Broccoli

Broccoli is the clearest dose-dependent food in this database: safe, then irritating, then toxic, on the same vegetable. The thresholds come from Dr. Jerry Klein, Chief Veterinary Officer at the American Kennel Club. Under 10 percent of total daily intake, broccoli is safe. Between 10 and 25 percent, it risks significant gastrointestinal irritation. Above 25 percent, it is considered toxic. A few small florets as a training treat and a bowl topped with broccoli are not the same decision. The compound behind this is the isothiocyanates concentrated in the florets — the same family of compounds marketed to humans as a benefit. In a dog's gut they act as an irritant. Signs are gas, abdominal discomfort, vomiting and diarrhea, and they typically show up 2 to 12 hours after the meal. To make the ceiling concrete: a 20 kg dog eating about 1,000 kcal a day has a 10 percent allowance of roughly 100 kcal, and broccoli runs about 35 kcal per 100 g, so roughly 285 g would already reach the limit. In practice nobody needs to approach that number; a few small florets is the sensible serving. The second hazard is physical. Broccoli stalks are dense and fibrous, and they are a documented cause of esophageal obstruction in dogs — a genuine emergency, not a stomachache. Never hand a dog a whole stalk to gnaw on, particularly a small breed. Peel the tough outer stem and chop it small, or simply serve chopped florets. Raw or lightly steamed both work. Nothing else goes on it: no salt, butter, oil, cheese sauce, garlic or seasoning blends. Broccoli from a casserole or a stir-fry is a different food. If your dog cleared a serving that likely exceeded a quarter of the day's food, call your veterinarian for advice even before symptoms appear. If a dog that swallowed a stalk starts gagging, drooling or cannot swallow, treat it as an emergency and go in. Do not induce vomiting at home — decontamination is a veterinary decision, and an obstructed esophagus makes it dangerous.