A recent study at Louisiana State University evaluated the clinical safety of an oral paste formulation of firocoxib in clinically healthy pony foals in a randomized controlled clinical trial. Firocoxib belongs to the coxib class of non-narcotic, non-steroidal, anti-inflammatory drugs.
In the past, little research has been done on the safety of firocoxib use in horses less than one year of age, horses used for breeding and pregnant or lactating mares.
Values for complete blood count, serum chemistry profile, urinalysis, pharmacokinetic assay, and gastric endoscopy were evaluated in eighteen Shetland pony foals treated with firocoxib or placebo for 14 days.
Safety of firocoxib use in foals
None of the foals presented adverse clinical effects after use of firocoxib and changes of pretreatment gastric endoscopy scores were not significantly different from evaluations at 7 and 14 days.
Foals were divided into 3 treatment groups. Group 1 and 2 foals received firocoxib while a 3rd group was administered an oral placebo.
Gastric endoscopy was performed on group 1 and 3 foals prior to treatment and on days 7 and 14 to monitor for the presence of gastric ulcers.
Group 2 and 3 foals had blood and urine samples taken sequentially for pharmacokinetic analysis, CBC, serum chemistry evaluation, and urinalysis. Physical examinations were performed prior to treatment and daily for 17 days.
When data was analyzed, none of the foals presented adverse clinical effects. There were no significant changes in CBC, biochemical profiles within groups, or differences between groups. Pretreatment gastric endoscopy scores were not significantly different from evaluations at 7 and 14 days.
Firocoxib was quickly absorbed with an observed maximum concentration at 2 hr, the first sampling interval, for the majority of animals. Firocoxib plasma concentrations decreased in a log-linear manner after reaching the maximum concentration and steady state concentrations were achieved by the 7th dose.
Administration of firocoxib did not cause any adverse effects on gastrointestinal, or hematological or serum biochemical variables. The drug appeared to be well tolerated, and followed a predictable pharmacokinetic pattern in 4-6 week old foals.