Written By hannah hollinger
Published: 07/24/2020Updated: 08/30/2021
Atenolol | Wag!

Atenolol is a beta-blocker that treats some types of heart disease, heart arrhythmias, and high blood pressure in dogs. Also known by the brand name Tenormin, atenolol is a prescription medication that is quite widely used in veterinary medicine.

However, in order to safely administer atenolol for dogs, it’s important to find out about the drug’s dosage, how it works, and what side effects it may produce. Keep reading for more information.


Atenolol is given orally as either a tablet or a compounded liquid. Atenolol comes in 25 mg, 50 mg, and 100 mg tablet sizes.

The typical dosage of atenolol for dogs is between 0.2 and 1 mg per kg of body weight, taken orally once or twice daily.

Dosage instructions

Atenolol for dogs can be given with or without food. This medication must be given according to the instructions provided by your veterinarian. Double doses should never be administered, and it’s recommended that you wash your hands after giving your pet this medication.

It’s also important to note that you should not stop giving atenolol abruptly unless your veterinarian directs you to do so. In most cases, if your pet needs to stop taking the medication, your veterinarian will advise you on how to gradually reduce their dosage so you can “taper” the amount of atenolol they are taking.


Atenolol is the most commonly used beta-blocker in veterinary medicine. It works by blocking the receptors on the heart that respond to adrenaline as a result of stress or excitement. This leads to a slower heart rate, more efficient function of the heart, and reduced blood pressure. It also helps suppress cardiac arrhythmias (or abnormal heartbeats).

As a result, atenolol for dogs is used to treat a number of conditions. These include heart diseases like subaortic stenosis, pulmonic stenosis, and hypertrophic cardiomyopathy; tachycardia; hyperthyroidism; and high blood pressure. It’s also frequently combined with digoxin when treating atrial fibrillation in dogs.

However, one study has also shown that atenolol doesn’t influence survival time in dogs with severe subaortic stenosis.


The cost of atenolol varies based on the dosage strength and form prescribed. Individual tablets range in price from 15¢ to 50¢ for dosage strengths between 25 mg and 100 mg respectively. Compounded liquid forms of atenolol cost anywhere from $15 to $40 for up to 30 ml.

Side effects

Atenolol for dogs may produce the following side effects:

Side effects of atenolol for dogs are more common in older dogs and pets with congestive heart failure. Report any potential side effects of atenolol to your vet, and seek veterinary attention immediately if your pet has an adverse reaction to the medication.


Before prescribing atenolol for your dog, a veterinarian will need to have a complete picture of your pet’s health and medical history. They’ll also need to be informed of all other medications your dog is currently taking to determine whether it’s safe for your dog to take atenolol.

Drug interactions

Atenolol may interact with the following types of drugs:

  • Antacids

  • Anesthetics

  • Calcium channel blockers (including amlodipine)

  • Diuretics (including furosemide)

  • Sympathomimetic drugs (including metaproterenol, epinephrine, and phenylpropanolamine)

  • Some heart medications (including diltiazem and digoxin)

  • Tranquilizers (including acepromazine)

  • Alpha blockers (including prazosin)

This is not a complete list, so be sure to disclose to your veterinarian all medications that your pet is currently taking.

Allergic reactions and sensitivity

Atenolol should not be given to dogs who are allergic to this medication. It should also not be used in pets with low blood pressure, a slow heart rate, or circulation problems.

Caution should be exercised when giving atenolol to pregnant or nursing pets or those with congestive heart failure. It also may not be suitable to give to pets with diabetes or kidney failure.

Frequently asked questions

Does my dog need a prescription for atenolol?

Yes. Atenolol is a prescription drug and should only be administered in line with your veterinarian’s instructions.

How should I store atenolol?

Atenolol tablets should be protected from light and moisture in a sealed container and stored at room temperature. Check the label for instructions on how to store the liquid form of this medication. Atenolol should also be stored out of reach of children at all times.

What happens if my dog overdoses on atenolol?

Seek emergency veterinary medical attention for your pet.

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© 2024 Wag Labs, Inc. All rights reserved.