Enthesiopathy with an abductor pollicis longus dysfunction in a Rough Collie dog

Abstract

APLAbductor pollicis longus E nthesiopathy is well documented as a distinctive pathological feature of spondyloarthropathy in human medicine, 1 however, few reports have been published in the veterinary literature 2,3 and most of these have been limited to the racing Greyhound. In Japan, dog racing is not a recognised sport, and this disease has not been described. Here we present a Rough Collie dog with thoracic limb lameness. Radiographic examination indicated enthesiopathy of the right short radial collateral ligaments accompanying abductor pollicis longus (APL) dysfunction.A 10-year-old female Collie dog weighing 32.6 kg and with weight-bearing lameness of the right foreleg was brought to the Tottori University Veterinary Teaching Hospital (TUVTH) in Japan. The dog had been exercised, with the owner riding a bicycle and the dog running alongside, for 2 km, twice daily, from a young age. From the age of 9 years, the dog showed mild lameness after this exercise that became severe after 30 min rest. The lameness had always resolved by the following morning. These signs continued for almost a year, and then became more severe over a period of a month. Upon admission, the dog showed slight weight-bearing lameness of the right front leg at the walk. On the dorso-medial side of the distal end of the radius, a firm nodular swelling and mild skin heat was observed. No pain was evident upon deep palpation, or on rotation or flexion of the carpal joint.Radiographs showed an osteophyte in the radius (Figure 1) and calcification on the medial surfaces of the radius and the carpal bones ( Figure 2). There were no inflammatory changes evident in the carpal joint. The density of the right flexor carpi radialis was less than that of the left.The owner declined surgical intervention, and treated the dog at home with 1 g/day each of glucosamine and fish collagen peptide orally for 2 weeks. There was no improvement in the dog's lameness, and identical radiographic findings were present in the right radius at the second examination.Osteophyte resection was performed under general anaesthesia using propofol and midazoram for induction, and inhalation anaesthesia with nitrous oxide, oxygen and isoflurane for maintenance. A skin incision was made over the osteophyte with a 2 cm margin at both the proximal and distal ends. Following subcutaneous tissue dissection, the osteophyte was easily visualised. The APL was trapped by the elongated osteophyte and the distal part of the APL was buried in firm connective tissue. Blunt dissection of the connective tissue revealed the distal APL, which was kinked at the osteophyte elongation. The osteophyte was completely removed using Rongeur forceps. Complete resection of the osteophyte was confirmed radiographically (Figure 3). Figure 1. Dorso-palmar radiographic view of the right carpal joint of a 10-year-old Rough Collie that had signs of lameness after exercise. There is soft tissue swelling (large white arrow) and an osteophyte with characteristic elongation (arrow head) and calcification (s...

Radiographic and Ultrasonographic Diagnosis of Stenosing Tenosynovitis of the Abductor Pollicis Longus Muscle in Dogs

“…While radiographic changes of de Quervain's disease in people are limited to radiolucent areas in the distal radial styloid with some soft tissue mineralization, stenosing tenosynovitis of the abductor pollicis longus in dogs was characterized by soft tissue swelling, a deep distal radial groove, bony proliferations along the abductor pollicis longus tendon sheath, and enthesopathies. These findings are consistent with those described in previous reports …”

“…Radiographs of the carpus in dogs with abductor pollicis longus tenosynovitis were characterized by a distinct distal radial sulcus, soft tissue swelling, and irregular mineralization located medial to the radial sulcus with varying mineralization . Histopathologic evaluation of these tendon sheaths reveal similar findings as in de Quervain's disease with thickening and chondroid or osseous metaplasia …”

“…Eight of the 30 dogs (27%) were mixed breeds and seven (23%) were Retrievers. Previous reports on abductor pollicis longus tenosynovitis include a German Shepherd, Golden Retriever, and Collie …”

“…Chronic front limb lameness in mid‐sized to large‐breed dogs with a firm swelling at the medial aspect of the antebrachiocarpal joint may be caused by stenosing tenosynovitis of the abductor pollicis longus muscle …”

“…Stenosing tenosynovitis of the abductor pollicis longus has been reported in dogs and treatment has been evaluated . The dogs presented with chronic front limb lameness and a firm swelling medial to the distal radius.…”