Canine Cruciate Injuries

So, to go along with the Bad Dog Agility podcast, here’s an actual Blog post about cruciate injuries in our dogs.  As we discussed on the podcast, I’ve experienced this injury both as a vet diagnosing the problem, as well as an owner who’s dog has been through TPLO surgery and rehab.  And unfortunately, Ticket is one of about 50% of dogs who will go on to tear the cruciate ligament on the opposite leg as well, so we will be going through it all again in the very near future.  Hopefully this will help you understand the injury and what comes after a little more.


Unlike people, who have 3 cruciate ligaments (anterior, posterior, and medial), dogs have two, and they are named differently.  The one most commonly injured is the cranial cruciate ligament (CCL).  The job of the CCL is to stabilize the tibia and prevent it from sliding forward during movement.  When the CCL is injured, the stifle (knee) joint becomes unstable, causing inflammation, pain, and swelling of the joint capsule.  Here is the basic knee anatomy, courtesy of DVM360:

There are a couple of different ways a dog can injure their cruciate ligament.  The most common occurs more in pet dogs, and is the middle-aged, overweight, large-breed dog.  This type of injury tends to be a degenerative process over time, until one day, the ligament tears completely.  The one we see more often in agility dogs is the case of a severe, abnormal force, on an otherwise normal knee.  Your dog steps in a hold, or plants and slips, and the force results in tearing of the CCL.  Of course, there’s a whole gradient between these two scenarios–we never REALLY know how normal a knee was prior to injury.  There may be other factors playing a role as well–dogs with straight stifles or medial luxating patellas may be predisposed to tearing their CCL.


So, when should you be worried about a cruciate injury in your dog?  The typical situation is a dog who was running around normally, and then comes up non-weight bearing lame on one of their rear legs.  You may see the inciting incident (a slip or fall), or you might see the lameness for the first time when your dog stands up after a nap.  Rest and anti-inflammatory pain meds may help in the short term, but what will typically happen is the problem will come back.  Many times your dog will look fine, you’ll go practice, and they’ll be lame again.

The “classic” diagnosis of a cruciate tear is made when your vet does a test and elicits “cranial drawer.”  This just means that the cranial cruciate ligament is no longer able to do it’s job, and the tibia is now able to slide forward.  Dr. Brian Beale, an orthopedic surgeon at Gulf Coast Veterinary Specialists here in Houston, demonstrates this on this video.  Of course, it’s not always that simple.  LACK of cranial drawer DOES NOT MEAN that your dog doesn’t have a torn ligament.  It is common for dogs to have a partial tear, and in that case, cranial drawer may not be seen since part of the ligament remains and tries to hold the tibia stable.  However, the dog will often show pain on extension of the knee.  On xrays, swelling of the stifle joint may be seen, and in chronic cases, arthritis may have started to develop.

Partial tear of CCL on Ticket

Partial tears can be tricky to diagnose.  You can sometimes manage a partial tear and continue to compete with your dog in the short-term–limit training, laser therapy and acupuncture, use of anti-inflammatory pain meds.  But virtually all partial tears will progress to a complete tear in *some* period of time.  I’ve researched it, and tried it myself, and there’s just nothing out there proven to keep a partial tear from progressing.  Plus,  your dog will be developing arthritis the entire time.  So it’s always better to do the surgery sooner, rather then later.

TPLO Surgery:

If your dog is diagnosed with a cruciate tear, the treatment of choice is surgery.  There are several different surgical options, but the one that anecdotally has the best return to performance is a procedure called Tibial Plateau Leveling Osteotomy (TPLO).  The TPLO changes the mechanics of the joint, by sawing the top of the tibia off, changing the angle, and then plating the bone back together.  By doing this, the cruciate ligament becomes unnecessary–the new mechanics of the joint prevent the tibia from sliding forward.  The joint is also examined, as other injuries can occur besides the cruciate tear (like a tear of the meniscus).

Ticket's knee after TPLO surgery


After surgery, your dog will need to be crated for 8 weeks!  This is non-negotiable.  Your dog has had their leg BROKEN, and it takes at least 8 weeks for bone to heal.  But you don’t just put your dog in the crate and forget about the surgery for 8 weeks.  Proper rehabilitation is CRUCIAL for your dog to get back to their pre-surgery level, as quickly as possible.  The goals of rehab are to return the joint to as close to a normal range of motion as possible, and regain muscle mass  and cardiovascular fitness.  The dog must also relearn how to use the joint with these new mechanics–often their proprioception, or ability to place and *know* what the leg is doing, is decreased, so rehab will address this as well.

In the beginning, your rehab will focus on passive range of motion (laying down your dog and carefully moving the stifle through a comfortable range of motion), and ice as needed for inflammation.  About two weeks after surgery, other activities can begin.  You’ll start with very short leash walks (5 minutes twice daily), slowly increasing over the next 6 weeks.  If you have access to a rehab facility, this is the perfect time to start work on the underwater treadmill.  The underwater treadmill is GREAT for providing resistance while walking, but also support for your dog’s body.  You will do exercises for proprioception as well as range of motion, like cavaletti.  And you will do strengthening exercises — incline walking, sit to stand exercises, doggy “squats,” physioball work, etc.  Every dog is an individual, and there is no one size fits all rehab program, so it’s important to have a program specific for YOUR dog and the progress they are making.  If you push your dog too fast, they may develop further inflammation of the knee, tendonitis, or failure of the hardware in the knee.  If you don’t push them fast enough, their return to full function may be delayed.

A note about swimming–I do NOT like swimming in the first 8 weeks after TPLO. If you’ve ever seen a dog’s legs kick when swimming, it is a very forceful and uncontrolled action. It may put a lot of force on that stifle joint, and cause problems. The underwater treadmill is a much safer option–save the swimming for later on, when the bone is healed.

Everyone wants to know how to keep a cruciate injury from happening to their dog.  The sad reality is, there’s not a lot you can do–if it’s going to happen, it will, whether you’re doing agility, or playing ball, or just going for a hike.  That said, here are a few tips for reducing the risk of cruciate injury.

  • Keep your dog thin and fit.  You don’t want him to be a weekend warrior–lots of walks, swimming, strengthening exercises, etc.
  • Warm up and cool down your dog before and after practice and runs at trials.  Ideally this is not hard play (chasing the ball), but walking/trotting for 10 minutes before and after each run.
  • Don’t work your dog too hard.  Especially in the summer months, where the heat can tire your dog out more quickly, make sure they are having plenty of breaks.  A tired dog will not protect himself as well as a fresh one.
  • Avoid working your dog on slick or damp surfaces.  If the grass is wet, it may be best to wait for it to dry out before training.  This isn’t always possible, but it is always a factor present in my mind when training, and I’m not going to work on tight wraps or threadles on a wet surface.


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