Cat poisoning: the first hour, and the toxins specific to cats

Quick answer

Contain the cat, stop it grooming, and phone while somebody else gathers the packaging. Warmth and quiet do more in the first hour than anything else you can do at home.

If you think your cat has been poisoned, the two things that change the outcome are speed and information. Phone a vet immediately, even if the cat looks well, and take the packaging, plant or product with you.

Do not try to make a cat vomit. There is no safe home emetic for cats, and the substances people use cause serious injury of their own.

• Separate the cat from the source, then contain it in one warm, quiet room.
• If anything is on the coat, stop the cat grooming before it swallows the rest of the dose.
• Photograph the label, the plant, or the tablet blister, and note the time and the amount.
• Looking normal proves nothing. Several of the worst poisonings for cats have a silent period.
• Never give a dog flea product to a cat, and never treat a cat with human painkillers.

:::danger
Three exposures need a same-hour phone call even in a cat with no symptoms at all.

Lilies of the Lilium and Hemerocallis groups, where pollen brushed onto the coat and groomed off is enough to cause kidney failure. Permethrin, the insecticide in many dog spot-on flea treatments, which cats cannot metabolise and which causes tremors and seizures. Paracetamol, also sold as acetaminophen, where the margin in a cat is so narrow that a single tablet intended for an adult human is treated as a life-threatening exposure.

In all three the treatable window is measured in hours, and in all three the cat can look completely well while the damage is happening.
:::

Decide in 60 seconds

Why cats are not small dogs

The single most important fact in feline toxicology is a liver difference. Cats have a limited ability to attach glucuronic acid to foreign molecules, which is one of the main routes mammals use to make drugs and plant compounds water soluble so they can be excreted.

The practical consequence is that a cat clears certain substances far more slowly than a dog or a person, so a normal household dose accumulates into a toxic one. Paracetamol, aspirin, phenolic disinfectants and many essential oils all sit in this group.

The second difference is behavioural. A cat that gets a substance on its fur will remove it with its tongue. Contact exposure and oral exposure are effectively the same event in a cat, which is why a spilled product is an emergency rather than a cleaning job.

The third is size. A quantity that is a fraction of a container to you can be a full dose to an animal weighing a few kilograms.

This is why "it was only a small amount" is not reassuring in a cat.

The exposures that matter most

Lilies.

True lilies, the genus Lilium, and day lilies, Hemerocallis, cause acute kidney injury in cats. Every part of the plant is implicated, including petals, leaves, stem, pollen and the water in the vase.

The mechanism is not fully characterised, but the target is the kidney tubule, and the injury is rapid. A cat that brushes past an arrangement and grooms pollen off its coat has taken a dose.

Plants with lily in the common name but not in these genera, such as peace lily and calla lily, are a different problem. They contain insoluble calcium oxalate crystals and cause immediate mouth pain, drooling and swelling rather than kidney failure. That is unpleasant but not usually fatal, and it is worth knowing which plant you actually have.

Permethrin and other pyrethroids.

Permethrin appears at high concentration in spot-on flea products licensed for dogs. Cats metabolise it poorly and are exquisitely sensitive.

Most cases are one of two stories: an owner using a dog product on a cat, or a cat that grooms or sleeps against a recently treated dog. Signs are neurological, typically muscle tremors that build into whole-body shaking, twitching of the ears and face, incoordination, and seizures. Body temperature rises because of the muscle activity, which adds a second problem on top of the first.

Paracetamol and other human analgesics.

Paracetamol produces a metabolite that a cat cannot detoxify efficiently. It binds to haemoglobin and converts it to methaemoglobin, which cannot carry oxygen.

The signs are distinctive: gums that look brown, grey or muddy rather than pink, laboured breathing, and swelling of the face and paws. Damage to red cells and to the liver follows.

Ibuprofen and naproxen cause gastric ulceration and kidney injury. Aspirin is cleared slowly enough in cats that repeated dosing accumulates. No human painkiller should be given to a cat by an owner, at any dose, for any reason.

Ethylene glycol antifreeze.

Sweet tasting, and lethal in small amounts. The first phase looks like drunkenness, with wobbling and vomiting. The cat then seems to improve. Crystals forming in the kidney tubules cause failure over the following days.

The antidote works best when it is given early, before the parent compound has been converted. Treatment on day one and treatment on day three are different conversations.

Rodenticides, directly or through a poisoned rodent.

There are several classes and they behave completely differently, so the packet matters.

A cat that eats a poisoned rodent can be affected by the same toxin at second hand, which is a genuine risk for anticoagulants in particular.

Cleaning products, essential oils and diffusers.

Concentrated pine oil and phenol based cleaners, tea tree oil, and undiluted essential oils are all problems for cats, by contact, by mouth or by inhalation. Benzalkonium chloride, in some disinfectant wipes and floor cleaners, causes tongue and mouth ulceration in cats that walk across a wet floor and then groom.

The pattern to recognise is drooling, a sore-looking mouth, and reluctance to eat one to two days after cleaning.

Alliums.

Onion, garlic, leek and chive, raw, cooked, dried or powdered, damage feline red blood cells and cause anaemia. The usual route is flavoured human food, gravy, or baby food containing onion powder.

What to do in the first hour

Have the carrier open and lined before you catch the cat. Take the packaging with you, not a photograph of it, if the original is available.

Separate the cat from the source first.

Close the door on the room, remove the plant, or move the cat. Do this before anything else, because continued exposure undoes everything that follows.

Stop the grooming.

If there is anything on the coat, the cat is still dosing itself. A soft buster collar, or wrapping the cat loosely in a towel while somebody phones, buys you time.

Phone before you bathe.

For an oily spot-on product the standard approach is a wash with lukewarm water and a mild washing-up liquid, working from the application site outwards, with gloves on. But a cat that is already tremoring can become dangerously cold when wet, and handling can worsen tremors. Ask first, then act.

Do not induce vomiting.

Hydrogen peroxide, used by some owners in dogs, causes severe haemorrhagic gastritis in cats and is not appropriate for them. Salt is dangerous in its own right. There is no reliable home emetic for a cat.

There are also exposures where vomiting must not be induced at all, including anything corrosive and anything petroleum based, because the return journey damages the oesophagus or is inhaled.

Do not give milk, oil, food or activated charcoal on your own initiative.

Milk does not neutralise poisons. Charcoal is genuinely useful for some toxins and useless or harmful for others, and a struggling cat can inhale it.

Collect the evidence.

The container, the plant with leaves attached, the blister pack, the bait box with its active ingredient name. Note the time of exposure, the maximum amount that could have been taken, and the cat's weight if you know it.

Keep the cat warm, dark and quiet during transport.

Tremoring cats overheat, so do not add heat pads to a shaking cat. A cold, wet cat needs warmth. Both need the carrier covered and the radio off.

Reading the cat while you travel

Gum colour is the fastest information you can gather. Learn where your cat's gums are pink when it is well, so a change is obvious.

Lift the lip gently and look at the gum above the canine tooth.

Count breaths while the cat is resting by watching the chest rise. A rate that is clearly faster than this cat's normal, or effort using the abdomen, is significant.

Distinguish a tremor from a seizure. A tremor is a fine, continuous shaking with the cat aware of you. A seizure involves loss of awareness, often with paddling, jaw chomping, drooling or loss of bladder control. Both matter, and the difference helps the vet.

The signs that come later, and the trap in the middle

Poisonings do not all progress in a straight line. Two of the most dangerous have a phase in which the cat looks better.

Lily exposure. Vomiting, drooling and lethargy in the first hours. Then an apparent recovery. Then, over the following one to three days, the kidney injury declares itself as increased or absent urine production, further vomiting, and collapse.

Antifreeze. Wobbling and vomiting, then a quiet phase, then kidney failure.

Anticoagulant bait. Days of nothing at all, then pale gums, breathlessness from bleeding into the chest, lameness from bleeding into a joint, or bruising.

This is why the advice is to attend on suspicion rather than on symptoms. Treatment given during the silent phase is what prevents the third phase.

What looks like poisoning but is not

Owners often reach for poisoning as the explanation for sudden collapse. Several feline emergencies present the same way and need different treatment.

A male cat straining, crying and collapsing is more likely to have a blocked bladder than a poisoning. That is equally urgent.

Sudden hind limb weakness with crying and cold back feet suggests a clot lodged at the aorta, not a toxin.

A cat found dazed after a fall or a road accident may have head trauma. Look for asymmetry, bleeding from the nose or ears, and a torn claw or scuffed pads.

Sudden collapse in a diabetic cat on insulin is hypoglycaemia until proven otherwise.

Panting and collapse in a hot environment is heatstroke, and cooling comes first.

Drooling and pawing at the mouth can be a fishbook, a grass blade, or a string wrapped under the tongue rather than a chemical.

Tell the vet what you found and what the cat was doing, not what you concluded. The conclusion is their job and the observations are yours.

What the vet will ask for

Expect blood tests to be repeated over days rather than once, because kidney and liver damage declares itself late. A normal first blood test after a lily or antifreeze exposure is not a discharge.

Prevention that is specific to cats

Do not keep Lilium or Hemerocallis lilies in a house with a cat, and check bouquets before they come through the door. Removing anthers does not make a lily safe.

Never apply a dog flea product to a cat. Read the species on the box every time, including when treating multiple pets in one session, and keep a treated dog and the cat apart until the application site is dry and for as long as the packaging specifies.

Store human medication in a closed cupboard rather than a bedside surface. Cats knock tablets off worktops and bat them across floors.

Keep antifreeze containers sealed and clean spills immediately, including on a driveway.

Choose disinfectants labelled as safe around cats, dilute as instructed, and keep the cat out of the room until floors are dry.

Ventilate when using essential oil diffusers, or avoid them where a cat lives. A cat cannot leave a closed room.

When to get help

Call immediately, at any hour, for a known or suspected exposure to lilies, permethrin, human painkillers, antifreeze, rodent or slug bait, or any human prescription medication.

Call immediately for tremors, seizures, collapse, laboured breathing, brown or blue gums, or a cat that cannot stand.

Call the same day for drooling, mouth ulceration, vomiting after a cleaning session, or a cat that is dull and off its food after any possible exposure.

Recovery is judged over days, not hours. Follow-up blood tests after a kidney or liver toxin are part of the treatment, not an optional extra.

If the cat is well and you are unsure whether an exposure counts, still call. A short conversation costs nothing, and the exposures that kill cats are the ones where the owner decided to wait and see.