While immediate symptoms of toxicity from onions would require more than the amount in this particular dog food (but much less than 'several pounds at a time'), the cumulative effects are largely unknown - and IMO probably misdiagnosed as hemolytic anemia from other causes or as other conditions such as immune mediated hemolytic anemia. Just as there are some dogs that can eat chocolate with no visible effects, I'm sure there are some dogs that can handle onions better than others. IMO, and I'm sure for alot of other pet owners, it's better to err on the side of caution and not allow ingestion of ANY known toxins, especially those with a possible cumulative effect.
The onion powder in this food is fairly high up on the ingredient list and that, IMO, is a risk that isn't worth taking.
We don't tell people what to feed or not feed, we simply offer our opinions when asked for them.
Livin in a Newfie Drool Zone