Mrs Bartlam brought "Meg" her 9 year old Border Collie to see me for a second opinion.

Mrs Bartlam felt that there had been a communication problem with the previous veterinary surgeon. This will no doubt raise a smile amongst my own clients who have struggled to get to grips with my Scottish accent over the years. "Meg's" condition however was more about what was said rather than how it was spoken.

"Meg" is a regular participant in agility trials, a performance athlete no less, and her owner had noticed a boney lump appear on her right front leg. This had caused some considerable concern and quite rightly the affected leg had been x-rayed.

The biggest worry in this kind of situation is the possibility of a bone tumour. This diagnosis carries the worst forecast and usually necessitates amputation with the likelihood of cancer spread. Most vets know this and x-rays are carried out to determine the patient's outlook.

Unfortunately the diagnosis of bone lesions (other than fractures) is difficult from x-rays alone because mixed patterns of bone destruction and bone production are frequently observed. Bone is constantly remodelling throughout life. Microscopic areas are both reabsorbed and replaced. Maintenance of the normal function and appearance of bone requires a balance between bone building (osteoblastic) and bone destruction (osteoclastic) activity.

Excessive activation of bone destroying cells (osteoclasts) leads to bone lysis, as in osteoporosis, a common disease in elderly woman. Alternatively, as in "Meg's" case, stimulation of the bone production cells (osteoblasts) leads to the production of new bone.

It is most important in these cases to correlate all the other additional information to make a definitive diagnosis. The fact that "Meg" was showing no sign of pain nor lameness was a very important sign. Bone tumours are notoriously painful and the lack of discomfort helped me to rule this diagnosis out.

In fact the boney lump so obvious on the x-ray was little more than an area of calcification of her tendon which had occurred probably in response to her athleticism during her agility trials. In short I was able to say to Mrs Bartlam, "Dinna worry, Meg'll be awright!" in my best brogue!

Terry Dunne BVMS, Cert SAO, MRCVS