Why your terrier needs more attention than the others
The quarter cup of cornbread mix your 6 kg terrier ate is enough to worry about added ingredients, not the cornmeal itself. While your other dogs avoided it, the small size of your terrier means any toxic additives would affect him more severely. Sugar isn't dangerous in this amount, but some mixes use xylitol as a sweetener—check the package label right away for this ingredient.
If the mix contains xylitol, don't wait for symptoms—call your vet with the brand name and amount consumed. Without xylitol, watch for stomach upset from the rich mix: pacing, lip-licking, or refusing his next meal. Your other dogs only need monitoring if they scavenged crumbs you might have missed under the counter.
How the next six hours differ for a small dog
At 6 kg, your terrier's metabolism processes ingredients faster than a larger dog, so symptoms would appear within two hours if xylitol is present. Even without it, the butter, milk powder, or baking soda in some mixes can cause pancreatitis in small breeds. Note the time he ate it—vets need this timeline if he starts drooling or seems unusually tired later.
For the next day, offer smaller, blander meals to ease his digestion. Skip treats to avoid overloading his system. If he normally has grain sensitivities, the wheat flour in most mixes might cause itchiness or ear irritation beyond just stomach issues.
When to relax about the uneaten mix
If the ingredient list shows no xylitol and your terrier shows no vomiting or tremors after twelve hours, the risk has passed. Cornbread mix isn't acutely toxic like chocolate or grapes—it's the extra ingredients that matter here. Wipe down the counter thoroughly so your other dogs don't find lingering traces later.
For future baking, store mixes in sealed containers well out of reach. Dogs often steal cornbread mixes for the fatty smell, not the taste, so a high shelf or latched cupboard works better than countertop storage. Your two unaffected dogs might investigate next time if they see the terrier getting away with it.
Why weight matters more than breed here
A 6 kg dog like your terrier would show xylitol poisoning symptoms faster than a 20 kg labrador eating the same amount. Smaller bodies concentrate toxins quicker, leading to low blood sugar or liver issues within an hour. Terriers aren't uniquely sensitive, but their size makes every bite count more.
Without xylitol, the main risk is gastrointestinal—diarrhea from the sudden fat and carb load. If he's acting normal but has soft stools tomorrow, a spoonful of plain pumpkin can help. Call the vet if he strains without passing anything or seems painful when you touch his belly.
The full verdict, portion guidance and serving notes are collected on the Cornmeal food facts page.