Can X-rays Detect a Torn ACL in Dogs?

X-rays help show joint and bone placement, aiding in the diagnosis of an ACL tear.
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The anterior cruciate ligament, or ACL, is actually the cranial, or anterior, cruciate ligament in dogs. One of the most common causes of rear leg lameness in dogs, according to Michigan Veterinary Specialists, the ligament stabilizes the rear knee joint, or stifle. To diagnose a torn ligament, a veterinarian conducts a number of tests, including X-rays.

Diagnostic Testing for the ACL

Diagnosing an ACL rupture begins with a thorough examination and evaluation of your dog’s gait. ACL tears typically occur after a traumatic or overexertion injury, so your veterinarian may ask about recent behavior or accidents. Next, an X-ray looks at the joint structure and bone placement. An X-ray will not show damaged ligaments but a change in bone positioning shows that the ligaments may not be stabilizing the joint correctly. The X-ray also helps rule out other conditions, such as arthritis. The veterinarian then manipulates the joint to check for stabilization using two tests -- the drawer test and the tibial compression test -- to help confirm a tear.