Project Description

Generic Name: atenolol
Brand Name: Tenormin

Atenolol, a beta-blocker, is commonly used in human and veterinary medicine to treat many disease states including high blood pressure and various cardiac diseases. Despite its use in animals, accidental overdose of atenolol can be dangerous for pets.


Please note that other beta-blockers (such as esmolol, propranolol, metoprolol, labetalol, and carvedilol) carry similar toxicity risks.

Signs and symptoms of toxicity: decreased heart rate, low blood pressure, altered mental status, seizures, and difficulty breathing. Signs may be seen as soon as 6 hours post ingestion or as long as 24 hours later (particularly with sustained-release formulations).

Toxic consumption: There is no established toxic threshold for pet consumption. All incidents of accidental exposure should be reported immediately.

– Osweiler, G, et al. (2011). Blackwell’s five-minute veterinary consult clinical companion. Small Animal Toxicology. [Kindle version]. Retrieved from