Four Household Poisons That Kill Cats

Four things in an ordinary home kill cats at doses a dog would survive: lily, permethrin, paracetamol and ethylene glycol. Pollen groomed off a whisker can start irreversible kidney failure, 6 ml of antifreeze is a lethal dose for a 4 kg cat, and one 500 mg paracetamol tablet is about 12 times the toxic dose. The first 2 hours decide whether treatment costs 500 RMB or whether there is nothing to treat.

The cat is not a small dog here. Cats lack the glucuronyl transferase pathway that clears paracetamol and pyrethroids, and their kidneys concentrate ethylene glycol metabolites. That is why the doses below are 10-100 times smaller than the canine figures on the same package, as the toxic dose tables show.

Lily: no safe amount, no antidote

Every part of Lilium and Hemerocallis is toxic, including petals, leaves, stamens, pollen and the vase water. A cat that grooms a single pollen grain off its shoulder has been exposed. Reported fatal cases involve 1-2 leaves, and there is no dose at which watching is reasonable.

The injury is acute tubular necrosis. Creatinine starts rising at 12-24 hours, urine output falls at 24-72 hours, and death follows at 3-6 days without dialysis. Treatment is aggressive IV fluids for 48-72 hours, begun within 18 hours: survival is high under 18 hours and poor after 24. There is no antidote, so the whole plan is speed.

Pyrethroids: a few drops of dog spot-on

Permethrin sits at 40-65% in dog spot-on products, and a few drops on the back of a cat's neck, or a cat grooming a treated dog, produces tremors, hypersalivation, twitching and a body temperature of 40-41 Celsius. Signs appear at 2-12 hours and last 1-3 days.

Wash the coat with dish soap and lukewarm water for 10 minutes to strip residue, then get methocarbamol and temperature control at the clinic. Most cats survive with 24-72 hours of care. The ones that die are usually bathed but not seen, or seen after 12 hours of tremors. Never use a dog product on a cat, even at a quarter dose.

Paracetamol: 10 mg/kg is the line

The toxic dose in cats is about 10 mg/kg, so a 4 kg cat is in trouble at 40 mg. One 500 mg tablet is 12 times that, and combination cold remedies carry 325-500 mg per tablet with no cat warning on the box. Signs begin at 1-4 hours: brown or grey gums from methemoglobin, facial swelling, vomiting, rapid breathing. Untreated death comes at 18-24 hours.

N-acetylcysteine is the antidote, best within 4-6 hours and still useful at 8-12 hours, with vitamin C, oxygen and a transfusion if methemoglobin passes 30%. Give nothing at home, including milk, oil or salt water, and do not wait for signs: at 40 mg the cat looks perfectly normal for 2 hours.

Antifreeze: 6 ml, one tablespoon

Ethylene glycol has a minimum lethal dose of 1.4-1.5 ml/kg, which for a 4 kg cat is 6 ml, about one tablespoon, or a 5% puddle in a garage licked twice. It tastes sweet, which is exactly why cats drink it.

Stage 1 runs 30 minutes to 12 hours: wobbling, vomiting, drinking more, looking drunk. Stage 2, 12-24 hours: fast breathing, fast heart, depression. Stage 3, 24-72 hours: no urine, calcium oxalate crystals, kidney failure. Fomepizole or ethanol within 3 hours is the difference between a cat that walks out in 48 hours and one that does not come home.

The windows on one page

Poison	Lethal dose, 4 kg cat	First signs	Useful window
Lily, any part	1-2 leaves or pollen	12-24 h: creatinine rise	fluids under 18 h
Permethrin 45-65%	a few drops on skin	2-12 h: tremors	bath and clinic under 12 h
Paracetamol	40 mg	1-4 h: brown gums	antidote under 4-6 h
Ethylene glycol	6 ml	30 min-12 h: drunk gait	fomepizole under 3 h
Ibuprofen	50 mg/kg, 200 mg	4-24 h: vomiting, melena	fluids under 6 h

First 10 minutes, before the car

• Remove the source and take the package, the plant label or the bottle with you; 100% of cases are easier with the container.
• Do not induce vomiting: caustics burn on the way down and again on the way up, the way a burn injury does, and hydrocarbons aspirate.
• No milk, oil, salt water or home charcoal; each one adds aspiration or sodium risk and delays the clinic.
• If the coat is contaminated, wash 10 minutes with lukewarm water and dish soap, no scrubbing, then dry.
• If the mouth is bleeding from a chewed stem, hold pressure for 5 minutes as for bleeding wounds and keep the cat still.
• Collect any vomit in a sealed bag, and write the time, the product and the estimated amount on your phone.
• Call the clinic or a poison line before driving, so an antidote or a catheter is ready on arrival.

When to drive, with zero observation

Any lily exposure, any permethrin on the skin, any paracetamol swallowed at any amount, any antifreeze lick, or any of these signs within 24 hours: drooling, vomiting twice or more, tremors, seizures, brown or grey gums, fast breathing, or a cat that stops drinking and hides. Do not wait for symptoms after a known lily or antifreeze exposure, because by the time they appear the window has usually closed.

Five habits that remove the risk

• No lilies in the house, including bouquets from guests; check for Lilium on the label at the door.
• Flea products labelled for dogs stay in a locked cabinet, and the cat is treated only with a cat product.
• Paracetamol and combination cold tablets in a closed box, never on a nightstand.
• Antifreeze stored in a sealed container, spills absorbed with cat litter within 10 minutes, garage door closed.
• Save the clinic number and the poison line in the phone under a 3 letter name so it is findable at 2 a.m.

Frequently asked