Non-steroidal anti-inflammatory drugs in equine orthopaedics

Assessing the inflammatory response in horses undergoing gastric ulceration using salivary ADA and S100A12 as biomarkers

The inflammatory status in horses with gastric ulcers was monitored by two inflammatory biomarkers, S100A12 and adenosine deaminase (ADA), using saliva samples from healthy and horses with gastric ulcers. Two trials were developed: an experimental trial, in which gastric ulceration was induced in 8 horses by feed deprivation, and a clinical trial, in which 20 horses without any symptomatology and 37 with symptoms compatible with gastric ulcers were used. S100A12 and ADA levels were measured in the saliva samples of all horses using previously validated assays. In both trials, horses with gastric ulcers had higher levels of S100A12 and ADA than healthy horses, demonstrating that inflammation is involved in the pathophysiology of gastric ulcers in horses. An intense reaction of ADA with a moderate increase of S100A12 was detected in the experimental trial, while different intensities in the inflammatory biomarkers were observed in clinical conditions when the ulcers were divided by gastric localization in glandular (EGGD) and squamous (ESGD). Since ADA has been shown to be released early in the inflammatory process and S100A12 is released later, by measuring them together we could more accurately assess the inflammatory process in equine gastric ulcers. Furthermore, a strong association was found between ADA and S100A12 (correlation coefficient of 0.84) in the experimental trial, while it was low-moderate (correlation coefficient of 0.39) in the clinical trial. Therefore, it could be concluded that both salivary biomarkers provide valuable information about the inflammation involved in gastric ulcers of horses and the state of the process.

Comparison of the chondrogenic potential of eBMSCs and eUCMSCs in response to selected peptides and compounds

BACKGROUND

Cartilage injuries pose significant challenges in horses and often lead to post-traumatic osteoarthritis (PTOA). Despite the advances in surgical and regenerative techniques, the result in most cases is the formation of a fibrocartilage repair tissue. Cell-based cartilage therapies are mainly focused on equine bone marrow-derived mesenchymal stem cells (eBMSCs) as they are easily accessible, and multipotent. Nonetheless, alternative allogeneic sources, for example equine umbilical cord matrix mesenchymal stromal cells (eUCMSCs), hold promise given their non-invasive and readily accessible nature. Considerable research has been dedicated to exploring chondroinductive factors (e.g., peptides and small compounds), aiming to replace growth factors for inducing chondrogenesis. However, these factors have not yet translated to the equine community. Therefore, in the current study, we selected from the literature two promising peptides, CM10 and CK2.1, and two promising compounds, kartogenin and SM04690, and assessed their chondroinductive potential with both eBMSCs and eUCMSCs. In addition, the chondroinductive potential of eBMSCs was evaluated in monolayer and spheroid culture in both hypoxia and normoxia in response to dexamethasone and/or transforming growth factor beta 3 (TGF-β3).

RESULTS

Following 21 days of culture, none of the evaluated chondrogenic factors resulted in a higher gene expression of chondrogenic markers compared to the positive or negative controls with eBMSCs or eUCMSCs. Interestingly, spheroid culture in hypoxia with dexamethasone treatment (without TGF-β or any compound or peptide) was sufficient to induce the chondrogenic differentiation of eBMSCs.

CONCLUSION

Based on cell response to the positive control, in the conditions employed in the current study, eBMSCs may be preferred over eUCMSCs for chondrogenesis. The current study supports the use of spheroid culture, and the use of dexamethasone over TGF-β or any of the compounds or peptides tested here from the prior literature to drive chondrogenesis with eBMSCs.

Analgesic efficacy of tapentadol in chronic joint disorders in horses: plasma serotonin concentration and adrenocortical response as biomarkers of pain-induced stress

The study aimed to evaluate the analgesic efficacy of tapentadol in horses, by determining plasma serotonin concentration and adrenocortical response, as biomarkers of pain stress in chronic joint disorders. Thirty-six horses (20 females and 16 males) were divided into three groups of 12 subjects each: group A, osteoarthritis (OA), grade 3-4 lameness; group B, OA, grade 5 lameness; and group C, no OA, no lameness, were enrolled. The orthopedic examination included flexion tests, and radiological and ultrasound examinations. The degree of lameness has been estimated from 0 to 5 according to the American Association of Equine Practitioners (AAEPs). Heart and respiratory rates (HR and RR) and blood pressure were recorded. Serotonin concentration and circulating cortisol levels were determined at baseline and the end of every week for 4 weeks. Biochemical parameters were recorded at baseline and the end of treatment with tapentadol. Subjects with OA were treated with tapentadol 0.5 mg kg-1. The response to painful stimulus on flexion tests was evaluated using the modified numeric pain rating scale (modified NRS 0-7) from baseline and the cumulative pain score (CPS 0-4) after the first week of treatment with tapentadol. The lameness decreased throughout the timeline in both groups (score from 3-4 to 1 in group A and score from 5 to 1 in group B) (p < 0.05). The NRS score decreased throughout the timeline (p < 0.05), from mild pain to no pain in group A (score 1-3 to 0) and from moderate pain to no pain in group B (score from 4 to 0). Physiological variables remained within the physiological range throughout the timeline. Cumulative pain scores ranged from 0.5 to 4 in group A and 1.5 to 7 in group B (p = 0.008). Serotonin concentrations remained unchanged throughout the timeline in all groups (p = 1.000) but in the OA groups, the concentrations were lower than control (p < 0.001). Circulating cortisol levels were reduced compared to baseline in subjects treated with tapentadol (p < 0.001). Tapentadol is effective in OA pain management in horses. Serotonin and cortisol may be utilized as biomarkers in the pain stress response. Serotonin can also determine the state of wellbeing of patients.

A retrospective comparison of postoperative outcomes in ovariectomised jennies (Equus asinus) treated with phenylbutazone or flunixin meglumine

BACKGROUND

Clinically, flunixin meglumine (FM) and phenylbutazone (PBZ) are preferentially selected for the treatment of visceral and musculoskeletal pain, respectively, in horses. In donkeys, there is no information to support or refute this conventional conjecture.

OBJECTIVES

To compare postoperative outcomes in a group of jennies treated with intravenous FM or oral PBZ.

ANIMALS

Fourteen jennies unilaterally ovariectomised by standing left flank laparotomy.

STUDY DESIGN

Retrospective cohort study.

METHODS

Data from medical records of ovariectomised jennies (case details, weight, non-steroidal anti-inflammatory drug [NSAID] protocol, surgery duration, operative sequence, anaesthesia protocol, physical examination findings and outcomes) were collected. From collated data, postoperative adverse events were defined as fever, tachycardia, tachypnea, inappetence, altered mentation, abnormal oral mucous membranes, bruxism, colic, incisional complications (i.e., drainage, oedema, peri-incisional emphysema and pain) and non-survival, then further divided into occurrence during the early (≤24 h) or late (>24 h) postoperative period for data analysis using R software. Chi-squared test was used to compare individual adverse events between groups (PBZ vs. FM) and moments (early vs. late). Significance was set at p ≤ 0.05.

RESULTS

PBZ treatment (8/14) was associated with (odds ratio, 95% confidence interval) more total (2.93, 1.97-4.36), early (3.01, 1.87-4.84) and late (2.69, 1.28-5.63) adverse events than FM treatment (6/14). Tachycardia (37.83, 2.21-646.66), tachypnoea (0.29, 0.13-0.66), altered mentation (2.78, 1.01-7.67), altered mucous membranes (18.38, 1.04-325.23), incisional oedema (44.33, 2.60-754.5) and incisional pain (47.78, 2.81-811.61) were significantly different between groups. Early adverse events significantly different between groups included tachycardia (50.2, 2.9-877.0), altered mentation (3.33, 1.08-10.29) and incisional pain (21.0, 1.2-374.5), with late adverse events being tachypnea (0.07, 0.01-0.62), incisional oedema (32.92, 1.85-584.28) and incisional pain (28.92, 1.62-515.68). Colic (2/8) and non-survival (1/8) were rare events that only occurred in the PBZ cohort and could not be further evaluated for differences.

MAIN LIMITATIONS

Small sample size; retrospective study; treatment bias; varied administration routes.

CONCLUSIONS

Oral PBZ may be inappropriate to use following abdominal surgery in donkeys.

CLINICAL RELEVANCE

More prospective and case-controlled studies are needed to evaluate the clinical efficacy of these two NSAIDs in donkeys.

Evaluation of gastrointestinal tract lesions and serum malondialdehyde levels after repeated oral administration of phenylbutazone in horses

Phenylbutazone (PBZ) is a widely used nonsteroidal anti-inflammatory drug for horses. However, because of its gastrointestinal side effects, its administration requires careful attention in veterinary practice. Malondialdehyde (MDA) is a serum biomarker associated with increased damage to the equine gastrointestinal system. This study investigated the hematological effects and alterations in the gastrointestinal tract and assessed serum MDA concentrations following repeated oral PBZ administration at clinical doses. Fourteen horses were randomly divided into control and treatment groups. All horses in the treatment group were administered 4.4 milligrams per kilogram of body weight of PBZ syrup orally twice a day for 7 days, whereas the control group received syrup as a placebo. The development of gastrointestinal side effects was investigated using gastroscopy, abdominal ultrasound, and fecal pH; serum MDA concentrations were assessed using a commercially available enzyme-linked immunosorbent assay kit. Data were compared between PBZ-treated and control horses before and after the treatment period. The treatment group exhibited decreased albumin and total protein concentrations. Moreover, this group exhibited a higher thickness of the right dorsal colon wall (p = 0.03) and had higher scores for squamous gastric ulcers (p = 0.01). Fecal pH was lower in the treatment group than in the control group after PBZ administration (p < 0.01). Although MDA concentrations were higher in the treatment group after PBZ administration, they did not differ significantly from those of the control group. This study highlighted the changes in hematological and gastrointestinal lesions resulting from PBZ administration in horses at clinical doses, even without clinical signs. However, MDA may not be an optimal biomarker for the early detection of gastrointestinal damage due to PBZ treatment in horses.

Functional infrared thermography imaging can be used to assess the effectiveness of Maxicam Gel® in pre-emptively treating transient synovitis and lameness in horses

Introduction

Diagnosing and treating lameness in horses is essential to improving their welfare. In equine orthopedic practice, infrared thermography (IRT) can indirectly detect soreness. Non-steroidal anti-inflammatory drugs can treat painful and inflammatory processes in horses. Using IRT, the efficacy of meloxicam (Maxicam Gel®) was evaluated in pre-treating transient synovitis in horses induced by a middle carpal joint injection of lipopolysaccharides (LPS) from E. coli 055:B5 at a dose of 10 endotoxin units.

Methods

In a cross-over design, six healthy horses were randomly assigned to receive either 0.6 mg/kg of oral Maxicam Gel® (MAXVO) or a mock administration (control group, C) following a two-week washout period. IRT of the middle carpal joint, visual lameness assessment and joint circumference were recorded over time. Clinical and hematological evaluations were performed. Synovial fluid aspirates were analyzed for total nucleated cell count, total protein, and prostaglandin E2. A mixed effects analysis of variance was performed for repeated measures over time, followed by Tukey's test. A multinomial logistic regression was conducted to determine whether there is a relationship between a thermography temperature change and the lameness score.

Results

There were no changes in joint circumference. The MAXVO group showed a lower rectal temperature 4 h after synovitis induction. The C group presented an increase in neutrophils and a decrease in total hemoglobin and hematocrit 8 h after induction. No changes were observed in the synovial fluid between groups. The horses that received meloxicam did not show clinically significant lameness at any time, while the C group showed an increase in lameness 2, 4, and 8 h after synovitis induction.

Discussion

IRT indicated that the skin surface temperature of the middle carpal joint was lower in horses who received meloxicam, suggesting a reduction in the inflammatory process induced by LPS. It was observed that the maximum temperature peaks in the dorsopalmar and lateropalmar positions can be utilized to predict the severity of lameness, particularly when the temperature rises above 34°C. Horses pre-treated with meloxicam showed either reduced or no indication of mild to moderate pain and presented a lowehr thermographic temperature, which indicates the effectiveness of Maxicam Gel® as an anti-inflammatory.

Pharmacokinetics of meloxicam in pigeons after single intravenous, oral, and intramuscular administration

This study aimed to determine the pharmacokinetics of meloxicam in pigeons. Twenty-four 7-wk-old meat pigeons (Columba livia) were randomly divided into 3 groups (PO, IM, and IV) and given a single dose of 1 mg/kg body weight of meloxicam. Plasma samples were taken at predetermined times, which were then analyzed using a validated high-performance liquid chromatography (HPLC) method and subjected to noncompartmental analysis using Phoenix software. Results indicated that meloxicam was absorbed effectively and quickly after PO and IM dosing. Peak concentrations (0.83 ± 0.21 and 1.59 ± 0.49 μg/mL) were achieved at 2 and 0.26 h, respectively, with mean absorption times of 2.56 ± 1.50 and 1.47 ± 0.89 h. Bioavailability was high at 86.31 ± 43.45% and 81.57 ± 52.58%, respectively, and the area under the concentration-time curve (AUC0-∞) was 5.33 ± 2.68 and 5.03 ± 3.26 h·µg/mL. After IV administration, the elimination was faster with a total body clearance (CL) of 188.75 ± 83.23 mL/h/kg, an elimination half-life (t1/2λz) of 1.76 ± 0.56 h, and a volume of distribution at steady-state (VSS) of 427.50 ± 188.43 mL/kg. Considering the lack of a precise analgesic threshold of meloxicam in pigeons and the notable differences in its analgesic threshold among various animal species, formulating a dosing regimen in pigeons presented a significant challenge. Based on the previous analgesic threshold (3.5 μg/mL) in parrots, a higher dose (e.g., 2 mg/kg) or shorter dosing interval (e.g., every 6 h) is recommended for treating pain in pigeons. Nonetheless, further pharmacodynamic research is required to verify these recommendations.

Equine Gastric Ulcer Syndrome: An Update on Current Knowledge

Equine Gastric Ulcer Syndrome (EGUS) is a term that has been used since 1999, initially being used to describe all gastric mucosal disease in horses. Since this time, the identification of two distinct main disease entities of the equine gastric mucosa have been described under the umbrella of EGUS; these are Equine Squamous Gastric Disease (ESGD) and Equine Glandular Gastric Disease (EGGD). In 2015 the European College of Equine Internal Medicine (ECEIM) released a consensus statement defining these disease entities. This document highlighted the lack of evidence surrounding EGGD compared to ESGD, and identified knowledge gaps for further research to be directed. Subsequently, many studies on EGGD have been published, especially on pathophysiology, diagnosis, and treatment. This article updates current knowledge on both ESGD and EGGD as understanding has evolved since the last large-scale review.

The Optimal Period of Staged Bilateral Total Knee Arthroplasty Procedures under Enhanced Recovery: A Retrospective Study

OBJECTIVE

The implications of the interval of staged bilateral total knee arthroplasty (TKA) procedures for postoperative complications and costs are not clear. We aimed to determine the optimal time interval between the two stages of bilateral TKA procedures under the enhanced recovery after surgery (ERAS) protocol.

METHODS

This retrospective study of collected data included bilateral TKA cases under the ERAS protocol performed between 2018 and 2021 at the West China Hospital of Sichuan University. The staged time was subdivided into three groups according to the interval between the first TKA and second contralateral TKA: group 1: 2- to 6-month, group 2: 6- to 12-month, and group 3: >12 months. The primary outcome was the incidence of postoperative complications. The secondary outcomes were the length of hospital stay (LOS), hemoglobin (Hb) decrease, hematocrit (Hct) decrease, and albumin (Alb) decrease.

RESULTS

We analyzed 281 patients who underwent staged bilateral TKAs between 2018 and 2021 at the West China Hospital of Sichuan University. Regarding postoperative complications, there were no statistically significant differences among the three groups (P = 0.21). For the mean LOS, the 6- to 12-month group had a significantly shorter LOS compared with the 2- to 6-month group (P < 0.01). There was also a significant decrease in Hct of the 2- to 6-month group compared with the 6- to 12-month group and the >12 months group (P = 0.02; P < 0.05, respectively).

CONCLUSION

Staging the second arthroplasty for more than a half year seems to offer a reduction in the rate of postoperative complications and LOS under ERAS protocol. ERAS shortens the interval of staged bilateral TKA by at least 6 months for patients who might receive their second surgery without the need to wait for an extended period.