Bone imaging allows the demonstration of the actual metabolism of the equin
e pedal and navicular bone. With bone scintigraphy the activity within area
s showing radiographic changes can be evaluated. 86 young horses were repea
tedly scaned in order to establish the value of bone scanning. Besides a ve
ry good correlation of clinical, radiological and scintigraphic findings in
most horses a number of cases were observed with increased uptake of the n
avicular bone but missing radiographic and clinical signs. A number of thes
e horse actually developed podotrochlosis but the rest did not. This behavi
our is explained by the physiological adaption of the bone metabolism to ch
anging loads, in a new retrospective study the increased-uptake of the navi
cular bone in horses with persisting lameness but lacking radiograhic alter
ations was further investigated. Intensive focal tracer accumulation in the
navicular bone, which also can be observed in the lateral view, was mainly
observed in chronically lame horses. The irritation of the navicular bone
metabolism can be considered as a pathological sign in certain occasions. P
eriodic re-examination of these cases is advised.