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

My dog chewed and swallowed an extended-release ADHD medication pill. Are these forms more dangerous than immediate-release?

Dogs · Emergency guide

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

Short answer

Yes, extended-release formulations are particularly dangerous because the medication is designed to be released slowly over many hours. When a dog chews the pill, it can damage the controlled-release coating, potentially causing a large, sudden dose to enter their system. This leads to a faster and more severe onset of symptoms like extreme agitation, rapid heart rate, high temperature, and tremors. This is a critical emergency. You must contact your vet or a poison control center immediately and bring the pill bottle with you so they know exactly what was ingested.

Why is one pill dangerous?

ADHD medicines contain amphetamines (Adderall, Vyvanse) or methylphenidate (Ritalin, Concerta). Dogs absorb them fast and their bodies cannot handle stimulants meant for a child’s weight.

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

  • Hyperactivity, restlessness, pacing
  • Rapid heart rate and breathing
  • Dilated pupils, drooling, panting
  • Tremors, seizures
  • Very high body temperature — life-threatening

What to do right now

  1. Call your vet immediately. Stimulant poisoning escalates fast.
  2. Bring the pill bottle — extended-release versions keep releasing for hours.
  3. Do not try to "run it off"; keep the dog quiet.
  4. Hospital treatment (sedation, cooling, IV fluids) greatly improves survival.
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 ADHD Medication (Stimulant) Poisoning emergency guide.

Open the full emergency guide: ADHD Medication (Stimulant) Poisoning →