Why diarrhoea is the red flag for a 4 kg cat
Those pellets likely contain ammonium salts or urea, which pull water into the intestines—a bigger problem for small cats than dogs. At 4 kg, your cat has less fluid reserve to counter dehydration from diarrhoea. The pellets' hard coating also prolongs toxin release, meaning symptoms may worsen over 12 hours.
Check the litter box for bloody streaks, which indicate intestinal lining damage. Unlike dogs, cats rarely drool conspicuously with nausea, so diarrhoea might be your only visible clue. Their fast metabolism processes some toxins quicker but leaves less margin for error with dehydrating substances.
Hidden risks beyond the gut
Some lawn fertilisers contain herbicides like 2,4-D, which cats absorb through their paw pads when stepping on dissolved pellets. Your cat's grooming habits then spread these chemicals orally. Even if initial vomiting seems mild, watch for later muscle tremors or difficulty jumping—neurological signs demand same-day vet care.
The pellets' size matters too—a 'few' for a cat means 2-3 pea-sized pieces, which concentrate toxins more than scattered dust would. Indoor cats lack the hydration habits of outdoor roamers, making diarrhoea especially dangerous. Offer water in a wide, shallow bowl to encourage drinking without associating it with the nausea source.
When to expect the worst symptoms
Most fertiliser toxins peak within 4-6 hours, but slow-release formulations can delay crises up to 24 hours. Your cat's current diarrhoea suggests the irritants are active, but neurological or metabolic effects may still be brewing. Time the episodes—if diarrhoea recurs more than twice hourly, dehydration is imminent.
Kneading behavior or excessive lip-licking may indicate mouth ulcers from pellet abrasions, another route for toxin entry. Unlike dogs, cats rarely vomit effectively after poisoning—what comes up is often just foam, leaving most toxins inside. This makes diarrhoea your primary window into their distress.
Emergency hydration tricks at home
Mix unflavored pediatric electrolyte solution (1 part) with water (3 parts)—cats accept this better than plain water post-exposure. Syringe-feed 5 ml every 30 minutes if they refuse to drink. Avoid milk or broth, which can worsen electrolyte imbalances from certain fertilisers.
Monitor the skin tent test: gently pinch the scruff—if it doesn't snap back within 2 seconds, dehydration is advancing. Diarrhoea alone might not warrant an ER trip, but paired with lethargy or cool paws, it signals crashing blood pressure. Your 4 kg cat has less reserve than larger pets, so act faster on worsening signs.
The step-by-step response, from the first minute to the vet visit, is in our Fertilisers & Plant Food emergency guide.