Cranial Cruciate Ligament (ACL) Rupture

This page is for educational purposes only and is not a substitute for veterinary diagnosis or emergency care. Always consult your primary veterinarian or a rehabilitation veterinarian before starting treatment. If your pet cannot walk, has sudden paralysis, severe pain, or breathing difficulty, seek urgent veterinary attention.

Also known as: cranial cruciate ligament (CCL) rupture; ACL tear / ACL rupture; cruciate disease; stifle instability.

In dogs, the cranial cruciate ligament (CCL) is the primary stabiliser that limits cranial tibial thrust and internal rotation of the stifle. When it partially or completely ruptures, the joint becomes mechanically unstable. Owners often notice sudden non-weight-bearing lameness after a twist or stumble — or a more insidious limp that worsens over weeks. Cats can tear the CCL too, though the presentation is less common and sometimes subtler.

Unlike many human ACL tears from sport trauma alone, canine cruciate disease frequently involves progressive ligament degeneration. Breed conformation, steeper tibial plateau angles, obesity, neuter status, and contralateral disease all feature in the clinical picture. Partial tears can progress to complete rupture. Meniscal injury commonly accompanies or follows instability.

Diagnosis is veterinary (orthopaedic exam, drawer/tibial compression tests, imaging as needed). Treatment may be surgical (for example TPLO, TTA, extracapsular repair, or other stabilising procedures) or carefully selected conservative management. Rehabilitation does not replace that decision — it supports pain control, muscle recovery, gait retraining, and safe return to function alongside your primary vet or surgeon. Cats with suspected cruciate injury often need quieter, shorter sessions — our cat physiotherapy service is designed for that low-stress orthopaedic pathway.

Signs vary by severity and by whether your pet is a dog or cat. Owners of dogs and cats often notice:

After veterinary diagnosis and clearance, rehab focuses on reducing pain behaviours, protecting the stifle during healing or implant recovery, and rebuilding quadriceps, hamstring, and core strength that support the joint.

Early phases may emphasise controlled leash walks, ice/heat guidance as appropriate, passive and active range of motion within surgeon limits, and owner education on crate rest, sling use, and non-slip floors. Later phases progress therapeutic exercise, proprioception, and — when cleared — hydrotherapy or underwater treadmill work for low-impact strengthening.

For surgical and non-surgical pathways, plans are individualised. We track girth, gait quality, sit-to-stand ease, and daily function — not promised percentage outcomes. Feline patients typically progress with land-based, low-stress protocols rather than intensive water work.

Rehabilitation plans at RehabVet are individualised after a veterinary assessment. We coordinate with your primary vet when imaging, medication, or surgery is part of the overall plan.

Depending on your pet’s examination findings, comfort, and goals, a plan may include one or more of the following:

Goals are set for the individual patient. Typical aims may include (not guarantees — outcomes vary):

We do not publish invented success percentages. Progress is tracked clinically (gait, strength, range of motion, pain behaviours, and home function) and plans are adjusted over time.

Educational content only — not a diagnosis. For emergencies, contact your nearest veterinary hospital.