Horse Side Vet Guide ®

Equine Health Resource

Steroids, Injectable & Oral



First used medically in the 1940’s, steroids are very potent anti-inflammatory medications that have many uses in human and equine veterinary medicine. They are based on and modeled after the body’s own corticosteroid hormone cortisol, which has many vital effects in the body, including a strong anti-inflammatory effect.

Steroids work by blocking the body’s main inflammatory cascade (arachidonic acid cascade) at a high level, reducing the production of many inflammatory mediators and reducing the action of inflammatory cells. This reduces the body’s response to an insult, and reduces body-wide inflammation, as well as local effects of swelling, redness, itchiness and irritation and pain.

Many different synthetic steroid types have been derived from the basic molecular model of cortisone. The most common injectable steroids used in equine veterinary practice are dexamethasone, methylprednisolone acetate (Depomedrol), triamcinolone acetate (Vetalog, Kenalog), and betamethasone. Each of these has different effects, potency and duration of action.

In equine veterinary medicine steroids are commonly used for a multitude of conditions including allergic skin conditions, airway disease, anaphylaxis, brain and spinal cord injury, autoimmune diseases and shock. Oral medications are often given when long-term treatment is needed.


Your vet chooses steroids when the powerful anti-inflammatory benefits for a particular condition offset the risk of side effects. Courses of steroids are usually tapered off to avoid the undesirable effects of discontinuation.


Whenever a horse is on long-term steroids, it is important to ensure that it receives the proper dose. You need to monitor the horse for the desired effect and for any of the mentioned side effects.

Related DiagnosesThis Treatment Might Be Used for these Diagnoses

Purpura Hemorrhagica, PH
Fly Bite Hypersensitivity
Recurrent Airway Obstruction, RAO
Pemphigus Foliaceus
Hives, Urticaria
Culicoides Hypersensitivity
Insect Stings, Centipede, or Spider Bites
Nerve Paralysis, Traumatic
Dust Cough, Irritated Airway from Dust
Biting Midge or Black Fly Infestation
Nerve Paralysis, Traumatic
Radial Nerve Paralysis
Summer Sores, Habronema
Fracture of Base of Skull & Brain Case
Vasculitis, Photoactive
Summer Pasture-Associated Obstructive Pulmonary Disease, SPAOPD
Acute Respiratory Distress Syndrome, ARDS
Autoimmune Hemolytic Anemia
Vasculitis, Generally
Equine Herpes Myeloencephalitis, EHM
Systemic Lupus Erythematosus, SLE
Biting Midge or Black Fly Infestation
Pastern Leukocytoclastic Vasculitis
Recurrent Airway Obstruction, RAO
Fly Irritation
Fly Bite Hypersensitivity
Capped Hock
Nodular Necrobiosis or Eosinophilic Granuloma
Chronic Undiagnosed Diarrhea in Adult Horses
Cervical Vertebral Malformation, CVM
Equine Canker
Older Horse Ataxia & Weakness
Cervical Vertebral Malformation, CVM
Cutaneous Lupus
Liver Disease, Acute Hepatitis
Lymphosarcoma, Generally
Temporohyoid Osteoarthropathy
Splints, Splint Exostosis
Intestinal Lymphosarcoma
Back Pain, Generally
Fracture of Tail
Lightning Strike
Hypoxemic-Ischemic Encephalopathy
Facial Nerve Paralysis
Nerve Diseases, Peripheral, Generally
Adrenal Insufficiency
External Ear Infections
Chronic Undiagnosed Diarrhea in Adult Horses
Multisystemic Eosinophilic Epitheliotrophic Disease, MEED
Osteoarthritis, OA, Generally
Poisonous Snake Bite, Rattlesnake or Pit Viper
Sweeny, Damaged Suprascapular Nerve
Equine Granulocytic Ehrlichiosis, EGE
Pastern Dermatitis, Scratches, Mud Fever
Leukemia, Cancer, Blood or Bone Marrow
Viral Upper Respiratory Tract Infections, Generally
Equine Viral Arteritis, EVA
Liver Failure, Generally
Neonatal Isoerythrolysis in Newborn Foal
Smoke Inhalation, Pneumonitis
Eastern, Western & Venezuelan Equine Encephalomyelitis
West Nile Virus, WNV
Equine Anaplasmosis
Endometritis, After Breeding
Bacteremia, Septicemia (in Adult)
Neoplasia, Tumor or Cancer, Guttural Pouch
Hemophilia- Clotting Factor VIII Deficiency
Neoplasia, Tumor or Cancer, Thorax
Protein-Losing Intestinal Diseases, Generally
Trochanteric Bursitis, Whorlbone
Carpal Hygroma, Synovial Hernia, Ganglion
Hyperesthetic Leukotrichia
Bone Tumor, Osteosarcoma

Consider Potential Side Effects & Complications

In horses, our greatest fear with the use of systemic (bodywide treatment) steroids is the development of laminitis.

Steroids dampen a normal immune response, possibly making the patient more susceptible to infection.

Steroids injected around injured ligaments and tendons may prolong healing.

Steroids at high doses over long time periods can cause Cushing's Disease signs.

Repeated doses of certain types of steroids injected into joints may ultimately be damaging to the articular cartilage and worsen joint disease.

Liver damage can be caused by prolonged use.

Consider Reasons Not To Use This Treatment

Steroids are not used at all or used with great caution in horses with laminitis or in danger of developing laminitis. Less dangerous steroids include methyprednisolone acetate, predisolone. More dangerous steroids include triamcinolone, a potent steroid commonly used in joints.

Steroids are also used cautiously in horses with known or presumed infection, and in pregnant mares.

Ideally, steroids should not be given near the time of vaccination, because they will dampen the desired immune reaction and formation of antibodies.

Is It working? Timeframe for effect

The apparent effect of steroids depend on the condition being treated.

In allergic reactions such as hives and RAO, horses given injectable steroids can show improvement within minutes to hours.

Questions To Ask My Vet

  • Do steroids pose any risk to my horse?
  • Is my horse at risk for laminitis after steroid treatment?
  • Do steroids damage joints into which they have been injected?
Boehringer Ingelheim Vetmedica Inc. Vetalog® Parenteral (triamcinolone acetonide)
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Author: Doug Thal DVM Dipl. ABVP


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