My dog ate Vitamin D3—what should I do?

Updated 2026-09-30 · 4 sources

Based on: US FDA – Center for Veterinary Medicine, Animal PoisonLine (UK, VPIS), Pet Poison Helpline

Call a vet now

Call your vet or the nearest emergency vet right now. Excessive vitamin D can lead to kidney failure and even death.

What to do now

What to do right now

  1. Call your vet or the nearest emergency vet.
  2. Note what was eaten, how much, and when.
  3. Bring the packaging.
  4. Keep your dog calm.
  5. Remove what is left.

Don't

  • Do not make your dog vomit unless a vet tells you to.
  • Do not give any human medicine.

Why it can be dangerous

Excessive vitamin D can lead to kidney failure and even death.[1] Cholecalciferol, also known as vitamin D3, is an active ingredient in some potent mouse and rat poisons.[3] Vitamin D rodenticide or supplement poisoning can show signs within hours or days.[1] Vitamin D supplements vary widely in dose, from 10 micrograms (400 IU) to 1.25 milligrams (50,000 IU).[2]

Signs to watch for

  • Vomiting
  • Loss of appetite
  • Increased thirst and urination
  • Excessive drooling
  • Weight loss
  • Kidney failure

After rodenticide or supplement poisoning, signs can appear within hours or days; diet-related problems are gradual.

Where it is found

  • Vitamin D supplements
  • Mouse poison
  • Rat poison

What the experts say

“Another common way that dogs get vitamin D toxicity is after accidentally eating certain chemicals meant to kill rodents like rats and mice, called cholecalciferol rodenticides.”

— US FDA – Center for Veterinary Medicine [1]
If your pet is struggling to breathe, has collapsed, is having a seizure or can't stand up: go to the nearest vet now.

Not sure how serious it is?

OkPaw asks a few quick questions about your pet and tells you in 30 seconds whether it can wait. Free on Google Play for Android.

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Common questions

How much Vitamin D3 is dangerous?

Vitamin D supplements can range from 10 micrograms (400 IU) to 1.25 milligrams (50,000 IU) per tablet or capsule; ask a vet about the product your dog ate.

Which signs should I watch for?

Possible signs include vomiting, loss of appetite, and diarrhea.[3]

How soon can signs start?

Rodenticide or supplement poisoning can show signs within hours or days.[1]

Sources

  1. US FDA – Center for Veterinary Medicine
  2. Animal PoisonLine (UK, VPIS)
  3. Pet Poison Helpline
  4. Acute vitamin D toxicosis in an adult cat, JFMS Open Rep 2026

How this page was made: written with the help of AI from the sources below, then checked claim by claim against those sources. Urgency levels follow OkPaw’s fixed safety rules. It is guidance, not a diagnosis. How we write our pages

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