Page 861 - Problem-Based Feline Medicine

39 – THE CAT WITH TREMOR OR TWITCHING 853

NEOPLASIA
● Neoplasia (p 858)
Tumors involving the cerebellum usually occur in middle-aged to older cats. Clinical signs of cere-
bella dysfunction may occur acutely or be more chronically progressive.

INFECTIOUS/INFLAMMATORY
● Cerebellar hypoplasia** (p 855)
Cats are born with or develop this disease immediately after birth. Clinical signs become apparent
when the cat begins moving and are most obvious when the animal begins walking (somewhere
between 4–8 weeks of age). Intention tremor, ataxia and hypermetria are often found.
● Encephalitis (p 859)
Viral, fungal, protozoan, bacterial, rickettsial and parasitic agents are potential causes. Multifocal
central nervous system signs are most common. Fever and leukocytosis are inconsistent findings.
Other signs of a polysystemic disease such as coughing, vomiting or diarrhea may be associated.
TRAUMA

● Head trauma* (p 856)
Usually associated with an acute onset of clinical signs reflective of an intracranial problem. Signs
present often include alterations in consciousness, paresis and cranial nerve abnormalities. Fresh
blood from lacerations on or around the head, skull fractures, blood in the ear canals and scleral
hemorrhage may be clues to a previous traumatic incident.
FINE TREMOR AND TWITCHING (UNINTENTIONAL)
DEGENERATIVE
● Degenerative diseases of the nervous system (p 867)
Some of these diseases are inherited with clinical signs beginning in cats less than 1 year of age.
Examples include hypomyelination or dysmyelination and motor neuronopathies. Affected animals
tend to have a “bouncy” movement. With other degenerative diseases, such as encephalomyelopa-
thy of young cats and spongiform encephalopathy, tremoring may be acquired in young to middle-
aged cats.
ANOMALY
● Myotonia (p 866)
Clinical signs are most often recognized in cats between 1–12 months of age. Classically affected
cats have a stiff-stilted gait with increased size of the muscles. Tremor, if present, is usually of
short duration and episodic.
METABOLIC
● Hypocalcemia* (p 862)
Most often occurs after thyroidectomy. Muscle weakness, tetany and tremors are typical.
Preparturient hypocalcemia presents as anorexia, lethargy, trembling, muscle twitching and weak-
ness. Primary hypoparathyroidism occurs in young to middle-aged cats and can result in similar
clinical signs.

continued