According to petMD, muscle strains in dogs are relatively uncommon, but the initial treatment for lameness of any type is very similar. Whether a dog has a muscle strain, muscle sprain or torn ligament, it is important to keep the dog from moving and prevent further injury. Very gently, check for obviously broken bones. If the dog can bear weight on the limb, it is unlikely to be a fracture.
In mild cases of lameness, apply a cold pack to the injured area to reduce the swelling. If the pain lasts more than 24 hours, switch to a warm compress. petMD suggests that for cases involving serious lameness, or lameness that lasts for more than 24 hours, veterinary care is advised. If the dog can walk on at least three legs, allow it to walk to the car on its own, but if it cannot limp in this way, carry it to the car.
According to a study published in Veterinary and Comparative Orthopaedics and Traumatology in 2005, all 22 dogs in the study were adequately treated for leg injuries following some combination of rest, physical therapy, muscle relaxers and nonsteroidal anti-inflammatory drugs. Surgery was not required for any of the dogs in the study, and all healed or exhibited improvement following the conservative treatment.