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Can You Give Human Painkillers to Horses?

You just finished a vigorous training routine with your horse, and all of a sudden, he is all cramped up with muscle pain. What do you do?  It’s too late for a vet to come out, so do you give your horse some of your human pain medication?

It would be dangerous and probably toxic to give your horse any human medication. Some human medications can cause serious side effects. There are many painkilling anti-inflammatory drugs available on the market for horses. It shouldn’t be necessary to use any human medication. You should always consult with your veterinarian before you give any medication to your horse anyway.  

You might think, if it works for me, why not work for my horse?  Let’s examine this argument a little further.

Why can I not use my human painkillers for my horse?

Firstly, horses are not humans. Human medication is not intended for use in horses, it’s designed for the human anatomy. The horse’s body is very different than the human body. A horse’s metabolism works differently than human metabolism. 

The FDA does not license human medication for Equine use. Veterinarians must use licensed medication by the FDA for horses and are legally obliged to follow that legislation. This legislation is to ensure the safety of the animal. Human painkilling medicine is tested for human use and has not been tested for use on horses. There is a basic standard of care principles that need to be followed when giving treatment.     

The dosage required to treat humans is very different than the dosage needed to treat your horse for pain.  

If you were thinking of giving your horse any human painkilling medication, you would have to calculate your horses’ body weight and adjust the dosage accordingly. That would probably result in a large number of drugs as a horse weighs a whole lot more than a human. The dosage would be so much higher.

So, how many boxes of Ibuprofen would that be? A dangerous risk to take; the higher the dose, the higher the chance of severe side effects.   

Some human painkillers can have toxic effects on horses and may cause kidney or liver failure and stomach ulceration. 

It is not advised to treat your horse for any ailment yourself if you are not entirely sure of the cause. It is always recommended to talk to your veterinarian first before treating your horse at home with any kind of medication. 

Inhibiting the pain without knowing what the real cause of the pain is might be very dangerous. Get your horse checked out by your vet to get a proper diagnosis and the cause of the pain.  

Suppose you feel that your horse needs an anti-inflammatory drug for some reason. In that case, you should use the appropriate medication designed for horses, prescribed by your veterinarian, never any human painkilling medication.           

What pain medication is safe and most commonly used for horses?

It is always helpful to have medication on hand at your stable to use in case of an emergency or if your veterinarian feels a home visit is unnecessary. In severe pain and inflammation cases, under the guidance of your veterinarian, you can administer any of these painkilling medications to your horse.

Pain and anti-inflammatory medication for horses

  • Non-Steroidal Anti-Inflammatory drugs or NSAID’s are most commonly used by veterinarians as painkillers in horses. These licensed medications include Phenylbutazone (Bute), Flunixin meglumine (Banamine) used for intestinal pain and inflammation like colic, Firocoxib (Equioxx), and Ketoprofen. All of these medications are available by veterinary prescription.
  • Corticoid steroids like Dexamethasone and Prednisone have strong anti-inflammatory actions. Corticoid steroids are primarily used for acute conditions like shock, hypersensitivity to insect bites, snakebite, hives, or chronic obstructed airway disease (heaves).
  • A well-known anti-inflammatory injectable polysulfated glycosaminoglycan product called Adequan can be administered by intramuscular injection to alleviate joint pain. Another joint pain and lameness treatment that is administered intravenously is hyaluronate called Legend. 

    It is easy to administer an intramuscular injection yourself; however, giving any intravenous injection should always be done by your veterinarian.
  • There are topical medications available to treat and reduce swelling and inflammation. DMSO (dimethyl sulfoxide) can be applied to any swollen or inflamed area to reduce swelling and pain. Some horses might show a skin reaction to DMSO, so pay attention to the site after applying the DMSO.
  • Surpass (diclofenac sodium) is cream when applied to penetrate the skin and the area beneath the skin to exert local anti-inflammatory properties, particularly useful for osteoarthritis. You should wear gloves when using this product.

Non anti-inflammatory pain medication for horses

Dipyrone, Capsaicin, and Acetaminophen are other pain medications that can be used that are not anti-inflammatory but target pain pathways directly.

These medications have their dosage and side effects and should always be discussed with your veterinarian first before use.

Non-Steroidal Anti-inflammatory drugs helpful or harmful?

It is distressful to see your horse in pain, and the first thing we want to do is to relieve the pain. Most horse owners have medication prescribed by their veterinarians on hand to give to their horses if need be, but can this always be the best option? 

Are you doing more harm than good? Your good intentions can be harmful. When used excessively or without veterinary guidance, the side effects of these drugs can seriously harm your horse. 

Excessive use of Phenylbutazone (Bute) can cause Jugular vein thromboses, gastric ulcers, kidney damage, and dorsal colitis. When a Bute injection is given improperly and touches the tissue outside of the vein during an attempted IV administration, it can cause skin and tissue damage.

Incorrectly administering an IV injection can also cause a blood clot or thrombus in the jugular vein, impeding blood flow from the head back to the heart.

Gastric ulceration

Gastric ulceration is a common side effect of NSAID’s. When administered orally through oral pastes or crushed tablets, it most often causes direct contact ulceration on the horse’s tongue, lips, or oral cavity. The bigger problem, however, is the damage it is causing to the stomach lining. 

A direct sign of this is horses going off their food and showing signs of colic. If your horse has to be on NSAID’s for an extended period, your veterinarian might suggest using gastro-protecting medication to use along with anti-inflammatory medicine.

The key is to give low doses of NSAID’s for short periods to try to avoid gastric ulcers. Ulcers cause protein loss, and your veterinarian can monitor this by checking for total blood protein to detect ulceration early.  Ulcers also cause clinical signs like colic with paste-like diarrhea.

Kidney damage

When giving NSAID’s to a dehydrated horse, you increase the risk of causing him permanent kidney damage.  Prostaglandins levels are reduced and are affected by NSAID’s. Prostaglandins regulate blood flow to the kidneys as they do to the stomach.

Reduced oxygen delivery to the kidneys causes ischemia (reduced blood flow). Reduced oxygenated blood flow to the kidneys will result in renal papillary necrosis (kidney tissue damage), resulting in decreased function. This is a sign that can be observed as frequent urination.

These side effects are just another reason why you should let your veterinarian treat your horse with NSAID’s and not treat your horse yourself. The veterinarian will be able to monitor the renal enzymes and hydration of your horse to rule out permanent damage to your horses’ kidneys. 

Horse Insurance policies: Can I claim if I used human medication on my horse?

A question to consider is, will my insurance company pay out when an unlicensed non-approved medication was used on my horse as a treatment?  If your horse has died and you used unlicensed human medication, you might not be able to claim from your insurance policy. 

Insurance companies often decline to settle any claims when an illegal unlicensed medication was used as treatment. Experimental and homeopathic medicines are excluded from Equine insurance policies.   

There is enough licensed Equine medication readily available on the market to use, and the need to use a human drug is considered unethical and unnecessary.    


Even though you might be tempted to use a human drug on your horse, please don’t consider it. It is not just as simple as it sounds. As we explained in this article and covered the many health risks to your horse, you should know that it can do more harm than good. A huge consideration is that you could end up losing coverage on your Equine insurance policy in the unfortunate event of the death of your horse. 

Using unlicensed human medication on your horse will only cause harm, and as a caring horse owner, that is probably the last thing you were aiming to do. The best thing you can do for your horse is to always consult with your veterinarian if there are any concerning health issues. 

It is far safer to have the appropriate licensed Equine medication available at your barn for your veterinarian to use. After all, you do want what is best for your horse.  

Anrie Diedericks

I've been around horses since I was 6 years old and started competing at the age of 9. Horses are my greatest passion and I am thrilled to be able to share my 23 (and counting) years of experience and knowledge with you.

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