A dog can get a pulled muscle (also known as soft-tissue trauma) from overexerting himself while participating in dog agility sports, retrieving and even just rough play. While they are painful, pulled muscles will usually heal within a week or two with some rest.
Limping and Swelling
Limping is the main symptom of a pulled muscle. Your dog may favour the limb that has been injured, or he may not use it all. Often, there is swelling at the site of the injury.
While some dogs don't always show signs of pain, there may be a yelp when the injury occurs. Most dogs will pant heavily when in pain. Your dog may act differently. She may have little appetite.
A diagnosis by your veterinarian is important in case your dog is suffering from more than soft-tissue trauma.
Restrict your dog's activity for at least two weeks so the pulled muscles can heal properly. According to Eric Barchas, DVM (see Resources), too much activity too soon can result in re-injury.
Never give your dog pain killers or anti-inflammatories without the advice of your veterinarian.
According to Dr. Barchas, overweight dogs are prone to soft-tissue trauma, as well as bone and joint injuries.