Page 711 - Problem-Based Feline Medicine

32 – THE CAT WITH SIGNS OF ACUTE SMALL BOWEL DIARRHEA 703

A PCV, TP and fecal examination are simple, inex- Deficits should be replaced over 4–6 hours or more,
pensive tests that should be used in cats that seem and ongoing losses estimated and additional fluid
lethargic or dehydrated. amounts added to the maintenance fluid rate calculated.
In cats with more persistent or severe clinical signs, Potassium supplementation of intravenous fluids
a dietary change, more extensive fecal analysis (zinc should be initiated once the cat is rehydrated and
sulfate flotations, culture or cytology) and additional should be monitored and adjusted based upon serum
evaluation of the hemogram or chemistry profile is potassium levels.
indicated.
Antimicrobial therapy is not routinely indicated for
treatment of acute, mild forms of gastroenteritis.
Differential diagnosis
The choice of antibiotic should be based on the sus-
Food intolerance (ingestion of substances that cause pected or known causative organism (Campylobacter,
an adverse response that is not immunologically medi- Clostridium spp., etc.).
ated, e.g. not food allergy) or dietary indiscretion
Cats with severe mucosal injury as evidenced by blood
(ingestion of foreign or usual foods or non-food sub-
loss or hypoproteinemia have the potential to develop
stances that cause GI disturbance) is a common cause
septicemia, or signs of systemic sepsis (fever, depres-
of acute gastroenteritis.
sion, leukocytosis, hypoglycemia, etc.). These cats
Bacterial or viral infections of the GI tract may be should receive broad-spectrum, parenteral antibiotics
mild and self-limiting, or severe and life-threatening, so effective against enteral pathogens (e.g. either alone or in
the clinical presentation must be carefully evaluated. combination: ampicillin, enrofloxacin, trimethoprim-
sulfadimethoxine, metronidazole or cephalexin).
Other causes of acute, mild gastroenteritis are inges-
tion of toxic substances (plant material, oil or other The most effective motility-modifying drugs for treat-
materials attached to hair coat, etc.). ment of diarrhea are the opioids (loperamide 0.08–0.16
mg/kg q 12 h or diphenoxylate 0.05–0.1 mg/kg q 12 h).
Opioids should be used with care in cats because safe,
Treatment effective dosages have not been established.
Fluid therapy is indicated if there are clinical signs of Anticholinergic drugs have no useful role in the
dehydration, or if the cat is unable to drink. symptomatic treatment of diarrhea in cats with gas-
troenteritis, because they reduce both peristaltic and
Balanced isotonic replacement electrolyte solutions
segmental intestinal motility contractions.
are the best fluid choices for cats with mild to moder-
ate metabolic acidosis and dehydration secondary to Intestinal protectants and absorbent agents (kaolin,
acute diarrhea. pectin, activated charcoal, barium, bismuth subsalicy-
late) may or may not be clinically effective, but are not
Fluids may be given subcutaneously in cats that are
harmful and are likely most beneficial when used in
only mildly dehydrated.
acute, non-specific enteritis.
In cats with severe dehydration or who are intolerant of
Bismuth subsalicylate, 0.25 ml/kg q 4–6 h, has been
subcutaneous fluid administration, intravenous replace-
shown to be most effective in acute small-intestinal
ment of fluid deficits is necessary.
diarrhea, but should be used cautiously in cats to
Oral rehydration therapy is effective in patients that decrease the possibility of salicylate toxicity.
are mildly dehydrated and can ingest oral fluids.
If vomiting is a concurrent problem, anti-emetic ther-
The maintenance rate for fluid therapy is 40–60 apy should also be initiated. Metoclopramide, 0.2–0.5
ml/kg/day, and replacement of fluid deficits is calcu- mg/kg q 6–8 h, or prochlorperazine, 0.1–0.5 mg/kg q 8 h,
lated by: are two commonly used anti-emetics. Anti-emetic
therapy should not be used if a gastric outflow
BW (kg) ¥ % dehydration = fluid deficit (liters) obstruction is suspected.