Cimetidine for Dogs - Dosage, Uses and Side Effects

María Besteiros
By María Besteiros, Expert veterinary assistant and canine/feline hairdresser.. Updated: February 28, 2024
Cimetidine for Dogs - Dosage, Uses and Side Effects

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Veterinarians often prescribe cimetidine to treat acid reflux and gastric ulcers in dogs. Acid reflux or gastroesophageal reflux is a digestive disorder in which stomach or intestinal contents enter the dog's esophagus. These substances irritate the esophageal mucosa and cause lesions in the esophagus. They irritate the esophageal mucosa and cause lesions that can become very serious.

In the following AnimalWised article you will learn everything you need to know about cimetidine for dogs, its dosage, uses, and possible side effects.


  1. What is cimetidine?
  2. What is cimetidine for dogs used for?
  3. Dosage of cimetidine for dogs
  4. Contraindications of cimetidine for dogs
  5. Side effects of cimetidine for dogs

What is cimetidine?

Cimetidine acts as a blocker of the histamine H-2 receptor. The activity of this receptor cell has been directly linked to the development of certain types of peptic ulcers. By effectively preventing this cell from functioning as it normally would, cimetidine can relieve your pet's symptoms associated with stomach ulcers. Specifically, the drug blocks the production of certain types of stomach acid. By effectively limiting the amount of stomach acid produced, cimetidine reduces the strain on your dog's stomach.

It was the first drug in human medicine to treat gastrointestinal ulcers, making it one of the longest-used drugs of its type. It is rapidly absorbed from the gastrointestinal tract, although absorption can be affected by the presence of food. Furthermore, it is metabolized in the liver and excreted in the urine.

This medication may also be helpful for other types of stomach problems, such as inflammation that occurs as a result of kidney damage or kidney failure.

Cimetidine is available in tablet or liquid form, and also as an injectable medication.

What is cimetidine for dogs used for?

The range of action of cimetidine is at the digestive level. Therefore, it is mainly used in dogs with:

  • Gastritis: Gastritis is defined as an inflammation of the gastric mucosa. It may occur in short episodes (acute) or over a long period of time (chronic) and may be associated with more serious conditions. The most common clinical signs of gastritis are sudden vomiting and decreased appetite (anorexia). Other clinical signs may include dehydration, lethargy or depression, increased thirst, blood in the vomit or stool, and abdominal pain. One of the most common causes of gastritis is kidney disease. Cimetidine is often used to treat this type of gastritis because although it cannot cure kidney disease, it can relieve its symptoms.

  • Gastric and duodenal ulcers: Dogs are very sensitive to the occurrence of ulcers caused by the use of non-steroidal anti-inflammatory drugs or NSAIDs. Gastric and duodenal ulcers are two types of peptic ulcers. A peptic ulcer is a sore on the inside of the stomach lining (gastric ulcer) or on the upper part of the small intestine (duodenal ulcer). A dog may have one or both types of ulcers at the same time. In these cases, the use of cimetidine or another drug from its group is controversial and other options are preferred.

  • Gastric reflux esophagitis: is defined as inflammation of the esophageal mucosa secondary to gastroesophageal reflux disease (GERD) in which gastric contents reflux into the esophagus or beyond (oral cavity, larynx, or lungs). Cimetidine is used in these cases to limit damage to the esophagus.

In some cases, cimetidine can also be used in certain chronic dermatological diseases to obtain an immunomodulatory effect.

If you want to learn more about gastritis in dogs, its causes, symptoms and treatment, do not hesitate to read our other article that explains everything you need to know about gastritis in dogs.

Dosage of cimetidine for dogs

Cimetidine may be administered orally to dogs, at a dosage of 10 mg per kg body weight, every 6-8 hours. It is administered before meals because absorption of cimetidine by food is impaired. In addition, cimetidine can also be injected intravenously, intramuscularly, which may be uncomfortable for the dog, or subcutaneously. Depending on the option chosen, the dose will be different, as for injection we are talking about 5 mg per kg every 12 hours. It is important that your dog completes the full course of medication recommended by your veterinarian.

This is the general dosage, but it can be adjusted according to the circumstances of each dog. For this reason, in any case, the veterinarian is the only professional who can decide on the most appropriate administration schedule.

If you want to learn more about acid reflux in dogs, its causes, symptoms and treatment, do not hesitate to read our other article that explains everything you need to know about acid reflux in dogs.

Contraindications of cimetidine for dogs

Logically, cimetidine cannot be given to dogs that have previously shown a hypersensitivity reaction to it or are suspected of being allergic to it. The signs of an allergic reaction to this drug are: hives, swelling or shortness of breath.

On the other hand, it must be administered with caution to dogs suffering from liver or kidney damage or failure.

Finally, cimetidine may react negatively with some other medications present in your pet's body. Therefore, it is important that you inform your veterinarian of any other medications that may be present in your pet's body before you begin administering cimetidine to your pet.

Kidney disease is relatively common in dogs, especially as they age. If you want to learn more about this disease, read this other article, where we explain what foods a dog with kidney disease should eat.

Side effects of cimetidine for dogs

Cimetidine is considered a very safe drug as long as it is administered according to the veterinarian's instructions and even if the dose is accidentally higher than recommended.

However, like all medications, it can have side effects that are usually minor or mild. These include:

  • Stomach upset
  • Vomiting
  • Diarrhea
  • Lethargy

If we notice any adverse effect after administering cimetidine to our dog, we must notify the veterinarian immediately. If you find that your dog has an upset stomach, there may be many reasons for this, not necessarily due to the administration of this drug, although it is advisable to suspend its use.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Cimetidine for Dogs - Dosage, Uses and Side Effects, we recommend you visit our Medicine category.

  • Carlson and Giffin. (2002). Canine Veterinary Practice Manual . Madrid. Editorial el Drac.
  • Veterinary Portal . (2018). Gastrointestinal pharmacology.
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Cimetidine for Dogs - Dosage, Uses and Side Effects