What vomiting within 30 minutes tells you
This rapid reaction suggests your 7 kg dog swallowed enough solanine from the stem to trigger immediate gut irritation. Unlike gradual food poisoning, plant alkaloids act fast — the vomiting is the body's attempt to limit absorption. Check the vomit for stem fragments; their presence means more toxin could be released as they digest.
The stems concentrate solanine where they attach to the plant, so even a short chewing session delivers a potent dose. Small dogs show symptoms quicker because their stomachs empty faster. If the vomit has a bitter smell or contains bile, the toxins are moving beyond the stomach already.
Neurological signs that escalate the emergency
Watch the back legs specifically — solanine affects nerve-muscle communication, causing a 'drunken' walk or difficulty standing after lying down. Your 7 kg dog is light enough that muscle weakness will show here first. Time these episodes; tremors lasting over 30 seconds or recurring every 10 minutes need urgent care.
Note pupil size if possible; solanine sometimes causes noticeable dilation. More subtle signs include exaggerated yawning or sudden disinterest in surroundings. These suggest the toxins are crossing into the central nervous system, which is riskier for small dogs due to their higher brain-to-body mass ratio.
Why today's meals matter in assessment
A full stomach when your dog chewed the stem might have slowed toxin absorption, buying you slightly more time. Ask yourself: was breakfast eaten normally? Any treats in the past 2 hours? Food in the gut can form a temporary barrier, though it won't prevent all solanine from entering the bloodstream.
However, if your dog was fasting or had diarrhoea earlier, the stem's toxins could hit harder. Dehydration from repeated vomiting stacks with the alkaloids' effects on circulation. Press gently between the shoulder blades — skin that tents for over 2 seconds shows dangerous fluid loss in a 7 kg animal.
The critical 4-hour window for small dogs
Most solanine poisoning cases declare themselves within this timeframe. Mark when the chewing happened and track symptom progression hourly. Two vomiting episodes plus either drooling or lethargy means the liver is struggling to process the toxins at this body weight.
Keep water available but don't force it — swallowing difficulties can develop. Move your dog to a cool area; solanine sometimes disrupts temperature regulation. If the gums develop a bluish tint or the vomiting contains blood streaks, transport immediately; these indicate the toxins are overwhelming the body's defenses.
The full verdict, portion guidance and serving notes are collected on the Tomato leaves & stems food facts page.