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My 9-year-old female dog with diabetes ate a quarter of a sugar-free protein bar. She's on insulin twice daily. Should I call the vet now?

Dogs · Food safety

Last reviewed: 2026-09-05 · Reference ranges: ASPCA, Pet Poison Helpline & Merck Veterinary Manual

Short answer

Yes, call your vet right away. Most sugar-free protein bars are sweetened with xylitol, which is extremely toxic to dogs — even one bar can cause a rapid drop in blood sugar and liver damage. Your dog's diabetic condition makes this especially dangerous, since she's already on insulin and her blood glucose could swing unpredictably. Do not induce vomiting without veterinary instruction. Bring the bar wrapper with you so the vet can check the exact ingredient list.

Protein & energy bars — Food safety facts

Do not feed · Dogs · full breakdown on the linked food page

Very often sweetened with xylitol or coated in chocolate. Treat every bar as toxic until you read the label.

Dogs and cats carry the same rating (Do not feed), so the notes below hold for either pet.

Protein & energy bars should not be given to dogs at all. Even a small amount can do harm, so there is no portion small enough to be safe.

Do not induce vomiting and do not give milk or oil to “dilute” it. Note the food and roughly how much was eaten, then call your vet or a pet poison hotline and follow their advice on whether to bring the pet in straight away.

Why these cautions matter

Even a gram or two of xylitol can trigger a sharp drop in a dog's blood sugar, and larger exposures go on to damage the liver.

Theobromine is the part that hurts. Pets clear it far more slowly than people do, so it builds up and reaches the heart and nervous system.

Added sugar brings empty calories, and over months that means weight gain and dental disease — both far harder to undo than to avoid.

Protein & energy bars has no place in everyday feeding: keep the rest of the day's food unchanged after this and watch the next walk and the stool that comes with it.

The full verdict, portion guidance and serving notes are collected on the Protein & energy bars food facts page.

Open the full food page: Protein & energy bars food facts →