ACL Tears in Dogs: What Pet Owners Should Know

By Marc Greenberg, DVM, MS, DACVS (SA)
Board Certified in Veterinary Surgery

Remember: This information does not replace consultation with and physical exam by a veterinarian. Always consult your veterinarian for advice about your specific pet. When in doubt about an emergency, call our VSEC emergency service and we can help guide you anytime, day or night: (914) 315-4600.

ACL (Anterior Cruciate Ligament, or more appropriately Cranial Cruciate Ligament (CCL) in dogs) tears are very common injuries in dogs. They are the most common cause of limping on a back leg and can affect dogs of all shapes and sizes.

How did my dog tear their ACL?

While some ACL tears can be caused by external trauma, most are degenerative in nature. Dogs are born with healthy ligaments, but over time, the ligament starts to fray, leading to progressive discomfort and limping.

How are ACL tears diagnosed?

ACL tears are typically associated with limping on the affected limb, swelling of the knee (stifle) joint, and discomfort on extension of the knee. When the ACL is completely torn, there is instability between the thigh (femur) and shin (tibia) bones. Your vet may be able to feel this instability on examination, but your pet's muscle tone and discomfort may make this assessment challenging. Pain medications or sedation can relax the muscles and ease discomfort, which can facilitate a more accurate orthopedic examination.

X-rays (radiographs) are also helpful for evaluating the affected joint. While the ligament itself does not show up on x-rays because it is the same density as the fluid around it, x-rays are nonetheless helpful for seeing other changes suggestive of an ACL tear and for ruling out other conditions that can impact the knee.

Advanced diagnostic imaging options such as X-ray are available at VSEC 24/7.

What are the treatment options for a dog’s ACL tear?

Nonsurgical and surgical options exist for managing dog ACL tears. Nonsurgical management consists of activity restriction, pain medications, physical rehabilitation, and time. Some dogs can show some improvement with nonsurgical management. And while the idea of avoiding surgery is appealing, there are some important disadvantages to consider. Pets lose muscle mass and range of motion over time, which can impact long-term mobility. When the ACL is torn, other structures like the menisci can become injured, which can worsen pain and slow mobility. Finally, about half of dogs that tear their ACL in one limb develop a tear on the opposite limb within about a year, which can substantially impact comfort and mobility.

What about a brace?

Most braces marketed for supporting dogs with ACL tears do not effectively neutralize the destabilizing forces and restore stability to the knee. While a custom-made brace may be a reasonable solution for pets with other health conditions, most pets experience more rapid and reliable healing with surgical stabilization of the knee.

What are the surgical options for an ACL tear?

If you elect to pursue ALC surgery for your dog, the first steps are getting your pet under anesthesia, preparing the knee for sterile surgery, and evaluating the structures within the knee. The ACL is evaluated and a tear is confirmed. The menisci are evaluated and the damaged portion is removed. Several surgical treatment options exist for stabilizing the knee, including extracapsular stabilization (lateral suture, or "fishing line technique"), tibial plateau leveling osteotomy (TPLO), tibial tuberosity advancement (TTA), and other osteotomy-based procedures. Your veterinarian and veterinary surgeon can discuss these techniques in greater detail, and help determine the most appropriate procedure for your pet.

Meet Dr. Greenberg, board-certified veterinary surgeon, who leads the surgery team at VSEC.

What does post-surgical recovery look like?

Most pets spend one night in the hospital after ACL surgery, to monitor their anesthetic recovery and ensure that they are as comfortable as possible. They will have an incision that takes approximately two weeks to heal. It is important to prevent your pet from licking or chewing at the incision during this time. The most important part of recovery is limiting your pet's activity to short leash walks for approximately two months while the site heals. After this time, your veterinarian and veterinary surgeon will evaluate your pet's progress and encourage a gradual return to normal activity if they are healing appropriately.

What is the long-term prognosis?

Most pets put progressively more pressure on the operated limb week by week. Long-term, they should be able to run, jump, play, and lead an active lifestyle. They may experience occasional stiffness or soreness when they first get up in the morning, or after heavy exercise if they are not appropriately conditioned.

What are the risks with ACL surgery?

There is a low risk associated with general anesthesia. Infection or delayed incision healing can occur, particularly if pets lick or chew at their incisions. If your pet is too active too early, the repair can fatigue and fail, which could necessitate revision surgery. Finally, there is a low risk of a delayed meniscal tear sometime after the initial injury. Your veterinarian and veterinary surgeon would outline the specific risks and considerations for your pet.

Can dog ACL tears be prevented?

There is no way to completely prevent ACL injuries in dogs. Some breeds, such as greyhounds, carry inherently lower risks of ACL tears. Overweight dogs are at an increased risk for tearing their ACL, so keeping your pet lean may reduce the likelihood of an ACL tear.

Dog ACL and CCL Surgery at VSEC

Veterinary Specialty & Emergency Center provides advanced veterinary surgical care in Westchester County and the surrounding area. Dr. Greenberg and our surgery team works closely with pet owners and referring veterinarians to diagnose and treat orthopedic injuries, ensuring pets and their families are supported every step of the way.

Learn more about Veterinary Specialty & Emergency Center’s surgery service.