Evaluation of the effect of mitragynine on naturally occurring osteoarthritic pain in a canine model, a prospective, randomized, crossover, double-blinded, placebo-controlled clinical trial

The University of Florida College of Veterinary Medicine is currently recruiting dogs with osteoarthritis (OA), for a clinical trial using kratom for the management of chronic pain.

Inclusion criteria: Client-owned dogs of any breed or sex weighing 15-60kg (33-132 lbs.), presenting with naturally occurring OA of the carpus, elbow, shoulder, tarsus, stifle, and/or hip joint(s) will be eligible for enrollment. Dogs will be included if they have clinical signs attributable to OA, as well as radiographic evidence of OA consistent with observed lameness. Dogs will be excluded if they have a history of orthopedic surgery within the last 6 months, lameness of less than 4 weeks duration, joint instability (except dogs with chronic, stable cranial cruciate ligament disease were eligible), neoplasia, marked neurologic disease, and any intra-articular injection performed within 6 months of enrollment.

Treatment: Dogs with OA will be randomly divided into two groups: one group will receive the study treatment (Mitragyna speciosa), and the other group will receive a placebo (sugar pill). Neither the dog owner or the veterinarian will be aware of which treatment each dog is receiving. Each treatment will be initiated for 4 weeks. After receiving the first treatment, animals will be crossed over to the opposite treatment for 4 weeks with a 2-week washout period in between. At the start and end of each 4-week period, blood will be collected for a complete blood count, and biochemistry analysis; a biochemistry analysis will also be performed in the middle of each 4-week period (2 weeks). At the middle (2 weeks) and the end of each 4-week block, blood samples will be obtained for evaluation of plasma concentrations of mitragynine. Dogs will be assessed at the beginning and end of each 4 week period for pain by using a combination of a physical exam, a wear​able monitor that documents pain (PainTrace), gait analysis, an at home activity monitor (health monitoring collar; PetPace), and a pet owner survey.

Cost: The study will cover the cost of all pain medications or placebo pills. It will also cover all bloodwork and monitoring systems (PainTrace, PetPace, gait analysis, and veterinary assessments). If needed, radiographs to confirm OA of at least 1 joint will be covered by the study if patient qualifies for enrollment.

Contact: Contact the Integrative and Mobility Medicine Service at the Small Animal Hospital 352-392-2235, or complete the Study Interest Form to see if your dog qualifies.

PI: Dr. Elizabeth Maxwell; emaxwell@ufl.edu


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