Peanut butter earns its place in the treat drawer: dogs love it, it hides pills gracefully, and it turns a lick mat or filled toy into twenty minutes of calm. The best choice is an unsalted peanut butter whose ingredient list is essentially just peanuts — no xylitol, minimal added salt and sugar.
Two moderating factors are worth keeping in mind. First, peanut butter is dense in fat and calories, so it should stay an occasional treat — veterinary guidance is that treats of all kinds should make up no more than about 10% of a dog's daily calories, and a spoonful of peanut butter uses that budget quickly, especially for small dogs. Second, the xylitol risk is not theoretical: sugar-free and "no sugar added" peanut butters that contain it are on store shelves, and even a small amount of xylitol can cause a dangerous drop in blood sugar. Read the jar once, and you can relax about it afterwards.
What to do
If your dog ate peanut butter containing xylitol, treat it as an emergency and call your vet or an animal poison line immediately. For plain, xylitol-free peanut butter, no action is needed beyond keeping portions small.
Sources
This page is informational and is not veterinary advice. If your pet has eaten something risky, contact your vet or an animal poison control line right away.