Flunixin Meglumine for Cow: Uses, Dosing & Side Effects

This information is for educational purposes only. Never give your pet any medication without your veterinarian's guidance. Dosing, frequency, and safety depend on your pet's specific health profile.

Flunixin meglumine is a prescription NSAID used in cattle to reduce inflammation, fever, and pain. Many pet parents know it by the brand name Banamine. In the U.S., cattle products include an injectable form and a transdermal pour-on form, and the route matters because each label has different approved uses, dosing instructions, and withdrawal times.

This medication does not treat the underlying infection by itself. Instead, it helps a cow feel better while your vet addresses the cause of the problem, such as respiratory disease, endotoxemia-related fever, or painful foot rot. Because cattle are food-producing animals, your vet also has to consider legal use, residue avoidance, and meat or milk withholding times before choosing a product.

Flunixin can be very helpful when used correctly, but it is not a casual over-the-counter pain reliever. NSAIDs can affect the stomach, intestines, kidneys, and normal prostaglandin pathways, so the safest plan is always to use the exact product, route, and schedule your vet recommends.

In cattle, flunixin meglumine is commonly used to control fever and reduce inflammation-related discomfort. The injectable cattle label supports use for pyrexia associated with bovine respiratory disease and endotoxemia-associated pyrexia. The transdermal cattle product is approved for pain associated with foot rot and for pyrexia associated with bovine respiratory disease.

In real farm practice, your vet may consider flunixin as part of a broader treatment plan when a cow is febrile, depressed, painful, or dealing with inflammatory disease. That often means pairing it with other care, such as antibiotics, fluids, hoof care, nursing support, or monitoring. The drug helps with comfort and inflammatory signs, but it does not replace diagnosis.

Your vet may also discuss whether the specific case fits the approved label or whether another option makes more sense. In food animals, that conversation is especially important because route, age class, lactation status, breeding status, and intended use all affect what is appropriate.

Flunixin dosing in cattle depends on the product and route. For injectable flunixin meglumine, the labeled cattle dose is 1.1 to 2.2 mg/kg (1 to 2 mL per 100 lb) by slow IV administration, either once daily as a single dose or divided into two doses 12 hours apart, for up to 3 days. The total daily dose should not exceed 2.2 mg/kg. The label specifically states that cattle use is approved only for intravenous administration, and intramuscular use can lead to violative tissue residues.

For Banamine Transdermal, the labeled cattle dose is 3.3 mg/kg (1.5 mg/lb; 3 mL per 100 lb) applied once topically in a narrow strip along the dorsal midline from the withers to the tailhead. This product is a single-dose treatment, not a repeated daily medication unless your vet gives a different legally appropriate plan.

Because this is a food-animal medication, dosing is only part of the safety picture. Your vet must also account for withdrawal times and class restrictions. Injectable flunixin labels note a 4-day slaughter withdrawal and that milk taken during treatment and for 36 hours after the last treatment must not be used for food; it is also not for use in dry dairy cows and not for veal calves. Banamine Transdermal labeling includes an 8-day slaughter withdrawal and a 48-hour milk discard time. Always confirm the exact withholding instructions for the specific product your vet dispenses.

Like other NSAIDs, flunixin can cause gastrointestinal and renal side effects. Problems are more likely if a cow is dehydrated, already has kidney, liver, or cardiovascular compromise, or is receiving other drugs that increase renal stress. Labeling for injectable flunixin warns that cattle at greatest risk for renal toxicity include those that are dehydrated or on concurrent diuretic therapy.

Watch for warning signs such as reduced appetite, depression, diarrhea, dark or bloody manure, blood in the urine, worsening dehydration, or a drop in milk production. In safety studies at higher-than-label repeated doses, cattle showed occasional blood in feces and/or urine. If you notice hematuria, fecal blood, marked lethargy, or a cow that seems to be getting worse instead of better, contact your vet promptly.

Rare anaphylactic-like reactions have also been reported with flunixin products in cattle and horses. With the transdermal product, your vet may also discuss handling precautions for people because accidental skin or eye exposure can be hazardous. If a cow has severe weakness, collapse, breathing difficulty, or sudden swelling after treatment, see your vet immediately.

The most important interaction rule is to avoid combining flunixin with other NSAIDs or corticosteroids unless your vet has a specific reason and monitoring plan. Using these drugs together can increase the risk of gastrointestinal ulceration and other adverse effects.

Caution is also needed when flunixin is used in cattle that are dehydrated, receiving diuretics, or taking other medications that may stress the kidneys. NSAIDs reduce prostaglandin production, and that can make renal blood flow more vulnerable in sick animals. If a cow is systemically ill, off feed, or volume depleted, your vet may adjust the plan or prioritize fluids and stabilization first.

Drug compatibility studies are limited, so if your cow is receiving antibiotics, reproductive drugs, fluids, or other supportive medications, let your vet know everything that has already been given. In breeding and periparturient cattle, your vet may also discuss reproductive cautions because NSAIDs can affect prostaglandin pathways, estrus timing, and parturition.