Why 2 kg changes everything
A few bites of green tomato can deliver a solanine dose equivalent to a whole tomato for your 2 kg cat — that’s the math of tiny bodies. Cats lack certain liver enzymes to break these toxins down efficiently, so what’s a mild snack for your 7 kg cat becomes a systemic threat for the smaller one. Watch her pupils: solanine often causes noticeable dilation within 90 minutes.
The smaller cat’s metabolism will also process the toxins faster, but not necessarily safer. Rapid absorption means signs like pawing at the mouth or excessive meowing may erupt suddenly rather than building gradually. Confine her in a carrier or small bathroom where you can monitor litter box output and prevent access to hiding spots that delay symptom spotting.
Weight splits risk unevenly
Your 7 kg cat would need to eat roughly triple the amount to reach the same toxin concentration per kilogram — but cats rarely overeat bitter greens voluntarily. The miniature’s nibbles likely represent a higher percentage of her daily food intake too, leaving less ‘safe’ stomach space to dilute the irritants.
Compare their behavior directly: if both cats sampled the tomatoes but only the smaller one is drooling or shaking her head, assume she’s clinically affected. Bigger cats may vomit once and move on, while tiny ones can spiral into lethargy from the same portion. Never assume ‘if the big cat is fine, the little one will be’ — their bodies aren’t running the same calculations.
Tiny bodies show subtler warnings
Small cats compensate differently — instead of dramatic vomiting, you might notice lip-licking, a tucked-up belly, or unusual stillness. These quiet signs are easy to miss but indicate nausea or abdominal pain. Check her gums: tacky saliva or a slower capillary refill time (press gently on gums; color should return in under 2 seconds) hints at dehydration starting.
Monitor respiratory rate: solanine can cause shallow breathing in extreme cases. Count breaths per minute while she’s resting (normal is 20-30). If her sides seem to move faster or she’s panting like a dog, her body may be struggling with metabolic acidosis, a dangerous pH imbalance.
The crossover point for vet care
For cats under 3 kg, one clear vomit episode or two bouts of diarrhea within an hour warrants a call. Their limited blood volume makes fluid loss critical faster than owners expect. If the smaller cat hasn’t eaten her normal food by hour 12 post-exposure, her recovery isn’t self-resolving.
Meanwhile, observe the 7 kg cat for 24 hours — his size buys monitoring time. But if either cat shows muscle tremors or can’t jump onto a usual perch, weight differences no longer matter; both need professional assessment. Keep them separated during observation to track who produces which signs.
The full verdict, portion guidance and serving notes are collected on the Tomato food facts page.