Xylitol Toxicosis
Xylitol – a 5-carbon sugar alcohol used as a sweetener; present in some sugar-free gums, candies, toothpastes, mouthwashes, vitamins, liquid medications, and baked goods. It is also available as a granulated powder for cooking and baking.
Ingestion by dogs can cause vomiting, weakness, ataxia, seizures, hypokalemia, hypophosphatemia/hyperphosphatemia, and hypoglycemia due to excess insulin release.
Mild to moderate elevations of ALT can be seen within 4 hours of ingestion.
Hepatic failure with high liver enzymes, hyperbilirubinemia, and coagulopathy may occur at dosages > 0.5 g/kg.
Dosages of > 0.075–0.1 g/kg of xylitol may cause hypoglycemia.
SIGNALMENT
Dogs—no breed, age, or sex predilection
Cats—toxicity not established
SIGNS
May develop within 15–30 minutes of exposure; with sugar-free gums, hypoglycemia may be delayed up to 12 hours.
Vomiting common.
Progressive lethargy, weakness, ataxia, collapse, and seizures.
Hepatic failure may be accompanied by vomiting and widespread hemorrhage including petechiae, ecchymosis, and gastrointestinal and abdominal bleeding.
Clinical signs of hypoglycemia may not be evident prior to onset of hepatic failure.
CAUSES & RISK FACTORS
Ingestion of xylitol or xylitol-containing products
DIAGNOSIS
DIFFERENTIAL DIAGNOSIS
Hypoglycemia
Insulin overdose
Sulfonylurea antihyperglycemic agents
Insulinoma (pancreatic β-cell tumor)
Acute Hepatic Failure
Acetaminophen
Aflatoxin
Blue-green algae
Amanita and similar hepatotoxic mushrooms
Iron
Sago palms (Cycad spp.)
Leptospirosis
CBC/BIOCHEMISTRY/URINALYSIS
Hypoglycemia
Hypokalemia
Hypophosphatemia or hyperphosphatemia
Increased ALT, AST, SAP—may be delayed up to 24–48 hours
Bilirubinemia
Thrombocytopenia
OTHER LABORATORY TESTS
Prolonged PT/PTT
Increased FDP, D-dimers and/or decreased fibrinogen
PATHOLOGIC FINDINGS
Severe hepatic necrosis
Widespread hemorrhage
TREATMENT
Decontamination—emesis if patient is asymptomatic; activated charcoal not likely to be beneficial.
Monitor at 1–2-hour intervals for hypoglycemia and hypokalemia and correct as needed.
Monitor for hepatic changes.
MEDICATIONS
DRUG(S)
Dextrose—0.5–1 g/kg IV followed by a 2.5–5% CRI—consider starting with dosages of > 0.1 g/kg.
Potassium chloride—supplement in fluids if potassium value < 2.5 mmol/L.
FOLLOW-UP
Monitor glucose levels for at least 24 hours.
Monitor hepatic enzymes, bilirubin, PT/PTT, and platelets for at least 72 hours.
Prognosis good for uncomplicated hypoglycemia with mild-to-moderate elevations of ALT; guarded to poor if severe hepatic necrosis occurs especially if hyperphosphatemia is present.
MISCELLANEOUS
ABBREVIATIONS
ALT = alanine aminotransferase
AST = aspartate aminotransferase
FDP = fibrin degradation products
PT = prothrombin time
PTT = partial thromboplastin time
Visit your veterinarian as early recognition, diagnosis, and treatment are essential.