Page 210 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.5 The hindlimb 185

VetBooks.ir 1.354 1.355

Figs. 1.354, 1.355 Dorsoplantar (1.354) and dorsolateral/plantaromedial (1.355) oblique radiographs of a
horse with osteoarthritis (spavin) of the distal intertarsal joint (centrodistal).

first evident on the dorsomedial or the dorsolateral 1.356
aspects of the TMT and DIT joints. Radiographic
findings include periarticular osteophyte formation,
localised subchondral bone lysis, narrowing of the
joint space and sclerosis of the distal and third tarsal
bones (Figs. 1.354–1.356). The correlation between
radiographic findings and lameness can be poor,
although other causes of distal tarsal and proximal
metatarsal pain should be considered, when there
is minimal radiographic pathology, to ensure that
another lesion is not present. Nuclear scintigraphy
may be used where no radiographic abnormalities
are present, when intra-articular blocks are difficult
to perform, or in horses presented for performance
problems rather than lameness. Increased uptake of
the radionuclide can be identified at the level of the
distal tarsal joints.

Management
Treatment for this condition originally involved Fig. 1.356 Dorsoplantar radiograph of the
working affected animals with the use of analgesics tarsus showing osteoarthritic changes of both the
in an attempt to provoke ankylosis of the joints. The centrodistal and talocalcaneal-centroquatral joints.
majority of horses, however, do not achieve fusion Note the marked bone lysis in the upper joint. (Photo
and lameness persists. Numerous treatments, both courtesy Graham Munroe)