Tag Archives: Jack Russell Terrier

Tremor and involuntary movements

Involuntary movement disorders result in some of the most dramatic clinical presentations in veterinary medicine. Classically, these disorders are present during periods of inactivity rather than during voluntary movement. Cerebellar disease, conversely, can result in apparent involuntary abnormalities during movement. Some involuntary movements are persistent while others are episodic. Certain involuntary movements have characteristics that allow for identification of specific causes, whereas others are only a reflection of dysfunction of the nervous or musculoskeletal systems. Clinically, it is important to first identify the type of involuntary movement present. Subsequently, a more directed approach can be used to establish the cause of the movement disorder. Clinical signs Involuntary movement disorders are less well classified in animals than in humans. Terms such as tics, twitches, shivering, shuddering and fasciculation are often used to describe episodic, irregular muscle contractions. They are usually manifested through abnormal motion of the limbs, trunk or head. There are seven forms of involuntary movement. Myoclonus Myoclonus is a shock-like contraction of a muscle or muscles that tends to occur repeatedly Read more […]


Paraparesis is a non-specific term for bilateral motor dysfunction of the pelvic limbs. Paraparesis is a very common presentation in small animal veterinary practice and can be caused by orthopaedic, muscle, neuromuscular junction, nerve and spinal cord dysfunction. More rarely, systemic and metabolic disorders can present as episodic or progressive paraparesis (e.g. cardiac and pulmonary dysfunction, endocrine and electrolyte disturbances) and animals with drug-induced side-effects (e.g. phenobarbital and potassium bromide) may show pelvic limb dysfunction manifested as ataxia. Diseases of the thoracolumbar spinal cord are the most common cause of paraparesis and, as late or misdiagnosis of many of these disorders can have catastrophic consequences for the patient, it is important to fully understand how to evaluate and manage paraparetic animals. Clinical signs Paraparesis, by definition, represents motor deficits in the pelvic limbs. Abnormal gait descriptions include: Ataxia ― loss of proprioception; incoordination Fatigability applies when one or more muscles become weaker with repetitive but normal use and may imply neuromuscular dysfunction Paresis ― reduced voluntary motor function Paralysis Read more […]