Torn ACL in Dogs: Limping or Something More Serious?

If your dog suddenly begins limping on a back leg, it can be difficult to know whether the injury is minor or something more significant.

One of the most common causes of sudden hind leg lameness is a cranial cruciate ligament tear, often referred to as a torn ACL. This ligament stabilizes the knee joint. When it becomes partially or completely torn, instability develops.



If you are in Akron and notice persistent limping, especially after running or jumping, evaluation is recommended to determine whether a torn ACL may be present.

What Is a Torn ACL in Dogs? 

In dogs, the ACL is called the cranial cruciate ligament or CCL. It helps prevent the tibia from shifting forward relative to the femur.

When this ligament weakens or tears, the knee becomes unstable. Over time, this instability leads to inflammation, pain, and arthritis.



Unlike in humans, most CCL tears in dogs develop gradually due to ligament degeneration rather than a single traumatic event.

Torn ACL Dog Symptoms

Symptoms vary depending on whether the tear is partial or complete.

Common signs include:

• Sudden or intermittent limping
• Dog limping back leg after exercise
• Difficulty rising
• Reluctance to jump
• Sitting with one leg extended outward
• Stiffness after rest

Some dogs carry the leg completely off the ground. Others bear weight but limp consistently.

Swelling around the knee may be noticeable in some cases.

Partial CCL Tear in Dogs 

A partial CCL tear can be more difficult to recognize.

Dogs with partial tears may limp intermittently. The limp may improve temporarily with rest and then return.

Because the ligament is not fully ruptured, instability may be subtle at first. However, partial tears often progress to complete rupture over time.

Early diagnosis allows treatment options to be discussed before the condition worsens.

How to Tell the Difference Between a Sprain and a Torn ACL 

Minor sprains typically improve within several days of rest.

A torn ACL, however, often results in persistent or recurring lameness. The limp may worsen after activity.

Veterinary examination includes specific orthopedic tests to assess joint stability. Radiographs may be recommended to evaluate joint changes and rule out other causes.



Because it is difficult to distinguish these injuries at home, evaluation is recommended when limping persists.

Treatment Options for Torn ACL 

Treatment depends on the size of the dog, activity level, and severity of the tear.

Small dogs with partial tears may sometimes be managed conservatively with rest and medication.

For most medium and large dogs, surgical stabilization provides the most predictable outcome.

Procedures such as Tibial Tuberosity Advancement, or TTA, alter the mechanics of the knee to restore stability without replacing the ligament.



Recovery typically involves restricted activity and structured rehabilitation.

What Happens If Surgery Is Delayed? 

Delaying surgery in a dog with a complete tear often results in:

• Progressive arthritis
• Muscle loss
• Increased joint instability
• Greater long-term discomfort



Some dogs also rupture the opposite cruciate ligament over time.

Discussing timing and treatment options early allows you to make informed decisions.

Frequently Asked Questions