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Medications Impact Autologous Treatment Options in HorsesBy Kentucky Equine Research Staff · January 10, 2018

Veterinarians use regenerative therapies to manage certain musculoskeletal conditions in horses. These therapies, which include stem cells, autologous cultured serum (ACS), and platelet-rich plasma (PRP), employ the injured horse’s own cells to treat the condition. Collected samples can be stored for future use. What if your horse was either on medication or had an underlying condition at the time of sample collection? How does that affect future use of the sample?

Consider the following scenario:

Your horse has osteoarthritis (OA), a common yet painful and progressive degeneration of the lining of articular cartilage found at the end of long bones. Your veterinarian recommends a nonsteroidal anti-inflammatory drug (NSAID) such as phenylbutazone (bute) or even an injectable product such as firocoxib. That same vet also recommends ACS. This involves collecting a sample of the horse’s blood and incubating it with specially designed beads to stimulate the production of anti-inflammatory molecules such as interleukin-1 receptor agonist proteins (IRAP). Those IRAP-rich samples can then be directly injected back into your horse’s affected joints, and some can also be saved for future use. Down the road, your horse is a little sore before competition and you know an NSAID cannot be administered, but ACS can. So your vet dives into her freezer to unearth the ACS. What if the sample contains a trace of the NSAID that your horse was on when the sample was collected? Will it result in a positive drug test?

“Various governing bodies, such as the United States Equestrian Foundation (USEF), the Association of Racing Commissioners International (ARCI), and the Fédération Equestre Internationale (FEI), have strict rules and penalties regarding allowable levels and withdrawal times; therefore, this is a valid and important question,” emphasized Laura Petroski, B.V.M.S., veterinarian for Kentucky Equine Research (KER).

While both NSAIDs and ACS remain important tools in the management of OA, along with nutritional supplements, using ACS “spiked” with an NSAID could result in serious repercussions. One research group* conducted a study and experimentally created the above-described scenario. They treated horses with firocoxib, prepared ACS following treatment with that NSAID, and later injected the ACS into the horses’ joints. Blood samples were subsequently collected and analyzed like any blood sample would be for equine competitions.

“The researchers found the amount of firocoxib in the ACS sample did not appear to be large enough to result in detectable systemic concentrations of the medication,” shared Petroski.

Nonetheless, the researchers noted, “Although we have determined that intra-articular administration of ACS derived from horses following two oral doses of firocoxib at a 24-h interval does not affect plasma concentrations of firocoxib, we cannot extrapolate this evidence to horses with maximal plasma concentrations of firocoxib that occur with longer term use (≥10 days) or to other medications. Further evaluation of different medications is required and should be pursued. The information gained from this study is vital for protecting the horse and the associated equestrian team from therapeutic drug administration resulting in an inadvertent positive test.”

While considering various options for joint health and managing OA, don’t forget that experts also recommend supplements containing glucosamine, chondroitin sulfate, omega-3 fatty acids.

“Always choose quality joint supplements, such as KER•Flex, Synovate HA, and EO•3 to support joint health,” Petroski advised.

In Australia, look for Glucos-A-Flex as well.

*Ortved, K.F., M.B. Goodale, C. Ober, et al. 2017. Plasma firocoxib concentrations after intra-articular injection of autologous conditioned serum prepared from firocoxib positive horses. Veterinary Journal. 230:20-23.