Can I give my dog metronidazole without food?

In this article:

• Can you give metronidazole to your dog without food?
• Benefits of giving metronidazole with food
• Risks of giving metronidazole to your dog on an empty stomach
• Summary

In this article

• Can you give metronidazole to your dog without food?
• Benefits of giving metronidazole with food
• Risks of giving metronidazole to your dog on an empty stomach
• Summary

Metronidazole is a prescription medication that’s sold under the brand name Flagyl. It’s in a class of medications called nitroimidazole antimicrobials. Metronidazole is FDA approved to treat a broad range of infections in humans, including skin infections, bacterial infections, protozoal infections, GI tract infections, and vaginal infections. It’s used off-label to treat various infections in dogs.

Metronidazole is “both an antibiotic and antiprotozoal medication that is prescribed for dogs with infections, including those caused by bacteria and protozoans such as Giardia,” says Amy Attas, VMD, veterinarian and author of Pets and the City: True Tales of a Manhattan House Call Veterinarian. In particular, the medication is a first-line treatment for dog diarrhea.

Here, we’ll consider the potential side effects of giving dogs metronidazole without food and how best to administer the medication so that your dog will feel better as soon as possible.

Can you give metronidazole to your dog without food?

Vets agree that it’s best to give metronidazole to a dog with food, rather than on an empty stomach. “It is generally recommended to give this medication with food to reduce potential gastrointestinal upset from it,” Dr. Attas says.

Bethany Hsia, DVM, veterinarian, and co-founder of CodaPet, is on the same page. “Most veterinarians recommend giving metronidazole with food to minimize your dog having a stomach ache or gastrointestinal upset,” Dr. Hsia describes. “Metronidazole can be harsh on your dog’s stomach so administering it with food can help reduce stomach irritation and also improve metronidazole’s effectiveness.”

While metronidazole could theoretically be given to dogs on an empty stomach, Nita Vasudevan, DVM, veterinary consultant for Embrace Pet Insurance, doesn’t recommend this. She says that the potential for an upset stomach is possible for any dog, but certain dogs have an increased risk; “Dogs with a history of digestive sensitivity or past stomach issues may be more prone to experiencing nausea, vomiting, or loss of appetite when metronidazole is administered on an empty stomach.” 

The bottom line? It’s better to be safe than sorry, so give your dog their metronidazole with food.

Benefits of giving metronidazole with food

It’s best to give metronidazole to dogs with food. The main benefit is that it reduces the risk of gastrointestinal side effects, including nausea and vomiting. But there are other benefits to consider, too.

First of all, metronidazole is “notoriously a very bitter medication,” says Dr. Vasudevan. Taking it with food “acts as a buffer, reducing direct contact between the stomach lining and the medication, which can be irritating,” she describes.

Other benefits include that your dog will be more likely to swallow the pill with food, and it reduces the likelihood that they will spit it out. “This method is often preferred to ensure the dog’s comfort and compliance,” Dr. Vasudevan says. She warns against crushing pills and adding them to food because this will make the medication less palatable, and the dog may not take the full dose of the drug.

Finally, in some cases, having your dog take metronidazole with food will ensure effectiveness. “The food combined with the medicine will help enhance absorption so your dog receives the full medical effect of the medicine while minimizing stomach discomfort,” says Dr. Hsia.

Risks of giving metronidazole to your dog on an empty stomach

While metronidazole is generally well tolerated in dogs, serious side effects are possible. These side effects are more likely to happen if you give metronidazole in high doses. Too much metronidazole can cause metronidazole toxicity.

​Possible side effects of metronidazole in dogs include:

• Decreased appetite
• Nausea
• Vomiting
• Seizures
• Neurological symptoms
• Neutropenia (when you have lower than normal levels of a type of white blood cell called neutrophils)
• Disturbances to the GI tract microbiome

The main risk of giving your dog metronidazole without food is that you would increase the chances of an upset stomach. This can manifest as nausea, vomiting, or diarrhea, says Dr. Vasudevan. The chances of this happening are greater for certain dogs. “In dogs with pre-existing conditions such as gastritis or other forms of stomach sensitivity, these side effects may worsen,” Dr. Vasudevan explains.

In rare cases, other serious side effects can happen if you administer metronidazole to your dog on an empty stomach. Doing so could lead to an overall refusal to eat, says Dr. Vasudevan, which would mean your dog doesn’t receive adequate treatment for their condition.

Besides making sure to take metronidazole with food, you should also review any other medications your dog is taking with their vet before giving them metronidazole. “While metronidazole is generally safe, potential drug interactions should be considered, particularly if the dog is on other medications that can irritate the stomach or alter gut flora,” Dr. Vasudevan advises.

Summary

It is safe and effective to give metronidazole to a dog, and it can be helpful in treating dog diarrhea, bacterial infections, and protozoal infections. Vets recommend that you give your dog metronidazole with food. This will decrease GI tract side effects like nausea and vomiting. It also makes the medication more palatable so that your dog won’t reject it.

If you have further questions or concerns about administering metronidazole to your dog, please contact your veterinarian. Your vet can also discuss potential side effects and the best dosage for your dog.