Effects of prolonged use of meloxicam in healthy horses: clinical, laboratory, gastroscopic, and electrocardiographic findings

Abstract

Non-steroidal anti-inflammatory drugs are extensively used in veterinary practice. COX-2 inhibitors are considered to be safer than non-selective inhibitors; however, there are few studies address of their long-term use in equine species. The goal of this study was to identify the possible adverse effects of meloxicam (a preferential COX-2 inhibitor) in healthy horses, administered at a dose of 0.6 mg/kg, orally, once a day, for 28 days. A paired test was performed with seven animals, and the clinical, hematological, biochemical, and gastroscopic parameters, as well as bleeding time, were evaluated in five timepoints and an electrocardiogram at three timepoints. No relevant adverse effects were observed in terms of the parameters evaluated. Significant differences were found in heart rate, AST and P wave duration, segmented neutrophils (%), and the levels of erythrocytes, hemoglobin, hematocrit, and MCH, compared with these parameters at T0; however, no animal manifested clinical alterations. Gastroscopy revealed discrete lesions (Grade 1) in the squamous gastric mucosa on day 14 of treatment in all animals; however, at the end of the study (day 28) these lesions had regressed to grade 0 in three of the horses and remained at grade 1 in the other four animals. Based on these results, we conclude that the use of meloxicam at a daily dose of 0.6 mg/kg, orally, for 28 consecutive days, did not cause relevant adverse effects in healthy horses.

Keywords

• Adverse effect
• Anti-inflammatory
• electrocardiogram
• Gastroscopy
• Equine.