Safety Assessment of an Oral Therapeutic Dose of Firocoxib on Healthy Horses

I remain uncertain about the coagulopathy problem stated below, the literature seems conflicted on this. However the conclusion: Administering firocoxib to horses is safe as it does not cause significant adverse reactions. seems spot on and this remains my go-to NSAID for longer-term administration to horses. Note in the article above about initial dose recommendations.
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Safety Assessment of an Oral Therapeutic Dose of Firocoxib on Healthy Horses
Vet Sci. 2023 Aug 22;10(9):531. doi: 10.3390/vetsci10090531.
Authors
Renatha A Araújo 1 , Nathali A A Sales 1 , Roberta C Basile 1 , Walter H Feringer-Junior 2 , Maricy Apparício 3 , Guilherme C Ferraz 1 , Antonio Queiroz-Neto 1
Affiliations

1 Laboratory of Equine Exercise Physiology and Pharmacology (LAFEQ), Department of Animal Morphology and Physiology, School of Agricultural and Veterinary Studies, São Paulo State University, FCAV/UNESP, Via de Acesso Prof. Paulo D. Castellane s/n., Jaboticabal 14884-900, SP, Brazil.
2 Department of Veterinary Medicine, Metropolitan University of Santos, UNIMES, Av. Gen. Francisco Glicério, 8, Santos 11045-002, SP, Brazil.
3 Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Rua Professor Doutor Walter Mauricio Correa, s/n., Botucatu 18618-681, SP, Brazil.

PMID: 37756053
DOI: 10.3390/vetsci10090531

Abstract

Firocoxib is a non-steroidal anti-inflammatory drug specifically formulated for veterinary medicine and selectively acts on inhibiting the cyclooxygenase 2 enzyme (COX-2). This study evaluated the possible adverse effects of administering oral therapeutic firocoxib on gastric mucosa, hematological parameters, coagulation cascade, and hepatic and renal biochemistry in healthy horses. Nine clinically healthy Arabian horses, approximately 9 years old, received 0.1 mg/kg of oral firocoxib for 14 days. The gastroscopic examination was conducted 1 day before starting treatment (D0) and two days after the last blood collection (D23). Venous blood samples were obtained for laboratory tests on day 1, immediately prior to the initiation of treatment (D1), after 7 and 14 days of treatment (D7 and D14), and 7 days after the conclusion of treatment (D21. No changes were found in the gastroscopic and hematological tests. Coagulation and serum biochemistry levels remain between these species’ average values. However, the increased activated partial thromboplastin time (aPTT) and prothrombin time (PT) indicate reduced blood coagulation capacity, which contradicts the expected effect of treatment with selective COX-2 inhibitors, as these drugs theoretically promote coagulation. Administering firocoxib to horses is safe as it does not cause significant adverse reactions. Therefore, it is a suitable option for managing inflammatory conditions in these animals with attention to an unexpected adverse anti-coagulopathy effect, and further study is warranted.

Keywords: coagulation; drug safety; firocoxib; gastroscopy; hematology; selective COX-2 inhibitor.