Why vomiting at the 2-hour mark matters
When a dog vomits two hours after eating ketchup, it tells us the stomach has had time to react to the irritants. The onion powder in ketchup can cause mild inflammation, triggering this response. Your 7 kg dog's small size means even two tablespoons deliver a noticeable dose of salt and sugar, but the real concern is the delayed vomiting—it suggests the stomach lining is responding to the onion compounds.
Watch for more vomiting over the next six hours. If it happens again, or if your dog acts lethargic or refuses water, call your vet. The salt content could lead to excessive thirst, while the sugar may cause a temporary energy spike followed by a crash. Small breeds like yours process these ingredients less efficiently than larger dogs.
The onion powder factor in a small dog
Two tablespoons of ketchup contain enough onion powder to potentially irritate a 7 kg dog's digestive tract. While not an emergency dose, the cumulative effect of salt, sugar, and onion compounds can overwhelm a small system. Dogs under 10 kg are more prone to gastrointestinal upset from even modest amounts of irritants.
You might notice slight diarrhea or decreased appetite over the next day. These usually resolve on their own, but if they persist beyond 24 hours, or if your dog seems unusually tired, seek veterinary advice. The vomiting you've already seen was likely the stomach's way of expelling some of the irritants.
What to expect over the next 12 hours
After the initial vomiting episode, most dogs stabilize within a few hours. Offer small amounts of water frequently—about a quarter cup every thirty minutes—to prevent dehydration without overwhelming the stomach. Hold off on food for at least four hours to let the digestive tract settle.
Monitor for signs like excessive panting, tremors, or continued vomiting, which would warrant an immediate vet visit. These would indicate either salt toxicity (unlikely at this dose but possible in sensitive dogs) or severe gastrointestinal irritation. For now, quiet rest in a comfortable space is the best approach.
When to transition back to normal meals
Once twelve hours have passed without further vomiting, introduce a bland diet of boiled chicken and rice in small portions. The high salt and sugar content of ketchup can temporarily disrupt gut bacteria balance, so easy-to-digest foods help reset the system. Divide the meal into four portions spaced two hours apart.
If your dog handles the first day of bland food well, you can gradually return to regular meals over the next two days. This cautious approach helps prevent rebound stomach upset. Remember that repeated exposure to ketchup—even in small amounts—can lead to chronic digestive issues in small dogs.
The full verdict, portion guidance and serving notes are collected on the Ketchup food facts page.