Written By Mel Lee-Smith
Published: 09/14/2020Updated: 08/30/2021
Antacids for Dogs | Wag!

Antacids are used to treat onset symptoms of heartburn, acid reflux, and other inflammatory gastrointestinal conditions. Due to the wide variety of antacid brands available over-the-counter, these drugs have a long list of potential side effects, drug interactions, and other considerations.

Veterinarians may prescribe antacids for dogs or advise pet parents to administer small doses of certain antacids formulated for human use. The dosage, efficacy, and side effects depend on the mineral compounds in the antacid and the presence of pre-existing conditions.


The dosage strength and amount will vary based on the condition and duration of treatment. Never administer antacids to your pet without explicit dosage instructions from your veterinarian. Antacids for dogs are available in tablet or liquid form.

A comprehensive study on treating stomach and intestinal ulcers in dogs notes that no specific dosage amounts have been recommended for small animals. Antacids are generally administered around the same time each day on an empty stomach, before your dog’s first meal.


Antacids are typically a short-term treatment to relieve symptoms rather than a long-term treatment for acid reflux and other stomach conditions. Antacids are also less effective than acid suppressants like famotidine in treating excessive stomach acid for a prolonged period.

Antacids are short-acting and must be administered several times a day for maximum efficacy. This is one reason why other, longer-acting solutions are preferred. Antacids containing magnesium and aluminum are considered the most effective.

Active ingredients in antacids for dogs

The active ingredients vary depending on the brand. Antacids contain mineral compounds like:

  • Calcium carbonate

  • Sodium bicarbonate

  • Aluminum hydroxide

  • Magnesium hydroxide

Some antacid formulations aren’t safe for dogs with liver or kidney problems.

Side effects

Potential side effects include: 

  • Bloat

  • Belching

  • Diarrhea

  • Constipation

  • Kidney damage*

  • Loss of appetite

  • Difficulty breathing

  • Irregular heartbeat

  • Blood pH imbalance

  • Electrolyte imbalance

  • Lethargy and weakness

Constipation and diarrhea are the most common side effects. Serious side effects are rare and are usually associated with the continued use of antacids. Electrolyte imbalance and irregular heartbeat can result from antacid overdose.

*Kidney damage is a potential side effect of long-term treatment with antacids containing aluminum or calcium. 

**Blood pH imbalance is more common in pets diagnosed with kidney disease and treated with antacids containing high levels of sodium and calcium.


Dogs generally don’t like the taste of antacids, whether in tablet or liquid form. Administering the medication may be challenging. Ask your vet for advice if your dog vomits or refuses to take it. Use caution when treating pregnant and lactating dogs with antacids.

Drug interactions

Because the list of potential drug interactions is a long one, you’ll need to consult your veterinarian if your dog takes any prescribed or over-the-counter medications.

Antacids may interact with the following drugs by affecting the body’s ability to absorb them or reducing their efficacy:

  • Aspirin

  • Penicillamine

  • Corticosteroids

  • Iron supplements

  • Sedatives (chlordiazepoxide)

  • Tranquilizers (phenothiazines)

  • Seizure medications (valproic acid)

  • Tuberculosis medications (isoniazid)

  • Antihistamines (cimetidine, ranitidine)

  • Heart medications (digoxin, quinidine)

  • Antifungal medications (ketoconazole)

  • Blood pressure medications (captopril)

  • Canine epilepsy medications (phenytoin)

  • Intestinal parasite treatments (chloroquine)

  • Certain antibiotics (tetracyclines, nitrofurantoin)

  • Pancreatic enzyme supplements (pancrelipase)

  • Potassium regulation drugs (sodium polystyrene sulfonate)

  • Pain relievers for inflammatory joint conditions (indomethacin)

Allergic reactions and sensitivity

Dogs with the following conditions should not take antacids containing magnesium or aluminum:

Frequently asked questions

Are antacids formulated for humans safe for dogs?

Certain human antacids are safe for dogs in small quantities of 0.25 mg/lb, according to Dr. Callum Turner, DVM. However, these are general guidelines. Always consult your veterinarian before administering any medications formulated for human use. Additionally, Dr. Turner notes that antacid treatment is a short-term solution to relieve onset symptoms.

What conditions do antacids treat in dogs?

Antacids can help treat gastrointestinal symptoms associated with a variety of conditions and treatments, including:

  • Heartburn

  • Acid reflux

  • Excessive stomach acid

  • Inflammation of the esophagus

  • Removal of the parathyroid gland

  • Excessive vomiting or regurgitating

  • Gastrointestinal ulcers and inflammation

  • Excess blood phosphate in pets with kidney disease

What should I do if I miss a dose?

Give the next dose at the scheduled time. Do not double up on doses. Consult your veterinarian if you miss a dose for specific instructions.

Is it possible for my dog to overdose on antacids?

While overdose is rare, it can have serious effects. As mentioned above, overdose can lead to electrolyte imbalance and irregular heartbeat. Long-term treatment with antacids containing aluminum can lead to aluminum poisoning and muscle and bone weakness.

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