Is Nitroglycerin tablets/spray Safe for Dogs?
Why it’s a problem
Nitroglycerin widens blood vessels, and an unsupervised dose can drop a dog’s blood pressure enough to cause weakness, fainting, and heart strain. Vets occasionally use carefully dosed formulations for heart failure, but human tablets and sprays are far too concentrated to be safe. Spilled spray or patch residue can also be absorbed through the mouth and skin.
How to keep your pet safe
Store tablets and spray in a closed cabinet, and keep the canister well out of chewing range. Wash hands after handling, and wipe up any spilled liquid or discarded patch residue immediately. Never let a pet lick skin where chest spray or a patch has been.
Warning signs to watch for
Weakness, wobbliness, stumbling, drooling, vomiting, pale or bluish gums, rapid then weak pulse, fainting, collapse.
When to call the vet
Call a veterinarian or pet poison hotline immediately if your dog bites a tablet sheet or licks spilled spray or a patch. Keep the dog quiet and calm during transport, since excitement worsens low blood pressure. Bring the product container.
Common questions
My dog licked my nitroglycerin spray off my hand — is that bad?
It can be. Nitroglycerin absorbs quickly and can cause a serious blood pressure drop. Call your vet or a pet poison hotline right away and describe the amount and timing.
Are used nitroglycerin patches dangerous to pets?
Yes — used patches still contain drug that can be absorbed by a mouth or stomach. Fold them sticky-side in and dispose of them in a container pets cannot open.
More medications hazards for dogs
This page is general educational information, not a substitute for professional veterinary advice. Every pet is different — if your animal ate or touched something concerning, contact your veterinarian or a pet poison hotline right away. In the US: Pet Poison Helpline (855) 764-7661, ASPCA Animal Poison Control (888) 426-4435 (fees may apply).