Ethylene glycol poisoning in small animals—name typical early signs and the antidote.

• A. Ataxia, vomiting, polyuria/polydipsia; fomepizole (or ethanol) with aggressive IV fluid therapy.
• B. Seizures and coma; administer diazepam.
• C. Diarrhea and dehydration; administer IV calcium.
• D. Jaundice and hepatic failure; administer vitamin K.

Answer: (A)

Ethylene glycol poisoning in small animals presents with signs that reflect early central nervous system depression and osmotic effects in the kidneys, so ataxia, vomiting, and polyuria/polydipsia are typical early clues. The best antidote is fomepizole (4-methylpyrazole), with ethanol as an alternative, paired with aggressive IV fluid therapy. Fomepizole blocks alcohol dehydrogenase, preventing the transformation of ethylene glycol into its toxic metabolites like glycolic acid that cause metabolic acidosis and kidney injury. By stopping the formation of these harmful compounds, it limits progression and helps the animal recover. If fluids are given aggressively, they support kidney perfusion and facilitate clearance of the parent compound and metabolites; in more severe cases, dialysis may be required to remove ethylene glycol and its toxins from the bloodstream. Other options don’t fit because their signs or treatments don’t align with ethylene glycol’s early presentation or its specific antidote mechanism.