4 Warning Signs Your Dog May Have a Torn ACL

30 March 2023
 Categories: , Blog


ACL stands for anterior cruciate ligament, and it's the ligament that connects your dog's thigh bone to their shin bone. As such, the ACL is very important for your dog's movement. Unfortunately, the ACL can sometimes be torn. There are several risk factors, including genetic issues and being overweight, but ACL tears generally occur when dogs suddenly put too much stress on one leg.

A torn ACL is a serious issue that requires treatment as soon as possible, so it's smart for owners to learn the most common symptoms. With that in mind, here are just four warning signs that your dog may have torn one of their ACLs.

1. Limping

If your dog avoids putting any of their weight on one leg, instead holding it up as they walk around, there's a good chance they have fully torn their ALC. This will usually happen suddenly when they are playing or running. If they only have a partial tear, limping may gradually worsen over weeks or even months. They may limp less after resting, then start once again as they return to their favourite activities.

2. Sitting Strangely

A torn ACL will usually interfere with a dog's ability to sit as well as move around. Instead of sitting normally with both legs tucked in, you may notice that your dog sticks one leg out to the side. This is because a torn ACL will cause pain when they bend their knee. Additionally, you may notice that they have trouble getting up from a sitting position, especially when they have been sitting for some time.

3. Low Energy

Sometimes a dog with only a partial ACL tear will still be able to move around almost as they used to, but they may be more hesitant to do so. This is because ACL tears will weaken surrounding joints and cause your dog pain as they move around. If this is the case, your dog may appear to go off their favourite physical activities, especially those that involve running or jumping.

4. Swelling

A torn ACL will result in temporary inflammation and swelling, and scar tissue will then start to form around the knee to cause a gradual thickening. If you think your dog may have torn their ACL, compare the size of their legs. If one knee looks bigger than the one on the opposite side, an ACL may have been torn.

For more information, contact a local vet.