Flunixin meglumine

What is this medication for?

• Alleviation of musculoskeletal inflammation/pain + visceral pain of colic (label); foal diarrheas, shock/colitis, post-surgery (extra-label adjuncts)
• BRD pyrexia, endotoxemia pyrexia/inflammation control (label); coliform mastitis endotoxic shock adjunct
• Respiratory-disease pyrexia (label)
• Largely superseded by modern NSAIDs — legacy dosing only

How is it given?

Give exactly as your veterinarian prescribed — never change the dose or stop on your own unless your veterinarian has told you to.

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• None commonly reported; call your clinic with any concern.

Worth a phone call to your veterinarian

• into a muscle injection pain/swelling (Route-related)
• stomach/intestinal ulceration/renal (class) (Preexisting-disease amplifier)

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• Rare anaphylaxis (rapid into a vein) (Administration-rate related)

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: Preexisting stomach/intestinal ulcers, renal/hepatic/hematologic disease; colic-patient sign-masking; dehydration (renal perfusion)

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • Other NSAIDs/corticosteroids
  • Enrofloxacin (dog data)
  • Aminoglycosides

Storage and handling

into a vein use preferred for colic; into a muscle in cattle = painful tissue damage + residue concerns; under the skin option exists for Banamine-S.

Good to know

• The colic classic: 1.1 mg/kg into a vein — genuinely alleviates visceral pain but cannot substitute for a referral decision: it can buy time AND hide deterioration simultaneously.
• Species-label inverse of small-animal NSAIDs: flunixin is THE large-animal FDA-approved NSAID (horse/cattle/swine) while being legacy-only in dogs — the mirror image of carprofen/meloxicam.
• Rapid-into a vein anaphylaxis + into a muscle-tissue reactions = the two administration rules (slow into a vein, avoid cattle into a muscle).
• If the first dose fails for pain, subsequent doses rarely help (Plumb's explicit note) — escalate the workup, not the dose.