They way dogs walk when they tear their ACL, is readily recognizable by veterinarians, but if you are a dog owner, chances are you know a thing or two about CCL injuries.
A torn CCL is a common issue among dogs, especially in certain breeds and dogs with specific lifestyles.
Considering the high incidence of the problem and its potential for progressing, it is normal for dog owners to wonder - how does a dog walk with a torn CCL? And, what can be done to treat or prevent tears?
In this article, we will discuss what happens when a dog ruptures its CCL how it impacts the anatomy and the dog's gait. We will cover the clinical signs and then discuss the diagnostic process and treatment options.
The Dog's Knee: A Short Lesson
To understand what a torn CCL is, and what it entails, you need to be familiar with the basic anatomy of the dog’s knee.
The knee joint is a hinge type of joint that keeps the knee stable during motion. The joint's stability is supported by the cruciate ligaments – fibrous bands connecting the distal thigh bone (femur) with the posterior shin bone (tibia).
There are two cruciate ligaments:
- Cranial (also known as anterior) crucial ligament
- Caudal (also known as posterior) crucial ligament.
As a hinge joint, the knee is fairly stabilized by the cruciate ligaments, which allow back and forth movements while restricting side-to-side motions.
CCL Tears in Dogs
There are two main causes of CCL tearing in dogs:
This occurs when the dog twists its leg on the knee joint level, usually when running and suddenly changing a direction.
When a dog runs, most of its weight is on the knee. Therefore, the excessive rotation will put strong shearing forces on the ligaments.
This is a chronic form of injury in which the ligaments progressively weaken due to repeated trauma or osteoarthritis. It starts with intermittent issues, which culminate with complete rupture.
Interestingly, CCL tearing is more likely to occur in young, large-breed, and active dogs like German Shepherds, Labrador Retrievers, Mastiffs, and Rottweilers.
However, small dogs can sustain CCL injuries too. Also, overweight dogs are at a higher than average risk of experiencing CCL tears.
There are several reasons dogs frequently suffer from CCL injuries and tearing. Those reasons include:
- Bad breeding: CCL itself is not a genetic issue, but hip dysplasia is hereditary and a known risk factor for cruciate ligament injuries.
- Natural conformation: Unlike people, dogs are always standing with their knees slightly bent, putting constant pressure on the joints.
- Inadequate levels of physical activity: most modern dogs have a sedentary lifestyle which leads to weight gain and poor conditioning.
- Weekend warrior syndrome: occurs in dogs with sedentary lifestyles during the week and episodes of high-impact exercises during weekends.
Signs of CCL Tears in Dogs
The telltale clinical signs of CCL tearing in dogs are the so-called toe touching posture and sloppy sit.
The Toe Touching Posture
The toe touching posture, as the name suggests, is a specific gait in which the dog's leg touches the ground only on a toe level.
Over time, based on whether the dog is healing or getting worse, it will either go back to bearing more weight on the leg or progress to limping.
Sloppy sit describes the way dogs with torn CCL sit down. Namely, instead of bending the knee and sitting squarely, they sit without flexing the leg.
The overall and exact clinical manifestation varies based on the intensity of the CCL injury. Generally speaking, CCL tears are extremely painful. However, dogs tend to hide the obvious signs which cause delayed diagnosis.
On the other hand, some dogs can be overdramatic when in pain and even refuse to eat or drink. Disinterest in everyday activity and reluctance to be physically active are also possible.
Diagnosing a Torn CCL in Dogs
The golden standard for diagnosing CCL tears in dogs is the cranial drawer test. A positive cranial test means the ligament is torn.
However, based on the situation, the vet may decide to perform additional tests. Here is a short overview of the tests.
Why Does My Dog Like My Girlfriend/Boyfriend More?
If your dog likes your girlfriend/boyfriend more, you may be upset from such preferential selection. As upsetting as this may sound, there may be several good reasons why Rover shows his preferences, but don't get upset by it.
Test number 1: Cranial Drawer Test
Do not be confused by the fancy medical term, the cranial drawer test is simple and easy to perform. Due to its simplicity and accuracy, it is the diagnostic mainstream.
To test, the vet will position the thumb and forefinger on the femur and the other hand on the tibia. The hand holding the femur stands still while the other hand slides back and forth, shifting the tibia.
If the ligament is intact and the joint stable, there will be no instability or movement. However, if the tibia slides forward, it means the cranial cruciate ligament is ruptured. In other terms, the tibia’s sliding means a positive cranial drawer test.
It should be noted that depending on the circumstances, the vet may suggest light sedation before the test. The test itself is not painful, but dogs tend to get tense which may affect the results.
Test number 2: Tibial Compression Exam
Another helpful test for diagnosing a torn CCL is the so-called tibial compression exam. Usually, this test is performed after the cranial drawer as an adjunctive.
To perform the test, the vet placed on hand around the end of the femur while the index is extended, covering the patella.
The other hand holds the foot and flexes the ankle. If there is CCL damage, the tibia moves forward.
Test number 3: Imaging Techniques
If the first two tests are inconclusive, the vet may suggest additional evaluations. They can also be helpful to determine the severity of the tearing and craft the right treatment plan.
There are several different imaging techniques. Which one is best for your dog is something the vet will explain before making the test. In general, the veterinarian will recommend one of the following:
Making an ultrasound is the ideal test as it gives plenty of information. However, when it comes to CCL tearing, the tests in not routinely performed. This is because it takes a highly trained eye to catch the signs of CCL damage.
As a method, this is less sensitive but cheaper and easier to make. The CCL itself is not visible on radiographs. However, a skilled radiologist can confirm the diagnosis based on local changes such as arthritis signs, effusion (fluid accumulation in the stifle), and tibial displacement to the femur.
Another way of taking a closer look at the CCL ligament and nearby tissues and structures is arthroscopy. As an endoscopic procedure, in the past, arthroscopy was complicated and costly, but today it is becoming a routine procedure.
Performing an MRI of the knee or affected legs are extra helpful as the technique allows excellent visualization of the different structures. However, MRI scanners are not readily available, and imaging can be quite expensive.
CCL Treatment For Dogs
The treatments for CCL tearing can be classified as medical and surgical. There are various factors that need to be considered when choosing the right approach. Such factors are:
- The severity of the injury
- The dog’s weight
- The dog's age
- The dog's lifestyle
- Financial considerations
In general, medical treatment is recommended for dogs less than 30 pounds and partial CCL tears, while dogs over 30 pounds need surgical treatments regardless of the type or CCL tearing.
Medical Treatment of CCL
The medical treatment focuses on managing the symptoms and preventing future complications.
Modalities falling under the medical treatment are cage rest, anti-pain medications (usually non-steroid anti-inflammatory drugs), joint supplements, physical therapy (cold laser, swimming).
Surgical Treatment of CCL
When it comes to surgeries, there are several options. Here are the potential surgical treatments for CCL tearing:
Lateral suture repair: an extracapsular technique, it is usually recommended for small dogs and owners with financial restrictions. To ensure normal joint function, dogs need extensive physical therapy after the procedure.
Tibial tuberosity advancement (TTA): this option is suggested for medium and large dogs. After the implant is placed and the resting phase is finished, pet owners are instructed to adhere to a strict physical therapy regimen.
Tibial plateau leveling osteotomy (TPLO): today, this is the most frequently performed surgery in dogs with torn CCLs. The surgery changes the entire dynamics of the knee. Once again, adjunctive physical therapy is advisable.
Preventing CCL Tears in Dogs
CCL tearing is not a completely preventable scenario. However, there are certain things pet owners can do to decrease the risk. Here are some useful tips on how to prevent CCL tears:
Choose the right breeder. It is important to get your pup from a reputable breeder that tests for hip dysplasia. Dogs with hip dysplasia are more likely to suffer knee issues later in life.
Maintain healthy body weight. Obesity is a risk factor that increases the chances of CCL tearing. To keep your dog’s body lean, you need to make mindful nutrition and exercise choices.
Year-round conditioning. It is important to exercise your dog regularly. As mentioned, the weekend warrior syndrome is a serious issue among modern dogs with sedentary lifestyles.