‐alpha (TNFα), and interleukin 1β concentrations compared to controls. No differences were detected between groups for cytokine mRNA expression. Furthermore, meloxicam decreased TNFα release in LPS‐activated monocyte cultures.

Conclusions and Clinical Importance

Meloxicam could be a feasible option for the treatment of endotoxemia and SIRS in donkeys. Additional studies are necessary to investigate possible meloxicam‐related posttranscriptional regulation and to compare this drug with other nonsteroidal anti‐inflammatory drugs (NSAIDs) in animals with endotoxemia.

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 (overall certainty levels high). Butorphanol and buprenorphine should not be considered appropriate as sole analgesic for such procedures (high certainty). The panel recommend the continuation of analgesia for 3 days following castration (moderate certainty) and conclude that phenylbutazone provided superior analgesia to meloxicam and firocoxib for hoof pain/laminitis (moderate certainty), but that enhanced efficacy has not been demonstrated for joint pain. In horses with colic, flunixin and firocoxib are considered to provide more effective analgesia than meloxicam or phenylbutazone (moderate certainty). Given the risk of adverse events of all classes of analgesic, these agents should be used only under the control of a veterinary surgeon who has fully evaluated a horse and developed a therapeutic, analgesic plan that includes ongoing monitoring for such adverse events such as the development of right dorsal colitis with all classes of NSAID and spontaneous locomotor activity and potentially ileus with opiates. Finally, the panel call for the development of a single properly validated composite pain score for horses to allow accurate comparisons between medications in a robust manner.

Sparing the gut: COX-2 inhibitors herald a new era for treatment of horses with surgical colic

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to manage a wide variety of conditions in horses, including management of colic. Flunixin meglumine is by far the most commonly used drug in the control of colic pain and inflammation and has become a go-to for not only veterinarians but also horse-owners and nonmedical equine professionals. NSAID use, however, has always been controversial in critical cases due to a high risk of adverse effects associated with their potent cyclo-oxygenase (COX) inhibition. There are two important COX isoenzymes: COX-1 is generally beneficial for normal renal and gastrointestinal functions and COX-2 is associated with the pain and inflammation of disease. Newer selective NSAIDs can target COX-2-driven pathology while sparing important COX-1-driven physiology, which is of critical importance in horses with severe gastrointestinal disease. Emerging research suggests that firocoxib, a COX-2-selective NSAID labelled for use in horses, may be preferable for use in colic cases in spite of the decades-long dogma that flunixin saves lives.

Oral Administration of Meloxicam Suppresses Low-Dose Endotoxin Challenge-Induced Pain in Thoroughbred Horses

Nonsteroidal anti-inflammatory drugs such as flunixin meglumine have been used to treat signs of systemic inflammatory conditions, but it is also known to have the side effect to small intestine mucosa. It may be considered to be due to inhibition of both cyclooxygenase (COX)-1 and COX-2. On the other hand, meloxicam is widely used in equine clinical practice and an effective nonsteroidal anti-inflammatory drug with the preferential inhibitory effect on COX-2. However, it has not yet been evaluated in equine systemic inflammation. The aim of this study was to evaluate the effect of meloxicam administered 60 minutes prior lipopolysaccharide (LPS)-induced inflammatory response in five Thoroughbred horses using a crossover test. Clinical parameters including body temperature, heart rate, respiratory rate, behavioral pain score, and hoof wall surface temperature were recorded, and plasma tumor necrosis factor-alpha, cortisol, and leukocyte counts were measured at various times before and after LPS infusion for 420 minutes. At time points 60, 90 (P < .01), 120, and 180 (P < .05) minutes, pain scores were significantly lower in meloxicam-treated horses. There was no significant difference in other parameters. In the present study, we revealed the analgesic effect of meloxicam using an equine low-dose endotoxin model.

Multicentre, blinded, randomised clinical trial comparing the use of flunixin meglumine with firocoxib in horses with small intestinal strangulating obstruction

BACKGROUND

Small intestinal strangulating obstruction (SISO) is associated with endotoxaemia which leads to an increased risk of death. Nonsteroidal anti-inflammatory drugs (NSAIDs) are used to treat signs of endotoxaemia by inhibiting cyclo-oxygenases (COX). COX-1 is expressed constitutively and promotes gut barrier function, whereas COX-2 is inducible and contributes to the signs of endotoxaemia. In preclinical SISO trials, intestinal barrier recovery was more complete with reductions in endotoxin permeability in horses treated with COX-2 selective NSAIDs as compared with horses treated with flunixin meglumine.

OBJECTIVES

We hypothesised that treatment of post-surgical SISO horses with firocoxib (COX-2 selective) would reduce the signs of endotoxaemia to a greater extent than flunixin meglumine (nonselective COX inhibitor) while continuing to provide similar levels of pain control.

STUDY DESIGN

Blinded randomised clinical trial.

METHODS

In addition to clinical monitoring, preoperative and 12-, 24- and 48-h post-operative plasma samples were assessed for prostaglandin E₂ (PGE₂ ), thromboxane B₂ (TXB₂ ), TNF⍺ and soluble CD14 (sCD14).

RESULTS

In 56 recruited SISO horses, either flunixin meglumine (1.1 mg/kg, i.v., q12h) or firocoxib (0.3 mg/kg, i.v. loading dose; 0.1 mg/kg, i.v., q24h) was given in the post-operative period in three university hospitals from 2015 to 2017. COX-2 selectivity was confirmed by a relative lack of inhibition of the COX-1 prostanoid TXB₂ by firocoxib and significant inhibition by flunixin meglumine (P = 0.014). Both drugs inhibited the COX-2 prostanoid PGE₂ . There were no significant differences in pain scores between groups (P = 0.2). However, there was a 3.23-fold increased risk (P = 0.04) of increased plasma sCD14 in horses treated with flunixin meglumine, a validated biomarker of equine endotoxaemia.

MAIN LIMITATIONS

Horses were all treated with flunixin meglumine prior to referral. In addition, many horses were treated with lidocaine, which has been shown to mitigate the deleterious effects of flunixin meglumine.

CONCLUSIONS

In SISO cases, firocoxib reduced a biomarker of endotoxaemia as compared with flunixin meglumine while continuing to provide similar levels of pain control.

Proportion of nonsteroidal anti-inflammatory drug prescription in equine practice

BACKGROUND

There is little knowledge of the prescription of nonsteroidal anti-inflammatory drugs (NSAIDs) and whether their prescription varies between countries.

OBJECTIVE

To describe prescription practices of NSAIDs in equids in the United Kingdom (UK), United States of America (USA) and Canada.

STUDY DESIGN

Descriptive observational study.

METHODS

Free-text electronic medical records from 141,543 equids from 10 equine practices in the UK, 255,777 equids from 7 equine practices with 20 branches from the USA and 2 practices with 7 branches from Canada were evaluated. A validated text-mining technique was used to describe the proportion of equids prescribed NSAIDs at least once in these countries. The choice of NSAIDs in orthopaedic and colic cases was evaluated.

RESULTS

The prescription of NSAIDs is more common in the USA (42.4%) and Canada (34.2%) than in the UK (28.6%). Phenylbutazone and flunixin meglumine were the drugs mostly prescribed in all countries. While flunixin meglumine was most prescribed with colic cases in all countries, a proportion received phenylbutazone despite this drug being licensed for use only with musculoskeletal disease. Phenylbutazone was the most commonly prescribed drug in cases with orthopaedic disease followed by flunixin meglumine in all countries. Only a small proportion of cases received meloxicam, ketoprofen or firocoxib.

MAIN LIMITATIONS

The retrospective design might have resulted in an unknown number of incomplete records, particularly in the reporting of colic and orthopaedic disease. Although the data set is large, the relatively small number of practices recruited from each country may introduce bias.

CONCLUSIONS

Clinical practice can differ between countries although the influence of individual practitioners and practice-specific policy on apparent intercountry differences requires further research. Despite several other NSAIDs being available and a substantial effort being made to evaluate their efficacy, the prescription of NSAIDs other than phenylbutazone and flunixin meglumine remains rather limited.

Advances in Diagnostics and Treatments in Horses with Acute Colic and Postoperative Ileus

Differentiating between medical and surgical causes of colic is one of the primary goals of the colic workup, because early surgical intervention improves prognosis in horses requiring surgery. Despite the increasing availability of advanced diagnostics (hematologic analyses, abdominal ultrasound imaging, etc), the most accurate indicators of the need for surgery remain the presence of moderate to severe signs of abdominal pain, recurrence of pain after appropriate analgesic therapy, and the absence of intestinal borborygmi. Investigation of novel biomarkers, which may help to differentiate surgical lesions from those that can be managed medically, continues to be an active area of research.

Occurrence, treatment protocols, and outcomes of colic in horses within Nairobi County, Kenya

Aim:

The aim of this study was to determine the treatments and their outcomes in horses with colic in Nairobi County, Kenya.

Materials and Methods:

This is a retrospective study to determine the occurrence, treatments, pain management, and outcomes of colic in horses in Nairobi County. Association between pain management protocols and the outcomes of colic with regard to recovery or death was also determined. Data collected from four equine practitioners were organized manually and given numerical codes as appropriate to facilitate entry into the computer. The coded data were entered into Microsoft Excel 2010 and exported to StatPlus pro 5.9.8 statistical package for analysis. Simple association tests were done between various factors and occurrence of colic.

Results:

The incidence of colic for the 11 years was 3.1%, which constituted 68.0% spasmodic colic, 27.8% impaction colic, and 4.2% displacement colic. Flunixin meglumine as a nonsteroidal anti-inflammatory drug (NSAID) was used as the only pain management treatment in 85.3% of the cases, flunixin meglumine and butorphanol as NSAID-OPIOD combination in 6.4% of the cases, while buscopan as an antispasmodic was recorded in 5.9% of the cases mainly in spasmodic colic. Univariate analysis revealed simple association between various factors and the type of colic a horse was having. There was an association between the type of colic and the decision-making on the pain management protocol to use, whether single analgesic protocol (χ²=22.5, p<0.001) or use of analgesic combinations (χ²=18.3, p<0.001). The type of colic strongly influenced the decision for performing nasogastric intubation (χ²=265, p<0.001), but performing nasogastric intubation was weakly (χ²=4.9, p=0.03) associated with horse recovery from colic. Type of colic also strongly influenced the need for the use of metabolic stimulants, particularly vitamin B-complex (χ²=99.3, p<0.001). Recovery or death of the horse from colic was strongly associated with the type of colic (χ²=250, p<0.001). The possibility of recurrence of colic was weakly (χ²=4.6, p=0.04) determined by the type of colic, a horse had. Multivariate logistic regression revealed that the main cause of death was intestinal displacement and the majority of the horses with intestinal displacement died (β-estimate 2.7, odds ratio=0.07, p=0.007) compared to horses that had impaction colic.

Conclusion:

The incidence of colic is 3.1%, and the most common type of colic is spasmodic followed by impaction. The most common pain management protocol for colic is NSAIDs, mainly flunixin meglumine, followed by flunixin-butorphanol combination. Surgery for horses with colic in Nairobi County is not commonly done due to impeding poor prognoses. The horse owners tend to prefer euthanasia for such cases.

Update on the use of cyclooxygenase-2-selective nonsteroidal anti-inflammatory drugs in horses

Nonsteroidal anti-inflammatory drugs work through inhibition of cyclooxygenase (COX) and are highly effective for the treatment of pain and inflammation in horses. There are 2 clinically relevant isoforms of COX. Cyclooxygenase-1 is constitutively expressed and is considered important for a variety of physiologic functions, including gastrointestinal homeostasis. Thus, NSAIDs that selectively inhibit COX-2 while sparing COX-1 may be associated with a lower incidence of adverse gastrointestinal effects. Various formulations of firocoxib, a COX-2-selective NSAID, labeled for use in horses are available in the United States. Equine practitioners should know that the FDA limits the use of firocoxib to formulations labeled for horses, regardless of price concerns. In addition, practitioners will benefit from understanding the nuances of firocoxib administration, including the importance of correct dosing and the contraindications of combining NSAIDs. Together with knowledge of the potential advantages of COX-2 selectivity, these considerations will help veterinarians select and treat patients that could benefit from this new class of NSAID.

Pain Management in Horses

There has been great progress in the understanding of basic neurobiologic mechanisms of pain, but this body of knowledge has not yet translated into new and improved analgesics. Progress has been made regarding pain assessment in horses, but more work is needed until sensitive and accurate pain assessment tools are available for use in clinical practice. This review summarizes and updates the knowledge concerning the cornerstones of pain medicine (understand, assess, prevent, and treat). It highlights the importance of understanding pain mechanisms and expressions to enable a rational approach to pain assessment, prevention, and management in the equine patient.

Treatment of endotoxaemia and septicaemia in the equine patient

Endotoxins, constituents of the cell wall of gram-positive and gram-negative bacteria, regularly result in severe illness and death in horses. In endotoxaemia, these constituents are present in the systemic circulation; in septicaemia, whole microbes invade normally sterile parts of the body. Interaction of these endotoxins with pathogen recognition receptors leads to an inflammatory response that cannot always be sufficiently contained and hence needs direct treatment. Over the last decennia, our understanding of the pathophysiology of endotoxaemia and septicaemia has significantly increased. Based on improved understanding of the interaction between receptors and endotoxins as well as the subsequent downstream signalling pathways, new therapeutic targets have been identified in laboratory animal species and humans. Important species differences in the recognition of endotoxins and pathogens by their receptors as well as the inflammatory response to receptor activation hamper extrapolation of this information to the horse (and other species). Historically, horses with endotoxaemia and septicaemia have been treated mainly symptomatically and supportively. Based on the identified therapeutic targets, this review describes the current knowledge of the treatment for endotoxaemia and septicaemia in the horse with reference to the findings in other animal species and humans.

Prevention of post operative complications following surgical treatment of equine colic: Current evidence

Changes in management of the surgical colic patient over the last 30 years have resulted in considerable improvement in post operative survival rates. However, post operative complications remain common and these impact negatively on horse welfare, probability of survival, return to previous use and the costs of treatment. Multiple studies have investigated risk factors for post operative complications following surgical management of colic and interventions that might be effective in reducing the likelihood of these occurring. The findings from these studies are frequently contradictory and the evidence for many interventions is lacking or inconclusive. This review discusses the current available evidence and identifies areas where further studies are necessary and factors that should be taken into consideration in study design.

The use of nonsteroidal anti-inflammatory drugs in critically ill horses

OBJECTIVE

To review the physiology of the cyclooxygenase (COX) enzymes with reference to the beneficial effects of nonsteroidal anti-inflammatory drugs (NSAIDs) related to their analgesic and antiendotoxic properties as well as the mechanisms responsible for adverse gastrointestinal, renal, and coagulation effects.

DATA SOURCES

Human and veterinary peer reviewed literature

VETERINARY DATA SYNTHESIS

NSAIDs are frequently administered to critically ill horses for their analgesic and anti-inflammatory effects. However, NSAIDs have significant side effects principally on the gastrointestinal mucosa and kidneys. These side effects may be exacerbated in critically ill horses if they have gastrointestinal damage or are volume depleted

CONCLUSIONS

This review provides important information for equine veterinarians and criticalists on the advantages and disadvantages of using traditional NSAIDs and newer equine COX-2 selective NSAIDs for the management of different conditions in critically ill horses.