1,9 Liver necrosis is considered to be less common with cats than with dogs. 10 Large doses of acetaminophen can also cause nephrotoxicity characterized by proximal tubule necrosis. The diagnosis of acetaminophen toxicity is most often based upon exposure history and the development of associated clinical signs. Other common hepatotoxic substances include iron, some mycotoxins, phosphorus, carbon tetrachloride, coal tar, phenolics, nitrosamines, thiacetarsemide, some benzimidazole anthelimintics, tannic acid, copper, vitamin A, pyrrolizidine alkaloid containing plants, blue green algae, and Amanita mushrooms. The objective of treatment in acetaminophen toxicity is to replenish glutathione, convert methemoglobin back to hemoglobin, and prevent or treat hepatic necrosis.
Stabilization is always a priority.
If the animal is dyspneic, oxygen therapy should be given. Whole blood transfusions or Oxyglobin may be necessary. Although the prognosis is good if animal is treated promptly and aggressively, animals with severe signs of methemoglobinemia or hepatic damage have poor to guarded prognosis. Emesis should be induced in asymptomatic dogs or cats, unless contraindications exist. 12,13 Gastric lavage is considered to be less effective than emesis, but may be performed if emesis is contraindicated.