Diagnosing Arthritis

X-rays

Why does my dog need an X-ray or CT scan ?

As osteoarthritis progresses there are lots of changes in the affected joint. The articular cartilage erodes, bone below that cartilage is exposed and hardens, the protective joint capsule becomes inflamed and thickened, and small growths of bone (osteophytes) form around the joint.

Recognising osteophyte formation on an X-ray or CT (computed tomography) scan is a clear indicator of arthritic change in that joint.

Other conditions that can mimic the signs of arthritis can be diagnosed by X-ray and CT scanning, such as fractures, dislocations, bone tumours, or bone infections. These require completely different treatments.

There may be limitations to using x-rays or CT scans, which may lead to further investigations by your vet…

  1. Bone changes occur later in the disease when lots of joint damage has already occurred.
  2. Bone changes can occur around mildly affected joints that aren’t the current source of pain, so the x-rays must be supported with a thorough orthopaedic examination to ensure that clinical signs and radiographic signs tally.
  3. X-rays don’t necessarily tell you whether the joint has arthritis and is unstable, needing surgical intervention. An orthopaedic examination is essential to do this.
  4. Changes to bones and tumours can look similar on X-rays.

However, combining a thorough hands on clinical examination, orthopaedic examination and x-rays or a CT scan is imperative to getting an accurate diagnosis to ensure appropriate treatment for your dog.