Why the cheese crisps matter more than plain chips
Cheese-flavored snacks almost always contain onion or garlic powder, which are far more dangerous to cats than the salt and fat in regular chips. Your 8 lb cat eating three means they've ingested enough seasoning to warrant monitoring, even if the quantity seems small. The other cats didn't consume any, so their risk is zero — this is purely about the one who stole the snacks.
Watch for excessive thirst or vomiting in the next 12 hours, as these are early signs of onion toxicity. The salt content may also make your cat drink more water than usual, but that alone isn't cause for alarm unless they're refusing food or acting lethargic.
The first 24 hours with a small flavored chip dose
At this amount, your cat likely won't show severe symptoms, but subtle changes matter. Check their gums — if they appear pale or yellowish, that's a vet visit. The fat content might cause mild stomach upset, so don't be surprised if they skip a meal or have looser stools tomorrow.
Since the crisps were eaten recently, you can offer a small amount of their regular food to help dilute any remaining seasoning in their stomach. Never induce vomiting or give milk, as these can worsen the situation. Just keep fresh water available and let their system process it naturally.
When cheese powder becomes a real emergency
If your cat starts panting, stumbling, or has diarrhea with blood, head to the vet immediately. These symptoms suggest the onion powder is affecting their red blood cells, which requires professional treatment. For an 8 lb cat, even a teaspoon of onion powder can be dangerous over time.
The other risk is dehydration from the salt load — pinch the skin at their shoulders. If it doesn't snap back quickly, or if their eyes look sunken, they need fluids. Otherwise, just monitor and restrict access to any human snacks, especially anything powdered or seasoned.
Why the other two cats aren't at risk
Simply watching the crisps won't expose your other cats to toxins — they'd need to ingest the seasoning directly. However, this is a good reminder to store snacks securely, as cats often learn stealing techniques from each other. The cheese aroma is particularly tempting for felines.
If you notice the 'innocent' cats begging more aggressively for human food in coming days, that's behavioral, not medical. Stick to their normal diet and discourage counter surfing before it becomes a habit that could lead to actual consumption next time.
The full verdict, portion guidance and serving notes are collected on the Chips / crisps food facts page.