Can my dog’s medication cause an upset stomach?

Dog owners never want to hear their dog is feeling ill. It can be especially frustrating when the medicine that’s supposed to make our pets feel better seemingly upsets their stomach. Read on if you have ever wondered:

• Why do medications sometimes cause an upset stomach in dogs?
• What are the common gastrointestinal side effects of canine medications?
• Which medications might make my dog feel ill?
• Can gastrointestinal side effects of medications be treated or prevented?

Fortunately, most dogs will not experience side effects from medication. If they do, the side effects are typically mild and go away on their own. It’s always good to know why a medicine might upset a dog’s stomach and what to do if it happens.

Some medications can irritate the digestive tract or disrupt the gut’s natural flora, causing an upset stomach. In other cases, an oral drug can taste bad and cause a dog to foam at the mouth or regurgitate it back up. In some cases, gagging and vomiting after giving medication is more related to behavior than the medication itself. If a dog is particularly difficult when receiving oral medications, the struggle between owner and dog might result in GI symptoms unrelated to the medication.

Most dogs taking medication experience no side effects. When side effects do occur, stomach upset and GI symptoms are the most common. Gastrointestinal side effects can include:

• Vomiting
• Diarrhea
• Regurgitation
• Gas
• Constipation

Mild vomiting and diarrhea are the most common side effects of canine medications. Other, more severe reactions are rare. Reading the package insert is a helpful place to learn more about medications, but you should always review this information with a qualified practitioner. Statements on package inserts can be challenging to fully understand without additional medical context. Your vet can help you understand how your dog’s medication works and what to look for if you are concerned about side effects. Always give medications according to the prescribing veterinarian’s directions. Call the prescribing veterinarian immediately if you think your dog is having an unexpected reaction to medication.

A wide variety of common canine medications can cause stomach upset as a side effect.

Antibiotics

Antibiotics treat bacterial infections by killing bacteria that are causing the illness. However, antibiotics can also kill beneficial bacteria that keep the gut biome healthy. When this occurs, nausea, vomiting, and diarrhea can result. Common antibiotics prescribed for dogs include:

• Metronidazole
• Doxycycline
• Amoxicillin

Anti-inflammatory medications

Nonsteroidal anti-inflammatory drugs (NSAIDs) and pain medications can irritate the digestive tract and stomach lining, resulting in GI upset. These medications are often used for short or long-term pain management, especially in cases of osteoarthritis. Common anti-inflammatories and pain medications prescribed to dogs include:

• Carprofen
• Meloxicam
• Grapiprant (Galliprant®)
• Robenacoxib (Onsior®)
• Deracoxib (Deramaxx®)
• Firocoxib (Previcox®)

In rare cases, anti-inflammatories and pain medications can cause gastrointestinal ulcers and liver failure in dogs. Since anti-inflammatories are more likely to cause stomach ulcers than other medications, it’s important to get veterinary attention if a dog experiences signs of illness or abdominal pain when taking them.

Allergy medications

Medications used to treat allergy symptoms are some of the most commonly prescribed medications for dogs. They can sometimes irritate the digestive tract, causing gastrointestinal side effects. Common allergy medications include:

• Atopica®
• Apoquel®
• Prednisone

In most cases, GI upset from taking allergy medications goes away on its own and no changes to the medication plan are needed.

Anesthesia and chemotherapy

Temporary nausea and vomiting in dogs are common after anesthesia or during chemotherapy. Once the drugs wear off, the side effects in these cases are expected to end. Dogs are closely observed during and after anesthesia and chemotherapy before they are discharged to minimize the likelihood for complications at home.

Side effects of chemotherapy drugs are far less severe in dogs than in people. The goal of cancer treatments in dogs is to relieve symptoms and allow pet parents to have a little more time with their friends. Canine protocols for cancer treatment are different from those for humans where high concentrations of chemo are used in an effort to completely eradicate cancerous cells from the body permanently.

It can be difficult to determine if a dog is expected to have side effects of medications before they take them. Veterinarians consider the possibility of side effects when prescribing medications and make informed recommendations accordingly. To help prevent an upset stomach from medication, dog owners can:

• Follow all instructions on the label and give the correct dosage, on time
• Avoid adding new medications without a vet’s approval
• Only administer medication to the individual it has been prescribed to
• Do not share doses of medications between animals
• Do not administer canine medications to cats and vice versa
• Store all medications out of reach of children and animals and in the correct storage conditions according to the label
• Let the prescribing vet know if their dog has had a side effect in the past
• Tell the vet about underlying health conditions and any other medications your pet is already on
• Ask a vet what to look out for while their dog is on medication

If you are confused about your dog's medication storage, dosage, or administration, it’s best to consult with a veterinarian to avoid potential problems. They’ll be happy to help and glad you asked for it.

When gastrointestinal side effects occur, they are usually mild, short-lived, and do not require any veterinary care. If a dog is particularly uncomfortable, a vet can sometimes change the dosage, offer an alternative medication, or give supportive care. In most cases, side effects wear off on their own without any changes. Most dogs do not experience side effects from medications, and the symptoms are often caused by an outside factor rather than the medication itself. In these cases, a vet may recommend diagnostics to determine why a dog has gastrointestinal symptoms.

“It’s hard to know for sure if your dog’s GI symptoms are from the medication, even if they started at the same time you started giving it,” explains Dr. Jo Myers. “Other causes of vomiting and diarrhea in dogs are much more common than as a result of medication.” If gastrointestinal side effects occur when your pet starts a medication, it’s best to talk to a veterinarian before changing anything. Do not stop, add, or change medications without your veterinarian’s approval.

If your dog’s stomach seems upset from medication, ask yourself a few questions to ensure it is being given properly:

• Are you following all the medication instructions, such as giving with or without food?
• Was vomiting or diarrhea listed as a side effect of the medication?
• Is the proper dosage being administered?
• Are you storing the medication according to the product label?

If you need additional information on your dog’s medication or help with a gastrointestinal side effect, an online virtual care appointment is an excellent tool to get help from home quickly.

Can dogs get sick from medication?

Most dogs will not experience medication side effects. When they do happen, mild vomiting or diarrhea are the most common and can lead to a lack of appetite. Ask your veterinarian about potential side effects with any new medications, and always store and administer them exactly as directed. If your dog develops new symptoms after starting a medication, contact the prescribing veterinarian.

Should I give my dog’s medicine with food?

Some medications are intended to be given with food, while others must be given on an empty stomach or with plenty of water. Thoroughly read the medication label for instructions, and talk to a veterinarian if you are unsure how to administer your dog’s medication.

What do I do if my dog throws up their medicine?

Contact a veterinarian for advice. The appropriate course of action depends on several variables and you don’t want to do something that could make the situation worse. Be ready to give the vet the name of the medication, the time between the drug’s administration and the dog vomiting, and the medicine’s dosage.