Effect of selective versus nonselective cyclooxygenase inhibitors on gastric ulceration scores and intestinal inflammation in horses.
Authors: Richardson Lauren M, Whitfield-Cargile Canaan M, Cohen Noah D, Chamoun-Emanuelli Ana M, Dockery Hannah J
Journal: Veterinary surgery : VS
Summary
# Editorial Summary Gastric ulceration remains a significant concern when administering nonsteroidal anti-inflammatory drugs to horses, yet limited evidence directly compares the gastrointestinal safety profiles of selective versus non-selective cyclooxygenase inhibitors in this species. Researchers conducted a randomised controlled trial in 25 healthy adult horses, administering either placebo, phenylbutazone (non-selective COX inhibitor), or firocoxib (COX-2 selective), daily for 10 days, with gastroscopic examination and fecal myeloperoxidase analysis at predetermined intervals to assess both gastric ulceration severity and intestinal inflammation. Phenylbutazone resulted in significantly higher glandular ulceration scores and elevated fecal myeloperoxidase concentrations compared to firocoxib, whilst firocoxib-induced inflammatory markers returned to baseline within 10 days of treatment cessation, unlike the phenylbutazone group. Whilst both drug classes induced measurable gastrointestinal injury, firocoxib demonstrated a considerably safer profile at the dosages studied, producing less severe ulceration and a faster resolution of intestinal inflammation. These findings support selective COX-2 inhibition as the preferable choice for prolonged NSAID therapy in horses requiring analgesia, particularly in animals with pre-existing gastric or colonic compromise, though clinicians should remain vigilant regarding individual variation in drug response.
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Practical Takeaways
- •If NSAID therapy is necessary in horses, firocoxib causes less severe gastric and intestinal damage than phenylbutazone, suggesting it may be the safer choice for GI health
- •Both common NSAIDs cause GI injury even at standard dosages; consider gastric and intestinal protective strategies or alternatives when possible, particularly for prolonged treatment
- •Firocoxib shows faster GI recovery after treatment cessation (within 10 days), whereas phenylbutazone effects persist longer—factor this into treatment planning and monitoring protocols
Key Findings
- •Both phenylbutazone and firocoxib induced gastric ulceration and intestinal inflammation, but phenylbutazone caused significantly higher glandular ulceration scores (P < 0.001)
- •Fecal myeloperoxidase (MPO) concentrations were significantly elevated only in the phenylbutazone group at day 10 (P = 0.0018), indicating greater intestinal inflammation
- •Firocoxib showed faster recovery with fecal MPO returning to near-baseline levels 10 days post-treatment, whereas phenylbutazone group remained elevated
- •COX-2 selective inhibitor (firocoxib) demonstrated less severe glandular gastric ulceration compared to non-selective COX inhibitor (phenylbutazone)