Suspect poisoning? US: ASPCA Poison Control (888) 426-4435 · UK: 01202 509 000 · Severe symptoms → nearest emergency vet now.

Is one prenatal vitamin dangerous for a 20-pound dog?

Dogs · Emergency guide

Last reviewed: 2026-09-05 · Reference ranges: ASPCA, Pet Poison Helpline & Merck Veterinary Manual

Short answer

Yes, this is an emergency. One prenatal vitamin often contains enough iron to poison a small dog. Even if your dog seems fine now, iron toxicity has delayed severe effects. Call the ASPCA poison line (888-426-4435) or an emergency vet immediately — bring the bottle with you.

Why is this dangerous?

Iron is directly corrosive to the stomach lining and, once absorbed, damages the liver and causes shock. Signs come in two phases: gut upset first, then a deceptive improvement, then severe deterioration 12–48 hours later.

Prenatal vitamins often contain 27–65 mg of elemental iron per tablet — a handful is a serious dose for a dog.

Why speed matters

Delaying care significantly worsens outcomes. Some signs appear hours or days later, so "looks fine right now" is not a reason to wait.

Signs to watch for

  • Vomiting, often bloody, and diarrhoea
  • Abdominal pain, drooling, not eating
  • Lethargy, weakness, fast heart rate
  • A period of seeming improvement (do not be reassured)
  • Shock, collapse, liver failure and seizures in severe cases

What to do right now

  1. Call a vet or poison line immediately — iron poisoning is time-critical even when the pet seems fine.
  2. Bring the bottle and count the missing tablets.
  3. Do not induce vomiting unless instructed; iron can burn on the way back up.
  4. Expect blood tests and hospital care, sometimes for several days.
If your pet shows any of the signs above, go to the nearest emergency vet now and call ahead.

The step-by-step response, from the first minute to the vet visit, is in our Iron Supplements & Prenatal Vitamins emergency guide.

Open the full emergency guide: Iron Supplements & Prenatal Vitamins →