Banamine is the most recognized brand name for flunixin meglumine, a potent nonsteroidal anti-inflammatory drug (NSAID) that is widely used in equine medicine. Originally manufactured by Merck Animal Health, Banamine has been a cornerstone of equine pain management for decades. It is particularly valued for its effectiveness against visceral (abdominal) pain, making it the go-to medication for colic episodes, as well as its anti-endotoxic properties and its usefulness in treating ocular inflammation. Flunixin meglumine is available in both injectable and oral paste formulations.
What Is Banamine Used For?
Banamine is FDA-approved for use in horses for the control of inflammation and pain associated with musculoskeletal disorders and for the alleviation of visceral pain associated with colic. Veterinarians commonly prescribe it for:
- Colic — Banamine is the first-line analgesic for equine colic pain. It provides rapid relief from the abdominal pain associated with gas colic, impaction colic, and other forms of gastrointestinal distress.
- Endotoxemia — Flunixin has unique anti-endotoxic properties at lower doses than those used for pain relief. It helps mitigate the inflammatory cascade caused by bacterial endotoxins released during serious infections or severe colic.
- Ocular inflammation — Banamine is commonly used to manage uveitis (moon blindness/equine recurrent uveitis) and other inflammatory eye conditions in horses.
- Musculoskeletal pain — Lameness, soft tissue injuries, and post-surgical pain.
- Fever reduction — Effective antipyretic for horses with elevated body temperature from infection or inflammation.
- Post-surgical pain management — Commonly used after colic surgery, orthopedic procedures, and other surgeries.
How Does Banamine Work?
Flunixin meglumine works by inhibiting cyclooxygenase (COX) enzymes, blocking the production of prostaglandins and thromboxanes that mediate pain, inflammation, and fever. Like phenylbutazone, flunixin is a non-selective COX inhibitor, affecting both COX-1 and COX-2.
What makes flunixin particularly useful for colic and endotoxemia is its potent effect on thromboxane production. Thromboxane is a key mediator of the inflammatory response to endotoxins (bacterial toxins released by gram-negative bacteria). By inhibiting thromboxane synthesis, flunixin helps reduce the systemic inflammatory response that can lead to shock, laminitis, and organ failure in horses with severe infections or colic.
The anti-endotoxic effect occurs at a lower dose (0.25 mg/kg) than the full analgesic dose (1.1 mg/kg), which is clinically important because veterinarians may use the lower dose specifically for endotoxemia management while minimizing side effects.
Dosage
Your veterinarian will determine the appropriate dose and treatment plan for your horse. General guidelines include:
| Indication | Dose | Route | Frequency | Duration |
|---|---|---|---|---|
| Colic pain / musculoskeletal pain | 1.1 mg/kg (500 mg for average horse) | IV or oral paste | Every 12-24 hours | Up to 5 days |
| Anti-endotoxic dose | 0.25 mg/kg | IV | Every 8 hours | As directed by vet |
| Ocular inflammation | 1.1 mg/kg | IV or oral | Every 12-24 hours | As directed by vet |
| Fever | 1.1 mg/kg | IV or oral | Every 12-24 hours | Until resolved |
Banamine is available as:
- Injectable solution (50 mg/mL): For intravenous administration by a veterinarian
- Oral paste (1500 mg/syringe): For administration by horse owners
- Oral granules: For mixing with feed
How to Give Banamine to Your Horse
Oral Paste (Owner Administration)
- The oral paste syringe is designed for direct oral administration, similar to deworming paste.
- Set the dose dial on the syringe to match your horse’s body weight.
- Insert the syringe into the corner of the horse’s mouth and deposit the paste onto the back of the tongue.
- Ensure the horse has swallowed the paste before releasing.
Injectable Solution (Veterinarian Only)
This is critically important: Banamine injectable must be given intravenously (IV), not intramuscularly (IM).
Intramuscular injection of flunixin meglumine can cause severe, potentially fatal Clostridial myositis (a life-threatening bacterial muscle infection). Cases of IM Banamine injection leading to Clostridial infection, extensive tissue destruction, and death have been well documented in equine veterinary literature. The caustic nature of the injectable solution damages muscle tissue, creating an anaerobic environment where Clostridial bacteria can thrive.
If you have injectable Banamine on your farm for emergency colic use, discuss with your veterinarian whether the oral paste formulation would be safer for owner administration. Many veterinarians now recommend keeping only the oral paste on hand for horse owners to administer, reserving injectable flunixin for IV administration by a veterinarian.
Side Effects
| Common Side Effects | Serious Side Effects (Contact Your Vet Immediately) |
|---|---|
| Mild GI irritation | Gastric or colonic ulceration (colic signs, dark/tarry stool) |
| Decreased appetite | Right dorsal colitis |
| Soft stool | Kidney damage or failure |
| Injection site complications (if given IM — see warning above) | |
| Oral ulceration | |
| Protein-losing enteropathy |
GI Ulceration Risk
Like all non-selective NSAIDs, flunixin inhibits the protective prostaglandins that maintain the gastrointestinal mucosal barrier. Prolonged use or high doses increase the risk of:
- Gastric ulceration (squamous and glandular regions of the stomach)
- Right dorsal colitis — a severe and potentially fatal large intestinal ulceration unique to NSAID use in horses
- Oral ulceration — particularly with oral paste formulations
The recommended maximum duration of use at full dose is five days. Risk factors for GI complications include dehydration, concurrent corticosteroid use, use of multiple NSAIDs, and pre-existing GI disease.
Masking Colic Signs
An important clinical consideration is that Banamine can be so effective at relieving colic pain that it may mask the progression of a surgical colic. This is why veterinarians emphasize that Banamine treats the symptom (pain) but not the underlying cause of colic. If a horse responds to Banamine but then shows recurring pain, or if the horse does not respond at all, this is important diagnostic information. Always contact your veterinarian when a horse shows signs of colic, even if you administer Banamine for immediate pain relief.
Drug Interactions
- Other NSAIDs (phenylbutazone, firocoxib): Never combine two NSAIDs. Wait for an appropriate washout period when switching between NSAIDs, as directed by your veterinarian.
- Corticosteroids: Concurrent use significantly increases GI ulceration risk.
- Aminoglycoside antibiotics (gentamicin, amikacin): Increased nephrotoxicity risk.
- Diuretics (furosemide): May increase risk of kidney damage in dehydrated horses.
Contraindications
Banamine should not be used in:
- Horses with known GI ulceration or right dorsal colitis
- Horses that are severely dehydrated (correct hydration first)
- Horses with kidney or liver disease
- Horses currently receiving another NSAID
- Horses with known hypersensitivity to flunixin
- Food-producing horses within the withdrawal period (relevant for horses entering the food chain in some jurisdictions)
Banamine vs. Phenylbutazone (Bute)
Both are non-selective NSAIDs, but they have different clinical strengths:
| Feature | Banamine (Flunixin) | Bute (Phenylbutazone) |
|---|---|---|
| Best for | Visceral (abdominal/colic) pain, endotoxemia, ocular inflammation | Musculoskeletal pain, lameness, laminitis |
| Anti-endotoxic properties | Strong (even at low dose) | Weak |
| Cost | More expensive | Less expensive |
| Forms | Injectable, oral paste, granules | Paste, tablets, powder, injectable |
| Duration of typical use | Short-term (up to 5 days) | Short to medium-term |
Your veterinarian will choose the most appropriate NSAID based on the specific condition and your horse’s health status. These medications should never be given together.
Storage
- Store at controlled room temperature, 59-86 degrees F (15-30 degrees C).
- Protect injectable solution from light.
- Do not freeze.
- Keep out of reach of children and other animals.
Cost & Availability
Banamine is a prescription medication available through veterinary clinics and equine pharmacies.
- Oral paste (1500 mg syringe): Approximately $8-15 per syringe
- Injectable solution (50 mL vial): Approximately $25-50 per vial
- Oral granules: Approximately $5-12 per packet
- Generic availability: Yes, generic flunixin meglumine is widely available at lower cost
Frequently Asked Questions
How quickly does Banamine work for colic? When given intravenously by a veterinarian, Banamine typically provides noticeable pain relief within 15-30 minutes. The oral paste takes somewhat longer, generally 30-60 minutes. However, Banamine treats pain, not the underlying cause of colic. Contact your veterinarian whenever your horse shows signs of colic.
Can I keep injectable Banamine in my barn for emergencies? While some horse owners keep injectable Banamine on hand, many veterinarians now recommend keeping only the oral paste formulation for owner-administered emergency use. This eliminates the risk of accidental intramuscular injection, which can cause fatal Clostridial infection. Discuss emergency preparedness with your veterinarian.
How long should I wait before switching from Banamine to bute (or vice versa)? Your veterinarian will advise on the appropriate washout period, which is typically at least 24 hours. Never overlap two different NSAIDs.
Is Banamine safe for foals? Flunixin can be used in foals but requires careful dosing and monitoring by a veterinarian. Foals are more susceptible to NSAID side effects including GI ulceration and kidney effects. Your veterinarian will determine if it is appropriate and at what dose.