Dogs experience shaking and leg tremors because they are suffering from a medical problem or because they are nervous, according to PetMD. In addition, some dogs are genetically predisposed to involuntary tremors.
Puppies who display trembling in the legs or other areas and who have not been fully vaccinated may be suffering from distemper, according to WebMD. Distemper is a viral infection that also causes coughing, fever and runny nose. Treatments for distemper include antibiotics, hydration via fluids, airway dilators and physical therapy.
Dogs of certain breeds are prone to shaking from what is known as GTS or General Tremor Syndrome. WebMD and PetMD explain that GTS occurs in dogs between the ages of nine months and two years, particularly afflicting the Maltese, West Highland terrier, Chow Chow, Dalmatian, Doberman pinscher, English bulldog, Samoyed, Labrador retriever and springer spaniel breeds. This condition is treated with rounds of corticosteroids.
Young dogs also develop the shakes after eating a toxic item such as a plant. Nausea is another cause of shaking. WebMD suggests looking for other signs of nausea such as salivating, lack of energy, lip smacking or vomiting. When these symptoms are present, owners should seek immediate emergency vet assistance.
Sometimes there is no detectable cause for leg trembling. If a dog is generally healthy, eating a well-balanced diet and there is nothing obvious that would cause a severe reaction, the shaking may be a physical quirk. The best way to determine the cause of leg shaking is to consult a veterinarian.