Last Updated on March 15, 2022 by Allison Price

Corticosteroids (or’steroids’) is a powerful anti-inflammatory drug that’s used often to treat lameness. There are many chemicals that can be used to treat lameness, but we use most often triamcinolone Acetonide (‘Adcortyl) and methylprednisolone Acetate (‘Depo–Medrone).

Corticosteroids, synthetic versions of cortisol (naturally produced by the adrenal glands), are synthetic forms of cortisol. They can have many effects on the body and even if they are injected into a structure like a joint, they will still escape into the horse’s systems to exert their influence. They are chemically related but they are not the same as anabolic steroids that promote muscle growth or weight gain.


Two main side effects to be aware of when using these drugs are infection and laminitis.

  • Steroids can cause infection because of the way they work. After steroids are injected, horses can become more susceptible to bacterial infections. This risk can be minimized by careful preparation of the skin before treatment, but cannot be eliminated.
  • Laminitis can occur in horses that have been treated with steroids. Horses can become laminitic even if they are older or have had previous cases.

These side effects are quite common. Rossdales partner Andy Bathe investigated this issue and published his findings in Equine Veterinary Journal, 39(1) 12-13. Three cases of laminitis (0.15%) were discovered after treatment of 2000 horses. Two of these cases had previously been diagnosed with laminitis and the owners had consented to therapy. One of the horses suffered no long-term complications, while the others were fully recovered. Our experience shows that infection rates after treatment are even lower.

While we don’t want to cause any discomfort or problems when caring for horses, all medications have side effects. It is important that clients are aware of these risks. Talk to your veterinary surgeon if you have further questions.