Typical area of arthritis is in the hind end. Dogs carry 60 percent of their body wt on the front legs normally, so arthritis will cause a dog to shift the wt distribution and carry even more wt on the front end. This increase wt distrib. will cause neck and shoulder problems. This is not a Vet problem and the usual treatment from your vet will be meds for pain.
Animal chiropractic will evaluate your dog in a way the vet does not with particular attention to bio-mechanics. If your dog has subluxation in the neck and or shoulder adjustments will correct this and improve movement and decrease pain.