Anterior Cruciate Ligament Rupture (or ACL Injuries) and Labrador Retrievers

Written on July 23, 2013 by Stuart Bliss, DVM, PhD, DACVS, CCRP Hospital: Port City Veterinary Referral Hospital

The Breed

Labrador Retriever

ACL injury is a common orthopedic problem in dogs, and we see this condition frequently in Labrador Retrievers. The Labrador Retriever breed has a long history of athleticism; they do very well in sporting activities such as hunting and agility. They are often trained for service, for example as guide dogs or therapy dogs. Many are used in search and rescue or other law enforcement roles. And of course they have wonderful temperaments and make great companions. However, they are very prone to ACL injury, and it is useful for owners of these dogs, or those planning to adopt a Lab, to be aware of this condition. This is especially true for anyone planning to train their Lab for sports or work activities.

What is the ACL and how does ACL injury develop?

ACL stands for Anterior Cruciate Ligament.  Just like in humans the ACL in the dog is a large ligament that spans the knee joint of the back leg.  The ACL is an important stabilizer of the knee, and keeps the movement of the joint smooth and even during activity.  ACL injury refers to tearing or rupture of this ligament.  When this occurs, the knee becomes loose, and the normal smooth movement of the joint is impaired.

This is an uncomfortable condition, and dogs with ACL injury are usually lame, that is, they limp and favor the leg especially during activity.  Some dogs may even hold the affected leg up completely.  In some dogs, especially sporting dogs, ACL rupture can occur due to a traumatic injury, such as a fall.  However, in many dogs, the ligament is an intrinsically diseased structure, and it can rupture more or less spontaneously as a result of a slow and gradual process of fraying and deterioration.  We refer to this as ACL disease.

How is this condition diagnosed?

ACL rupture is diagnosed by simple physical examination.  It is a fairly easy diagnosis to make.

  • We start by standing back and observing a dog’s overall gait, and assessing both the nature and the severity of the lameness.
  • We then evaluate the stability of the joint with a hands-on manipulation called the drawer test  – there is a very characteristic sliding looseness that develops in the joint when the ACL is ruptured.
  • Xrays of the knee are often taken at the time of evaluation.  Xrays provide good information about the overall condition of the joint, and they are essential for planning surgery, but they are not necessary to make the basic diagnosis.

Is this a condition for which surgery is recommended?

Yes, surgical repair is recommended for most dogs with ACL rupture.  There are many different surgical procedures that can be used to treat this condition.  Picking the procedure that is best for an individual dog is a key part of the process.  All surgical procedures used for correction of ACL rupture in dogs share the same basic goal which is to improve stability of the joint, and to restore and maintain long term mobility and quality of life.  With careful planning, surgical repair of ACL rupture offer a very good long-term prognosis, and complications are rare.  Full recovery from surgery takes about 2-3 months, and involves modest control and restriction of exercise.  Physical rehabilitation can also be very beneficial during the recovery period.

What should an owner do if they suspect their Labrador Retriever has an ACL injury?

We strongly recommend that owners contact their primary care veterinarian for an initial examination.  If ACL rupture is diagnosed, a referral to a surgical specialist may be an option.  Specialists have a good deal of experience with ACL problems, and can be a valuable resource for both owners and primary care veterinarians when it comes to managing this condition.

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