Iron Supplement
ToxicIron causes GI bleeding, shock, and liver failure in dogs. Merck puts decontamination above 50 mg/kg of elemental iron and treatment above 80 mg/kg. The deceptive part is the apparent recovery in the middle.
This food guide has not been reviewed by a veterinarian. It summarises general information from sources and should not be used to decide whether a food is suitable for an individual dog or to assess an emergency.
Check before feeding
Do not offer as a treat
There is no recommended treat portion for this hazardous item. If swallowed, contact a vet with the amount, time and product details. Do not induce vomiting yourself.
Signs and health concerns
This list includes both observable signs and conditions identified through examination or testing. It cannot establish the cause or whether an exposure is safe.
- Vomiting
- Bloody diarrhoea
- Black, tarry stool
- Abdominal pain
- Lethargy
- Reduced activity and responsiveness
- Fever
- Shock or circulatory failure
- Liver failure
- Reduced urine output
- No urine production
More about this food
The dangerous thing about iron is its timeline. The Merck Veterinary Manual states that clinical signs usually develop within 6 hours — vomiting and diarrhea first — followed by hypovolemic shock, depression, fever, acidosis, and liver failure 12-24 hours later, often with a period of apparent recovery in between. That middle window is how a dog who vomited at breakfast, perked up by lunch, and had a canceled vet appointment ends up in shock overnight.
The dose that matters is elemental iron, not tablet weight. Merck says ingestion above 50 mg/kg of elemental iron generally warrants decontamination, and above 80 mg/kg calls for additional treatment and monitoring. For an 11 lb dog that is 250 mg and 400 mg. A standard 325 mg ferrous sulfate tablet contains about 65 mg of elemental iron, so four of them put an 11 lb dog past the decontamination threshold. Salt forms differ: ferrous sulfate is roughly 20% iron, ferrous fumarate about 33%, ferrous gluconate about 12%. Read the elemental iron line on the Supplement Facts panel and use that number.
Prenatal vitamins are the classic exposure in an American house — high iron content, big bottles, and often left on a nightstand. Children's chewable vitamins with iron are the other one, because they are formulated to taste good and a dog will not stop at one.
Signs run from vomiting and diarrhea, sometimes bloody, and abdominal pain into depression, fever, shock, black stool, then liver failure and reduced or absent urine output. Treatment is time-sensitive: Merck notes serum iron can be checked 4-6 hours after exposure, chelation may be needed above 500 mcg/dL, and deferoxamine is most effective within 24 hours of ingestion, continued until urine color returns to normal over 12-72 hours. Note that iron does not bind well to activated charcoal, which is why Merck lists magnesium hydroxide and calcium carbonate for decontamination instead.
What to do now: record the product, the elemental iron per tablet, how many are missing, the time, and your dog's weight, then call your veterinarian, an emergency clinic, or the ASPCA Animal Poison Control Center at (888) 426-4435. Bring the bottle. Do not induce vomiting at home, and do not let the quiet middle hours talk you out of going.
Frequently asked questions
- He ate some iron pills this morning and seems fine now.
- That is the trap. Merck describes an apparent recovery between the early vomiting and the shock, acidosis, and liver failure that arrive 12-24 hours later. Looking well right now is not reassurance. Call your vet with the elemental iron per tablet and your best count of what is missing.
- How do I tell how much iron was actually in those tablets?
- Use the elemental iron figure, not the compound weight. A 325 mg ferrous sulfate tablet is about 65 mg elemental. Ferrous sulfate is roughly 20% iron, fumarate about 33%, gluconate about 12%. Multiply elemental mg by tablets, divide by your dog's weight in kg, and compare with 50 and 80 mg/kg.
- Are prenatal or children's chewable vitamins as risky as iron tablets?
- Prenatals are high in iron and belong in the same category. Children's chewables have less per piece but taste like candy, so dogs eat many, and they add vitamin D and zinc to the picture. Count what is gone, bring the full label, and call rather than estimate.