Poisoning guide
Xylitol poisoning: the sweetener that acts in 15 minutes
Gum, mints, toothpaste and sugar-free peanut butter. Xylitol drops a dog's blood sugar faster than almost any other household food — and the dose that matters is tiny.
The short version
- Two thresholds: about 0.1 g/kg causes dangerous hypoglycaemia. About 0.5 g/kg can cause liver failure.
- One piece of gum can do it. A single 1 g piece of sugar-free gum is 0.2 g/kg for a 5 kg dog — double the hypoglycaemia threshold.
- Speed: blood sugar crashes within 15–30 minutes. Liver enzymes rise over 8–12 hours.
- It is everywhere: gum, mints, toothpaste, sugar-free baking, some peanut butters, vitamins and nasal sprays.
- Every exposure is a vet call. This is one of the few food toxins where the correct response is immediate and unconditional.
The mechanism: an insulin surge, not a poison
Xylitol is a sugar alcohol used as a low-calorie sweetener. In people it has almost no effect on blood sugar. In dogs, it is absorbed into the bloodstream within minutes and misinterpreted by the pancreas as a massive glucose load. The pancreas responds the only way it knows how: it releases a large pulse of insulin.
The result is profound hypoglycaemia — blood sugar falling fast enough to cause weakness, collapse, tremors and seizures. This phase begins within 15 to 30 minutes and is the reason xylitol is more urgent than chocolate. There is no slow build-up to observe.
At higher doses a second, separate injury appears. Xylitol is metabolised in the liver through a pathway that depletes energy stores in liver cells, causing necrosis. Liver enzymes climb over 8 to 12 hours, and in severe cases coagulation fails and the dog develops a bleeding disorder. The two phases can overlap, which makes treatment more than just a glucose drip.
How much is too much
| Dog weight | Hypoglycaemia risk (0.1 g/kg) | Liver injury risk (0.5 g/kg) |
|---|---|---|
| 2.5 kg | 0.25 g | 1.25 g |
| 5 kg | 0.5 g | 2.5 g |
| 10 kg | 1.0 g | 5 g |
| 20 kg | 2.0 g | 10 g |
| 30 kg | 3.0 g | 15 g |
To put that in perspective: a typical piece of sugar-free gum contains 0.3–1.0 g of xylitol, a mint around 0.1–0.5 g, and a sugar-free protein bar can contain 5–10 g. Toothpaste is often 20–25% xylitol by weight, so a chewed tube is a serious exposure. A 5 kg dog eating two pieces of gum has already crossed the hypoglycaemia threshold and may be approaching the liver threshold.
The 12-hour treatment timeline
- 0–30 minutes: ingestion. Vomiting may be induced by a vet if the dog is seen quickly enough.
- 30–60 minutes: hypoglycaemia. Weakness, wobbling, collapse, tremors, possibly seizures.
- 1–8 hours: monitoring and intravenous glucose. Blood sugar is checked repeatedly because it can crash again after an initial correction.
- 8–12 hours: liver enzyme measurement. Rising ALT and ALP indicate hepatic injury and change the treatment plan.
- 24–72 hours: continued monitoring in serious cases, including clotting times if liver involvement is significant.
Where xylitol actually hides
This is the part that catches people out, because the products do not look like sweets.
- Chewing gum and mints — the classic source, often in a bag on the floor
- Toothpaste and mouthwash — frequently 20%+ xylitol
- Sugar-free baking and desserts — cakes, brownies, ice cream
- Peanut butter and nut butters — "no added sugar" versions often use xylitol instead
- Protein powders and meal replacement shakes
- Chewable vitamins and supplements — including some pet supplements
- Nasal sprays and throat lozenges
The label may say xylitol, birch sugar, birch bark extract, E967 or simply natural sweetener. If you cannot identify the sweetener, do not share the product with your dog.
With most foods, observation is reasonable. With xylitol it is not. Blood sugar can drop within 15 minutes, and a dog can deteriorate from normal to seizing faster than you can drive to the clinic. Call the vet on the way.
Erythritol, sorbitol and maltitol are not xylitol, and their risk profile in dogs is different — mostly GI upset rather than hypoglycaemia. But labels are frequently vague, and the safe assumption is that any sugar alcohol in a dog's mouth warrants a call.