My 4 year old German Shepherd’s back legs shake. I notice this when we go on walks and he stops to smell something, play in the yard, and even when he’s drinking from his water bowl. He runs and plays and has no trouble jumping on the couch or bed. My vet recommended just keeping an eye on it. I just want to ensure that I shouldn’t be doing something else. Can dogs get Parkinson’s disease?
The shaking you see is due to the muscles in his legs contracting, which needs to happen in a normal fashion so your dog can walk and run. The reason for the unintentional muscle contraction can often be difficult to determine. Older German Shepherds commonly develop a disease called degenerative myelopathy, which is a slowly worsening weakness of the hind legs. This is caused by a slow degeneration or die back, of the nerves in the spinal cord. The lack of nerve signals to the muscles of the hind legs can be seen as knuckling of the hind feet or shaking because of the weak muscle contractions. A veterinary neurologist or surgeon can often diagnose this by excluding other causes.
Pain can also cause shaking of leg muscles. Knee or hip pain can manifest as tremors in the hind legs. After examination, a veterinary orthopedic surgeon will be able to tell if joint disease is causing the problem in your dog and tell you what to do about it. Commonly, ligament damage in the knees or arthritis in the hips will cause pain induced shaking of the hind legs.
Parkinson’s disease has not been diagnosed in dogs. We do see other causes of whole body tremors such as white shaker syndrome seen in middle-aged Maltese and West Highland White Terriors, congenital nerve defects in the brain and spinal cord in puppies, and whole body tremors due to kidney failure, high thyroid hormone, low blood sugar or low calcium. Shaking can also be caused by benign things like fear, fatigue, and cold. However, usually this occurs all over the animal and not just in the back legs.
Jonathan Miller, DVM,MS,DACVS (Surgery)
Jonathan Miller, DVM, Diplomate American College of Veterinary Surgeons