Page 294 - Problem-Based Feline Medicine

286 PART 5 CAT WITH ACUTE ILLNESS

Minimize further absorption (cutaneous and gas- Activated charcoal is an effective absorbent for
trointestinal decontamination). many poisons including vitamin K antagonist
● Bath the cat if there is poison on the skin (e.g. per- rodenticides, ethylene glycol, alkaloids, organophos-
methrin) phate and other insecticides, acetylsalicylic acid,
● Remove the source of the poison. NSAIDS and barbiturates. It is not effective with
● Irrigate oral cavity if there is poison in the mouth most caustic or corrosive agents.
(e.g. after mouthing a Bufo toad). If clinical signs ● Catharsis is used to promote elimination of the
are due to unpleasant taste or oral irritation (hyper- toxin in the stool. It should always be used follow-
salivation, agitation +/– vomiting) after milk or liq- ing the use of activated charcoal and should not be
uid from a can of tuna. used in the presence of diarrhea. Catharsis may
● Induction of emesis. Xylazine 0.44 mg/kg IM reli- have to be repeated every 4–6 hours as with
ably causes vomiting in 5–20 minutes. The effect activated charcoal. Catharsis using non-absorbed
can be reversed with yohimbine 0.1–0.5 mg/kg IV. salts or sugars will cause dehydration that must be
If xylazine is not available, or for induction of vom- addressed with fluid therapy.
iting at home, use fresh 3% hydrogen peroxide, – Salts: sodium sulfate (Glauber’s salts, pre-
2 ml/kg PO, or syrup of ipecac, 3–6 ml/kg diluted ferred) or magnesium sulfate (Epsom salts), 1/2
1:1 with water, PO or by gavage (i.e. via stomach level teaspoon per kg in 5–10 volumes of tepid
tube). Vomiting should occur within 10–30 min- water, by gavage. Magnesium sulfate may cause
utes. Hydrogen peroxide and syrup of ipecac treat- central nervous system depression, should not be
ments may be repeated once if the initial treatment repeated, and must be used cautiously in renal
is ineffective. failure. These salts are the preferred cathartics in
● Induction of emesis is absolutely contraindicated lead poisoning as lead will precipitate as unab-
in the presence of a caustic or volatile poison, sorbable lead sulfate.
impaired gag reflex, laryngeal paralysis, extreme – Sugars: sorbitol 70% solution (preferred) or
weakness or unconsciousness, and is relatively con- lactulose, 3 ml/kg. The most practical prod-
traindicated in the presence of seizures or dyspnea. uct to use in the non-specific treatment of poi-
● If induction of emesis is ineffective or con- soning is a commercial product that combines
traindicated, perform gastric lavage. Establish activated charcoal and sorbitol in a suspen-
light general anesthesia if the cat is not uncon- sion.
scious and place a cuffed endotracheal tube extend- – Colonic lavage (“high enema”), 20 ml/kg tepid
ing 2–3 cm beyond the teeth. Position the cat with water.
the head and thorax slightly lowered. Pass a tube
Enhance elimination.
the same size or slightly larger than the endotra-
● Diuresis. Diuresis will hasten renal elimination of a
cheal tube into the stomach, deliver 5–10 ml/kg
toxin only if it is reabsorbed by the renal tubules,
tepid water, and aspirate with a 60 ml syringe or
e.g. ethylene glycol. Diuresis may be achieved with
aspiration bulb. Repeat the procedure 10–15 times.
fluid therapy, furosemide, mannitol or dextrose (see
Kink the stomach tube as it is removed from the
Acute renal failure, page 282).
stomach. Addition of activated charcoal at the dose
● Ion trapping. A toxin must be unionized to be
below to the lavage solution will increase its effec-
reabsorbed by the renal tubules. Elimination of
tiveness.
acidic toxins (e.g. aspirin) may be hastened by
● Solid poisons (e.g. lead) may be removed by
alkalinizing the urine using sodium bicarbonate.
endoscopy or gastrotomy/enterotomy.
Elimination of alkaline toxins (e.g. strychnine)
● Absorption of remaining poison. Give a slurry of
may be hastened by acidifying the urine using
activated charcoal by gavage, 1–5 g/kg dissolved
saline or ammonium chloride.
in 3–5 ml of tepid water/g charcoal, after induction
● Peritoneal dialysis or hemodialysis.
of emesis or when gastric lavage is complete.
Treatment may need to be repeated every 4–6 hours Specific therapy.
for 2–3 days because the poison may return to the ● Anticoagulant rodenticide – vitamin K (see page 509,
intestinal tract by enterohepatic circulation. The Bleeding Cat).