Does My Dog Have an ACL Injury?

Ask The Vet: Does My Dog Have An ACL Injury?

In this post in our Ask The Vet series we discuss ACL injuries in big dogs with Dr.  Scott Perry, DVM, a preferred Provider with Vet24seven’s www.Ask.Vet community spoke with us at length about various injuries that can befall our beloved big dogs.

Joint pain is part of the aging process for dogs, both large and small, but the big breeds – Great Danes, Mastiffs, Doberman Pinschers, Boxers, Newfoundlands and others are more prone to hip and joint issues. Even though aging and potentially life-altering joint issues may be a part of life, there are steps pet owners can take to assure their dog has a high quality of life.

Bear in mind that joint issues are not merely a sign of aging as joint problems such as anterior cruciate ligament (ACL) can strike a big dog because he is overweight or any other number of reasons caused by wear and tear on the muscles.

Does My Dog Have an ACL Injury?

We asked Dr. Perry, “How can a pet parent tell if their pet has an ACL injury?” It’s sometimes difficult, he said, because ACL injuries in big dogs can present as a dog who appears to be limping because he stepped on something. “Your dog may stand and only put weight on the tips of his toes and that leads the owner to believe he stepped on something when he was out in the yard.”

Dr. Perry said that, “overweight large breed dogs are predisposed to this condition because there is more tension and pressure put on the ligament. That is why it is so important for dog owners to make certain their pet is at his or her ideal weight.”

ACL injuries in big dogs 

How is an ACL injury diagnosed? “This isn’t a problem that is too hard to diagnose when we see this pet. The pet owner will think maybe he stepped on something because he’s limping,” Dr. Perry explained. “It is also confusing because there could be a waxing and waning of the limp.” This, he said, is especially true if there is a partial tear in the ligament. “The limp could go on for many months, all the while causing further damage to the ligament.”

Your veterinarian will perform a complete physical and orthopedic exam with the patient awake. The dog may shift her weight onto the “good leg” while in the exam room. Your vet will be examining your dog to differentiate knee pain from hip dysplasia and lumbo-sacral disease. A study in the Journal of American Veterinary Medical Assn in 2005 showed that “32% of dogs referred to a surgeon for hip dysplasia, in fact have had a torn ACL… and 94% of those dogs with an ACL tear had concurrent radiographic signs of hip dysplasia.” A medial buttress may be palpable at the medial aspect of the knee. The medial buttress represents thickening of the medial joint capsule from chronic instability.

Is a complete tear more noticeable than a partial ACL tear?

“A complete tear is harder for your dog to mask because the joint will be more unstable,” Dr. Perry explained. “With a complete tear we are talking about two bones – the femur and the tibia – that are rubbing against one another. This will cause your dog considerable pain.”

As a caution, Dr. Perry said, “a well-muscled dog may still be able to hide the pain and the instability simply because his hind quarters have more muscles to support the joints.” In that case, he said, it’s hard for a veterinarian to diagnosis because the dog will tense up when he’s touched. “In this case, we typically need to make a diagnosis under sedation so the muscles are relaxed and we can fully examine her.”

Should I take my dog to the vet immediately when I see a limp?

Many pet parents don’t want to be alarmist when it comes to seeing their dog limp. How do we know when we should be calling the veterinarian or taking a wait-and-see stance? Dr. Perry said, “If you’re witnessing the toe touch, I’d contact your veterinarian for an orthopedic examination. Even if your dog is well-muscled, if he’s been limping for a day or two it may require an x-ray for a proper diagnosis.”

In the next article in our Ask The Vet series, Dr. Perry explains the various types of surgeries available, their effectiveness and how long and how involved recovery is.Dr. Scott Perry

About Dr. Scott Perry, DVM: He is a Preferred Provider with Vet24seven’s www.Ask.Vet community and AskNow free veterinarian text messaging service. He was raised in Montana and studied veterinary medicine in Southern California at Western University of Health Sciences. He has worked in various emergency hospitals and general practices. His primary medical focus is on dogs, cats, and exotic pets and his professional interests include dermatology, ophthalmology, orthopedics, and animal behavior. When not working Dr. Perry enjoys outdoor activities such as running and paddle boarding, and playing with his dog, Charlie.