Lameness in an 18 Year Old Quarter Horse

Written by a CuraCore Veterinary Medical Acupuncture course graduate. Signed release obtained from client/author. 10L2018034

Abstract
When faced with a chronic, intermittent lameness, a multimodal approach to pain management is likely needed for adequate comfort as well as to reduce the use of pharmaceuticals. The patient in this case report suffered from multiple problems (congenital orthopedic disease and acquired inflammatory airway disease), which makes medical management somewhat difficult when balancing pain control and corticosteroids. The compensatory mechanisms causing upper forelimb pain in this patient may be managed with acupuncture and massage as a complement to traditional western medicine to provide a more comprehensive whole-body health plan.

History
The patient in this case is an 18 year-old gelding quarter horse with chronic intermittent bilateral front limb lameness. He had a previous history of large coffin bone extensor process fragments bilaterally in the front feet, as well as chronic inflammatory airway disease that has been treated seasonally (summer/fall) with dexamethasone. His orthopedic disease had previously been managed with once to twice annual injections to the front distal interphalangeal joints, wide-webbed aluminum shoes (spring through fall), and 2 grams of phenylbutazone intravenously or orally as needed (about once to twice monthly from June through September). Joint injections generally contained hyaluronate sodium, triamcinolone, and amikacin. The patient is group-housed in a small dry lot with minimal turnout in the summer months, and he is seasonally used for team roping and occasional ranch work. One of the owner’s largest concerns was the periodic usage of both phenylbutazone and dexamethasone as recommended by a local equine internal medicine specialist. There have never been clinical signs of gastrointestinal disturbance prior to presentation.

Examination
He presented in January 2019 for a general wellness check-up and lameness evaluation. His lameness exam revealed a grade 1 lameness of the left front limb and grade 2 lameness of the right front limb (1). His lameness was most readily apparent in the inside front limb when trotting on the longe line. He was negative to hoof testers and flexion tests. No neurologic abnormalities were noted, and there was no current sign of respiratory difficulty. The myofascial palpation evaluation revealed a limited range of motion in the superficial myofascia of the left mid-thorax (near acupuncture points BL-13 to BL-15), and focal areas of taut muscular bands (trigger points) located in the left extensor carpi radialis and right infraspinatus muscle bellies.

Problem List
This gelding’s problem list included: large bone chips from the extensor processes of the distal phalanges, chronic intermittent bilateral front limb lameness, trigger points, and superficial myofascial immobility.

Differential Diagnoses
Previously documented bone chips may have been a congenital non-union, degenerative change, or traumatic injury to the front limbs. The history of his lameness slowly progressing over time and the symmetrical appearance of these particular bone chips suggest a congenital non-union or weakness of the extensor processes. Consultation, several years prior, with a local equine surgeon resulted in the decision to manage this problem medically, rather than removing the fragments.
Possible causes of his front limb lameness included: chronic inflammatory reaction to the congenital un-united extensor process of the coffin bone, traumatic injury involving the upper front limbs, selenium toxicity, referred pain, degenerative joint disease, or a laminitic episode. Trigger points and myofascial tension were likely caused by compensatory changes in the upper limbs and posture due to chronic lower limb pain. The patient’s history and lack of other signs of metabolic disease made compensatory change due to chronic inflammation the most likely cause of his upper limb pain and resulting lameness.

Treatment
On the day of presentation, pain was not noted within this gelding’s front feet. Special attention was paid to the patient’s chronic upper limb tension and trigger points. Some acupuncture points was used in his first treatment to provide local relief through manual manipulation to improve range of motion in the superficial myofascia and endorphin release prior to acupuncture (2). Dry needle acupuncture was used to provide segmental, local, and parasympathetic neuromodulation. The first treatment began with massage along the shoulders and thoracic spine to allow him time to become comfortable in the treatment area. Sterile, single-use acupuncture needles (Seirin J-Type) were used for all treatments. 0.25mm x 30mm needles were placed in acupuncture points: GV-14, Bai-Hui, and bilateral LI-16. 0.20mm x 30mm needles were placed in bilateral LI-10, LI-7, SI-12, SI-11, and SI-9. These needles were in place for approximately 15 minutes when the patient became somewhat restless, so treatment was ended for the day.
The second treatment took place 8 days later. Trigger points were noted in the left front extensor carpi radialis m. and right infraspinatus m. Some stretching and massage was performed prior to acupuncture. Points selected for dry-needling with 0.30 x 30mm needles were GV-14 and Bai-Hui. 0.25mm x 30mm needles were placed in points(all bilateral) LI-16, SI-11, SI-9, BL-13, and BL-15. 0.20mm x 30mm needles were placed in his left LI-11, and bilateral LI-10 points. The patient stood well for this treatment, and needles were left in place for 20 minutes.
The third treatment was performed approximately one week later. The patient appeared to be comfortable and moved easily on this presentation. One mild trigger point was noted in the left common digital extensor, between LI-11 and LI-10. 0.30mm x 30mm needles were placed in GV-14 and Bai-Hui. 0.25mm x 30mm needles were placed in (bilateral) LI-16, LI-10, SI-11, and in the trigger point between LI-11 and LI-10. This treatment lasted for about 20 minutes.

Discussion
This gelding appeared to move more comfortably after myofascial manipulation and some neuromodulation of the caudal cervical to mid-thoracic spinal nerves and trigger points. His comfort appeared to improve with each treatment, and the needle size was increased with each treatment as he was appearing to accept them. He will require long-term medical care involving joint injections to his front coffin joints and front shoes; acupuncture alone is unlikely to completely resolve his chronic pain (3, 4). As his primary problem appears to be the extensor process fragments that are not to be surgically removed or repaired, he will require repeated treatments to address his chronic pain in order to keep him comfortable enough to keep performing while keeping a good quality of life. His treatment plan is truly multi-modal, involving some pharmaceutical use and general management guidelines including shoes and turnout to keep the seasonal inflammatory airway disease at a manageable level. The goal in this case to is to reduce the use of pharmaceuticals while still providing long-term comfort and increased performance.

References
1. American Association of Equine Practitioners [homepage on the Internet] Lexington, KY, USA: American Association of Equine Practitioners [updated monthly]; [Last accessed February 26, 2019]. Lameness exams: Evaluating the lame horse. Available from: https://aaep.org/horsehealth/lameness-exams-evaluating-lame-horse.
2. Kaada B, TorsteinbØ O. Increase of plasma beta-endorphins in connective tissue massage. Gen Pharmacol. 1989;20(4):487-9.
3. Faramarzi B, Lee D, May K, Dong F. Response to acupuncture treatment in horses with chronic laminitis. Can Vet J. 2017 Aug; 58(8): 823–827.
4. Robinson KA, Manning ST. Efficacy of a single-formula acupuncture treatment for horses with palmar heel pain. Can Vet J. 2015 Dec; 56(12): 1257–1260.