PHYSICAL EXAMINATION

The most important test is a thorough orthopaedic examination. Some dogs show obvious signs of pain, such as flinching, whining, or withdrawing a painful leg. While these signs help narrow down the problem area, they don't provide a diagnosis. Physical clues, such as joint instability, can be very helpful in diagnosing the cause of lameness.

In some cases, a physical test can even provide a definitive diagnosis. For instance, the positive cranial draw test shown here confirms an injured ACL. However, in most dogs, a physical examination only provides clues that guide your veterinarian in deciding which additional tests are most appropriate.

RADIOGRAPHY

Most veterinary clinics have the necessary equipment and expertise to perform radiography, commonly known as “x-rays”. A thorough physical examination beforehand allows a veterinarian to target specific areas of concern, reducing the number of x-ray exposures, time under sedation, and cost.

Radiographs have certain limitations. While they can effectively identify abnormalities, they don’t always provide a definitive diagnosis. Additionally, there may be a discrepancy between radiographic findings and clinical signs. For instance, hip dysplasia is frequently an incidental finding. In other words, many dogs have hip dysplasia but another problem (e.g. a knee ligament injury) is causing their lameness. In the United Kingdom, sedation is mandatory when taking radiographs of dogs. This measure protects hospital staff from the harmful effects of cumulative radiation exposure.

ADVANCED IMAGING

Advanced imaging is sometimes the only way to diagnose a subtle problem. Tests including the word "scan" aren't always better than simpler tests. Every test involves a trade-off. Advanced imaging techniques like CT and MRI have drawbacks as well as benefits. For example, they aren't available in all clinics, and they are relatively expensive. Interpretation often requires specialist input, so diagnosis is sometimes delayed. The extra cost of advanced imaging doesn't guarantee a diagnosis. Some problems are too subtle for the most sensitive tests to detect. This means that extra tests are sometimes necessary. Typical examples are joint fluid analysis, arthroscopy, and surgical biopsy.

Advanced imaging techniques like CT scans and MRI are sometimes the only way to diagnose a subtle problem. Their drawbacks are high cost, lack of availability in all clinics, and scans may require specialist interpretation, which can delay diagnosis. Additionally, some problems are simply too subtle to be detected by even the most advanced imaging tests.

In some patients, more invasive procedures, such as joint fluid analysis, arthroscopy (keyhole surgery), or surgical biopsy, may be necessary. Ultimately, the decision of whether or not to order an advanced imaging test should be made on a case-by-case basis, taking into account the individual patient's unique needs and circumstances.

IMPORTANT NOTE

In dogs, “arthritis” is not a definitive diagnosis. It's a secondary problem, with many possible causes. About one-third of dogs that exhibit lameness receive a definitive diagnosis. The others are often labeled as having “arthritis” without knowing why. This limits the treatment options to palliative care, which focuses on managing pain and discomfort rather than addressing the underlying cause.