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

Blood Pressure & Heart Medicines

ACE inhibitors, beta blockers and calcium channel blockers are dosed for a human adult. One tablet can drop a small pet’s blood pressure to a dangerous level.

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

Treat this as a potential emergency — not a "wait and see" situation.
Contact your vet before symptoms even appear.

US: ASPCA Animal Poison Control (888) 426-4435 · Pet Poison Helpline (855) 764-7661

UK: Veterinary Poisons Information Service 01202 509 000

Why is it dangerous to pets?

ACE inhibitors (enalapril, lisinopril, ramipril), beta blockers (atenolol, metoprolol, propranolol) and calcium channel blockers (amlodipine, diltiazem, verapamil) all lower heart rate or blood pressure. In a pet with a fraction of a human body weight, a therapeutic human dose becomes an overdose that causes shock.

Some of these tablets are also xylitol-containing chewables, adding a second, fast-acting poison.

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.

Symptoms of bp-meds poisoning

  • Weakness, collapse, fainting after standing
  • Very slow heart rate, weak pulse
  • Pale gums, cold limbs
  • Wobbliness, disorientation, vomiting
  • Difficulty breathing and shock in severe cases

What to do right now

  1. Go to an emergency vet now — blood pressure support and IV fluids may be needed within minutes to hours.
  2. Bring the pill bottle so the vet knows the drug class and strength.
  3. Carry the pet rather than letting it walk, and keep it warm.
  4. Do not give food or water if the pet is drowsy or collapsing.
If your pet shows any of the signs above, go to the nearest emergency vet now and call ahead.

Sources & further reading

  • ASPCA Animal Poison Control — pet poison database & dosage references
  • Pet Poison Helpline — toxicology triage guidelines
  • Merck Veterinary Manual — toxicology monographs
  • Vets Now (UK) — emergency toxicosis guidance