Reflex sympathetic dystrophy in a dog.

Reflex sympathetic dystrophy is a well-recognized syndrome in human patients following injury to an extremity. The syndrome may include hyperesthesia and autonomic changes. The autonomic changes are initial vasodilatation followed by vasoconstriction (e.g., edema followed by cyanosis, and cool skin); hyper- or hypohydrosis; atrophic changes in the skin, subcutis, and muscles; and osteoporosis. Early treatment with a short course of steroids and infiltration of the painful site with lidocaine may alleviate symptoms. If that fails, sympathetic ganglionic block with lidocaine (and possibly steroids) or surgical sympathectomy may provide resolution. A case of reflex sympathetic dystrophy in a dog is presented, involving bilateral distal hind-limb edema and hyperesthesia.