What Does It Mean When a Dog Arches Its Back?

A dog arching its back means the back curves upward into an arc, usually from being startled or preparing to attack. It can also result from abdominal pain or spinal injury and disease pain, such as lumbar disc herniation, spinal arthritis, spondylitis, or nucleus pulposus protrusion.

Finally, some breeds or individuals are born with skeletal abnormalities or deformities causing spinal issues, which can also produce an arched back.