Onions vs. Garlic vs. Chives: Which Is Worse for Dogs?
Garlic is stronger gram-for-gram, onion exposures are usually bigger, and every allium damages red blood cells, cooked or raw.
Short answer: garlic is more potent gram-for-gram, but onion exposures are usually bigger, so both end in the same place: damaged red blood cells and, in serious cases, anemia. Every allium counts: onions, garlic, chives, leeks, scallions, raw, cooked, or powdered.
Side by side
| Onion | Garlic | Chives / leeks | |
|---|---|---|---|
| DogSafe severity | 6/10 | 6/10 | Treated like onion |
| Potency per gram | Baseline | Roughly 3–5× stronger | Similar to onion |
| Typical exposure | Cooked dishes, scraps | Powder, supplements, seasoning | Garden and herb boxes |
| Cooked still toxic? | Yes | Yes | Yes |
| Worst form | Onion soup mix, powder | Garlic powder: far stronger than fresh | Concentrated in dishes |
The powder problem
Dehydration concentrates the toxin. A teaspoon of onion or garlic powder represents far more allium than the same volume of fresh, which is why soup mixes, seasoned meats, and garlic-powder-heavy leftovers are the most common serious exposures, not a dropped slice of onion.
Why the damage shows up late
Alliums oxidize hemoglobin inside red blood cells, and the body then removes those damaged cells. That takes time: weakness, pale gums and dark urine often appear two to five days after the meal, when owners have forgotten the exposure. If your dog ate a meaningful amount this week and now seems weak or off-color, that history matters: tell your vet.
Bottom line
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