Effects of calcium dobesilate on horses with an increased signal intensity in the navicular bone in fat suppressed images on MRI: pilot study

Early stages of navicular disease (ND) in horses have been observed to be associated with chronic lameness. These early stages of disease have been recognised as increased signal intensity in fat suppressed images in the spongiosa of the navicular bone (NB). Calcium dobesilate (CD) has an effect on pressure dynamics in the subchondral bone of osteoarthritic joints of rabbits and could potentially be used as a treatment for the early stages of ND in horses. The aim of this pilot study was to monitor the lameness and the MRI changes in 12 horses diagnosed with chronic foot pain and demonstrating increased signal intensity in fat suppressed images in the spongiosa of the NB. Twelve horses with fore foot lameness of between one month and two year's duration were selected for the study. Inclusion criteria were: absence of radiographic findings on standard foot radiographs and an increased signal intensity in fat suppressed images in the spongiosa of the NB without concurrent lesions detected on MRI scans of the foot. Horses were treated with CD and a controlled exercise regimen and were re-evaluated cl nically and with MRI two and four months after diagnosis. In 10 of 12 horses (83 %) lameness improved between the first and second examination and in 10 horses (91%) between the first and third examinations. Eight of 12 horses were sound at the end of the trial. There was a general trend for reduction in the severity of MRI abnormalities during the study period. Calcium dobesilate is a potential treatment option for horses with foot pain associated with increased signal intensity in fat suppressed images in the spongiosa of the NB. The results of this pilot study suggest that a double blind controlled clinical trial into the effectiveness of CD is warranted.