Injury

• The skeletal muscles in a dog's legs are connected to the bones by a series of fibers that are designed to contract with each movement. Each time a dog moves, these fibers meet some sort of resistance. In the case of most dogs, this resistance comes when their legs meet the ground. This resistance is what allows them to run, jump and play. However, if the resistance is very sudden or too strong, the muscle fibers can tear. This is a pulled muscle. While a pulled muscle can occur in any dog, they are more common in overweight or older dogs.
  
  

Symptoms

• Muscles tears cause swelling at the point of injury. This area will be very tender. A dog with a pulled muscle will limp and try to walk on its non-injured legs. While it may be difficult to see through your dog's fur, some pulled muscles cause bruising.
  
  

Diagnosis

• If your dog exhibits any of the above symptoms, it is important to take it to a veterinarian immediately. While your dog likely has a simple muscle pull, it is essential to rule out a more serious injury before treatment can begin. Many symptoms of a muscle tear can be similar to those of other injuries. Your veterinarian will be able to recommend a course of treatment.
  
  

Recovery

• Improvement is generally seen in three to five days for dogs with mild to moderate muscle pulls. Most veterinarians will prescribe an anti-inflammatory drug to lessen swelling and pain. It is important to make sure your dog rests during its recovery. If your dog does not show any improvement within a week, schedule another appointment with your veterinarian.