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Written by a Medical Acupuncture for Veterinarians course graduate. Author’s name available upon request.  Signed release obtained from client/author. 4387

Abstract: An 11 year-old American Quarter Horse (QH) gelding used in team roping as a heel horse received 3 acupuncture treatments at 1 week intervals for bilateral hind limb lameness and thoracic, lumbar and lumbosacral epaxial muscle soreness as well as caudal thigh muscle soreness. The horse has stayed in work and the clinical response to treatment, as well as the owner’s satisfaction have been excellent.

History: Dunny, an 11 year-old QH gelding rope horse was purchased by the current owner about 2 months prior to the initial exam. He has no known medical problems. He was used moderately by the previous owner and has been used heavily by the current owner. The owner noticed that he was not stopping as hard as he had been starting 7-10 days prior to the initial examination but had not been able to detect a lameness while riding him. Pre purchase radiographs taken by another veterinarian were reportedly within normal limits at the time of sale about 2 months ago.

Physical Exam: The horse is in good physical condition with a body condition score of 6/9. The horses pulse (36 bpm) and respiratory rate (10 bpm) are within acceptable limits but the temperature was not taken. The horse appears to be in good general health. At a trot, a grade 2/5 (AAEP) left hind lameness is noted. There is no sensitivity to hoof testers on any of the four feet. Full hindlimb flexion (Spavin Test) results in a positive 3/3 response after 60 seconds of flexion bilaterally. Lower limb flexion (fetlock) yields a positive 1/3 response. There is no discernible synovial effusion in any joint of the hind limb. Forelimb flexions (fetlock and carpal) result in no change to the horses gate. The myofascial exam revealed bilateral trigger points adjacent to the vertebral bodies of C4-5 in the caudal cervical region on both sides (right is worse than left). The ileocostalis and and longissimus muscle systems are very tight and very sensitive to light palpation bilaterally from the caudal border of the scapula to the tuber sacrale. Both the semitendinosus and semimembranosus on the right and left hind limb are tight and sensitive to palpation. There is a fluid filled mass over the right semimembranosus that has reportedly been present for at least the past 8 months unchanged.

Medical Decision Making: The horse has no history of tying up (exertional rhabdomyolysis) but the extensive muscle soreness forced consideration of a primary myopathy. The combined lameness and myofascial exams direct treatment towards muscle soreness in the large epaxial and hamstring muscle groups and consideration of joint, tendon or ligament causes of lameness. The primary decision to think through was whether the lameness was solely the result of muscle and myofascial pain or if there was an overworked joint causing synovitis or early arthritic pain.

Differential Diagnoses:
Muscle/myofascial pain in the epaxial and hamstring muscle groups (r/o primary myopathy, r/o simple overuse, r/o secondary to lower hindlimb lameness)

Left hindlimb lameness / positive Spavin tests (r/o distal intertarsal (DIT) / tarsometatarsal (TMT) synovitis / early osteoarthritis, r/o proximal suspensory desmitis, r/o pain from stifle flexion)

Diagnosis: Hock radiographs were recommended but declined at the initial examination since they were found to be acceptable at the time of the recent pre purchase exam. A presumptive diagnosis of DIT/TMT synovitis and muscle and myofascial pain secondary to overuse was made. Response to therapy was followed to determine if additional diagnostics or treatments would be necessary.

Acupuncture Treatments: The owner elected pursue treatment of the horses hocks with an injection of 60 mg methylprednisolone and 125 mg amikacin into each TMT joint and acupuncture. Acupuncture sessions were scheduled for every 7 days for 3 weeks. Point selection was based on myofascial exam findings and included: bilateral GB 21 (cervical trigger point), LI 16 (cervical trigger point), LI 17 (cervical trigger point), Bai Hui (hind limb lameness), BL 13, 15, 18, 21-26, 36, 40 and 2 unnamed points following the bladder line on both hind limbs that divided that space between BL 36 and 40 into quadrants. Dry needling was used for the initial treatment with 0.25 x 30 mm Seirin needles. The horse was sedated for the initial treatment but not for subsequent treatments. Follow up examinations yielded similar but much less profound myofascial exam findings so the exact same treatment protocol was used for all 3 sessions. The horses exercise routine was modified to allow for 2 days off following acupuncture treatment (performed on Tuesdays) and fewer practice runs during the week. It was also recommended at the initial examination that the horse switch to Ultium feed.

Outcomes and Discussion: The response following the initial treatment (which included TMT joint injection) resulted in an estimated 75% improvement in the sensitivity to palpation along the epaxial muscle groups and caudal thighs at the 2nd treatment session. The lameness was no longer detectable at a trot 7 days following bilateral TMT joint injection and initial acupuncture treatment and the response to full limb flexion was reduced to a positive 1/3 response. The degree of improvement at the 3rd sessions was not as profound but subjectively improved from the 2nd visit. The horse stayed in work throughout the treatment protocol (with 2 days off following acupuncture treatments) and returned to his previous level of performance. With the degree of muscle soreness this horse showed, it seems plausible that the entire source of his lameness and lessened performance was related to muscle pain and myofascial restriction. It was recommended to the owner that monthly treatments would be beneficial to prevent wind up that and incorporating electroacupuncture may stimulate a more profound neuromodulation to address the slight residual soreness that these three sessions did not fully resolve. This case highlighted the intersection of the myofascial exam and the lameness exam and reinforced that these two exams are very complimentary of one another in the workup of a lameness complaint.