A spasm is a sudden and involuntary contraction or tightening of a muscle in the body. It usually causes a brief and often painful movement or twitching. Full definition
Call your veterinarian immediately if your pet exhibits uncontrollable movements or muscle spasms of the legs, lips, jaw, tongue, face or other body part, agitation, jitteriness, shortness of breath or insomnia. (1800petmeds.com)
Symptoms of overdose may include drowsiness, confusion, and uncontrollable movements of the legs, face and tongue, muscle spasm of the neck, tremor, irritability and agitation. (1800petmeds.com)
Also slow, relaxed static stretching is useful in relieving spasms in muscles that are healing after an injury (pulled muscle). (personaltraining4u.net)