Muscle Tears in Dogs

What Are Muscle Tears in Dogs?

A muscle tear is an injury to the muscle caused by a trauma to that area, either directly or indirectly. Tears can happen at three points, or areas, of the muscle:

• At the point of origin (a bony bump or nodule where the thick, fibrous bands of the tendon, located at the ends of the muscle, attach to the underlying bone). This is the anchor point of the muscle.

• In the tendon (the area of thick, fibrous bands that connect the meaty portion of the muscle to the bone or bones that it moves). Tendons act as a tether from the muscle to the anchor point.

• Within the muscle belly (the central section of a muscle that is filled with myofibers, which control relaxing and contracting). The muscle belly is responsible for the movements of the muscle; these movements include everything from blinking to running.

A direct trauma can be caused by an incident like a broken leg, where the breaking of the bone moves, stretches, and can sever surrounding muscles and tendons. An indirect trauma is seen when the animal twists or overloads the muscle, causing it to stress to the point of tearing.

Once the location of the tear is identified, it is time to determine what type of tear it is. There are two types of tears:

• Partial: This is a tear that only extends partway through the muscle. A partial tear means the muscle is still attached on either end but has lost its full strength and integrity.

• Complete: This is a tear that extends through the entire muscle. A full tear means the muscle has been completely detached from where it should be.

While uncomfortable to downright painful, a muscle tear is not a medical emergency. If your pet has a muscle tear, please make an appointment with your regular veterinarian for an exam and workup. There is no need for a very expensive emergency visit for this injury.

Symptoms of Muscle Tears in Dogs

Things to look for as signs of a muscle tear include:

• Pain when the area is touched

• Limping

• Swelling of the muscle

• Bruising in the painful area

• Abnormal limb stance, such as the hock—the angled joint in the middle of a hind leg—resting on the ground

Muscle tears are an internal injury and not always easily seen on the outside. If a tear is mild, symptoms may be difficult to detect. If your dog has any of the signs listed above, something is definitely wrong.

If your dog seems to be favoring one leg and not using it as much as the others, run your hands over all parts of the limb. Swelling from a muscle tear will feel a bit firmer and warmer than other areas. Your dog may flinch when you touch this area.

By watching and noting how your dog walks, and running your hands over the painful limb, you can begin to better understand where your dog is hurt. Relay this important information to your veterinarian.

Causes of Muscle Tears in Dogs

Our canine friends are very athletic and can get themselves injured in many ways. Commonly, these include:

• Engaging in heavy exercise with no warmup

• Jumping higher or longer than the dog can comfortably do, thus overloading the muscles

• Wrenching or tweaking the joints while jumping and playing

• Chronic stress, such as long-distance running on hard surfaces

Any muscle can tear if it is stretched past its capacity, but the most common muscle tears are seen in the major muscles of the front and back legs.

How Veterinarians Diagnose Muscle Tears in Dogs

Your veterinarian has many diagnostic tools to help identify a torn muscle:

• Blood work can show elevations in enzymes (specifically creatine phosphokinase), supporting the diagnosis of a torn muscle.

• X-rays allow your veterinarian to see the soft tissue and bone within the injured area. Some tears can cause fragments of bone to pull away from the main bone. Other types of tears may cause bony calcifications where the tendon attaches. Occasionally, x-rays will show where there are areas of soft tissue swelling within the dog.

• Ultrasounds can reveal disruption of tendon fibers within the muscle where a tear is located.

• CT or MRI scans give the highest level of detail, with computerized 360-degree views of your dog’s structures. Your regular veterinarian may not have this specialized imaging equipment but can refer you to a specialty clinic that does.

Treatment of Muscle Tears in Dogs

Supportive care for a partial muscle tear involves immediate rest, placing the dog on a nonsteroidal anti-inflammatory (NSAID) medication, and applying a cold compress to help decrease swelling. Depending on which muscle is torn, a mild compression bandage can be placed to help alleviate swelling.

For mild partial tears, your veterinarian may start a passive physical therapy program intended to prevent complications during healing. After a week or so of therapy, and once cleared by your veterinarian, your dog may engage in restricted and carefully controlled exercise, such as short leash walks (no rampages at the dog park, jumping, or running).

Complete muscle tears need to be surgically corrected for your dog to regain full function of the muscle and of the portion of the body that the muscle moves. Surgery is usually performed a few days after the injury occurs to allow for the swelling and inflammation to go down. After surgery, the dog generally has a passive physical therapy routine, followed by at least a month of strictly controlled exercise to allow for proper healing and prevent further injury.

Can Muscle Tears in Dogs Heal on Their Own?

With supportive care and rest, many partial tears can develop fibrous scar tissue and heal themselves. Complete tears will never heal back to normal on their own. They may cause further problems down the road if the severed end of the muscle develops scar tissue attaching to surrounding tissues, disrupting how the surrounding muscle functions. A complete tear will ideally be surgically fixed and allowed to heal for a period before returning to normal function.

Recovery and Management of Muscle Tears in Dogs

Which muscle, where it is located, and what type of tear occurred are the main determinants of how long it takes to recover. Tears involving tendons and ligaments require a much longer time frame, because they do not heal as fast as muscle due to lower blood flow in these areas. A mild tear may take as little as a few weeks to return to normal function, while a complete tear requiring surgery may take months.

In both types of tears, restricted activity is key. After the initial period of rest to allow the swelling, pain, and inflammation to recede, carefully controlled activity (such as short leash walks or passive range-of-motion physical therapy) is important.

Complete inactivity and immobilization of a muscle or group of muscles after an injury can lead to permanent contraction of those muscles. Permanent contraction is where the muscles are pulled tight and remain that way. A permanently contracted muscle can no longer function, and the limb becomes stiff and unable to move. Therefore, controlled exercise is extremely important.

Prevention of Muscle Tears in Dogs

A few simple steps can help minimize the chance that your dog will get a muscle tear:

• Let your dog warm up before activity. A five-minute walk can help to get blood flowing and make the muscles more elastic before the dog does a high-energy or high-load activity.

• Make sure your dog is supervised when playing with other animals. Dogs can get wild and overstretch their muscles easily while having a blast in your yard or at a dog park.

• Avoid games or toys with an increased chance of causing a muscle tear or a chronic muscle injury. Games where the animal pivots or turns quickly, has sudden stops, or makes a large leap all come with increased risks for muscle injury. These games include fetch, dock diving, hunting, agility sports, and herding.