Page 304 - Problem-Based Feline Medicine

296 PART 5 CAT WITH ACUTE ILLNESS

History of thyroidectomy within the previous Other signs that are sometimes observed include mus-
2 weeks. cle tremors, vomiting, vocalizing, circling, panting,
diarrhea or urination.
Differential diagnosis Hypoglycemia is unlikely to stimulate eating behavior
in a cat; it is more likely to cause anorexia.
Acute poisoning is main differential diagnosis for
acute anorexia and depression progressing to muscle
tremors and seizures. Diagnosis
Hypoglycemia may cause similar signs. Clinical hypoglycemia usually results from insulin
overdose in a diabetic cat. This is confirmed by meas-
uring blood glucose levels and by prompt resolution of
Treatment
clinical signs following intravenous dextrose or intra-
Tremors or seizures: muscular glucagon.
● 10% calcium gluconate 0.5–1.0 ml/kg, or 10% cal-
Portable glucose meters have a tendency to measure
cium chloride 0.15–0.5 ml/kg, given IV over 10–15
falsely low values. A diagnosis of hypoglycemia should
min. Temporarily stop administration if bradycar-
be reconsidered if the signs do not improve once blood
dia, QT-interval shortening or vomiting occur. Both
glucose increases in response to intravenous glucose or
solutions are caustic (calcium chloride >> calcium
glucagon. Lack of response to sugar solutions
gluconate) if extravasated.
rubbed on the gums or given by stomach tube does
● If severe initial signs or recurrent signs, follow with
not rule out hypoglycemia, because most absorption
10% calcium gluconate 0.25–0.375 ml/kg/h CRI.
of glucose occurs in the small intestine. Cats with
Long-term management: severe signs such as coma may not respond if there is
● Vitamin D and oral calcium preparations – see The irreversible brain damage.
Cat With Tremor or Twitching (page 864).
● Cats with post-thyroidectomy hypoparathyroidism
Differential diagnosis
typically regain parathyroid function within 2
weeks to 6 months. Other causes of neurologic disease. See The Cat With
Stupor or Coma (page 821) and The Cat With Seizures,
ACUTE HYPOGLYCEMIA Circling and/or Changed Behavior (page 809).
Some poisonings may cause similar signs, e.g. vocaliz-
Classical signs ing, mydriasis, vomiting, diarrhea, polypnea, tremors,
● Acute depression in an insulin-treated cat. seizures and stupor (see Acute poisoning and enveno-
● Weak wobbly gait. mation, above).
● Muscle fasciculations. Hypocalcemia may also cause lethargy and anorexia
● Dilated pupils. progressing to muscle tremors and seizures.

See main reference on page 236 for details (The Cat Hypoglycemia may also be a finding in acute pancre-
With Polyuria and Polydipsia). atitis, porto-systemic shunts, hepatic lipidosis, cholan-
giohepatitis, and overwhelming sepsis, but it is usually
a marker of disease rather than a cause of clinical signs.
Clinical signs

Clinical signs of hypoglycemia most often occur in
Treatment
insulin-treated diabetic cats.
A Somogyi reaction should not be relied upon to rescue
Signs may be mild and include lethargy or increased
a cat from hypoglycemia.
somnolence, a weak wobbly gait and mydriasis, or be
more severe and include seizures, stupor or coma. Give 50% dextrose at 0.5–1.0 ml/kg IV.