Sudden rear leg lameness in your dog

The most common reasons for sudden rear leg lameness in your dog are fractures, muscle tears and torn ligaments.

Fractures (broken bones) generally only happen with major injury such as when a dog gets hit by a car. However, in some toy breeds with fine leg bones, fractures can occur when the dog jumps down off a high object like furniture. We even saw a dog recently who got his foot stuck in a hole---the dog moved but the leg did not, creating a fractured tibia in the lower part of the leg. Stepping on a small dog can also break bones, but it would be unlikely in a large breed such as a lab or golden.. Dogs that have broken bones will be very lame---usually not putting their foot on the ground at all. Sometimes, if a small bone such as a toe is broken, the dog will bear some weight on the foot. Since dogs are four legged, they get around pretty readily on three legs, so will typically manage to be able to get up and move if only one leg is broken. With major injuries from trauma such as car accidents, multiple breaks can occur, causing greater difficulty getting up. This is especially true for a fractured pelvis. When I was a child, our boxer was hit by a motorcycle. He broke his pelvis and walked on his front legs only for several weeks. It is good for him that he was able to balance so well!

Fractures take a minimum of 6 weeks to heal. In older pets or severe fractures, healing can take even longer----up to 8-12 weeks. Broken bones cause severe pain and lack of function.  Most fractures need a splint or even bone surgery for proper healing and prolonged pain medication. Bone surgery is most often done by a specialist in veterinary orthopedic surgery. University veterinary teaching hospitals and specialty clinics are the best places for bone surgery.

Muscle tears, sprains and strains are typically much less severe than fractures & heal much more quickly. Radiographs (Xrays) are used to help differentiate fractures from soft tissue injury. Most dogs with muscle tears and strains should be rested to allow the area to heal. Ice can be applied for 10 minute intervals to the affected area, if your dog tolerates it. Many dogs with this type of injury benefit from a short course of muscle relaxants or anti-inflammatories.

Rest is also important for proper healing of breaks and strains. Many dogs will only rest if confined to a small area such as a kennel.

Like fractures, torn ligaments heal slowly and may require surgical correction. The most common ligament tear in the dog is the torn anterior cruciate ligament. This ligament crosses inside the knee joint---when injured it causes sudden and often severe rear leg lameness.

Next time, we will talk specifically about the ACL in the dog and options for treatment.