If your dog's paws twitch in his sleep, it isn't necessarily cause for alarm -- he may simply be dreaming. Dogs experience stages of sleep just like humans do, and in some cases, they may shake and twitch as a result. Chronic and severe shaking, however, can indicate a more serious condition that requires medical attention. Carefully monitoring your dog while he sleeps can help you identify the cause of his shaking.
People and dogs both experience different stages of sleep, including rapid eye movement, or REM sleep. This is the lightest form of sleep, and during this period, the actions you experience in dreams may manifest in reality. For humans, this may mean reaching out with your hands, sleep-talking or screaming. In dogs, this frequently means shaking and twitching paws, and kicking with the legs.
Epilepsy is a medical condition that causes a dog to lose control of his body, twitching or shaking uncontrollably for a period typically ranging 30 to 90 seconds. Dogs who suffer from epilepsy, a brain disorder, most frequently experience seizures while they're either resting or sleeping. If your dog shakes his paws in his sleep, then, it could indicate he has the condition even if he never has an apparent seizure while awake.
What to Do
If your dog shakes his paws in his sleep, monitor the severity and conditions of his shaking. If it's disturbing your own sleep, or if he is whimpering or barking, you can wake him for softly saying his name. Touching or shaking him, however, may be risky -- if he wakes up confused from a dream, he may bite your hand before he gets his bearings. Covering him with a blanket may help, too, as your dog may be shaking his paws because he's too cold. If you suspect epilepsy, calling your dog's name won't wake him up -- monitor the duration, severity and frequency of his shaking episodes so that you can report them to your veterinarian.
If your veterinarian determines that your dog is shaking his paws in his sleep because of epilepsy, he may recommend a course of treatment that will help control the seizures. While there is no known cure for epilepsy, it can be treated with medication and vet-recommended dietary changes -- anti-epileptic drugs can otherwise lead to unhealthy weight gain.