Page 307 - Problem-Based Feline Medicine

16 – THE CAT WITH ACUTE DEPRESSION, ANOREXIA OR DEHYDRATION 299

tremia. Idiogenic osmols form in hypernatremia to pro- anorexia and depression are reported by the owners.
tect the brain against dehydration; these osmols result Anorexia and depression may be due to esophageal pain.
in cerebral edema if serum sodium concentration is
lowered too quickly. Because the rate at which hyper- Diagnosis
natremia developed is often not known, a general
Diagnostic imaging or endoscopy is required to iden-
recommendation is to lower serum sodium level by
tify foreign material. The latter is required to identify
1–2 mmol/L/h.
esophagitis.
Assess percent dehydration and replace using 0.9%
saline over 4–8 hours if acute dehydration and over
PRIMARY ANOSMIA
8–12 hours if chronic dehydration.
Once the cat is rehydrated, calculate free water deficit: Classical signs
Deficit (L) = 0.6 × body weight (kg) × ([Na ÷ 140] – 1). ● Anorexia.
Give this volume over 12–24 h if the cat’s mentation is
normal, and over 24–48 h if mentation is abnormal. Clinical signs
Give furosemide 0.5 mg/kg IV if hypernatremia per- Anorexia and cat may sniff less.
sists and the cat is normally hydrated.
Diagnosis
Consider antidiuretic hormone therapy (e.g. DDAVP) if
there is diabetes insipidus (see The Cat With Polyuria History of olfactory tractotomy for inappropriate elim-
and Polydipsia, page 231). ination behavior.
No reaction to placement of noxious stimuli in front of
Prognosis nose.

The prognosis for hypernatremic cats with head trauma
is poor; the prognosis for uncomplicated correction of FELINE LEUKEMIA VIRUS INFECTION
hypernatremia with other disorders is good and overall
prognosis is determined by the underlying disorder. Classical signs
● Fever.
ESOPHAGEAL FOREIGN BODY AND ● Signs of secondary infections, hematologic
INFLAMMATION disorders, or neoplasia.

Classical signs
Clinical signs
● Regurgitation.
Feline leukemia virus infection usually causes fever;
● Anorexia and depression.
anemia and other hematologic disorders; immunosup-
pression leading to secondary infections; lymphoma,
See main reference on page 616 for details (The Cat With
myeloproliferative disorders, and fibrosarcomas and
Signs of Regurgitation (Acute or Chronic)).
neurologic disorders.
Occasionally the only sign of infection is acute depres-
Clinical signs
sion, anorexia and dehydration.
Cats with esophageal foreign bodies or esophagitis (e.g.
secondary to treatment with tetracyclines) are typically
Diagnosis
presented for regurgitation (or vomiting as perceived by
the owner), dysphagia or gagging. However, this may A feline leukemia virus test should be considered in the
be intermittent, so that only non-specific signs such as work-up of a cat with acute depression and anorexia.