Banamine® (Flunixin) for Horses

PetMD’s medications content was written and reviewed by veterinary professionals to answer your most common questions about how medications function, their side effects, and what species they are prescribed for. This content shouldn’t take the place of advice by your vet.

What Is Banamine® Used for in Horses?

Also available as generic flunixin, Banamine® is an FDA-approved, non-steroidal anti-inflammatory (NSAID) prescription medication that’s available as an oral paste and an intravenous injection.

In horses, Banamine® is FDA-approved to help alleviate pain, swelling, and fever due to musculoskeletal disorders, as well as alleviate to pain and inflammation associated with colic.

It is also sometimes used at a lower dose for horses experiencing endotoxemia due to other disease processes.

Other brand names for flunixin for horses include Prevail®, Vetameg®, and Flu-Nix®.

Compounded Banamine®

In certain circumstances, your vet may recommend a compounded formulation of flunixin.

Compounded medications are prescribed if there’s a specific reason your horse’s health can’t be managed by an FDA-approved drug, such as if your animal has trouble taking pills in capsule form, the dosage strength is not commercially available, or the animal is allergic to an ingredient in the FDA-approved medication.

Compounded medications are not FDA-approved. They’re created by either a veterinarian or a licensed pharmacist on an individual basis to best suit an animal’s particular needs.

Your veterinarian will determine if a compounded medication is the right option for your horse, based on individual health needs.

How Banamine® Works in Horses

Flunixin is an NSAID that reduces fever and offers pain relief by blocking the COX pathways that produce prostaglandins, which are naturally occurring chemicals that trigger inflammation.

Due to its ability to block other COX pathways, flunixin can potentially cause negative side effects associated with digestion, kidney health, and clotting.

Directions for Banamine® in Horses

Follow the directions on the drug label or as provided by your veterinarian.

Dosing varies greatly by species and the disease process for which the medication is being used.

For horses, dosing is typically every 12 hours or as needed up to twice daily. Giving extra doses of this medication is not likely to have any benefit but can pose health risks for your horse, so only give as directed.

Directions will also vary based on the type of medication:

• Injectable:

  • While the injectable version of Banamine® is labeled for intravenous (IV) or intramuscular usage (IM), IM usage can cause clostridial myositis (see side effects section for more information) and is not recommended despite this route being on the drug label.

  • If your veterinarian leaves injectable flunixin for you to have on hand for emergencies and you are not comfortable giving medication intravenously, they may advise you to give the injectable liquid by mouth or prescribe you the paste version.

• Paste:

  • The paste form of flunixin, including Banamine® paste, is generally given orally once daily or divided and given twice daily.

  • The dose is based on a horse's weight and is generally recommended to be given a maximum of five to seven days in a row to avoid any negative side effects.

Missed a Dose?

Speak with your veterinarian about what to do if you forget to give a dose of flunixin. Generally, they may instruct you to give it when you remember, or if it’s almost time for your next dose, to skip the missed dose and resume your normal dosing schedule.

In most cases, do not give extra or double doses.

Possible Side Effects of Banamine® in Horses

Most horses tolerate the use of flunixin well. If your horse has been given an injection of this medication into the muscle, monitor the injection site for the following possible side effects:

• Swelling

• Redness

• Stiffness

• Wound formation

Horses treated with this medication for long periods of time are at an increased risk for:

• Stomach ulcers

• Colonic ulcers and inflammation

• Severe diarrhea

• Kidney damage

Intramuscular injection of flunixin is not recommended in horses because it can lead to a condition called clostridial myositis that occurs when a type of bacteria called Clostridia grows on the damaged muscle.

A clostridia infection can cause muscle inflammation and release toxins into the body, which can be life-threatening.

This medication should not be given into an artery. Injection into an artery may cause:

• Incoordination

• Difficulty walking/stumbling

• Increased breathing rate

• Muscle weakness

• Seizure

• Death if a horse has a traumatic backward flip or fall

It’s important to note that if your animal does not respond to the first dose of flunixin, then it is not likely to control their pain or symptoms. Speak with your veterinarian to discuss other options if your animal is not showing improvement on this medication.

If you believe your horse may be experiencing any side effects, consult your veterinarian. 

Human Side Effects

Banamine® is not intended for use in humans.

If you get this medication in your eyes, immediately flush them with water and seek medical attention.

If you accidentally ingest medication for animals, immediately seek medical attention or call the national Poison Control Center hotline at 800-222-1222.

Monitoring Your Horse

No specific monitoring is required for Banamine®, but your veterinarian may recommend routine testing depending on your animal’s individual needs, other medications they may be on, and/or the issue that initially caused your horse to be placed on this medication.

When To Call Your Vet

Call your veterinarian if any of the following apply:

• Severe side effects are seen (see above)

• Your animal's condition worsens or does not improve with treatment

• You see or suspect an overdose

• You have additional questions or concerns about the use of flunixin

• Your animal is not responding to this medication

Banamine® Overdose in Horses Information

A Banamine® overdose—or giving for prolonged periods—can increase the risk for stomach ulcers, colonic ulcers and inflammation, and kidney damage in horses.

Signs of an overdose include:

• Fresh blood in the manure

• Diarrhea

• Signs of colic

If you suspect an overdose or that a small animal got into this medication, immediately contact your veterinarian, seek emergency veterinary care, or contact an animal poison control center. Consultation fees often apply.

• Pet Poison Helpline® 855-764-7661

• ASPCA® Animal Poison Control 888-426-4435

How To Store Banamine® for Horses

Follow these tips when storing your horse’s Banamine®:

• Flunixin paste should be stored at controlled temperatures less than 77 degrees F (25 degrees C). Do not freeze.

• Carefully dispose of used needles in accordance with all federal, state, and local environmental laws.

• Keep out of reach of children and pets.

• Always confirm storage requirements by reading the label.