Cruciate ligament ruptures

Team Walmart Pets

June 1, 2021


min read

Cranial cruciate ligament (CCL) rupture is the most common knee injury in dogs, and the number one cause of sudden hind leg lameness. Because these injuries are so prevalent, dog ACL surgery is the most often performed procedure for pups under the knife at the vet. 

Torn ACL in dogs

The knee joint is when the femur (thigh bone), the tibia (shin bone), and the kneecap meet. Cartilage acts as a cushion in the area between the femur and the tibia, and the joint is held together by ligaments – primarily the CCL (similar to an ACL in humans). It keeps the tibia from slipping out from under the femur. 

When your dog’s cruciate ligament is either partially or completely torn (ow) the knee joint becomes unstable, weight-bearing, and especially moving, painful. And when your dog does injure their knees, you need to get it treated ASAP. Otherwise, arthritis can flare up in as little as one to three weeks after the original injury.

You can try some of these joint supplements to keep your dog’s joints healthy between vet visits. But before you start giving them to your dog, make sure you clear it with your vet first.


Cranial cruciate ligament ruptures result from accidents or from the degeneration of the ligament. In dogs, degeneration happens because of aging, genetics or obesity. If a degenerative condition is to blame for ligament rupture, there is a 30 to 40 percent chance that rupture will occur in the other leg within a year.

In cats, torn ACLs commonly result from accidents, although many vets think that ligament degeneration can be a factor for cats just like it is for dogs. When an accident causes CCL rupture in cats, about 40 percent of cases sustain tears of additional stifle ligaments as well. In other words—there’s a 40% chance that a cat who tears their CCL, their surgery will be more extensive.

Breeds at high risk of knee ruptures

Certain dog breeds are more likely to tear their cruciate ligament ruptures as a result of their breed. Newfoundland dogs are a good example, and torn tendons are also common in the Labrador Retriever, Golden Retriever, Rottweiler, Bichon Frise and St. Bernard.  

Signs + symptoms

  • Sudden onset lameness: this is when your dog or cat acts to signal their physical discomfort. It ranges from toe-touching to not putting weight on their injured leg. 
  • Vocalization of pain: This is an easy one—if you hear your pet whimper or yelp, and see them start to act differently, a tear has likely occurred. 
  • Swelling: If gone unnoticed, the affected knee will become swollen. Without treatment, it could develop into active degenerative joint disease.


Sudden onset hind leg lameness in a large dog is generally considered a cranial cruciate ligament rupture until proven otherwise. Your vet will be able to tell you, after checking the stability of your pet’s knee. If they can slide the tibia forward under the femur, that confirms a rupture of the cranial cruciate ligament. Imaging of the knee can confirm this and reveal any other potential issues.  

Torn ACL treatment and recovery time

When medium or large dogs rupture their cruciate ligaments, it often requires surgery, which can be covered by your pet insurance.  For cats and smaller dogs to recover from this injury, a lot of times all it takes is some rest. Once in a while, they’ll need surgery as well.

There are three dog ACL surgeries. Your vet will know which surgery will benefit your pet the most.

  • Extracapsular repair: This surgery can be performed without special equipment, which is always a plus.  Heavy sutures are used to stabilize the stifle joint by mimicking the cruciate ligament, and this surgery generally has dogs back to weight-bearing condition within two weeks.
  • Tibial Plateau Leveling Osteotomy (TPLO) and Tibial Tuberosity Advancement (TTA): In these procedures, the tibial bone is cut and rearranged to a more favorable position and held in place with a metal plate. Because these surgeries are more complex, longer recovery periods are needed to allow for bone healing.


With corrective surgery, it’s very likely your pet returns to the regular ol’ self. However, with ACL tears, the recovery time can be challenging and stressful for both pets and their parents. Depending on which surgery is performed, strict exercise restrictions could be in place for weeks or even months, which can be particularly tough for active, energetic dogs and their parents.  

Your vet should thoroughly review the post-op plans with you before you return home, including any pain meds your dog will need. Many vets also recommend physical therapy as part of your pet’s recovery. You might have to adjust your schedule to help your pet heal.  

Pet Health


Photo by Honest Paws on Unsplash