Ethylene Glycol Toxicity

Introduction

Ethylene Glycol is a sweet tasting fluid that is the main constituent of anti-freeze products.. Consequently in northern hemishpere ethylene glycol toxicity is frequently encountered in practice. It has a relatively low minimum lethal dose, and its sweet, palatable taste makes it attractive to dogs, cats and other small animals. , ,

Signalment

• Dogs: all ages, both sexes, following intoxication lower incidence of fatalities in dogs compared to cats
• Cats: all ages, both sexes
• Birds
• Other including pigs and cattle

Diagnosis

Clinical Signs

Severity of clinicals signs is inversely proportional to amount ingested. Time post-ingestion is also important..

• Dogs: Ataxia, mild to severe increasing depression and other neurological signs, tachycardia, tachypnoea, polydypsia, polyuria, dehydration, anorexia, emesis, miosis, hypothermia
  • if untreated coma and death, or if lesser amount ingested oliguric acute renal failure within 2 to 7 days after ingestion ., .
    • if untreated anuric acute renal failure
• Cats: Ataxia, pronounced depression and other neurological signs, tachycardia, tachypnoea, polyuria, dehydration, anorexia, emesis, miosis ,

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• • coma and death if untreated, or if lesser amount ingested oliguric acute renal failure within 1 day after ingestion
    • if untreated anuric acute renal failure

Laboratory Tests

• Metabolic Acidosis, increased serum osmolality, increased anion gap, decreased plasma bicarbonate concentration, decreased PCO2, decrease blood pH
• increased urea and creatinine, hyperkalaemia,
• Hyperphosphataemia due to acute renal failure .
  • Hypocalcaemia as a consequence of this.

Ultrasonography

• Renal accumulation of calcium oxalate crystals results in hyperechogenicity upon ultrasound examination .

Biopsy

• Needle or surgical wedge biopsy of kidney .

Pathology

• Tetany results from the binding of Ethylene Glycol meatabolites to calcium ions present in serum .

Treatment

• Ethanol: useful in both dogs and cats .

• 4-methylpyrazole:Dogs only mode of action is to inhibit ADH in the liver. Recommended doses are 20mg per kg of a 50mg/ml solution (intravenous) followed by 15mg per kg (intravenous) 12 hours and 24 hours later and a final dose of 5mg per kg 36 hours later .

Ethylene Glycol is a weak acid. Therefore in order to increase the rate of renal clearance sodium bicarbonate can be administered to dogs. Intravenous administration of sodium bicarbonate at a concentration of 1-2 mmol/kg every 3 to 6 hours achieves sufficient alkalinisation of the urine.