A Guide to ACL Injury and How to Avoid It in Your Dog

A Guide to ACL Injury and How to Avoid It in Your Dog


One of the great things about being a dog owner is the energy and enthusiasm your pet can bring to your life. Whether it's daily walks, jogging in the park or accompanying you on weekend hikes, your canine friend can help you to stay fit and active, along with offering you companionship and affection. However, just like their owners, dogs can also be prone to injuries some of which can result in the need for surgery and aftercare.

A torn anterior cruciate ligament (ACL) injury, also known as a cranial cruciate ligament (CCL) injury, is one of the most common injuries in dogs. It has been reported that as many as 85% of all orthopedic injuries in dogs are related to some form of ACL injury.

What Is an ACL Dog Injury?

The ACL is a thin connective tissue between the tibia, just below the knee, and the femur, which is just above the knee. The main function of this ligament is to provide the dog's knee with stability. The cruciate ligaments form a crisscross structure within the knee joint, controlling the back and forth motion when the dog bends its knee.

The ACL is responsible for limiting hyperextension by preventing the tibia from sliding out too far in front of the femur or too far back, thereby giving correct internal rotation to the knee. A torn ACL will cause the tibia to slide forward in relation to the femur each time the dog puts weight on the injured leg, indicating a 'positive cranial drawer sign'.

The rubbing caused by ACL tears in dogs can cause inflammation and pain and can permanently hinder their ability to walk and run if left untreated. ACL injuries are also the most common reason for hind limb lameness.

A torn ACL will often heal through rest and physical therapy and a dog can recover from such an injury without the need for surgery as alternatives such as joint supplements and orthopedic braces are sufficient. If your dog has sustained an injury in this area or requires joint support, a dog ACL brace could help to reduce any pain and improve the quality of your dog's life.

If surgery is required it will vary depending on the severity of the injury. This could involve the insertions of a small wire into the femur in order to hold the knee in position, or a more complex procedure requiring the need for metal plates and screws.

Causes of ACL Injuries in Dogs

Certain predisposing factors can contribute to ACL injuries in dogs. These include the following:

Hip Dysplasia: This is often caused by overnutrition and bad breeding in dogs at an early age causing overcompensation, over time. Hip dysplasia puts additional weight onto one leg thereby weakening the ACL in that knee. Hyperextension or a particular movement can result in a tear.

Natura Load: Dogs naturally walk with their knees bent causing their ACL to carry weight or be 'loaded' most of the time.

Obesity: Excess weight can cause obesity in dogs, often as a result of poor diet and lack of exercise. Over time, this will put additional strain on and weaken the ACL.

Lack of Regular Exercise: Due to busy work schedules and lifestyles many people do not give their dogs regular and consistent exercise and to make up for this over exert their pets on weekends or other occasions. A lack of regular exercise can cause a dog's muscles to weaken making their ligaments more prone to injury.

Undetected Early Warning Signs: Underlying joint issues in dogs often go undetected and undiagnosed. Failure to recognize these early warning signs can exacerbate ACL joint injuries.

Genetic Predisposition: It is possible for any breed of dog to develop ACL, however, larger breeds are most at risk of tearing this ligament.

ACL Symptoms

Below are some of the symptoms to look for if you suspect your dog has torn or injured its ACL:

  • Lameness or limping in the hind legs
  • Difficulty bearing weight on one leg
  • Joint stiffness when rising from a resting position or following exercise
  • Visible swelling around the knee
  • Difficulty jumping or standing
  • Abnormal sitting, standing or lying down posture such as one leg sticking out
  • Incorrect back and hip posture
  • Audible clicking sound when walking

If you suspect an ACL injury in your dog or notice any of the symptoms listed, it is important to consult a veterinarian as soon as possible. An ACL injury can result in long-term lameness and irreversible joint damage if left untreated as well as extreme pain and physical discomfort for your pet.

Tips to Prevent an ACL Injury in Your Dog

Tips to Prevent an ACL Injury in Your Dog

There are many things you can do to keep your dog fit and healthy, reducing the risk of it sustaining an ACL injury. This includes the following:

Daily Exercise: Lack of regular exercise will weaken the ligaments and muscles surrounding the knee. Avoid extreme bursts of exercise, such as weekend walks after little or no activity during the week. Gentle warm-ups are also advisable before any strenuous exercise such as running or hiking. Ensuring your pet receives regular, moderate exercise will keep it healthy and strong and reduce the risk of an injury.

Maintain a Healthy Weight: The heavier your dog is, the more strain will be placed on its knees. Feeding your pet a healthy diet, without overfeeding, will help it to maintain a healthy weight. Dog food options that can offer joint support, as well as manage weight, are an ideal way to cater to your pet's nutritional needs while protecting their knees.

Add Supplements: A good quality joint supplement will provide your dog with the essential nutrients it needs to keep its joints healthy and strong. Fish oils containing omega-3 fatty acids can be beneficial for your dog, as they contain anti-inflammatory properties and can improve mobility, assist joint repair and reduce degeneration in joints.

Avoid High Jumps: Avoid playing games such as frisbee or catch which cause your pet to jump excessively high as it can result in hyperextension or a wrong movement upon landing.

By following the guidance in this article and looking out for some of the symptoms and early warnin