Peer-reviewed veterinary case report
Effects of ketorolac eye drops on blood and stool tests in healthy
By Mendes, Matheus Anthony et al.·Published in Veterinary ophthalmology·2026·Faculdade de Medicina Veteriná, Brazil·View original on PubMed →
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Original publication title: Systemic Effects of Ocular Instillation of 0.4% Ketorolac Trometamol and Luminol-Based Detection of Fecal Occult Blood in Healthy Cats.
- Species:
- cat
Plain-English summary
A group of healthy cats received eye drops containing 0.4% ketorolac trometamol three times a day for 15 days to see if it affected their health. By the end of the study, the cats showed some changes in their blood tests, including higher cholesterol and lower potassium levels, but these were still within normal ranges. However, 10 out of 12 cats tested positive for hidden blood in their stool after treatment, indicating possible gastrointestinal bleeding. The study suggests that while the eye drops were generally safe, they could cause some liver and gastrointestinal issues in healthy cats.
People also search for: cat eye drops side effects · cat gastrointestinal bleeding symptoms · ketorolac for cats safety
Abstract
OBJECTIVES: To assess the impact of thrice-daily instillation of 0.4% ketorolac trometamol (KT) over 15 days on blood count, serum biochemistry, and urinalysis in healthy cats. Additionally, we tested the efficacy of luminol to detect fecal occult blood (FOB) in feces. METHODS: A placebo-controlled, randomized study was conducted with 24 healthy cats. In 12 cats, each eye received either 40 μL of KT or saline (S) every 8 h for 15 days. An additional 12 cats received saline in both eyes and served as controls (S). Baseline blood count, serum biochemical analysis, urinalysis, and FOB testing were performed before the study and after each 15-day treatment period. RESULTS: Baseline blood count, serum biochemistry, and urinary values were within reference limits for both treatments. By day 15, increased cholesterol (p = 0.002) and decreased potassium (p = 0.01) levels were observed in KT. Despite these changes, all measurements remained within reference limits, except for ALT, which significantly increased at day 15 in KT when compared to baseline (p = 0.01) and S (p = 0.003). At baseline, all fecal samples from KT and S tested negative for FOB. By day 15, 10 of 12 KT samples tested positive for FOB (p < 0.0001). CONCLUSION: This study demonstrates that thrice-daily instillation of KT for 15 days induces a subclinical hepatocellular injury and gastrointestinal bleeding, with potential effects on potassium levels in healthy cats. Luminol proved to be a reliable test for detecting fecal occult blood in the feces of healthy cats.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/41532761/