Paroxysmal Dyskinesia Suspected as Canine Epileptoid Cramping Syndrome in a Young Yorkshire Terrier Dog

A 9-month-old intact female Yorkshire terrier dog was presented with episodic partial seizure-like cramping of the limbs. The patient's episodes began six months previously; the interval between episodes became shorter, and the duration of the episodes increased. Various tests including neurologic examination, blood examination, abdominal radiography, ultrasonographic examination, angiographic computed tomography (CT) and brain magnetic resonance imaging (MRI) detected no remarkable changes. After these tests were conducted, the patient's condition was suspected to be canine epileptoid cramping syndrome (CECS), which could be a form of paroxysmal dyskinesia (PD), and as a trial therapy, Science Diet k/d (Hill's Pet Nutrition, Topeka, KS, U.S.A.) was prescribed. The clinical signs were dramatically reduced after diet therapy, and we diagnosed the patient with CECS. This is the first case report of CECS in a Yorkshire terrier dog.