In a seven years old cow, which died with severe symptoms of lameness, the fluoride content was measured of nearly all the bones. From each type of bone several samples of fat-free dry bone dust were collected and analysed for fluoride in order to obtain more information about the most respresentative sample area for the diagnosis of fluorosis. Taking into account a five percent deviation of the mean vague for all the bones analysed and using our sampling technique, the fluoride levels of ribs, thoracic vertebrae, lumbar vertebrae, sacral bones and pelvis seem to be the most representative. However, due to the unequal distribution of fluoride, between the compact and cancellous fraction, especially in long bones, the method of sampling seems to be extremely important. [ABSTRACT FROM AUTHOR]