Why wrapper residue isn't a buckwheat issue
The sticky bits your cat licked likely contained microscopic buckwheat crumbs—maybe a few grains' worth. Plain buckwheat won't harm cats, even if they ate a whole spoonful. The real risk here is the wrapper material: some cats shred and swallow waxed paper or foil linings, causing intestinal blockages.
Since your cat just licked it, focus on physical signs like pawing at her mouth (could mean plastic stuck to her tongue) or hacking coughs (suggests a paper scrap in her throat). These would appear within an hour, not days later.
How cats process grains differently
Cats lack the enzymes to digest grains efficiently, but tiny amounts pass through harmlessly. Buckwheat is safer than wheat or corn because it's less likely to trigger allergies. Your cat's lick delivered maybe 0.1g of actual grain—less than she'd get grooming herself after walking on a crumbly floor.
Watch her litter box for the next 24 hours: completely normal stools mean her system ignored the buckwheat. If you see constipation or mucus-coated poop, it's probably from stress over the new taste, not toxicity. Offer extra water to help things move along.
The honey or sugar factor in granola bars
While the wrapper likely had minimal buckwheat, some granola bars contain honey or sugar—both sticky substances that cling to packaging. A few licks won't harm your cat, but repeated exposure could contribute to weight gain or dental issues over years.
Signs of sugar overload (very rare from licking) include hyperactivity followed by a crash. You'd notice this within 2 hours—racing around, then sleeping deeply. Your cat's calm behavior confirms she didn't ingest enough to matter. Wipe her gums with a damp cloth if you're worried about stickiness.
When cats chew instead of lick
Some cats progress from licking to biting wrappers, especially crinkly ones. Aluminum foil or plastic coatings can slice gums or cause choking. Check your cat's mouth for redness or broken teeth if she was alone with the wrapper for a while.
Buckwheat itself becomes a concern only if mixed with toxic ingredients like raisins or chocolate—common in granola bars. Since your cat just tasted the outside, those dangers don't apply here. Store bars in sealed containers to avoid future curiosity.
The full verdict, portion guidance and serving notes are collected on the Buckwheat food facts page.