Xylitol (birch sugar)
ToxicDog-specific and biphasic: xylitol triggers a massive insulin release causing hypoglycemia above ~0.1 g/kg, and acute hepatic necrosis above ~0.5 g/kg. Increasingly labeled "birch sugar," which defeats label scanning.
This food guide has not been reviewed by a veterinarian. It summarises general information from sources and should not be used to decide whether a food is suitable for an individual dog or to assess an emergency.
Check before feeding
Do not offer as a treat
There is no recommended treat portion for this hazardous item. If swallowed, contact a vet with the amount, time and product details. Do not induce vomiting yourself.
Signs and health concerns
This list includes both observable signs and conditions identified through examination or testing. It cannot establish the cause or whether an exposure is safe.
- Vomiting
- Lethargy
- Poor coordination or balance
- Weakness
- Collapse
- Seizures
- Low blood sugar
- Liver failure
More about this food
Xylitol is an ordinary sugar alcohol for people, and a species-specific poison for dogs. A dog's pancreas reads xylitol as glucose and releases a dose-dependent flood of insulin, dropping blood sugar hard. Humans and cats do not have this response. At higher doses a separate mechanism produces acute hepatic necrosis, hypothesized to come from ATP depletion or reactive oxygen species generation.
Two thresholds matter. Hypoglycemia starts above roughly 0.1 g/kg (100 mg/kg); the risk of hepatic failure starts above roughly 0.5 g/kg (500 mg/kg). For a 22 lb (10 kg) dog that is 1.0 g and 5 g of xylitol respectively. A single piece of sugar-free gum holds about 0.3 to 1.0 g, so one to three pieces can be hypoglycemic for that dog and five to fifteen reach the hepatotoxic range. A chewed-up blister pack of gum is not a wait-and-see event.
Timing splits in two. Hypoglycemia can begin within 30 minutes, but may be delayed 12 to 18 hours when the xylitol sits in a slow-release substrate. Liver injury declares itself between 12 and 72 hours. Early signs are vomiting, lethargy, ataxia, weakness, collapse, tremors and seizures; the hepatic phase brings icterus and coagulopathy.
The labeling problem is the practical trap. US manufacturers increasingly declare xylitol as "birch sugar" or "wood sugar," so owners scanning for the word xylitol miss it. It shows up in sugar-free gum and mints, toothpaste and dental rinses, some peanut butters, chewable vitamins and children's liquid medications. The proposed Paws Off Act (H.R. 5261) would require a pet warning on such labels, but it is not law you can rely on today — read the full ingredient panel yourself.
If you suspect ingestion, call your veterinarian, an emergency hospital, or the ASPCA Animal Poison Control Center at (888) 426-4435 immediately rather than waiting for symptoms; once hypoglycemia starts, minutes count and travel time becomes the variable. Bring the packaging and ingredient panel. Do not induce vomiting at home — a hypoglycemic dog is at high aspiration risk — and do not force honey or sugar water into a dog that is dull or unconscious unless a veterinarian directs you to.
Frequently asked questions
- How much xylitol is toxic to a dog?
- Above about 0.1 g/kg for hypoglycemia and about 0.5 g/kg for liver failure. A 10 kg dog reaches those at 1 g and 5 g, which is roughly one to three pieces of gum and five to fifteen pieces.
- The label says birch sugar, not xylitol. Same thing?
- Yes. Birch sugar and wood sugar are xylitol under different names, with identical risk. Treat the ingestion as a xylitol exposure and call your vet or the APCC at (888) 426-4435 right away.
- Is xylitol dangerous to cats too?
- No. Cats do not show the insulin release that drives this poisoning, so they are not considered at risk. The danger is specific to dogs, which is why dog-proofing gum and dental products matters.