Banamine vs Bute for Horses

Understanding the Distinction Between Flunixin Meglumine and Phenylbutazone in Equine Medicine

Updated December 15, 2023 | By: Carolyn Hammer, DVM, PhD
equine veterinarian administering banamine (flunixin meglumine) injection for a horse.

For horse owners, the health and well-being of their horses is of utmost importance. When managing inflammation and pain, veterinarians often prescribe Banamine® or Bute. But have you ever wondered why one is used versus the other?

Understanding Equine Inflammation

Inflammation is a natural and important immune response that occurs within a horse’s body. It is a protective mechanism against injury, infection, or irritation. Inflammation is a complex process involving various immune system cells, the chemical signals they release, and the resulting effects of those chemical signals on body tissues (like blood vessels).

When the horse’s body detects a harmful invader (such as bacteria or viruses) or tissue damage, an inflammatory response is triggered. The purpose of inflammation is to remove the harmful invader, initiate the healing process, and restore normal tissue function. Inflammation is characterized by symptoms such as redness, swelling, heat, pain, and sometimes loss of function in the affected area.

The immune system releases chemical signals that dilate blood vessels, allowing more blood to flow to the affected area. This increased blood flow brings immune cells to the site of injury or infection, where they help remove the disease agent and repair damaged tissue.

Inflammation is generally a short-lived response that resolves once the injury or infection is healed; however, chronic inflammation (a prolonged and persistent inflammatory response) can occasionally develop and may last for weeks, months, or even years.

While inflammation is a necessary process for healing and protection, it can also cause discomfort and damage if it becomes excessive or prolonged. In such cases, treatments like non-steroidal anti-inflammatory drugs may be used to help alleviate the symptoms and reduce inflammation.

What are NSAIDs for Horses?

NSAID stands for non-steroidal anti-inflammatory drug. These drugs are commonly used in both human and veterinary medicine to relieve pain, reduce inflammation, and lower fever. NSAIDs work by inhibiting the production of prostaglandins – a type of natural chemical molecule that is normally produced in the body. There are a variety of prostaglandins that your horse’s body makes, some of which are responsible for promoting inflammation and pain while others provide protection to the lining of the stomach and intestine.

Banamine vs Bute

The most frequently prescribed NDSAIDs for horses are generally known by their commercial or common names. Banamine® is the commercial name for the drug flunixin meglumine, while bute is the common name for the drug phenylbutazone.

Both products work to non-specifically block prostaglandin production. This means they block the prostaglandins associated with inflammation, but also the “good” prostaglandins associated with gastrointestinal protection. Although both drugs block prostaglandin formation, they have different chemical compositions, different dosing, and are favored for different situations based on their varying effects.

Bute (Phenylbutazone) for Horses

Bute is primarily used for the treatment of pain and inflammation associated with the musculoskeletal system (muscle, bones and joints). It is often administered to provide pain relief associated with lameness and laminitis. Since the cost of bute is lower than the other NSAIDs, it is often given to horses needing long-term pain management.

It is commercially available in powder, tablet, paste, and injectable forms. The injectable form is labeled for intravenous (IV) injection only and is very damaging to the surrounding tissue if given outside of the vein. Severe inflammation and sloughing of the skin can result.

Banamine (Flunixin Meglumine) for Horses

Banamineis primarily used for the treatment of pain associated with abdominal, respiratory and eye inflammation. It is commonly used to reduce the pain associated with colic. Banamine is commercially available in paste and injectable forms and in certain situations compounded formulations of powder, granules or capsules can be used.

The injectable form of Banamine should be also given IV, although it does say it can be given intramuscularly (IM). Administering Banamine IM is NOT recommended. Although rare, disastrous and life-threatening clostridium infections can result after IM administration.

Risks and Adverse Effects

Like any drug, both Banamine and bute can have unwanted side effects. Gastric ulceration is the most common side effect and results from decreased formation of the protective prostaglandins that line the gastrointestinal tract. Negative side effects such as reduced kidney function can also occur, especially in horses that are dehydrated. The risk for adverse side effects increase with higher doses, when used in horses that are dehydrated, and when used in horses with kidney or liver disease.

Companies spend significant amounts of time and money to develop the drugs we use. Dosages and the dosing schedule are carefully developed and rigorously tested to ensure the maximum benefit while minimizing negative side effects. Altering label doses or the timing or route of administration can not only affect the efficacy of the drug, but it can also greatly impact the risk of negative side effects.

Additionally, Banamine and bute should not be used together. Research has shown that there is no improved benefit to their use together and instead the risk for unwanted side effects is greatly increased.

As a reminder, Banamine and bute are prescription drugs and should be used with guidance from your horse’s veterinarian. Your vet can recommend the appropriate NSAID, dosage, and duration of treatment based on the specific condition and needs of your horse. For example, the dose of Banamine required for anti-inflammatory effects is lower than the dose required for pain relief. Thus, it is very important to understand what the underlying condition is before reaching for an NSAID.

Supplements That May Support a Normal Inflammatory Response

Ingredients in nutritional supplements such as devil’s claw, turmeric and omega-3 fatty acids are all purported to have anti-inflammatory benefits. While these products won’t replace NSAID use, owners may want to give them a try for managing chronic inflammation and pain.

Follow this link for recommendations on other things owners can do to manage their horse’s pain instead of giving bute long-term.

SmartPak strongly encourages you to consult your veterinarian regarding specific questions about your horse's health. This information is not intended to diagnose or treat any disease, and is purely educational.