- Prenatal/iron pills are toxic
- Within hours
- Affects: Gut, liver & heart
Why this verdict for cats
Iron supplements are toxic to cats, irritating the gut and damaging organs. Keep all vitamins out of reach and call your vet if any are eaten.
Warning signs to watch for
- Vomiting
- Diarrhea
- Lethargy
⚠ If your cat ate iron supplements
Act immediately — don't wait for symptoms.
- Call your vet or a pet poison helpline right away.
- Note how much was eaten and when.
- Do not induce vomiting unless a professional tells you to.
Iron tablets and prenatal vitamins are an easily overlooked poison, partly because 'vitamins' sounds benign and partly because the bottles are large, rattle appealingly and are often kept in a bedside drawer rather than a locked cabinet.
How much is safe?
What matters is elemental iron, not the tablet weight — a 325 mg ferrous sulphate tablet contains about 65 mg of elemental iron. Signs generally begin above roughly 20 mg of elemental iron per kg of body weight, and doses above about 60 mg/kg are potentially lethal. For a 10 kg dog that puts serious toxicity within reach of a modest handful of tablets. Prenatal vitamins, multivitamins with iron and some fertilisers are the common sources.
What happens if a cat eats too much?
Iron poisoning famously comes in stages, and stage two is a trap. First, within six hours, iron corrodes the gut: vomiting, often with blood, diarrhoea and abdominal pain. Then comes an apparent recovery lasting up to a day, when the pet seems to improve. Stage three brings the real damage as iron floods the liver — lethargy, collapse, low blood pressure, liver failure and bleeding problems. Scarring of the stomach outlet can appear weeks later.
⚠ What to do if your cat ate iron supplements
Call your vet or a poison line with the product name, the elemental iron per tablet and how many are missing (ASPCA 888-426-4435 · Pet Poison Helpline 855-764-7661). Bring the bottle — the arithmetic matters and label wording is confusing. Activated charcoal does not bind iron, so treatment relies on decontamination, fluids and, for high doses, a chelating drug called deferoxamine. Do not be reassured by the quiet period after the initial vomiting.
⚠️ Worried your pet got into this?
Frequently asked questions
My dog ate a few gummy multivitamins — same risk?
Usually much lower, since most gummy vitamins contain little or no iron, but check the label and call. Some also contain xylitol, which is its own emergency.
Is a rusty nail or iron object the same problem?
No. Metallic iron objects are mainly an obstruction or zinc risk. Ingested iron salts from supplements are what cause this poisoning.
More medications for cats
By the CanMyPet Editorial Team · Reviewed against ASPCA Animal Poison Control, the American Kennel Club (AKC) and Pet Poison Helpline · Last updated July 31, 2026.
Sources
- ASPCA — People Foods to Avoid Feeding Your Pets
- American Kennel Club — Dog Nutrition
- Pet Poison Helpline — Poison List