Three products get called mothballs, and only one of them is camphor. Naphthalene, paradichlorobenzene (PDCB), and camphor have different targets: blood, liver, and brain respectively. The 2-hour line matters because most signs start 1 to 2 hours after a cat or dog eats a ball, licks a treated blanket, or beds down in a closed wardrobe, and camphor seizures can begin in 15 to 90 minutes. Read the ingredient line before anything else.
3 products, 3 different poisons
Naphthalene balls are the old-fashioned type, smell of coal tar, and are the most dangerous to cats because they trigger oxidative damage to red blood cells. PDCB balls smell sharply of a public toilet, sink in water rather than floating, and hit the liver and the nervous system. Camphor products, natural or synthetic, are the seizure risk, and they also arrive as ointments, balms, and essential oils at 5 to 20 percent strength. A ball weighs 2 to 5 g, which is enough to matter for a 4 kg cat at a few hundred mg per kg. Never assume the label says what the drawer smells like: check the pack, and photograph it.
Why cats are hit harder at the same dose
Cats are poor at glucuronidation, one of the liver pathways that clears these compounds, so a dose that makes a dog vomit once can put a cat in hemolytic crisis. Add grooming: a cat that walks across a treated shelf picks up residue and swallows it over hours, which spreads the exposure and blurs the timeline. A 4 kg cat that ingests even 1 g of a naphthalene ball is at 250 mg per kg, well into the range where reports describe Heinz body anemia and brown, muddy gums within 6 to 24 hours. Small body weight, no warning signs at hour 1, and a habit of sleeping in the wardrobe is the worst combination.
The 2-hour line, split by route
Swallowed: signs typically start 1 to 2 hours after ingestion, and decontamination by a vet is most useful inside that same 2-hour window. Do not induce vomiting at home; these compounds are volatile and aspiration into the lungs is worse than the stomach contents. Inhaled: a 10 square metre room with 4 fresh balls can reach an irritating concentration within 2 hours, so open 2 windows, keep the pet out, and ventilate for at least 30 minutes before letting it back in. Skin contact: wash with lukewarm water and a mild soap for 10 minutes, then dry, and do not seal the pet in a carrier while it is still damp and off-gassing.
Signs worth timing to the minute
Early: tearing, drooling, squinting, and a head-shy cat that avoids light, usually within 60 minutes. Gut: vomiting 1 to 6 times, abdominal pain in the first 2 to 6 hours. Neuro: tremors, a staggering walk, head pressing, then seizures, which for camphor can arrive in 15 to 90 minutes. Blood: pale or brown gums, weakness, fast breathing, and dark urine as red cells break down, with Heinz bodies detectable on a smear from 24 to 72 hours. Liver values can climb by 48 to 72 hours even when the pet looks normal at hour 6, so a recheck is part of the plan, not an optional extra.
Which product, which target
| Product | Smell and look | Main target | Size or strength | Signs start | First 2 hours |
|---|---|---|---|---|---|
| Naphthalene | coal tar, flakes off, floats | red blood cells | 1 ball, 2 to 5 g | 1 to 2 hours | call within 60 minutes |
| Paradichlorobenzene | toilet-cleaner sharp, sinks | liver, nerves | 1 ball, 2 to 5 g | 1 to 4 hours | ventilate 30 minutes, call |
| Natural camphor | medicinal, waxy ball | brain | 1 ball, 2 to 4 g | 15 to 90 minutes | call, keep quiet 2 hours |
| Camphor balm or oil | medicinal, greasy | brain, skin | 5 to 20 percent, 20 g tube | 30 to 60 minutes | wash skin 10 minutes |
The 2-hour column is not the point at which you may relax. It is the point after which a vet's options narrow from removing the poison to supporting the damage.
The wardrobe, the blanket, and the 2 wash cycles
Vapor settles into fabric, and a cat that sleeps on a treated blanket is exposed for 8 hours a night. Remove every treated item, air the room for 24 hours with the door closed to the pet, and wash fabrics twice at 60 C before reuse. Keep the pet out of that room for 3 days while the residue fades. If the exposure was in a carrier or a pet bed, throw the bedding out rather than washing it; 1 ball in a 40 litre carrier is a small, sealed gas chamber.
What the clinic will want to know
4 facts: the product name from the pack, the number of balls missing, the pet's weight, and the hour of exposure. Then the route: eaten, inhaled, or licked off the coat. A blood smear and a packed cell volume (PCV) at hour 6 and again at 24 hours tell the hemolysis story, and a PCV falling 5 points in 24 hours is a real signal. Bring the packaging, even if it is torn, because the label decides whether the case is a blood problem or a brain problem. The same ingredients are indexed on the toxin page.
When to skip the call and drive
Any seizure, any tremor that repeats, brown or grey gums, breathing above 40 per minute at rest, a temperature above 40 C, or a cat that cannot stand. Do not wait for vomiting to confirm the exposure. A cat that has eaten 1 ball and looks fine at hour 1 can be in trouble by hour 6, and the 2-hour line is exactly where the cheap interventions live.
5 steps for the next 2 hours
- Photograph the pack and the drawer, count how many balls are missing, and note the time.
- Move the pet to a ventilated room, open 2 windows, and keep the door shut for 30 minutes.
- Call the clinic, give the 4 facts and the route, and ask about the 2-hour window by name.
- Wash any contacted skin for 10 minutes with lukewarm water, and do not induce vomiting.
- Bag the remaining balls and the treated fabric separately, and put both out of reach before you leave.
Store the packing list of every pest product you own next to the household toxin checklist, and check the same page before you buy the next box of balls.
Terms mentioned in this article
Frequently asked
Are all mothballs the same poison?
No. Naphthalene attacks red blood cells, paradichlorobenzene targets the liver and nervous system, and camphor is a seizure risk. The ball size, 2 to 5 g, is similar, but the 2-hour response differs. Read the ingredient line on the pack and photograph it before you call the clinic.
How fast do mothball signs appear in a cat?
Most signs start 1 to 2 hours after ingestion, and camphor can cause seizures in 15 to 90 minutes. Vomiting may be the first visible event, but a cat can look normal at hour 1 and be in hemolytic crisis by hour 6, which is why the first 2 hours are when the useful interventions happen.
Should I make my dog vomit after eating a mothball?
No. These compounds are volatile and aspiration into the lungs is more dangerous than leaving them in the stomach. Call the clinic instead, ventilate the room, wash contacted skin for 10 minutes, and bring the packaging. A vet can decide on decontamination inside the 2-hour window with proper equipment.