Secondary bone tumours in the dog.

During a 2 1/2-year period 209 dogs with 218 malignant tumours were examined for skeletal metastases. There were 77 malignant tumours without visceral or skeletal metastases. Twenty-four (17%) of the 141 tumours with visceral metastases also had skeletal metastases. Ninety-eight of these tumours were of epithelial origin, and of these 21 (21.4%) had skeletal metastases. In 14 dogs, more than one bone had a metastatic tumour. The humerus, femur and vertebral column were most frequently involved. The lung was the most frequent site of metastatic tumours; then, in order, the liver, kidney and skeleton. The incidence of primary and secondary bone tumours was similar. Metastatic bone disease in the dog is far more common than is generally realized.