Why 5 kg cats react differently to toxins
A feline liver processes theobromine (from chocolate) 5x slower than a dog's, meaning symptoms can appear delayed. For a 5 kg cat, even 10g of dark chocolate in a protein bar causes dangerous heart rhythm changes. Xylitol's hypoglycemic effects also last longer in cats — up to 24 hours versus 12 in dogs.
The charcoal given will turn stools black for 1-2 days. This is normal, but save a sample if it's tarry or contains undigested bar chunks. These suggest intestinal blockage from the bar's binding agents, requiring follow-up X-rays.
Hour-by-hour signs of improving or worsening
First 6 hours post-charcoal: Monitor for regurgitation (different from vomiting — it'll be undigested bar material). True vomiting now means the toxin is still absorbing. Check gum colour every hour — pale pink is good, white or yellow needs emergency care.
Hours 6-24: Hydration is critical. Lift the scruff — if it doesn't snap back within 2 seconds, subcutaneous fluids may be needed. Offer wet food mixed with water, but don't force-feed. Refusal to eat for over 12 hours warrants a vet revisit.
The hidden recovery challenges
Many protein bars contain guar gum or chicory root, which cause feline gas pain. Your cat may assume a 'meatloaf' position with elbows tucked under. A warm compress on the belly helps, but avoid human simethicone products unless prescribed.
Litter box monitoring is essential — bloody urine or straining suggests oxalate crystals from certain protein bar ingredients. Scoop twice daily and note any changes in output volume or frequency.
When to resume normal feeding
After 24 hours without vomiting, reintroduce food as 1 tbsp of plain chicken every 4 hours. Avoid commercial treats for 72 hours — their additives stress the recovering liver. The vet may recommend a hepatic support diet for 2-4 weeks depending on bloodwork.
Watch for delayed neurological signs like stumbling or head tilting up to 5 days later — these indicate late-stage toxin effects. Keep your cat strictly indoors during recovery; disorientation makes them prone to accidents.
The full verdict, portion guidance and serving notes are collected on the Protein & energy bars food facts page.