Page 871 - Problem-Based Feline Medicine

39 – THE CAT WITH TREMOR OR TWITCHING 863

A complete neurological examination should be per- Prevention
formed to identify pain or deficits suggesting an under-
Flea prevention.
lying spinal lesion.
Decrease stress in the environment.
Spinal radiographs should be performed to rule out
lumbar and lumbosacral lesions.
HYPOCALCEMIA*
Biopsy of the paraspinal muscles should be used to rule
out vacuolar myopathy.
Classical signs
IgM and paired IgG titers 3–4 weeks apart can be used to
● Tremor associated with this disorder is
help rule out active toxoplasmosis.
usually of short duration and episodic.
Differential diagnosis ● Stiffness and muscle spasm may also
occur.
Rule out dermatitis, lumbosacral spinal or nerve ● Twitching of the ears or facial muscles may
root compression and intracranial disease. be present.
● Weakness, lethargy and anorexia are
Determine if the cat is exhibiting normal behavior dur-
typical.
ing estrus.
Treatment
Pathogenesis
Initial treatment should be with anti-inflammatory
Decreases in calcium decrease the threshold for neu-
drugs. Corticosteroid therapy (prednisolone) may help
ronal and muscle depolarization.
if a flea allergy or other inflammatory stimulus is sus-
pected. NSAIDs like piroxicam or meloxicam or mege- Hypocalcemia most often results from iatrogenic
strol can also be tried. injury to the parathyroid gland during surgical
removal of thyroid tumors.
Strict flea control may improve clinical signs.
Primary hypoparathyroidism is reported but is rare.
Behavior-modifying drugs such as the tricyclic antide-
pressants amitryptyline (2 mg/kg or 5–10 mg/cat PO q Hypocalcemia associated with queening (eclampsia)
24 h), clomipramine (1–5 mg/cat PO q 12–24 h) or the is rarely reported but occurs.
selective seritonin uptake inhibitors fluoxetine (Prozac
0.5–4 mg/cat PO q 24 h) or paroxetine (Paxil, 0.5
mg/kg PO q 24 h) may be helpful in some cats.
Clinical signs
Anticonvulsants (phenobarbital beginning at 3 mg/kg PO
Clinical signs include weakness, tetany and tremors.
q 12 h with dose adjustments to maintain trough serum
levels at 20–35 μg/ml) may help if anti-inflammatory Spontaneous muscle depolarization can manifest as
and behavior-modifying drugs are unsuccessful. muscle fasciculation, cramping, rigidity and twitching.
Feeding food without preservatives has been suggested Queens with preparturient hypocalcemia present with
as helpful. anorexia, lethargy, trembing, muscle twitching and
weakness. They resemble the clinical picture of hypocal-
Carnitine/coenzyme Q12 may help cats with vacuolar
cemia in cows (predominantly weakness), rather than
myopathy. Also antioxidants and omega-3 fatty acids
the violent muscle tremor of eclampsia in dogs.
may be useful.
Cats with primary hypoparathyroidism are more often
Decrease environmental stress.
male and typically range from 6 months to 7 years of
age. Signs include lethargy and anorexia and a sudden
Prognosis
or gradual onset of neuromuscular signs including focal
Consistent results with any treatment have not been (e.g. ears or facial muscles) or generalized muscle
obtained. tremors, seizures, weakness or ataxia.