Page 291 - Problem-Based Feline Medicine

16 – THE CAT WITH ACUTE DEPRESSION, ANOREXIA OR DEHYDRATION 283

– Osmotic diuretics should not be used in the Opioid analgesics should be considered at standard
presence of hyperosmolality (e.g. ethylene gly- doses for cats with swollen and painful kidneys or oral
col poisoning, diabetic ketoacidosis), dehydra- ulceration.
tion or overhydration.
Peritoneal dialysis, pleural dialysis, hemodialysis or
Monitor urea, creatinine and phosphorus levels (ini- transplantation should be considered for cats with
tially once daily). anuria or severe oliguria.
● A rapid fall in serum urea and creatinine levels
in the first 24–48 hours of fluid therapy indicates
Prognosis
that there was a substantial pre-renal component
to azotemia. Mild decreases in urea and creatinine There are few reports of acute renal failure in cats due
levels during the following week are usually due to to causes other than ethylene glycol or lily poisoning
mild ongoing volume expansion and the cat should (see below). Most cats with hemodynamically medi-
be watched closely for over-hydration. Decreases ated non-oliguric acute renal failure and cats with
in urea and creatinine levels due to improved pyelonephritis will probably recover with appropriate
renal function usually take 10–14 days to appear. critical care, but may have residual or worsened
After renal function improves and then stabilizes, chronic renal failure. In general, the prognosis for
fluids may be tapered. Urea and creatinine levels non-oliguric renal failure is better than for oliguric or
will rise when fluids are tapered. anuric renal failure. Without dialysis, the prognosis is
typically considered poor if there is persistent olig-
Obtain minimum blood sample sizes. Frequent blood
uria or anuria.
sampling may lead to anemia and hypoproteinemia that
will affect use of PCV and total protein values to moni-
tor hydration. Anemia may require correction by trans- Prevention
fusion.
Minimize prolonged renal hypoperfusion. Correct fluid
Dopamine is not recommended as its effects are uncer- deficits and hypotension promptly in cats with chronic
tain in cats and its benefit in acute renal failure in renal failure.
humans is being questioned.
Begin intravenous fluids preoperatively in elderly cats
Antiemetics. Prochlorperazine, chlorpromazine, undergoing surgery, to prevent acute exacerbation of
yohimbine, metoclopramide and ondansetron may be chronic renal failure.
used to control vomiting. Metoclopramide is a less
Minimize exposure to ethylene glycol and lilies. Use
effective antiemetic in the cat than in the dog. It is elim-
aminoglycosides and other nephrotoxic drugs judi-
inated via the kidney so an initial dose of 0.2 mg/kg, SC,
ciously and avoid in elderly cats and in cats with
twice daily is recommended (dose range 0.2–0.5 mg/kg
chronic renal failure.
three times a day). It may also be given by constant rate
infusion at a dose of 0.005–0.02 mg/kg/h (lower end of
the range recommended initially). Prochlorperazine and
ACUTE POISONING AND EVENOMATION*
chlorpromazine may cause hypotension.
Gastrointestinal protectants. Ranitidine and famoti- Classical signs
dine (H2 blockers) are eliminated via the kidney (about
● Acute depression.
2/3–3/4 of the dose) so an initial dose of 0.5 mg/kg IV
● Other specific signs: weakness, tremor, GIT
once daily is recommended. Sulcralfate 0.25–0.5 g PO
signs.
three times a day may be used if it does not increase
vomiting.
See main reference on page 594 for details (The Cat
Nutritional support. This may include nasoesophageal With Salivation) and page 481 (The Bleeding Cat) and
or esophageal feeding in cats that are not vomiting, page 381 (The Pyrexic Cat), page 812 (The Cat With
and parenteral nutrition. Seizures, Circling and/or Changed Behavior for