Firocoxib's Effect on Equine Osteoarthritis-Related Pain

Firocoxib could benefit horses suffering from osteoarthritis-related pain or lameness

The results of a recently completed study indicate that oral administration of the non-steroidal anti-inflammatory drug (NSAID) firocoxib could benefit horses suffering from osteoarthritis-related pain or lameness.

In 2007 firocoxib, (marketed as Equioxx) was introduced as an alternative to non-steroidal anti-inflammatory drugs commonly used to treat osteoarthritis-associated pain in horses. Unlike its predecessors, which targeted both COX-1 and COX-2 enzymes, manufacturers designed firocoxib to specifically target and suppress the COX-2 enzyme, which produces chemicals responsible for pain and inflammation, while sparing the COX-1 enzyme that maintains normal gastric mucosal protection and kidney function.

To produce data regarding the safety, effects, and palatability of oral firocoxib paste for horses, a team of researchers led by James Orsini, DVM, Dipl. ACVS, associate professor of surgery at University of Pennsylvania's Veterinary Medical School, recently evaluated firocoxib use in a multibreed population of horses across 25 states.

The team employed 390 client-owned horses older than one year treated by an American Association of Equine Practitioners member veterinarian for osteoarthritis-associated lameness or joint pain. The team assigned each horse a lameness grade between 2 and 4 (on a 0 to 5 scale, with 5 being most severe).

Horses underwent three lameness examinations by the attending veterinarian (Day 0, Day 7, and Day 14) and caregivers received a 14-day supply of firocoxib with specific administration directions.

Key findings in the study included:

  • Nearly 97% of responding caregivers reported that the firocoxib paste was palatable to their horse and that it was easy to administer.
  • On Day 7, veterinarians reported that 70.7% of horses showed improvement in lameness while less than 1% of horses showed more severe lameness;
  • On Day 14, veterinarians reported that nearly 79% of horses showed improvement in lameness while 2.6% showed more severe lameness;
  • Overall, the higher the lameness grade, the less likely firocoxib was to resolve the lameness completely; and
  • Veterinarians reported mild, adverse side effects (all resolving after firocoxib administration ceased) in 0.9% of horses.

The team concluded that firocoxib "significantly improved lameness scores, comfort, and mobility in most horses treated for naturally occurring osteoarthritis."

The team noted that additional long-term safety and efficacy studies of oral firocoxib in horses are warranted.

The study, "Evaluation of oral administration of firocoxib for the management of musculoskeletal pain and lameness associated with osteoarthritis in horses," appeared in the American Journal of Veterinary Research in May 2012. The abstract is available online.

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.