Xylitol poisoning in dogs and cats
Toxic agent: Xylitol, a sugar alcohol · Reviewed 2026-08-18
Phone a vet now, before reading on. Have ready: your pet's weight, roughly how much was eaten and when, and the packaging if there is any. ASPCA Animal Poison Control (+1 888 426 4435), Pet Poison Helpline, or Animal PoisonLine in the UK.
Xylitol is one of the fastest-acting household poisons for dogs. A few pieces of sugar-free gum can put a small dog into a hypoglycaemic crisis within half an hour.
What it actually does
In dogs, xylitol triggers a rapid and massive release of insulin from the pancreas — an effect it does not have in humans. Blood glucose crashes. At higher doses it also causes acute liver necrosis by a mechanism that is still not fully understood, and that liver injury can appear even in dogs whose blood sugar was successfully corrected.
How much matters
Two separate thresholds, two separate problems:
| From about 0.1 g/kg | Hypoglycaemia — the emergency that happens within the hour |
|---|---|
| From about 0.5 g/kg | Acute liver failure, which can develop over 24–72 hours |
| One piece of sugar-free gum | commonly 0.3–1 g of xylitol, so a 5 kg dog can cross the first threshold on a single piece |
The gum figure is the reason this substance is different from most on this list: the dangerous quantity is a normal quantity. Read the label — xylitol is often listed simply as 'sugar alcohol'.
What you will see, and when
Onset: 10 to 30 minutes for hypoglycaemia. Liver injury may not show for a day or more.. Typical course: Hypoglycaemia can require 24–48 hours of glucose support; liver monitoring runs for 72 hours.
- 10–30 minutesVomiting, then weakness, staggering, tremors
- 30–60 minutesCollapse, seizures — this is the hypoglycaemic crisis
- 24–72 hoursJaundice, bleeding, lethargy if the liver has been injured
What the vet will do
Blood glucose is checked immediately and corrected with intravenous dextrose, often for a day or more. Activated charcoal binds xylitol poorly, so decontamination matters less here than early glucose support. Liver values are monitored for three days even after the sugar stabilises, and liver protectants may be started.
Outlook
Excellent if glucose is corrected early. Guarded once liver failure is established.
Dogs and cats are not the same here
This is a dog problem. Cats have not been shown to release insulin in response to xylitol, and reported feline cases are rare — but ferrets are affected like dogs.
Where it comes from in a normal house
- Sugar-free chewing gum and mints
- Some peanut butter brands — check every jar before using it for pills
- Sugar-free baked goods and protein bars
- Toothpaste, mouthwash and dental gels
- Some liquid medications and nasal sprays
The thing people get wrong
“It is an artificial sweetener, so a bit will just upset their stomach.”
Xylitol does not act like a sweetener in a dog's body, it acts like an insulin injection. The dose that causes a crisis is smaller than the dose in a couple of pieces of gum.
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Get PawLife on the App StoreFrequently asked questions
How much Xylitol is dangerous?
The gum figure is the reason this substance is different from most on this list: the dangerous quantity is a normal quantity. Read the label — xylitol is often listed simply as 'sugar alcohol'.
How long after exposure to Xylitol do symptoms start?
10 to 30 minutes for hypoglycaemia. Liver injury may not show for a day or more.. Vomiting, then weakness, staggering, tremors. Hypoglycaemia can require 24–48 hours of glucose support; liver monitoring runs for 72 hours.
Is Xylitol worse for cats or dogs?
This is a dog problem. Cats have not been shown to release insulin in response to xylitol, and reported feline cases are rare — but ferrets are affected like dogs.
Is it true that: It is an artificial sweetener, so a bit will just upset their stomach.
Xylitol does not act like a sweetener in a dog's body, it acts like an insulin injection. The dose that causes a crisis is smaller than the dose in a couple of pieces of gum.
Related emergencies
Sources
This page is information, not veterinary advice. Toxic doses vary with body weight, age, breed and individual sensitivity, and the figures above exist to explain what a vet is assessing, never to decide that an amount is safe. If you are reading this because something has already been eaten, call a vet.