A far too common discussion I engage in is how to Prevent ACL tears in labradors . An ACL tear or Anterior Cruciate Ligament rupture is either a complete tear or partial tear of the Ligament and is a common injury in dogs. Joints in dogs, as in humans, need to be free of muscle so that they have room to flex. The legs have muscles above the knee joint that are connected to the lower half of the leg via a cord or ligament that passes through the knee and attaches to the leg bone on the side. The muscles contract, they pull the ligament, the ligament passes through the knee joint and pulls the lower bone of the leg allowing for the dog to move and run. See the above picture for details.
Once a tendon is torn there is play in the knee joint. A Lab can have a partial or a complete tear. This type of injury can be recognized by:
⦁ hind limb weakness
⦁ instability of the knee
⦁ swelling of the knee
⦁ sudden hind limb pain
If you recognize any of these symptoms in your dog you may be able to make things easier by getting him/her to the veterinarian right away. Your vet will perform some preliminary tests to see if further examining is required. During the test the tibia is moved forward or away from the femur like pulling a drawer open in order to determine any amount of play in the joint. If the Doctor suspects a tear or a partial ACL tear they may order a radiograph or an MRI. During the MRI your Lab will be sedated so they lie completely still.
As mentioned earlier surgery will be required to repair the tear. Early diagnosis and repair of a partially torn ACL may result in a more complete and quicker recovery for your Retriever. If left untreated partial tears almost always result in a complete tear over the next few weeks or months so if you see any of these symptoms please seek your Veterinarian’s attention right away.
Once your Labrador has had their surgery you can expect them to be able to bear weight on the leg by about 10 days. Full function will be achieved by between three and four months post op. If you can detect this injury early and treat it before things worsen there is less chance of arthritis or future tears for your dog.
What causes an ACL tear? There are a few possibilities however it most always is because a forced twisting of the dog’s knee joint-an internal rotation of the tibia when the joint is partially flexed. Running at high speed and planting the hind leg while the body momentum moves forward is the cause. Another but less common would be trauma to the ligament such as something falling on your dog and damaging/twisting the knee and leg. We have had a report from one of our Labrador Retriever puppies Toronto that she was running to go outside, approached the top of the porch with only 3 steps, jumped off from the top (they have no concept of this being too high and they may injure themselves) landed and tried to run adjacent to the momentum coming off the porch and tore her ACL doing so. For this reason as well as developing hip dysplasia from the jarring force of jumping off a step we recommend no stairs for young puppies until they learn to walk, not run. It is advisable for everyone to leash their dog and control it up and down the stairs so that you can restrain them should they want to jump off of the top.
One of the most common ways this stress is put on the knee is from the dog being obese. Imagine a dog being 10 or 15 lbs overweight. Picture a 15 lb dumbell or maybe the weight of a few bags of milk in a back pack on your back and you take off to chase a frisbee. You get into a full sprint and the frisbee changes directions causing you to plant your legs and pivot 90 degrees to the left(yes I just heard my knees snap too!). Imagine the stress on your knees and tendons without the weight. Now you have all this extra weight pulling on your tendons for long periods of time so you can stop and change direction. This is what happens with an overweight Labrador Retriever not to mention the other risks that being overweight bring such as diabetes, heart disease, difficulty breathing, heat intolerance, decreased liver function and lastly increased surgical and anesthetic risk.
Factors other than obesity that increase risk for an ACL injury with your Labrador Retriever are conformational deformities, being over five years old, rupturing one side increases the likelihood of your Lab rupturing the other side within one to three years, and immune medicated diseases. Now we aren’t telling you to bubble wrap your dog, rather there are a few things you can do to help ensure they are fit and you have worked to decrease the likelihood of an ACL injury.
Of the reported causes many seem to have been due to what some Veterinarians call Weekend Warrior Syndrome. If your normal exercise patterns with your dog are for example, a 15 minute walk around the block at an average walking pace then they will not be conditioned for a 5 hour fetch session during a sunny day in the bush or at the beach on the weekend. It’s been reported that it is common for a Labrador Retriever owner to see a beautiful sunny day forecast and take their Labs out for the day without adequate conditioning prior. Then, if the Lab is overweight, combined with not being use to the intensity of running and changing, direction, they get out and run their little legs off because this is what they do and don’t have the concept of not being in condition or being overweight. Snap goes the tendon.
So to prevent this being the correct weight is important as a daily aspect of pet care. While standing over your lab look from their head down to their tail. Right before the tail you should be able to see an indent in each side of their body. This is their tummies. They should have a shape and not look like a sausage. You should be able to see the outline of the rib cage but you should not be able to see any ribs. If you see ribs, they are too lean. After the weight is correct, they can’t jump from walking as exercise right to running full out for 5 hours. Fetch or running sessions need to be gradually built from a few minutes up to what your dog is comfortable with. It’s like running a marathon, you can’t walk around the mall for 15 minutes and expect that to be adequate training to run a marathon. So slow, gradual conditioning is required in order to work up to a 5 hour fetch-a-thon. Some higher intensity running each day is also recommended. It does not only benefit your dog’s tendon strength it helps exhaust them so they can more easily settle in the home.
Here is to proper weight Labs, building up their physical abilities and enjoying them injury free for a long time to come. If you have done all of this to prevent an injury and one still happens, don’t be hard on yourself. Sometimes things are out of our control. Let’s be thankful for veterinary medicine and the procedures they have developed so that we are able to enjoy our dogs even after accidents happen.
