Ruptured Cranial Cruciate Ligament (ACL) in Dogs


Overview of Ruptured Cranial Cruciate Ligament in Dogs

The cranial cruciate ligament, also referred to as anterior cruciate ligament or ACL, is located within the stifle (knee) joint and acts to stabilize the femur on the tibia. The ligament can be torn as a result of an acute traumatic event or more commonly it ruptures due to a slow progressive breakdown of the ligament. 

When the tear is sudden and complete, lameness may be severe and such that your dog refuses to bear weight on the leg. When the tear is partial or incomplete an intermittent lameness that is more noticeable after heavy exercise may be seen. Your dog may seem more lame on some days than others.

In large dogs (greater than 30 pounds), the joint usually becomes arthritic and the joint thickens if surgical stabilization is not performed.

What to Watch For

Symptoms of Ruptured ACL in dogs include: 

  • Sudden onset of rear limb lameness
  • Gradual onset of lameness in a rear limb
  • Diagnosis of Ruptured Cranial Cruciate Ligament in Dogs

    The diagnosis is generally made by your veterinarian during the physical examination. Your veterinarian will want to know whether the lameness occurred gradually or suddenly, whether it is intermittent or continuous, and whether or not it is exacerbated by exercise.

    Your dog will be observed at rest, walking and trotting. The leg will be palpated (felt) and the knee joint will be evaluated for swelling, evidence of pain, thickening, “clicking” on flexion and extension, and the range of motion (flexion and extension) determined.

    Specific tests to evaluate the integrity of the cranial cruciate ligament include a cranial drawer test or a tibial compression test, which are used to determine if there is increased movement in the joint. The movement in one knee will be compared to the movement in the other rear limb.

    Both stifle joints may be radiographed for comparison. X-rays may show joint swelling and various degrees of arthritis depending on the length of time the rupture has been present.

    Treatment of Ruptured Cranial Cruciate Ligament in Dogs

  • Small dogs (less than 30 pounds)

    Small dogs often do well without surgery. Your veterinarian may recommend that you strictly confine your dog for six weeks, may suggest that your dog lose weight if he is overweight and may prescribe a short course of anti-inflammatory medication.

    If your dog fails to improve over a 6 to 8 week period, surgery may be recommended.

  • Large dogs (greater than 30 pounds)

    Large dogs clearly benefit from surgery because medical management usually results in chronic lameness. There are many different surgical options. The basic principle of the surgery is to stabilize the femur on the tibia. This can be accomplished by placing implants within the knee joint, or around the knee joint, or by altering the dynamics of the joint itself. Your veterinarian may prefer a certain surgical technique or suggest referral to a veterinary surgical specialist for consideration of some of the more complex surgical procedures.

  • Home Care and Prevention

    Depending on the type of surgery that has been performed, your dog may go home with a soft padded bandage on the leg. If this is the case, check the toes daily for swelling or discomfort and keep the bandage clean and dry by putting a plastic bag over the foot when your dog goes outside to go to the bathroom.

    If there is no bandage, the incision can be monitored for swelling, redness or discharge.

    Stitches or staples should be removed at 10-14 days.

    Regardless of the surgical technique used, your dog should be kept quiet for a period of six weeks, with no jumping on or off furniture. Don’t let your pet go up or down stairs if possible and allow only short leash walks to go to the bathroom.

    Anti-inflammatory medication may be prescribed for the first week following surgery.

    After six weeks you can begin to increase your dog’s exercise slowly and gradually until he returns to his normal levels approximately sixteen weeks after surgery.

    In cases of acute cruciate ligament rupture there is nothing to prevent the injury from occurring. When the problem is intermittent and more chronic, prompt veterinary attention and treatment can reduce the amount of arthritic damage that will occur within the knee joint.

    In-depth Information on Canine Ruptured Cranial Cruciate Ligament 

    Sudden onset hind leg lameness following cruciate ligament injury can be so severe as to produce lameness as profound as a long bone fracture. Unlike a fracture, swelling and pain are restricted to the stifle (knee) joint.


    Pg 1 of 3


    Leave a Reply

    Your email address will not be published. Required fields are marked *