Isolating the exposed 4 kg cat
One symptomatic cat means immediate action for both. Confine the chewing cat in a bathroom with water and a litter box—this limits its movement while you assess symptoms. Drooling confirms crystal contact, but watch closely for pawing at the face or hiding, which suggests escalating pain.
The unaffected cat isn't safe just because it avoided the plant initially. Dieffenbachia sap on paws or fur can transfer during grooming. Wipe both cats' faces and paws with a damp cloth, then separate them until you've relocated the plant.
Why height isn't enough for cat-proofing
Cats leap onto refrigerators and bookshelves—elevation alone won't deter them. The plant must go behind a door the cats can't open, like a basement or secured balcony. If that's impossible, repot it into a hanging basket with a macrame hanger (no solid shelves underneath for leverage).
Check nearby surfaces for fallen leaves or sap droplets. Cats investigate chewable items later, so vacuum thoroughly. Consider citrus peels around the plant's new location—many cats dislike the smell.
Monitoring the chewing cat's mouth
Calcium oxalate crystals cause pain peaks at 30 minutes and 2 hours post-exposure. Offer a shallow dish of cool water rather than forcing rinses—stressed cats resist handling. A lickable treat like meat baby food (no onions) encourages swallowing to clear crystals.
Loud purring or open-mouth breathing are red flags—they indicate throat swelling. Feel the jawline for heat or puffiness. If the cat stops grooming entirely, the tongue may be too sore—a vet can prescribe anti-inflammatory gel.
Long-term prevention for multi-cat homes
Replace Dieffenbachia with safer greenery like spider plants or cat grass. Some cats develop plant-chewing habits after one incident, so observe both pets for new interest in foliage.
For the next week, check the exposed cat's food intake—oral pain sometimes manifests as selective eating. Use wide, flat dishes to avoid whisker stress compounding discomfort. If either cat shows renewed drooling, inspect houseplants again for hidden damage.
The step-by-step response, from the first minute to the vet visit, is in our Dieffenbachia (Dumb Cane) emergency guide.