Veterinary spinal manipulation, VSMT, is like chiropractic medicine in humans. It is a proactive healthcare system that looks at the overall health of the dog and tries to prevent future disease/injury, instead of treating a pet when they are already sick/injured.
When someone who is properly trained in VSMT looks at your dog, they are ultimately looking at the nervous system.
They assess the all the joints, but particularly the spine for areas where the vertebrae are not moving correctly.
This abnormal motion, usually hypomobility, causes decreased feedback of information from your pets body into the spinal cord and up to the brain.
When the brain is getting bad information in, it sends bad information back out and predisposes your pet to injury.
Also, lack of feedback into the spinal cord causes increased pain and decreased muscle function.