Why the 25 kg dog's portion changes everything
With lamb stew, the actual cumin content per bite is microscopic—perhaps 1/8 teaspoon spread across the entire pot. Your larger dog's few bites might contain less than a single cumin seed's worth when diluted in broth and meat. At 25 kg, his body mass can handle this trace amount effortlessly, just as humans tolerate spices in home cooking.
Focus on the stew's other ingredients instead: onions and garlic are the usual culprits in savory dishes. Since you're only asking about cumin, we'll assume those were omitted. The bigger risk would be fatty meat causing pancreatitis, but the tiny portion he ate makes that unlikely unless he has a history of it.
The puppy's missed meal as a non-issue
At 5 kg, your puppy's smaller size would make even safe foods like cumin slightly riskier in large doses—but 'large' here means tablespoons of pure spice, not cooked traces. Since he didn't eat any stew, we're spared the question of whether his developing digestive system could handle the oil content. This simplifies your night to monitoring just one pet.
Puppies often react more strongly to new foods, so skipping the stew may have been a blessing. Introducing rich meats and spices suddenly can cause loose stools even without toxicity. Keep an eye on his next bowel movement regardless, as dietary changes sometimes trigger mild upsets unrelated to the cumin.
When cooked spices behave differently than raw
Cumin's essential oils, which could irritate in concentrated raw form, mellow significantly during stewing. The prolonged heat breaks down compounds that might bother sensitive stomachs, leaving mostly flavor molecules that pass through harmlessly. This makes the cooked version in your stew safer than if your dog found raw cumin seeds to chew.
That said, watch for individual reactions like licking lips excessively or mild lethargy—not from toxicity, but from the unfamiliar taste. Dogs often make funny faces after eating something new, which owners can mistake for distress. True cumin allergies are rare but would show as skin itching rather than digestive issues.
Why you don't need to compare their reactions
With two dogs, owners often expect to contrast symptoms, but here the scenarios are too different. The big dog's exposure was minimal and diluted, while the puppy had none—so any vomiting or diarrhea would point to a separate issue like dietary indiscretion or a non-cumin ingredient.
If the larger dog shows stomach upset, consider the stew's richness rather than the cumin. A few bites of fatty lamb could cause more trouble than spices in some dogs. But given the small portion, even this is unlikely unless he's prone to digestive sensitivity.
The full verdict, portion guidance and serving notes are collected on the Cumin food facts page.